Health economic evaluation alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (E-PROSPECT): a cost-effectiveness analysis.

PURPOSE: We sought to compare the cost-effectiveness of probiotics and usual care with usual care without probiotics in mechanically ventilated, intensive care unit patients alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (PROSPECT). METHODS: We conducted a health economic evaluation alongside the PROSPECT randomized control trial (October 2013-March 2019). We adopted a public healthcare payer's perspective. Forty-four intensive care units in three countries (Canada/USA/Saudi Arabia) with adult critically ill, mechanically ventilated patients (N = 2,650) were included. Interventions were probiotics (Lactobacillus rhamnosus GG) vs placebo administered enterally twice daily. We collected healthcare resource use and estimated unit costs in 2019 United States dollars (USD) over a time horizon from randomization to hospital discharge/death. We calculated incremental cost-effectiveness ratios (ICERs) comparing probiotics vs usual care. The primary outcome was incremental cost per ventilator-associated pneumonia (VAP) event averted; secondary outcomes were costs per Clostridioides difficile-associated diarrhea (CDAD), antibiotic-associated diarrhea (AAD), and mortality averted. Uncertainty was investigated using nonparametric bootstrapping and sensitivity analyses. RESULTS: Mean (standard deviation [SD]) cost per patient was USD 66,914 (91,098) for patients randomized to probiotics, with a median [interquartile range (IQR)] of USD 42,947 [22,239 to 76,205]. By comparison, for those not receiving probiotics, mean (SD) cost per patient was USD 62,701 (78,676) (median [IQR], USD 41,102 [23,170 to 75,140]; incremental cost, USD 4,213; 95% confidence interval [CI], -2,269 to 10,708). Incremental cost-effectiveness ratios for VAP or AAD events averted, probiotics were dominated by usual care (more expensive, with similar effectiveness). The ICERs were USD 1,473,400 per CDAD event averted (95% CI, undefined) and USD 396,764 per death averted (95% CI, undefined). Cost-effectiveness acceptability curves reveal that probiotics were not cost-effective across wide ranges of plausible willingness-to-pay thresholds. Sensitivity analyses did not change the conclusions. CONCLUSIONS: Probiotics for VAP prevention among critically ill patients were not cost-effective. Study registration data www. CLINICALTRIALS: gov (NCT01782755); registered 4 February 2013.

RéSUMé: OBJECTIF: Nous avons cherché à comparer le rapport coût-efficacité d'un traitement avec probiotiques ajoutés aux soins habituels avec des soins habituels prodigués sans probiotiques chez les patients des soins intensifs sous ventilation mécanique dans le cadre de l'étude PROSPECT (Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial). MéTHODE: Nous avons réalisé une évaluation de l'économie de la santé parallèlement à l'étude randomisée contrôlée PROSPECT (octobre 2013-mars 2019). Nous avons adopté le point de vue d'un payeur public de services de santé. Quarante-quatre unités de soins intensifs dans trois pays (Canada/États-Unis/Arabie saoudite) prenant soin de patients adultes gravement malades sous ventilation mécanique (n = 2650) ont été inclus. Les interventions ont été les suivantes : probiotiques (Lactobacillus rhamnosus GG) vs placebo administrés par voie entérale deux fois par jour. Nous avons recueilli les données concernant l'utilisation des ressources en soins de santé et estimé les coûts unitaires en dollars américains (USD) de 2019 sur un horizon temporel allant de la randomisation au congé de l'hôpital / décès. Nous avons calculé des rapports coût-efficacité différentiels (RCED) en comparant les probiotiques vs les soins habituels. Le critère d'évaluation principal était le coût différentiel par événement évité de pneumonie associée au ventilateur (PAV); les critères d'évaluation secondaires étaient les coûts par diarrhée associée au Clostridioides difficile (DACD), diarrhée associée aux antibiotiques (DAA) et mortalité évitées. L'incertitude a été étudiée à l'aide d'analyses d'amorçage et de sensibilité non paramétriques. RéSULTATS: Le coût moyen (écart type [ÉT]) par patient était de 66 914 (91 098) USD pour les patients randomisés au groupe probiotiques, avec une médiane [écart interquartile (ÉIQ)] de 42 947 USD [22 239 à 76 205]. En comparaison, pour ceux ne recevant pas de probiotiques, le coût moyen (ÉT) par patient était de 62 701 USD (78 676) (médiane [ÉIQ], 41 102 USD [23 170 à 75 140]; coût différentiel, 4213 USD; intervalle de confiance [IC] à 95%, -2269 à 10 708). En matière de rapports coût-efficacité différentiels pour les événements de PAV ou DAA évités, les probiotiques étaient dominés par les soins habituels (plus coûteux, avec une efficacité similaire). Les RCED étaient de 1 473 400 USD par événement de DACD évitée (IC 95 %, non défini) et de 396 764 USD par décès évité (IC 95 %, non défini). Les courbes d'acceptabilité coût-efficacité révèlent que les probiotiques n'étaient pas rentables dans de larges gammes de seuils plausibles de volonté de payer. Les analyses de sensibilité n'ont pas modifié les conclusions. CONCLUSION: Les probiotiques utilisés pour prévenir la PAV chez les patients gravement malades n'étaient pas rentables. Enregistrement de l'étude : www.clinicaltrials.gov (NCT01782755); enregistrée le 4 février 2013.

Effect of Probiotics on Incident Ventilator-Associated Pneumonia in Critically Ill Patients: A Randomized Clinical Trial.

Importance: Growing interest in microbial dysbiosis during critical illness has raised questions about the therapeutic potential of microbiome modification with probiotics. Prior randomized trials in this population suggest that probiotics reduce infection, particularly ventilator-associated pneumonia (VAP), although probiotic-associated infections have also been reported. Objective: To evaluate the effect of Lactobacillus rhamnosus GG on preventing VAP, additional infections, and other clinically important outcomes in the intensive care unit (ICU). Design, Setting, and Participants: Randomized placebo-controlled trial in 44 ICUs in Canada, the United States, and Saudi Arabia enrolling adults predicted to require mechanical ventilation for at least 72 hours. A total of 2653 patients were enrolled from October 2013 to March 2019 (final follow-up, October 2020). Interventions: Enteral L rhamnosus GG (1 × 1010 colony-forming units) (n = 1321) or placebo (n = 1332) twice daily in the ICU. Main Outcomes and Measures: The primary outcome was VAP determined by duplicate blinded central adjudication. Secondary outcomes were other ICU-acquired infections including Clostridioides difficile infection, diarrhea, antimicrobial use, ICU and hospital length of stay, and mortality. Results: Among 2653 randomized patients (mean age, 59.8 years [SD], 16.5 years), 2650 (99.9%) completed the trial (mean age, 59.8 years [SD], 16.5 years; 1063 women [40.1%.] with a mean Acute Physiology and Chronic Health Evaluation II score of 22.0 (SD, 7.8) and received the study product for a median of 9 days (IQR, 5-15 days). VAP developed among 289 of 1318 patients (21.9%) receiving probiotics vs 284 of 1332 controls (21.3%; hazard ratio [HR], 1.03 (95% CI, 0.87-1.22; P = .73, absolute difference, 0.6%, 95% CI, -2.5% to 3.7%). None of the 20 prespecified secondary outcomes, including other ICU-acquired infections, diarrhea, antimicrobial use, mortality, or length of stay showed a significant difference. Fifteen patients (1.1%) receiving probiotics vs 1 (0.1%) in the control group experienced the adverse event of L rhamnosus in a sterile site or the sole or predominant organism in a nonsterile site (odds ratio, 14.02; 95% CI, 1.79-109.58; P < .001). Conclusions and Relevance: Among critically ill patients requiring mechanical ventilation, administration of the probiotic L rhamnosus GG compared with placebo, resulted in no significant difference in the development of ventilator-associated pneumonia. These findings do not support the use of L rhamnosus GG in critically ill patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02462590.

2023 ISTH update of the 2022 ISTH guidelines for antithrombotic treatment in COVID-19.

Based on emerging evidence from the COVID-19 pandemic, the International Society on Thrombosis and Haemostasis (ISTH) guidelines for antithrombotic treatment in COVID-19 were published in 2022. Since then, at least 16 new randomized controlled trials have contributed additional evidence, which necessitated a modification of most of the previous recommendations. We used again the American College of Cardiology Foundation/American Heart Association methodology for assessment of level of evidence (LOE) and class of recommendation (COR). Five recommendations had the LOE upgraded to A and 2 new recommendations on antithrombotic treatment for patients with COVID-19 were added. Furthermore, a section was added to answer questions about COVID-19 vaccination and vaccine-induced immune thrombotic thrombocytopenia (VITT), for which studies have provided some evidence. We only included recommendations with LOE A or B. Panelists agreed on 19 recommendations, 4 for nonhospitalized, 5 for noncritically ill hospitalized, 3 for critically ill hospitalized, and 2 for postdischarge patients, as well as 5 for vaccination and VITT. A strong recommendation (COR 1) was given for (a) use of prophylactic dose of low-molecular-weight heparin or unfractionated heparin in noncritically ill patients hospitalized for COVID-19, (b) for select patients in this group, use of therapeutic-dose low-molecular-weight heparin/unfractionated heparin in preference to prophylactic dose, and (c) for use of antiplatelet factor 4 enzyme immunoassays for diagnosing VITT. A strong recommendation was given against (COR 3) the addition of an antiplatelet agent in hospitalized, noncritically ill patients. These international guidelines provide recommendations for countries with diverse healthcare resources and COVID-19 vaccine availability.

ISTH guidelines for antithrombotic treatment in COVID-19.

Antithrombotic agents reduce risk of thromboembolism in severely ill patients. Patients with coronavirus disease 2019 (COVID-19) may realize additional benefits from heparins. Optimal dosing and timing of these treatments and benefits of other antithrombotic agents remain unclear. In October 2021, ISTH assembled an international panel of content experts, patient representatives, and a methodologist to develop recommendations on anticoagulants and antiplatelet agents for patients with COVID-19 in different clinical settings. We used the American College of Cardiology Foundation/American Heart Association methodology to assess level of evidence (LOE) and class of recommendation (COR). Only recommendations with LOE A or B were included. Panelists agreed on 12 recommendations: three for non-hospitalized, five for non-critically ill hospitalized, three for critically ill hospitalized, and one for post-discharge patients. Two recommendations were based on high-quality evidence, the remainder on moderate-quality evidence. Among non-critically ill patients hospitalized for COVID-19, the panel gave a strong recommendation (a) for use of prophylactic dose of low molecular weight heparin or unfractionated heparin (LMWH/UFH) (COR 1); (b) for select patients in this group, use of therapeutic dose LMWH/UFH in preference to prophylactic dose (COR 1); but (c) against the addition of an antiplatelet agent (COR 3). Weak recommendations favored (a) sulodexide in non-hospitalized patients, (b) adding an antiplatelet agent to prophylactic LMWH/UFH in select critically ill, and (c) prophylactic rivaroxaban for select patients after discharge (all COR 2b). Recommendations in this guideline are based on high-/moderate-quality evidence available through March 2022. Focused updates will incorporate future evidence supporting changes to these recommendations.

Impact of employing primary healthcare professionals in emergency department triage on patient flow outcomes: a systematic review and meta-analysis.

OBJECTIVES: To identify, critically appraise and summarise evidence on the impact of employing primary healthcare professionals (PHCPs: family physicians/general practitioners (GPs), nurse practitioners (NP) and nurses with increased authority) in the emergency department (ED) triage, on patient flow outcomes. METHODS: We searched Medline (Ovid), EMBASE (Ovid), Cochrane Library (Wiley) and CINAHL (EBSCO) (inception to January 2020). Our primary outcome was the time to provider initial assessment (PIA). Secondary outcomes included time to triage, proportion of patients leaving without being seen (LWBS), length of stay (ED LOS), proportion of patients leaving against medical advice (LAMA), number of repeat ED visits and patient satisfaction. Two independent reviewers selected studies, extracted data and assessed study quality using the National Institute for Health and Care Excellence quality assessment tool. RESULTS: From 23 973 records, 40 comparative studies including 10 randomised controlled trials (RCTs) and 13 pre-post studies were included. PHCP interventions were led by NP (n=14), GP (n=3) or nurses with increased authority (n=23) at triage. In all studies, PHCP-led intervention effectiveness was compared with the traditional nurse-led triage model. Median duration of the interventions was 6 months. Study quality was generally low (confounding bias); 7 RCTs were classified as moderate quality. Most studies reported that PHCP-led triage interventions decreased the PIA (13/14), ED LOS (29/30), proportion of patients LWBS (8/10), time to triage (3/3) and repeat ED visits (5/6), and increased the patient satisfaction (8/10). The proportion of patients LAMA did not differ between groups (3/3). Evidence from RCTs (n=8) as well as other study designs showed a significant decrease in ED LOS favouring the PHCP-led interventions. CONCLUSIONS: Overall, PHCP-led triage interventions improved ED patient flow metrics. There was a significant decrease in ED LOS irrespective of the study design, favouring the PHCP-led interventions. Evidence from well-designed high-quality RCTs is required prior to widespread implementation. PROSPERO REGISTRATION NUMBER: CRD42020148053.

Interventions and strategies involving primary healthcare professionals to manage emergency department overcrowding: a scoping review.

OBJECTIVES: To conduct a scoping review to identify and summarise the existing literature on interventions involving primary healthcare professionals to manage emergency department (ED) overcrowding. DESIGN: A scoping review. DATA SOURCES: A comprehensive database search of Medline (Ovid), EMBASE (Ovid), Cochrane Library (Wiley) and CINAHL (EBSCO) databases was conducted (inception until January 2020) using peer-reviewed search strategies, complemented by a search of grey literature sources. ELIGIBILITY CRITERIA: Interventions and strategies involving primary healthcare professionals (PHCPs: general practitioners (GPs), nurse practitioners (NPs) or nurses with expanded role) to manage ED overcrowding. METHODS: We engaged and collaborated, with 13 patient partners during the design and conduct stages of this review. We conducted this review using the JBI guidelines. Two reviewers independently selected studies and extracted data. We conducted descriptive analysis of the included studies (frequencies and percentages). RESULTS: From 23 947 records identified, we included 268 studies published between 1981 and 2020. The majority (58%) of studies were conducted in North America and were predominantly cohort studies (42%). The reported interventions were either 'within ED' (48%) interventions (eg, PHCP-led ED triage or fast track) or 'outside ED' interventions (52%) (eg, after-hours GP clinic and GP cooperatives). PHCPs involved in the interventions were: GP (32%), NP (26%), nurses with expanded role (16%) and combinations of the PHCPs (42%). The 'within ED' and 'outside ED' interventions reported outcomes on patient flow and ED utilisation, respectively. CONCLUSIONS: We identified many interventions involving PHCPs that predominantly reported a positive impact on ED utilisation/patient flow metrics. Future research needs to focus on conducting well-designed randomized controlled trials (RCTs) and systematic reviews to evaluate the effectiveness of specific interventions involving PHCPs to critically appraise and summarise evidence on this topic.

Layperson-Led vs Professional-Led Behavioral Interventions for Weight Loss in Pediatric Obesity: A Systematic Review and Meta-analysis.

Importance: The appropriate approach for weight loss among children and adolescents with overweight and obesity remains unclear. Objective: To evaluate the difference in the treatment outcomes associated with behavioral weight loss interventions led by laypersons and professionals in comparison with unsupervised control arms among children and adolescents with overweight and obesity. Data Sources: For this systematic review and meta-analysis, the Medical Literature Analysis and Retrieval System Online (MEDLINE), Embase, the Cochrane Library, and Cumulative Index of Nursing and Allied Health Literature (CINAHL) databases were searched from January 1, 1996, to June 1, 2019. Study Selection: Included in this study were randomized clinical trials (RCTs) of behavioral interventions lasting at least 12 weeks for children and adolescents (aged 5-18 years) with overweight and obesity. Exclusion criteria included non-RCT studies, interventions lasting less than 12 weeks, adult enrollment, participants with other medical diagnoses, pharmacological treatment use, and articles not written in English. Two of 6 reviewers independently screened all citations. Of 25 586 citations, after duplicate removal, 78 RCTs (5780 participants) met eligibility criteria. Data Extraction and Synthesis: A bayesian framework and Markov chain Monte Carlo simulation methods were used to combine direct and indirect associations. Random-effects and fixed-effect network meta-analysis models were used with the preferred model chosen by comparing the deviance information criteria. This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO) and followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Main Outcomes and Measures: The immediate and sustained changes in weight and body mass index (BMI) standardized mean difference (SMD) were primary outcomes planned before data collection began, whereas waist circumference and percent body fat were secondary outcomes. The hypothesis being tested was formulated before the data collection. Results: Of 25 586 citations retrieved, we included 78 RCTs (5780 participants), with a follow-up of 12 to 104 weeks. Compared with the control condition, random-effects models revealed that professional-led weight loss interventions were associated with reductions in weight (mean difference [MD], -1.60 kg [95% CI, -2.30 to -0.99 kg]; 68 trials; P < .001) and BMI (SMD, -0.30 [95% CI, -0.39 to -0.20]; 59 trials; P < .001) that were not sustained long term (weight MD, -1.02 kg [95% CI, -2.20 to 0.34 kg]; 21 trials; P = .06; BMI SMD, -0.12 [95% CI, -0.46 to 0.21]; 20 trials; P < .001). There was no association between layperson-led interventions and weight loss in the short-term (MD, -1.40 kg [95% CI, -3.00 to 0.26 kg]; 5 trials; P = .05) or long-term (MD, -0.98 kg [95% CI, -3.60 to 1.80 kg]; 1 trial; P = .23) compared with standard care. No difference was found in head-to-head trials (professional vs layperson MD, -0.25 kg [95% CI -1.90 to 1.30 kg]; 5 trials; P = .38). Conclusions and Relevance: This systematic review and meta-analysis found that professional-led weight loss interventions were associated with short-term but not sustained weight reduction among children and adolescents with overweight or obesity, and the evidence for layperson-led approaches was insufficient to draw firm conclusions.

Efficacy and safety of high-dose influenza vaccine in elderly adults: A systematic review and meta-analysis.

INTRODUCTION: Older adults are prioritized for influenza vaccination but also have lowered antibody responses to the vaccine. Higher-doses of influenza antigen may increase immune response and thus be more effective. Our objectives were to compare the efficacy and safety of the high-dose influenza vaccine to the standard-dose influenza vaccine in the elderly (age>65). METHODS: Data sources: Randomized trials (RCTs) from Medline (Ovid), EMBASE (Ovid), Cochrane Library (Wiley), ClinicalTrials.gov, reference lists of relevant articles, and gray literature. STUDY SELECTION: Two reviewers independently identified RCTs comparing high-dose influenza vaccine (60µg of hemagglutinin per strain) to standard-dose influenza vaccine (15µg of hemagglutinin per strain) in adults over the age of 65years. DATA EXTRACTION: Two reviewers independently extracted trial-level data including population characteristics, interventions, outcomes, and funding sources. Risk of bias was assessed using the Cochrane Risk of Bias tool. RESULTS: We included seven eligible trials; all were categorized as having a low (n=3) or unclear (n=4) risk of bias. Patients receiving the high-dose vaccine had significantly less risk of developing laboratory-confirmed influenza infections (Relative Risk 0.76, 95%CI 0.65 to 0.90; I2 0%, 2 trials, 41,141 patients). Post-vaccination geometric mean titres and seroprotection rates were also higher in high-dose vaccine recipients. There were no protocol-defined serious adverse events in the included trials in either group. CONCLUSIONS: In elderly adults, the high-dose influenza vaccine was well-tolerated, more immunogenic, and more efficacious in preventing influenza infections than the standard-dose vaccine. Further pragmatic trials are needed to determine if the higher efficacy translates into higher vaccine effectiveness in adults over the age of 65.

Behavior change interventions and policies influencing primary healthcare professionals' practice-an overview of reviews.

BACKGROUND: There is a plethora of interventions and policies aimed at changing practice habits of primary healthcare professionals, but it is unclear which are the most appropriate, sustainable, and effective. We aimed to evaluate the evidence on behavior change interventions and policies directed at healthcare professionals working in primary healthcare centers. METHODS: Study design: overview of reviews. DATA SOURCE: MEDLINE (Ovid), Embase (Ovid), The Cochrane Library (Wiley), CINAHL (EbscoHost), and grey literature (January 2005 to July 2015). STUDY SELECTION: two reviewers independently, and in duplicate, identified systematic reviews, overviews of reviews, scoping reviews, rapid reviews, and relevant health technology reports published in full-text in the English language. DATA EXTRACTION AND SYNTHESIS: two reviewers extracted data pertaining to the types of reviews, study designs, number of studies, demographics of the professionals enrolled, interventions, outcomes, and authors' conclusions for the included studies. We evaluated the methodological quality of the included studies using the AMSTAR scale. For the comparative evaluation, we classified interventions according to the behavior change wheel (Michie et al.). RESULTS: Of 2771 citations retrieved, we included 138 reviews representing 3502 individual studies. The majority of systematic reviews (91%) investigated behavior and practice changes among family physicians. Interactive and multifaceted continuous medical education programs, training with audit and feedback, and clinical decision support systems were found to be beneficial in improving knowledge, optimizing screening rate and prescriptions, enhancing patient outcomes, and reducing adverse events. Collaborative team-based policies involving primarily family physicians, nurses, and pharmacists were found to be most effective. Available evidence on environmental restructuring and modeling was found to be effective in improving collaboration and adherence to treatment guidelines. Limited evidence on nurse-led care approaches were found to be as effective as general practitioners in patient satisfaction in settings like asthma, cardiovascular, and diabetes clinics, although this needs further evaluation. Evidence does not support the use of financial incentives to family physicians, especially for long-term behavior change. CONCLUSIONS: Behavior change interventions including education, training, and enablement in the context of collaborative team-based approaches are effective to change practice of primary healthcare professionals. Environmental restructuring approaches including nurse-led care and modeling need further evaluation. Financial incentives to family physicians do not influence long-term practice change.

Systematic review of interventions for depression and anxiety in persons with inflammatory bowel disease.

BACKGROUND: Depression and anxiety are common in inflammatory bowel disease (IBD) and can affect disease outcomes, including quality of life and success of disease treatment. Successful management of psychiatric comorbidities may improve outcomes, though the effectiveness of existing treatments in IBD is unknown. METHODS: We searched multiple online databases from inception until March 25, 2015, without restrictions on language, date, or location of publication. We included controlled clinical trials conducted in persons with IBD and depression or anxiety. Two independent reviewers reviewed all abstracts and full-text articles and extracted information including trial and participant characteristics. We also assessed the risk of bias. RESULTS: Of 768 unique abstracts, we included one trial of pharmacological anxiety treatment in IBD (48 participants), which found an improvement in anxiety symptoms (p < 0.001). There was a high risk of bias in this trial. We found no controlled clinical trials on the treatment of depression in persons with IBD and depression and no controlled clinical trials reporting on psychological interventions for anxiety or depression in IBD. CONCLUSIONS: Only one trial examined an intervention for anxiety in adults with IBD and no trials studied depression in adults with IBD. The level of evidence is low because of the risk of bias and limited evidence.

Probiotic supplementation during pregnancy or infancy for the prevention of asthma and wheeze: systematic review and meta-analysis.

OBJECTIVE: To evaluate the association of probiotic supplementation during pregnancy or infancy with childhood asthma and wheeze. DESIGN: Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: Medline, Embase, and Central (Cochrane Library) databases from inception to August 2013, plus the World Health Organization's international clinical trials registry platform and relevant conference proceedings for the preceding five years. Included trials and relevant reviews were forward searched in Web of Science. REVIEW METHODS: Two reviewers independently identified randomised controlled trials evaluating probiotics administered to mothers during pregnancy or to infants during the first year of life. The primary outcome was doctor diagnosed asthma; secondary outcomes included wheeze and lower respiratory tract infection. RESULTS: We identified 20 eligible trials including 4866 children. Trials were heterogeneous in the type and duration of probiotic supplementation, and duration of follow-up. Only five trials conducted follow-up beyond participants' age of 6 years (median 24 months), and none were powered to detect asthma as the primary outcome. The overall rate of doctor diagnosed asthma was 10.7%; overall rates of incident wheeze and lower respiratory tract infection were 33.3% and 13.9%, respectively. Among 3257 infants enrolled in nine trials contributing asthma data, the risk ratio of doctor diagnosed asthma in participants randomised to receive probiotics was 0.99 (95% confidence interval 0.81 to 1.21, I(2)=0%). The risk ratio of incident wheeze was 0.97 (0.87 to 1.09, I(2)=0%, 9 trials, 1949 infants). Among 1364 infants enrolled in six trials, the risk ratio of lower respiratory tract infection after probiotic supplementation was 1.26 (0.99 to 1.61, I(2)=0%). We adjudicated most trials to be of high (ten trials) or unclear (nine trials) risk of bias, mainly due to attrition. CONCLUSIONS: We found no evidence to support a protective association between perinatal use of probiotics and doctor diagnosed asthma or childhood wheeze. Randomised controlled trials to date have not yielded sufficient evidence to recommend probiotics for the primary prevention of these disorders. Extended follow-up of existing trials, along with further clinical and basic research, are needed to accurately define the role of probiotics in the prevention of childhood asthma. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (CRD42013004385).