Midwife continuity of care models versus other models of care for childbearing women.

BACKGROUND: Midwives are primary providers of care for childbearing women globally and there is a need to establish whether there are differences in effectiveness between midwife continuity of care models and other models of care. This is an update of a review published in 2016. OBJECTIVES: To compare the effects of midwife continuity of care models with other models of care for childbearing women and their infants. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Trials Register, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) (17 August 2022), as well as the reference lists of retrieved studies. SELECTION CRITERIA: All published and unpublished trials in which pregnant women are randomly allocated to midwife continuity of care models or other models of care during pregnancy and birth. DATA COLLECTION AND ANALYSIS: Two authors independently assessed studies for inclusion criteria, scientific integrity, and risk of bias, and carried out data extraction and entry. Primary outcomes were spontaneous vaginal birth, caesarean section, regional anaesthesia, intact perineum, fetal loss after 24 weeks gestation, preterm birth, and neonatal death. We used GRADE to rate the certainty of evidence. MAIN RESULTS: We included 17 studies involving 18,533 randomised women. We assessed all studies as being at low risk of scientific integrity/trustworthiness concerns. Studies were conducted in Australia, Canada, China, Ireland, and the United Kingdom. The majority of the included studies did not include women at high risk of complications. There are three ongoing studies targeting disadvantaged women. Primary outcomes Based on control group risks observed in the studies, midwife continuity of care models, as compared to other models of care, likely increase spontaneous vaginal birth from 66% to 70% (risk ratio (RR) 1.05, 95% confidence interval (CI) 1.03 to 1.07; 15 studies, 17,864 participants; moderate-certainty evidence), likelyreduce caesarean sections from 16% to 15% (RR 0.91, 95% CI 0.84 to 0.99; 16 studies, 18,037 participants; moderate-certainty evidence), and likely result in little to no difference in intact perineum (29% in other care models and 31% in midwife continuity of care models, average RR 1.05, 95% CI 0.98 to 1.12; 12 studies, 14,268 participants; moderate-certainty evidence). There may belittle or no difference in preterm birth (< 37 weeks) (6% under both care models, average RR 0.95, 95% CI 0.78 to 1.16; 10 studies, 13,850 participants; low-certainty evidence). We arevery uncertain about the effect of midwife continuity of care models on regional analgesia (average RR 0.85, 95% CI 0.79 to 0.92; 15 studies, 17,754 participants, very low-certainty evidence), fetal loss at or after 24 weeks gestation (average RR 1.24, 95% CI 0.73 to 2.13; 12 studies, 16,122 participants; very low-certainty evidence), and neonatal death (average RR 0.85, 95% CI 0.43 to 1.71; 10 studies, 14,718 participants; very low-certainty evidence). Secondary outcomes When compared to other models of care, midwife continuity of care models likely reduce instrumental vaginal birth (forceps/vacuum) from 14% to 13% (average RR 0.89, 95% CI 0.83 to 0.96; 14 studies, 17,769 participants; moderate-certainty evidence), and may reduceepisiotomy 23% to 19% (average RR 0.83, 95% CI 0.77 to 0.91; 15 studies, 17,839 participants; low-certainty evidence). When compared to other models of care, midwife continuity of care models likelyresult in little to no difference inpostpartum haemorrhage (average RR 0.92, 95% CI 0.82 to 1.03; 11 studies, 14,407 participants; moderate-certainty evidence) and admission to special care nursery/neonatal intensive care unit (average RR 0.89, 95% CI 0.77 to 1.03; 13 studies, 16,260 participants; moderate-certainty evidence). There may be little or no difference in induction of labour (average RR 0.92, 95% CI 0.85 to 1.00; 14 studies, 17,666 participants; low-certainty evidence), breastfeeding initiation (average RR 1.06, 95% CI 1.00 to 1.12; 8 studies, 8575 participants; low-certainty evidence), and birth weight less than 2500 g (average RR 0.92, 95% CI 0.79 to 1.08; 9 studies, 12,420 participants; low-certainty evidence). We are very uncertain about the effect of midwife continuity of care models compared to other models of care onthird or fourth-degree tear (average RR 1.10, 95% CI 0.81 to 1.49; 7 studies, 9437 participants; very low-certainty evidence), maternal readmission within 28 days (average RR 1.52, 95% CI 0.78 to 2.96; 1 study, 1195 participants; very low-certainty evidence), attendance at birth by a known midwife (average RR 9.13, 95% CI 5.87 to 14.21; 11 studies, 9273 participants; very low-certainty evidence), Apgar score less than or equal to seven at five minutes (average RR 0.95, 95% CI 0.72 to 1.24; 13 studies, 12,806 participants; very low-certainty evidence) andfetal loss before 24 weeks gestation (average RR 0.82, 95% CI 0.67 to 1.01; 12 studies, 15,913 participants; very low-certainty evidence). No maternal deaths were reported across three studies. Although the observed risk of adverse events was similar between midwifery continuity of care models and other models, our confidence in the findings was limited. Our confidence in the findings was lowered by possible risks of bias, inconsistency, and imprecision of some estimates. There were no available data for the outcomes: maternal health status, neonatal readmission within 28 days, infant health status, and birth weight of 4000 g or more. Maternal experiences and cost implications are described narratively. Women receiving care from midwife continuity of care models, as opposed to other care models, generally reported more positive experiences during pregnancy, labour, and postpartum. Cost savings were noted in the antenatal and intrapartum periods in midwife continuity of care models. AUTHORS' CONCLUSIONS: Women receiving midwife continuity of care models were less likely to experience a caesarean section and instrumental birth, and may be less likely to experience episiotomy. They were more likely to experience spontaneous vaginal birth and report a positive experience. The certainty of some findings varies due to possible risks of bias, inconsistencies, and imprecision of some estimates. Future research should focus on the impact on women with social risk factors, and those at higher risk of complications, and implementation and scaling up of midwife continuity of care models, with emphasis on low- and middle-income countries.

Landiolol and Organ Failure in Patients With Septic Shock: The STRESS-L Randomized Clinical Trial.

Importance: Patients with septic shock undergo adrenergic stress, which affects cardiac, immune, inflammatory, and metabolic pathways. ß-Blockade may attenuate the adverse effects of catecholamine exposure and has been associated with reduced mortality. Objectives: To assess the efficacy and safety of landiolol in patients with tachycardia and established septic shock requiring prolonged (>24 hours) vasopressor support. Design, Setting, and Participants: An open-label, multicenter, randomized trial involving 126 adults (≥18 years) with tachycardia (heart rate ≥95/min) and established septic shock treated for at least 24 hours with continuous norepinephrine (≥0.1 µg/kg/min) in 40 UK National Health Service intensive care units. The trial ran from April 2018 to December 2021, with early termination in December 2021 due to a signal of possible harm. Intervention: Sixty-three patients were randomized to receive standard care and 63 to receive landiolol infusion. Main Outcomes and Measures: The primary outcome was the mean Sequential Organ Failure Assessment (SOFA) score from randomization through 14 days. Secondary outcomes included mortality at days 28 and 90 and the number of adverse events in each group. Results: The trial was stopped prematurely on the advice of the independent data monitoring committee because it was unlikely to demonstrate benefit and because of possible harm. Of a planned 340 participants, 126 (37%) were enrolled (mean age, 55.6 years [95% CI, 52.7 to 58.5 years]; 58.7% male). The mean (SD) SOFA score in the landiolol group was 8.8 (3.9) compared with 8.1 (3.2) in the standard care group (mean difference [MD], 0.75 [95% CI, -0.49 to 2.0]; P = .24). Mortality at day 28 after randomization in the landiolol group was 37.1% (23 of 62) and 25.4% (16 of 63) in the standard care group (absolute difference, 11.7% [95% CI, -4.4% to 27.8%]; P = .16). Mortality at day 90 after randomization was 43.5% (27 of 62) in the landiolol group and 28.6% (18 of 63) in the standard care group (absolute difference, 15% [95% CI, -1.7% to 31.6%]; P = .08). There were no differences in the number of patients having at least one adverse event. Conclusion and Relevance: Among patients with septic shock with tachycardia and treated with norepinephrine for more than 24 hours, an infusion of landiolol did not reduce organ failure measured by the SOFA score over 14 days from randomization. These results do not support the use of landiolol for managing tachycardia among patients treated with norepinephrine for established septic shock. Trial Registration: EU Clinical Trials Register Eudra CT: 2017-001785-14; isrctn.org Identifier: ISRCTN12600919.

A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest.

BACKGROUND: Concern about the use of epinephrine as a treatment for out-of-hospital cardiac arrest led the International Liaison Committee on Resuscitation to call for a placebo-controlled trial to determine whether the use of epinephrine is safe and effective in such patients. METHODS: In a randomized, double-blind trial involving 8014 patients with out-of-hospital cardiac arrest in the United Kingdom, paramedics at five National Health Service ambulance services administered either parenteral epinephrine (4015 patients) or saline placebo (3999 patients), along with standard care. The primary outcome was the rate of survival at 30 days. Secondary outcomes included the rate of survival until hospital discharge with a favorable neurologic outcome, as indicated by a score of 3 or less on the modified Rankin scale (which ranges from 0 [no symptoms] to 6 [death]). RESULTS: At 30 days, 130 patients (3.2%) in the epinephrine group and 94 (2.4%) in the placebo group were alive (unadjusted odds ratio for survival, 1.39; 95% confidence interval [CI], 1.06 to 1.82; P=0.02). There was no evidence of a significant difference in the proportion of patients who survived until hospital discharge with a favorable neurologic outcome (87 of 4007 patients [2.2%] vs. 74 of 3994 patients [1.9%]; unadjusted odds ratio, 1.18; 95% CI, 0.86 to 1.61). At the time of hospital discharge, severe neurologic impairment (a score of 4 or 5 on the modified Rankin scale) had occurred in more of the survivors in the epinephrine group than in the placebo group (39 of 126 patients [31.0%] vs. 16 of 90 patients [17.8%]). CONCLUSIONS: In adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a significantly higher rate of 30-day survival than the use of placebo, but there was no significant between-group difference in the rate of a favorable neurologic outcome because more survivors had severe neurologic impairment in the epinephrine group. (Funded by the U.K. National Institute for Health Research and others; Current Controlled Trials number, ISRCTN73485024 .).

The challenges of trials in reproductive medicine: can a Bayesian approach help?

Reproductive medicine is imbued with debates over the results of key trials. This has resulted in heterogeneity in clinical practice and a disconnect between researchers and the patient group they aim to treat. The criticisms of trials originate from the nature of reproductive health conditions and limitations imposed in designing trials to assess effect in a patient group with heterogenous pathologies leading to the same condition. This leads to challenges in balancing the difficulties of recruiting an enriched patient cohort versus the dilutionary effect and need for subgroup analysis from wider recruitment. These challenges manifest as a failure to achieve traditional statistical significance. One potential solution to overcoming these inherent challenges is that of a Bayesian statistical approach. Using examples from the literature we demonstrate the benefits of a Bayesian approach. Taking published data and using a flat prior (no background information used), a Bayesian re-analysis of the PRISM and EAGeR trials is presented. This demonstrated a 94.7% chance of progesterone and a 95.3% probability of aspirin preventing miscarriage, in contrast to the original trial conclusions. These highlight the role a Bayesian approach can play in overcoming the challenges of trials within reproductive health.

Do we need to adjust for interim analyses in a Bayesian adaptive trial design?

BACKGROUND: Bayesian adaptive methods are increasingly being used to design clinical trials and offer several advantages over traditional approaches. Decisions at analysis points are usually based on the posterior distribution of the treatment effect. However, there is some confusion as to whether control of type I error is required for Bayesian designs as this is a frequentist concept. METHODS: We discuss the arguments for and against adjusting for multiplicities in Bayesian trials with interim analyses. With two case studies we illustrate the effect of including interim analyses on type I/II error rates in Bayesian clinical trials where no adjustments for multiplicities are made. We propose several approaches to control type I error, and also alternative methods for decision-making in Bayesian clinical trials. RESULTS: In both case studies we demonstrated that the type I error was inflated in the Bayesian adaptive designs through incorporation of interim analyses that allowed early stopping for efficacy and without adjustments to account for multiplicity. Incorporation of early stopping for efficacy also increased the power in some instances. An increase in the number of interim analyses that only allowed early stopping for futility decreased the type I error, but also decreased power. An increase in the number of interim analyses that allowed for either early stopping for efficacy or futility generally increased type I error and decreased power. CONCLUSIONS: Currently, regulators require demonstration of control of type I error for both frequentist and Bayesian adaptive designs, particularly for late-phase trials. To demonstrate control of type I error in Bayesian adaptive designs, adjustments to the stopping boundaries are usually required for designs that allow for early stopping for efficacy as the number of analyses increase. If the designs only allow for early stopping for futility then adjustments to the stopping boundaries are not needed to control type I error. If one instead uses a strict Bayesian approach, which is currently more accepted in the design and analysis of exploratory trials, then type I errors could be ignored and the designs could instead focus on the posterior probabilities of treatment effects of clinically-relevant values.

Comparison of Bayesian and frequentist group-sequential clinical trial designs.

BACKGROUND: There is a growing interest in the use of Bayesian adaptive designs in late-phase clinical trials. This includes the use of stopping rules based on Bayesian analyses in which the frequentist type I error rate is controlled as in frequentist group-sequential designs. METHODS: This paper presents a practical comparison of Bayesian and frequentist group-sequential tests. Focussing on the setting in which data can be summarised by normally distributed test statistics, we evaluate and compare boundary values and operating characteristics. RESULTS: Although Bayesian and frequentist group-sequential approaches are based on fundamentally different paradigms, in a single arm trial or two-arm comparative trial with a prior distribution specified for the treatment difference, Bayesian and frequentist group-sequential tests can have identical stopping rules if particular critical values with which the posterior probability is compared or particular spending function values are chosen. If the Bayesian critical values at different looks are restricted to be equal, O'Brien and Fleming's design corresponds to a Bayesian design with an exceptionally informative negative prior, Pocock's design to a Bayesian design with a non-informative prior and frequentist designs with a linear alpha spending function are very similar to Bayesian designs with slightly informative priors.This contrasts with the setting of a comparative trial with independent prior distributions specified for treatment effects in different groups. In this case Bayesian and frequentist group-sequential tests cannot have the same stopping rule as the Bayesian stopping rule depends on the observed means in the two groups and not just on their difference. In this setting the Bayesian test can only be guaranteed to control the type I error for a specified range of values of the control group treatment effect. CONCLUSIONS: Comparison of frequentist and Bayesian designs can encourage careful thought about design parameters and help to ensure appropriate design choices are made.

Cost-effectiveness of adrenaline for out-of-hospital cardiac arrest.

BACKGROUND: The 'Prehospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug Administration In Cardiac Arrest' (PARAMEDIC2) trial showed that adrenaline improves overall survival, but not neurological outcomes. We sought to determine the within-trial and lifetime health and social care costs and benefits associated with adrenaline, including secondary benefits from organ donation. METHODS: We estimated the costs, benefits (quality-adjusted life years (QALYs)) and incremental cost-effectiveness ratios (ICERs) associated with adrenaline during the 6-month trial follow-up. Model-based analyses explored how results altered when the time horizon was extended beyond 6 months and the scope extended to include recipients of donated organs. RESULTS: The within-trial (6 months) and lifetime horizon economic evaluations focussed on the trial population produced ICERs of £1,693,003 (€1,946,953) and £81,070 (€93,231) per QALY gained in 2017 prices, respectively, reflecting significantly higher mean costs and only marginally higher mean QALYs in the adrenaline group. The probability that adrenaline is cost-effective was less than 1% across a range of cost-effectiveness thresholds. Combined direct economic effects over the lifetimes of survivors and indirect economic effects in organ recipients produced an ICER of £16,086 (€18,499) per QALY gained for adrenaline with the probability that adrenaline is cost-effective increasing to 90% at a £30,000 (€34,500) per QALY cost-effectiveness threshold. CONCLUSIONS: Adrenaline was not cost-effective when only directly related costs and consequences are considered. However, incorporating the indirect economic effects associated with transplanted organs substantially alters cost-effectiveness, suggesting decision-makers should consider the complexity of direct and indirect economic impacts of adrenaline. TRIAL REGISTRATION: ISRCTN73485024 . Registered on 13 March 2014.

Patient safety incidents and medication errors during a clinical trial: experience from a pre-hospital randomized controlled trial of emergency medication administration.

AIM: To assess and evaluate patient safety incidents and in particular, medication errors, during a large multi-center pre-hospital trial of emergency therapy (PARAMEDIC2), in order to inform and improve future pre-hospital medicines trials. METHODS: The PARAMEDIC2 trial was undertaken across five NHS Ambulance Services in England and Wales with randomisation between December 2014 and October 2017. Patients with an out -of-hospital cardiac arrest unresponsive to initial resuscitation were randomly assigned to 1 mg intravenous adrenaline or matching placebo. Records were reviewed to identify trial medication errors involving documentation and/or clinical protocol errors occurring in trial participants. Causes of medication errors, including root cause analysis where available, were reviewed to identify patterns and themes contributing to these errors. RESULTS: Eight thousand sixteen patients were enrolled, of whom 4902 received trial medication. A total of 331 patient safety incidents was reported, involving 295 patients, representing an overall rate of 3.6% of these, 166 (50.2%) were documentation errors while 165 (49.8%) were clinical protocol/medication errors. An overall rate of 0-4.5% was reported across all five ambulance services, with a mean of 2.0%. These errors had no impact on patient care or the trial and were all resolved CONCLUSION: The overall medication error rate of 1.8% primarily consisted of administration of open-label adrenaline and confusion with trial medication packs. A similar number of patients had documentation errors. This study is the first to provide data on patient safety incidents relating to medication errors encountered during a pre-hospital trial of emergency medication administration and will provide supporting data for planning future trials in this area.

Using Bayesian adaptive designs to improve phase III trials: a respiratory care example.

BACKGROUND: Bayesian adaptive designs can improve the efficiency of trials, and lead to trials that can produce high quality evidence more quickly, with fewer patients and lower costs than traditional methods. The aim of this work was to determine how Bayesian adaptive designs can be constructed for phase III clinical trials in critical care, and to assess the influence that Bayesian designs would have on trial efficiency and study results. METHODS: We re-designed the High Frequency OSCillation in Acute Respiratory distress syndrome (OSCAR) trial using Bayesian adaptive design methods, to allow for the possibility of early stopping for success or futility. We constructed several alternative designs and studied their operating characteristics via simulation. We then performed virtual re-executions by applying the Bayesian adaptive designs using the OSCAR data to demonstrate the practical applicability of the designs. RESULTS: We constructed five alternative Bayesian adaptive designs and identified a preferred design based on the simulated operating characteristics, which had similar power to the original design but recruited fewer patients on average. The virtual re-executions showed the Bayesian sequential approach and original OSCAR trial yielded similar trial conclusions. However, using a Bayesian sequential design could have led to a reduced sample size and earlier completion of the trial. CONCLUSIONS: Using the OSCAR trial as an example, this case study found that Bayesian adaptive designs can be constructed for phase III critical care trials. If the OSCAR trial had been run using one of the proposed Bayesian adaptive designs, it would have terminated at a smaller sample size with fewer deaths in the trial, whilst reaching the same conclusions. We recommend the wider use of Bayesian adaptive approaches in phase III clinical trials. TRIAL REGISTRATION: OSCAR Trial registration ISRCTN, ISRCTN10416500 . Retrospectively registered 13 June 2007.

Adrenaline and vasopressin for cardiac arrest.

BACKGROUND: Adrenaline and vasopressin are widely used to treat people with cardiac arrest, but there is uncertainty about the safety, effectiveness and the optimal dose. OBJECTIVES: To determine whether adrenaline or vasopressin, or both, administered during cardiac arrest, afford any survival benefit. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase and DARE from their inception to 8 May 2018, and the International Liaison Committee on Resuscitation 2015 Advanced Life Support Consensus on Science and Treatment Recommendations. We also searched four trial registers on 5 September 2018 and checked the reference lists of the included studies and review papers to identify potential papers for review. SELECTION CRITERIA: Any randomised controlled trial comparing: standard-dose adrenaline versus placebo; standard-dose adrenaline versus high-dose adrenaline; and adrenaline versus vasopressin, in any setting, due to any cause of cardiac arrest, in adults and children. There were no language restrictions. DATA COLLECTION AND ANALYSIS: Two review authors independently identified trials for review, assessed risks of bias and extracted data, resolving disagreements through re-examination of the trial reports and by discussion. We used risk ratios (RRs) with 95% confidence intervals (CIs) to compare dichotomous outcomes for clinical events. There were no continuous outcomes reported. We examined groups of trials for heterogeneity. We report the quality of evidence for each outcome, using the GRADE approach. MAIN RESULTS: We included 26 studies (21,704 participants).Moderate-quality evidence found that adrenaline increased survival to hospital discharge compared to placebo (RR 1.44, 95% CI 1.11 to 1.86; 2 studies, 8538 participants; an increase from 23 to 32 per 1000, 95% CI 25 to 42). We are uncertain about survival to hospital discharge for high-dose compared to standard-dose adrenaline (RR 1.10, 95% CI 0.75 to 1.62; participants = 6274; studies = 10); an increase from 33 to 36 per 1000, 95% CI 24 to 53); standard-dose adrenaline versus vasopressin (RR 1.25, 95% CI 0.84 to 1.85; 6 studies; 2511 participants; an increase from 72 to 90 per 1000, 95% CI 60 to 133); and standard-dose adrenaline versus vasopressin plus adrenaline (RR 0.76, 95% CI 0.47 to 1.22; 3 studies; 3242 participants; a possible decrease from 24 to 18 per 1000, 95% CI 11 to 29), due to very low-quality evidence.Moderate-quality evidence found that adrenaline compared with placebo increased survival to hospital admission (RR 2.51, 95% CI 1.67 to 3.76; 2 studies, 8489 participants; an increase from 83 to 209 per 1000, 95% CI 139 to 313). We are uncertain about survival to hospital admission when comparing standard-dose with high-dose adrenaline, due to very low-quality evidence. Vasopressin may improve survival to hospital admission when compared with standard-dose adrenaline (RR 1.27, 95% CI 1.04 to 1.54; 3 studies, 1953 participants; low-quality evidence; an increase from 260 to 330 per 1000, 95% CI 270 to 400), and may make little or no difference when compared to standard-dose adrenaline plus vasopressin (RR 0.95, 95% CI 0.83 to 1.08; 3 studies; 3249 participants; low-quality evidence; a decrease from 218 to 207 per 1000 (95% CI 181 to 236).There was no evidence that adrenaline (any dose) or vasopressin improved neurological outcomes.The rate of return of spontaneous circulation (ROSC) was higher for standard-dose adrenaline versus placebo (RR 2.86, 95% CI 2.21 to 3.71; participants = 8663; studies = 3); moderate-quality evidence; an increase from 115 to 329 per 1000, 95% CI 254 to 427). We are uncertain about the effect on ROSC for the comparison of standard-dose versus high-dose adrenaline and standard-does adrenaline compared to vasopressin, due to very low-quality evidence. Standard-dose adrenaline may make little or no difference to ROSC when compared to standard-dose adrenaline plus vasopressin (RR 0.97, 95% CI 0.87 to 1.08; 3 studies, 3249 participants; low-quality evidence; a possible decrease from 299 to 290 per 1000, 95% CI 260 to 323).The source of funding was not stated in 11 of the 26 studies. The study drugs were provided by the manufacturer in four of the 26 studies, but neither drug represents a profitable commercial option. The other 11 studies were funded by organisations such as research foundations and government funding bodies. AUTHORS' CONCLUSIONS: This review provides moderate-quality evidence that standard-dose adrenaline compared to placebo improves return of spontaneous circulation, survival to hospital admission and survival to hospital discharge, but low-quality evidence that it did not affect survival with a favourable neurological outcome. Very low -quality evidence found that high-dose adrenaline compared to standard-dose adrenaline improved return of spontaneous circulation and survival to admission. Vasopressin compared to standard dose adrenaline improved survival to admission but not return of spontaneous circulation, whilst the combination of adrenaline and vasopressin compared with adrenaline alone had no effect on these outcomes. Neither standard dose adrenaline, high-dose adrenaline,vasopressin nor a combination of adrenaline and vasopressin improved survival with a favourable neurological outcome. Many of these studies were conducted more than 20 years ago. Treatment has changed in recent years, so the findings from older studies may not reflect current practice.

Effect of Protocolized Weaning With Early Extubation to Noninvasive Ventilation vs Invasive Weaning on Time to Liberation From Mechanical Ventilation Among Patients With Respiratory Failure: The Breathe Randomized Clinical Trial.

Importance: In adults in whom weaning from invasive mechanical ventilation is difficult, noninvasive ventilation may facilitate early liberation, but there is uncertainty about its effectiveness in a general intensive care patient population. Objective: To investigate among patients with difficulty weaning the effects of protocolized weaning with early extubation to noninvasive ventilation on time to liberation from ventilation compared with protocolized invasive weaning. Design, Setting, and Participants: Randomized, allocation-concealed, open-label, multicenter clinical trial enrolling patients between March 2013 and October 2016 from 41 intensive care units in the UK National Health Service. Follow-up continued until April 2017. Adults who received invasive mechanical ventilation for more than 48 hours and in whom a spontaneous breathing trial failed were enrolled. Interventions: Patients were randomized to receive either protocolized weaning via early extubation to noninvasive ventilation (n = 182) or protocolized standard weaning (continued invasive ventilation until successful spontaneous breathing trial, followed by extubation) (n = 182). Main Outcomes and Measures: Primary outcome was time from randomization to successful liberation from all forms of mechanical ventilation among survivors, measured in days, with the minimal clinically important difference defined as 1 day. Secondary outcomes were duration of invasive and total ventilation (days), reintubation or tracheostomy rates, and survival. Results: Among 364 randomized patients (mean age, 63.1 [SD, 14.8] years; 50.5% male), 319 were evaluable for the primary effectiveness outcome (41 died before liberation, 2 withdrew, and 2 were discharged with ongoing ventilation). The median time to liberation was 4.3 days in the noninvasive group vs 4.5 days in the invasive group (adjusted hazard ratio, 1.1; 95% CI, 0.89-1.40). Competing risk analysis accounting for deaths had a similar result (adjusted hazard ratio, 1.1; 95% CI, 0.86-1.34). The noninvasive group received less invasive ventilation (median, 1 day vs 4 days; incidence rate ratio, 0.6; 95% CI, 0.47-0.87) and fewer total ventilator days (median, 3 days vs 4 days; incidence rate ratio, 0.8; 95% CI, 0.62-1.0). There was no significant difference in reintubation, tracheostomy rates, or survival. Adverse events occurred in 45 patients (24.7%) in the noninvasive group compared with 47 (25.8%) in the invasive group. Conclusions and Relevance: Among patients requiring mechanical ventilation in whom a spontaneous breathing trial had failed, early extubation to noninvasive ventilation did not shorten time to liberation from any ventilation. Trial Registration: ISRCTN Identifier: ISRCTN15635197.

Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial.

BACKGROUND: Mechanical chest compression devices have the potential to help maintain high-quality cardiopulmonary resuscitation (CPR), but despite their increasing use, little evidence exists for their effectiveness. We aimed to study whether the introduction of LUCAS-2 mechanical CPR into front-line emergency response vehicles would improve survival from out-of-hospital cardiac arrest. METHODS: The pre-hospital randomised assessment of a mechanical compression device in cardiac arrest (PARAMEDIC) trial was a pragmatic, cluster-randomised open-label trial including adults with non-traumatic, out-of-hospital cardiac arrest from four UK Ambulance Services (West Midlands, North East England, Wales, South Central). 91 urban and semi-urban ambulance stations were selected for participation. Clusters were ambulance service vehicles, which were randomly assigned (1:2) to LUCAS-2 or manual CPR. Patients received LUCAS-2 mechanical chest compression or manual chest compressions according to the first trial vehicle to arrive on scene. The primary outcome was survival at 30 days following cardiac arrest and was analysed by intention to treat. Ambulance dispatch staff and those collecting the primary outcome were masked to treatment allocation. Masking of the ambulance staff who delivered the interventions and reported initial response to treatment was not possible. The study is registered with Current Controlled Trials, number ISRCTN08233942. FINDINGS: We enrolled 4471 eligible patients (1652 assigned to the LUCAS-2 group, 2819 assigned to the control group) between April 15, 2010 and June 10, 2013. 985 (60%) patients in the LUCAS-2 group received mechanical chest compression, and 11 (<1%) patients in the control group received LUCAS-2. In the intention-to-treat analysis, 30 day survival was similar in the LUCAS-2 group (104 [6%] of 1652 patients) and in the manual CPR group (193 [7%] of 2819 patients; adjusted odds ratio [OR] 0·86, 95% CI 0·64-1·15). No serious adverse events were noted. Seven clinical adverse events were reported in the LUCAS-2 group (three patients with chest bruising, two with chest lacerations, and two with blood in mouth). 15 device incidents occurred during operational use. No adverse or serious adverse events were reported in the manual group. INTERPRETATION: We noted no evidence of improvement in 30 day survival with LUCAS-2 compared with manual compressions. On the basis of ours and other recent randomised trials, widespread adoption of mechanical CPR devices for routine use does not improve survival. FUNDING: National Institute for Health Research HTA - 07/37/69.

Midwife-led continuity models versus other models of care for childbearing women.

BACKGROUND: Midwives are primary providers of care for childbearing women around the world. However, there is a lack of synthesised information to establish whether there are differences in morbidity and mortality, effectiveness and psychosocial outcomes between midwife-led continuity models and other models of care. OBJECTIVES: To compare midwife-led continuity models of care with other models of care for childbearing women and their infants. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (25 January 2016) and reference lists of retrieved studies. SELECTION CRITERIA: All published and unpublished trials in which pregnant women are randomly allocated to midwife-led continuity models of care or other models of care during pregnancy and birth. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach. MAIN RESULTS: We included 15 trials involving 17,674 women. We assessed the quality of the trial evidence for all primary outcomes (i.e. regional analgesia (epidural/spinal), caesarean birth, instrumental vaginal birth (forceps/vacuum), spontaneous vaginal birth, intact perineum, preterm birth (less than 37 weeks) and all fetal loss before and after 24 weeks plus neonatal death using the GRADE methodology: all primary outcomes were graded as of high quality.For the primary outcomes, women who had midwife-led continuity models of care were less likely to experience regional analgesia (average risk ratio (RR) 0.85, 95% confidence interval (CI) 0.78 to 0.92; participants = 17,674; studies = 14; high quality), instrumental vaginal birth (average RR 0.90, 95% CI 0.83 to 0.97; participants = 17,501; studies = 13; high quality), preterm birth less than 37 weeks (average RR 0.76, 95% CI 0.64 to 0.91; participants = 13,238; studies = eight; high quality) and less all fetal loss before and after 24 weeks plus neonatal death (average RR 0.84, 95% CI 0.71 to 0.99; participants = 17,561; studies = 13; high quality evidence). Women who had midwife-led continuity models of care were more likely to experience spontaneous vaginal birth (average RR 1.05, 95% CI 1.03 to 1.07; participants = 16,687; studies = 12; high quality). There were no differences between groups for caesarean births or intact perineum.For the secondary outcomes, women who had midwife-led continuity models of care were less likely to experience amniotomy (average RR 0.80, 95% CI 0.66 to 0.98; participants = 3253; studies = four), episiotomy (average RR 0.84, 95% CI 0.77 to 0.92; participants = 17,674; studies = 14) and fetal loss less than 24 weeks and neonatal death (average RR 0.81, 95% CI 0.67 to 0.98; participants = 15,645; studies = 11). Women who had midwife-led continuity models of care were more likely to experience no intrapartum analgesia/anaesthesia (average RR 1.21, 95% CI 1.06 to 1.37; participants = 10,499; studies = seven), have a longer mean length of labour (hours) (mean difference (MD) 0.50, 95% CI 0.27 to 0.74; participants = 3328; studies = three) and more likely to be attended at birth by a known midwife (average RR 7.04, 95% CI 4.48 to 11.08; participants = 6917; studies = seven). There were no differences between groups for fetal loss equal to/after 24 weeks and neonatal death, induction of labour, antenatal hospitalisation, antepartum haemorrhage, augmentation/artificial oxytocin during labour, opiate analgesia, perineal laceration requiring suturing, postpartum haemorrhage, breastfeeding initiation, low birthweight infant, five-minute Apgar score less than or equal to seven, neonatal convulsions, admission of infant to special care or neonatal intensive care unit(s) or in mean length of neonatal hospital stay (days).Due to a lack of consistency in measuring women's satisfaction and assessing the cost of various maternity models, these outcomes were reported narratively. The majority of included studies reported a higher rate of maternal satisfaction in midwife-led continuity models of care. Similarly, there was a trend towards a cost-saving effect for midwife-led continuity care compared to other care models. AUTHORS' CONCLUSIONS: This review suggests that women who received midwife-led continuity models of care were less likely to experience intervention and more likely to be satisfied with their care with at least comparable adverse outcomes for women or their infants than women who received other models of care.Further research is needed to explore findings of fewer preterm births and fewer fetal deaths less than 24 weeks, and all fetal loss/neonatal death associated with midwife-led continuity models of care.

Paravertebral block versus thoracic epidural for patients undergoing thoracotomy.

BACKGROUND: Operations on structures in the chest (usually the lungs) involve cutting between the ribs (thoracotomy). Severe post-thoracotomy pain can result from pleural (lung lining) and muscular damage, costovertebral joint (ribcage) disruption and intercostal nerve (nerves that run along the ribs) damage during surgery. Poor pain relief after surgery can impede recovery and increase the risks of developing complications such as lung collapse, chest infections and blood clots due to ineffective breathing and clearing of secretions. Effective management of acute pain following thoracotomy may prevent these complications and reduce the likelihood of developing chronic pain. A multi-modal approach to analgesia is widely employed by thoracic anaesthetists using a combination of regional anaesthetic blockade and systemic analgesia, with both non-opioid and opioid medications and local anaesthesia blockade.There is some evidence that blocking the nerves as they emerge from the spinal column (paravertebral block, PVB) may be associated with a lower risk of major complications in thoracic surgery but the majority of thoracic anaesthetists still prefer to use a thoracic epidural blockade (TEB) as analgesia for their patients undergoing thoracotomy. In order to bring about a change in practice, anaesthetists need a review that evaluates the risk of all major complications associated with thoracic epidural and paravertebral block in thoracotomy. OBJECTIVES: To compare the two regional techniques of TEB and PVB in adults undergoing elective thoracotomy with respect to:1. analgesic efficacy;2. the incidence of major complications (including mortality);3. the incidence of minor complications;4. length of hospital stay;5. cost effectiveness. SEARCH METHODS: We searched for studies in the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 9); MEDLINE via Ovid (1966 to 16 October 2013); EMBASE via Ovid (1980 to 16 October 2013); CINAHL via EBSCO host (1982 to 16 October 2013); and reference lists of retrieved studies. We handsearched the Journal of Cardiothoracic Surgery and Journal of Cardiothoracic and Vascular Anesthesia (16 October 2013). We reran the search on 31st January 2015. We found one additional study which is awaiting classification and will be addressed when we update the review. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) comparing PVB with TEB in thoracotomy, including upper gastrointestinal surgery. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors (JY and SG) independently assessed the studies for inclusion and then extracted data as eligible for inclusion in qualitative and quantitative synthesis (meta-analysis). MAIN RESULTS: We included 14 studies with a total of 698 participants undergoing thoracotomy. There are two studies awaiting classification. The studies demonstrated high heterogeneity in insertion and use of both regional techniques, reflecting real-world differences in the anaesthesia techniques. Overall, the included studies have a moderate to high potential for bias, lacking details of randomization, group allocation concealment or arrangements to blind participants or outcome assessors. There was low to very low-quality evidence that showed no significant difference in 30-day mortality (2 studies, 125 participants. risk ratio (RR) 1.28, 95% confidence interval (CI) 0.39 to 4.23, P value = 0.68) and major complications (cardiovascular: 2 studies, 114 participants. Hypotension RR 0.30, 95% CI 0.01 to 6.62, P value = 0.45; arrhythmias RR 0.36, 95% CI 0.04 to 3.29, P value = 0.36, myocardial infarction RR 3.19, 95% CI 0.13, 76.42, P value = 0.47); respiratory: 5 studies, 280 participants. RR 0.62, 95% CI 0.26 to 1.52, P value = 0.30). There was moderate-quality evidence that showed comparable analgesic efficacy across all time points both at rest and after coughing or physiotherapy (14 studies, 698 participants). There was moderate-quality evidence that showed PVB had a better minor complication profile than TEB including hypotension (8 studies, 445 participants. RR 0.16, 95% CI 0.07 to 0.38, P value < 0.0001), nausea and vomiting (6 studies, 345 participants. RR 0.48, 95% CI 0.30 to 0.75, P value = 0.001), pruritis (5 studies, 249 participants. RR 0.29, 95% CI 0.14 to 0.59, P value = 0.0005) and urinary retention (5 studies, 258 participants. RR 0.22, 95% CI 0.11 to 0.46, P value < 0.0001). There was insufficient data in chronic pain (six or 12 months). There was no difference found in and length of hospital stay (3 studies, 124 participants). We found no studies that reported costs. AUTHORS' CONCLUSIONS: Paravertebral blockade reduced the risks of developing minor complications compared to thoracic epidural blockade. Paravertebral blockade was as effective as thoracic epidural blockade in controlling acute pain. There was a lack of evidence in other outcomes. There was no difference in 30-day mortality, major complications, or length of hospital stay. There was insufficient data on chronic pain and costs. Results from this review should be interpreted with caution due to the heterogeneity of the included studies and the lack of reliable evidence. Future studies in this area need well-conducted, adequately-powered RCTs that focus not only on acute pain but also on major complications, chronic pain, length of stay and costs.

Human factors in prehospital research: lessons from the PARAMEDIC trial.

BACKGROUND: There is an urgent need to develop prehospital research capability in order to improve the care of patients presenting to emergency medical services (EMS). The Prehospital Randomised Assessment of a Mechanical compression Device In Cardiac arrest trial, a pragmatic cluster randomised trial evaluating the LUCAS-2 device, represents the largest randomised controlled trial conducted by UK ambulance services to date. The aim of this study was to identify and analyse factors that may influence paramedic attitudes to, and participation in, clinical trials. METHODS: Personal and organisational experience from this trial was assessed by feedback from a workshop attended by collaborators from participating EMS and a survey of EMS personnel participating in the trial. A work systems model was used to explain the impact of five interwoven themes-person, organisation, tasks, tools & technology and environment-on trial conduct including gathering of high-quality data. RESULTS: The challenge of training a geographically diverse EMS workforce required development of multiple educational solutions. In order to operationalise the trial protocol, internal organisational relationships were perceived as essential. Staff perceptions of the normalisation of participation and ownership of the trial influenced protocol compliance rates. Undertaking research was considered less burdensome when additional tasks were minimised and more difficult when equipment was unavailable. The prehospital environment presents practical challenges for undertaking clinical trials, but our experience suggests these are not insurmountable and should not preclude conducting high-quality research in this setting. CONCLUSIONS: Application of a human factors model to the implementation of a clinical trial protocol has improved understanding of the work system, which can inform the future conduct of clinical trials and foster a research culture within UK ambulance services. TRIAL REGISTRATION NUMBER: ISRCTN08233942.

Effect of Using the Same vs Different Order for Second Readings of Screening Mammograms on Rates of Breast Cancer Detection: A Randomized Clinical Trial.

IMPORTANCE: Interpreting screening mammograms is a difficult repetitive task that can result in missed cancers and false-positive recalls. In the United Kingdom, 2 film readers independently evaluate each mammogram to search for signs of cancer and examine digital mammograms in batches. However, a vigilance decrement (reduced detection rate with time on task) has been observed in similar settings. OBJECTIVE: To determine the effect of changing the order for the second film reader of batches of screening mammograms on rates of breast cancer detection. DESIGN, SETTING, AND PARTICIPANTS: A multicenter, double-blind, cluster randomized clinical trial conducted at 46 specialized breast screening centers from the National Health Service Breast Screening Program in England for 1 year (all between December 20, 2012, and November 3, 2014). Three hundred sixty readers participated (mean, 7.8 readers per center)-186 radiologists, 143 radiography advanced practitioners, and 31 breast clinicians, all fully qualified to report mammograms in the NHS breast screening program. INTERVENTIONS: The 2 readers examined each batch of digital mammograms in the same order in the control group and in the opposite order to one another in the intervention group. MAIN OUTCOMES AND MEASURES: The primary outcome was cancer detection rate; secondary outcomes were rates of recall and disagreements between readers. RESULTS: Among 1,194,147 women (mean age, 59.3; SD, 7.49) who had screening mammograms (596,642 in the intervention group; 597,505 in the control group), the images were interpreted in 37,688 batches (median batch size, 35; interquartile range [IQR]; 16-46), with each reader interpreting a median of 176 batches (IQR, 96-278). After completion of all subsequent diagnostic tests, a total of 10,484 cases (0.88%) of breast cancer were detected. There was no significant difference in cancer detection rate with 5272 cancers (0.88%) detected in the intervention group vs 5212 cancers (0.87%) detected in the control group (difference, 0.01% points; 95% CI, -0.02% to 0.04% points; recall rate, 24,681 [4.14%] vs 24,894 [4.17%]; difference, -0.03% points; 95% CI, -0.10% to 0.04% points; or rate of reader disagreements, 20,471 [3.43%] vs 20,793 [3.48%]; difference, -0.05% points; 95% CI, -0.11% to 0.02% points). CONCLUSIONS AND RELEVANCE: Interpretation of batches of mammograms by qualified screening mammography readers using a different order vs the same order for the second reading resulted in no significant difference in rates of detection of breast cancer. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN46603370.

Midwife-led continuity models versus other models of care for childbearing women.

BACKGROUND: Midwives are primary providers of care for childbearing women around the world. However, there is a lack of synthesised information to establish whether there are differences in morbidity and mortality, effectiveness and psychosocial outcomes between midwife-led continuity models and other models of care. OBJECTIVES: To compare midwife-led continuity models of care with other models of care for childbearing women and their infants. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2015) and reference lists of retrieved studies. SELECTION CRITERIA: All published and unpublished trials in which pregnant women are randomly allocated to midwife-led continuity models of care or other models of care during pregnancy and birth. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. MAIN RESULTS: We included 15 trials involving 17,674 women. We assessed the quality of the trial evidence for all primary outcomes (i.e., regional analgesia (epidural/spinal), caesarean birth, instrumental vaginal birth (forceps/vacuum), spontaneous vaginal birth, intact perineum, preterm birth (less than 37 weeks) and overall fetal loss and neonatal death (fetal loss was assessed by gestation using 24 weeks as the cut-off for viability in many countries) using the GRADE methodology: All primary outcomes were graded as of high quality.For the primary outcomes, women who had midwife-led continuity models of care were less likely to experience regional analgesia (average risk ratio (RR) 0.85, 95% confidence interval (CI) 0.78 to 0.92; participants = 17,674; studies = 14; high quality), instrumental vaginal birth (average RR 0.90, 95% CI 0.83 to 0.97; participants = 17,501; studies = 13; high quality), preterm birth less than 37 weeks (average RR 0.76, 95% CI 0.64 to 0.91; participants = 13,238; studies = 8; high quality) and less overall fetal/neonatal death (average RR 0.84, 95% CI 0.71 to 0.99; participants = 17,561; studies = 13; high quality evidence). Women who had midwife-led continuity models of care were more likely to experience spontaneous vaginal birth (average RR 1.05, 95% CI 1.03 to 1.07; participants = 16,687; studies = 12; high quality). There were no differences between groups for caesarean births or intact perineum.For the secondary outcomes, women who had midwife-led continuity models of care were less likely to experience amniotomy (average RR 0.80, 95% CI 0.66 to 0.98; participants = 3253; studies = 4), episiotomy (average RR 0.84, 95% CI 0.77 to 0.92; participants = 17,674; studies = 14) and fetal loss/neonatal death before 24 weeks (average RR 0.81, 95% CI 0.67 to 0.98; participants = 15,645; studies = 11). Women who had midwife-led continuity models of care were more likely to experience no intrapartum analgesia/anaesthesia (average RR 1.21, 95% CI 1.06 to 1.37; participants = 10,499; studies = 7), have a longer mean length of labour (hours) (mean difference (MD) 0.50, 95% CI 0.27 to 0.74; participants = 3328; studies = 3) and more likely to be attended at birth by a known midwife (average RR 7.04, 95% CI 4.48 to 11.08; participants = 6917; studies = 7). There were no differences between groups for fetal loss or neonatal death more than or equal to 24 weeks, induction of labour, antenatal hospitalisation, antepartum haemorrhage, augmentation/artificial oxytocin during labour, opiate analgesia, perineal laceration requiring suturing, postpartum haemorrhage, breastfeeding initiation, low birthweight infant, five-minute Apgar score less than or equal to seven, neonatal convulsions, admission of infant to special care or neonatal intensive care unit(s) or in mean length of neonatal hospital stay (days).Due to a lack of consistency in measuring women's satisfaction and assessing the cost of various maternity models, these outcomes were reported narratively. The majority of included studies reported a higher rate of maternal satisfaction in midwife-led continuity models of care. Similarly, there was a trend towards a cost-saving effect for midwife-led continuity care compared to other care models. AUTHORS' CONCLUSIONS: This review suggests that women who received midwife-led continuity models of care were less likely to experience intervention and more likely to be satisfied with their care with at least comparable adverse outcomes for women or their infants than women who received other models of care.Further research is needed to explore findings of fewer preterm births and fewer fetal deaths less than 24 weeks, and overall fetal loss/neonatal death associated with midwife-led continuity models of care.

Alternative versus standard packages of antenatal care for low-risk pregnancy.

BACKGROUND: The number of visits for antenatal (prenatal) care developed without evidence of how many visits are necessary. The content of each visit also needs evaluation. OBJECTIVES: To compare the effects of antenatal care programmes with reduced visits for low-risk women with standard care. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 March 2015), reference lists of articles and contacted researchers in the field. SELECTION CRITERIA: Randomised trials comparing a reduced number of antenatal visits, with or without goal-oriented care, versus standard care. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked for accuracy. We assessed studies for risk of bias and graded the quality of the evidence. MAIN RESULTS: We included seven trials (more than 60,000 women): four in high-income countries with individual randomisation; three in low- and middle-income countries with cluster randomisation (clinics as the unit of randomisation). Most of the data included in the review came from the three large, well-designed cluster-randomised trials that took place in Argentina, Cuba, Saudi Arabia, Thailand and Zimbabwe. All results have been adjusted for the cluster design effect. All of the trials were at some risk of bias as blinding of women and staff was not feasible with this type of intervention. For primary outcomes, evidence was graded as being of moderate or low quality, with downgrading decisions due to risks of bias and imprecision of effects.The number of visits for standard care varied, with fewer visits in low- and middle- income country trials. In studies in high-income countries, women in the reduced visits groups, on average, attended between 8.2 and 12 times. In low- and middle- income country trials, many women in the reduced visits group attended on fewer than five occasions, although in these trials the content as well as the number of visits was changed, so as to be more 'goal-oriented'.Perinatal mortality was increased for those randomised to reduced visits rather than standard care, and this difference was borderline for statistical significance (risk ratio (RR) 1.14; 95% confidence interval (CI) 1.00 to 1.31; five trials, 56,431 babies; moderate-quality evidence). In the subgroup analysis, for high-income countries the number of deaths was small (32/5108), and there was no clear difference between the groups (RR 0.90; 95% CI 0.45 to 1.80, two trials); for low- and middle-income countries perinatal mortality was significantly higher in the reduced visits group (RR 1.15; 95% CI 1.01 to 1.32, three trials).There was no clear difference between groups for our other primary outcomes: maternal death (RR 1.13, 95%CI 0.50 to 2.57, three cluster-randomised trials, 51,504 women, low-quality evidence); hypertensive disorders of pregnancy (various definitions including pre-eclampsia) (RR 0.95, 95% CI 0.80 to 1.12, six studies, 54,108 women, low-quality evidence); preterm birth (RR 1.02, 95% CI 0.94 to 1.11; seven studies, 53,661 women, moderate-quality evidence); and small-for-gestational age (RR 0.99, 95% CI 0.91 to 1.09, four studies 43,045 babies, moderate-quality evidence).Reduced visits were associated with a reduction in admission to neonatal intensive care that was borderline for significance (RR 0.89; 95% CI 0.79 to 1.02, five studies, 43,048 babies, moderate quality evidence). There were no clear differences between the groups for the other secondary clinical outcomes.Women in all settings were less satisfied with the reduced visits schedule and perceived the gap between visits as too long. Reduced visits may be associated with lower costs. AUTHORS' CONCLUSIONS: In settings with limited resources where the number of visits is already low, reduced visits programmes of antenatal care are associated with an increase in perinatal mortality compared to standard care, although admission to neonatal intensive care may be reduced. Women prefer the standard visits schedule. Where the standard number of visits is low, visits should not be reduced without close monitoring of fetal and neonatal outcome.