Changes in exhaled volatile organic compounds following indirect bronchial challenge in suspected asthma.

BACKGROUND: Inhaled mannitol provokes bronchoconstriction via mediators released during osmotic degranulation of inflammatory cells, and, hence represents a useful diagnostic test for asthma and model for acute attacks. We hypothesised that the mannitol challenge would trigger changes in exhaled volatile organic compounds (VOCs), generating both candidate biomarkers and novel insights into their origin. METHODS: Participants with a clinical diagnosis of asthma, or undergoing investigation for suspected asthma, were recruited. Inhaled mannitol challenges were performed, followed by a sham challenge after 2 weeks in participants with bronchial hyper-responsiveness (BHR). VOCs were collected before and after challenges and analysed using gas chromatography-mass spectrometry. RESULTS: Forty-six patients (mean (SD) age 52 (16) years) completed a mannitol challenge, of which 16 (35%) were positive, and 15 of these completed a sham challenge. Quantities of 16 of 51 identified VOCs changed following mannitol challenge (p<0.05), of which 11 contributed to a multivariate sparse partial least square discriminative analysis model, with a classification error rate of 13.8%. Five of these 16 VOCs also changed (p<0.05) in quantity following the sham challenge, along with four further VOCs. In patients with BHR to mannitol distinct postchallenge VOC signatures were observed compared with post-sham challenge. CONCLUSION: Inhalation of mannitol was associated with changes in breath VOCs, and in people with BHR resulted in a distinct exhaled breath profile when compared with a sham challenge. These differentially expressed VOCs are likely associated with acute airway inflammation and/or bronchoconstriction and merit further investigation as potential biomarkers in asthma.

EVALUATION OF THE FIRST OLDER PEOPLE'S EMERGENCY DEPARTMENT IN ENGLAND - A RETROSPECTIVE COHORT STUDY.

BACKGROUND: The complexity of older patients along with trends in poorer outcomes in the emergency department (ED) has prompted research into how EDs can adapt to meet the needs of an aging population. A separate Older People's Emergency Department (OPED) has been proposed to improve care at the front door. OBJECTIVE: Compare patient flow in a dedicated OPED at a University Hospital in Norfolk, United Kingdom, against that of the main ED. METHODS: We carried out a retrospective cohort study to compare older patients attending the ED in 2019 against those attending the newly formed OPED service in 2020. Multivariable logistic regression was performed to estimate adjusted odds ratios (emergency admissions, meeting England's 4-h national target, re-admissions, all-cause 30-day mortality, clinical frailty screening, and discharge to original place of residence). RESULTS: Clinical assessment in the OPED did not significantly lower the proportion of patients admitted to the hospital (adjusted odds ratio 0.84; 95% confidence interval 0.61-1.16).  There were significant reductions in overall time spent in the department, time to initial clinician review, and time to frailty screening. Patients seen in the OPED were more likely to meet the national 4-h target and more likely to be discharged to their original place of residence. CONCLUSIONS: Assessment in the OPED was not associated with a significantly reduced likelihood of hospitalization. However, patients had a shorter wait for clinical assessment, with concomitant reduction in department length of stay.

Cognitive decline associated with anticholinergics, benzodiazepines and Z-drugs: Findings from The Irish Longitudinal Study on Ageing (TILDA).

AIMS: To estimate the association between patterns of anticholinergic, benzodiazepine and Z-drug medication use and change in cognitive function in middle-aged and older adults. METHODS: This prospective cohort study used data from the first three waves of The Irish Longitudinal Study on Ageing (TILDA), including community-dwelling adults aged ≥50 years followed for up to 4 years (n = 7027). Cognitive function was assessed using the Mini Mental State Examination, animal naming test and word recall tests. Regular medication use was self-reported at baseline and follow-up interviews at 2 and 4 years. Pharmacy dispensing claims for a subset (n = 2905) allowed assessment of medication use between interviews and cumulative dosage. Medication use at consecutive waves of TILDA was analysed in relation to change in cognitive function between waves. RESULTS: Strongly anticholinergic medications (Anticholinergic Cognitive Burden scale 3), benzodiazepines and Z-drugs were reported by 7.3%, 5.8% and 5.1% of participants, respectively, at any time during the study. Adjusting for potential confounders, new anticholinergic use between interviews was associated with change in recall score (-1.09, 95% confidence interval -1.64, -0.53) over 2 years compared to non-use, but not with MMSE (0.07; 95% CI -0.21, 0.34) or animal naming (-0.70; 95% CI -1.43, 0.03). The pharmacy claims analysis was consistent with this finding. Other hypothesised associations were not supported. CONCLUSIONS: Except for new use of anticholinergic medications, no other findings supported a risk of cognitive decline over 2-year periods in this middle-aged and older cohort. Patients and prescribers should weigh this potential risk against potential benefits of commencing anticholinergic medications.

Calcium intake, calcium supplementation and cardiovascular disease and mortality in the British population: EPIC-norfolk prospective cohort study and meta-analysis.

The role of dietary calcium in cardiovascular disease prevention is unclear. We aimed to determine the association between calcium intake and incident cardiovascular disease and mortality. Data were extracted from the European Prospective Investigation of Cancer, Norfolk (EPIC-Norfolk). Multivariable Cox regressions analysed associations between calcium intake (dietary and supplemental) and cardiovascular disease (myocardial infarction, stroke, heart failure, aortic stenosis, peripheral vascular disease) and mortality (cardiovascular and all-cause). The results of this study were pooled with those from published prospective cohort studies in a meta-analsyis, stratifying by average calcium intake using a 700 mg/day threshold. A total of 17,968 participants aged 40-79 years were followed up for a median of 20.36 years (20.32-20.38). Compared to the first quintile of calcium intake (< 770 mg/day), intakes between 771 and 926 mg/day (second quintile) and 1074-1254 mg/day (fourth quintile) were associated with reduced all-cause mortality (HR 0.91 (0.83-0.99) and 0.85 (0.77-0.93), respectively) and cardiovascular mortality [HR 0.95 (0.87-1.04) and 0.93 (0.83-1.04)]. Compared to the first quintile of calcium intake, second, third, fourth, but not fifth quintiles were associated with fewer incident strokes: respective HR 0.84 (0.72-0.97), 0.83 (0.71-0.97), 0.78 (0.66-0.92) and 0.95 (0.78-1.15). The meta-analysis results suggest that high levels of calcium intake were associated with decreased all-cause mortality, but not cardiovascular mortality, regardless of average calcium intake. Calcium supplementation was associated with cardiovascular and all-cause mortality amongst women, but not men. Moderate dietary calcium intake may protect against cardiovascular and all-cause mortality and incident stroke. Calcium supplementation may reduce mortality in women.

Smoking cessation after acute coronary syndrome: A systematic review and meta-analysis.

BACKGROUND: Smoking cessation is an effective secondary prevention measure after acute coronary syndrome (ACS). We conducted a systematic review with the aim to better understand which patients have a greater propensity to quit smoking and the risk factors for continued smoking after ACS. METHODS: We searched MEDLINE and EMBASE for studies that evaluated smoking cessation after ACS. The pooled rate of smoking cessation across included studies was performed. Random effects meta-analysis for different variables and their association with smoking cessation was conducted. RESULTS: A total of 39 studies with 11 228 patients were included in this review. The pooled rate of smoking cessation following ACS across 38 studies was 45.0%. Factors associated with greater likelihood of smoking cessation were attendance at cardiac rehabilitation (OR 1.90 95% CI 1.44-2.51), married/not alone (OR 1.68 95% CI 1.32-2.13), intention/attempt to quit smoking (OR 1.27 95% CI 1.11-1.46), diabetes mellitus (OR 1.24 95% CI 1.03-1.51) and hospitalised duration (OR 1.09 95% CI 1.02-1.15). Variables associated with a lower likelihood of smoking cessation were depression (OR 0.57 95% CI 0.43-0.75), chronic obstructive pulmonary disease/lung disease (OR 0.73 95% CI 0.57-0.93), previous admission with acute myocardial infarction/cardiac admission (OR 0.61 95% CI 0.47-0.80), cerebrovascular disease/transient ischaemic attack (OR 0.42 95% CI 0.30-0.58) and unemployment (OR 0.37 95% CI 0.17-0.80). CONCLUSIONS: The majority of smokers with an ACS continue to smoke after admission. Patients attending cardiac rehabilitation show increased odds of quitting while people who are depressed and those with chronic lung disease were less likely to quit smoking and should be targeted for intensive smoking cessation interventions.

Adverse effects of Z-drugs for sleep disturbance in people living with dementia: a population-based cohort study.

BACKGROUND: Sleep disturbance is common in dementia and often treated with Z-drugs (zopiclone, zaleplon, and zolpidem). While some observational studies suggest that Z-drugs are associated with adverse events such as falls and fracture risks in older people, this has not been studied in dementia. METHODS: We used data from 27,090 patients diagnosed with dementia between January 2000 and March 2016 from the Clinical Practice Research Datalink linked to Hospital Episodes Statistics data in England. We compared adverse events for 3532 patients newly prescribed Z-drugs by time-varying dosage to (1) 1833 non-sedative-users with sleep disturbance; (2) 10,214 non-sedative-users with proximal GP consultation matched on age, sex, and antipsychotic use; and (3) 5172 patients newly prescribed benzodiazepines. We defined higher dose Z-drugs and benzodiazepines as prescriptions equivalent to ≥ 7.5 mg zopiclone or > 5 mg diazepam daily. Cox regression was used to estimate hazard ratios (HRs) for incident fracture, hip fracture, fall, mortality, acute bacterial infection, ischaemic stroke/transient ischaemic attack, and venous thromboembolism over a 2-year follow-up, adjusted for demographic- and health-related covariates. RESULTS: The mean (SD) age of patients was 83 (7.7) years, and 16,802 (62%) were women. Of 3532 patients prescribed Z-drugs, 584 (17%) were initiated at higher doses. For patients prescribed higher dose Z-drugs relative to non-users with sleep disturbance, the HRs (95% confidence interval) for fractures, hip fractures, falls, and ischaemic stroke were 1.67 (1.13-2.46), 1.96 (1.16-3.31), 1.33 (1.06-1.66), and 1.88 (1.14-3.10), respectively. We observed similar associations when compared to non-sedative-users with proximal GP consultation. Minimal or inconsistent excess risks were observed at ≤ 3.75 mg zopiclone or equivalent daily, and for mortality, infection, and venous thromboembolism. We observed no differences in adverse events for Z-drugs compared to benzodiazepines, except lower mortality rates with Z-drugs (HR [95% confidence interval] of 0.73 [0.64-0.83]). CONCLUSIONS: Higher dose Z-drug use in dementia is associated with increased fracture and stroke risks, similar or greater to that for higher dose benzodiazepines. Higher dose Z-drugs should be avoided, if possible, in people living with dementia, and non-pharmacological alternatives preferentially considered. Prescriptions for higher dose Z-drugs in dementia should be regularly reviewed. TRIAL REGISTRATION: ENCePP e-register of studies, EUPAS18006.

Efficacy and safety profile of statins in patients with cancer: a systematic review of randomised controlled trials.

PURPOSE: A growing body of preclinical and observational research suggests that statins have potential as a therapeutic strategy in patients with cancer. This systematic review of randomised controlled trials (RCTs) in patients with solid tumours aimed to determine the efficacy of statin therapy on mortality outcomes, their safety profile and the risk of bias of included studies. METHODS: Full-text articles comparing statin therapy versus control in solid tumours and reporting mortality outcomes were identified from Medline and Embase from conception to February 2020. A systematic review with qualitative (primarily) and quantitative synthesis was conducted. This systematic review was prospectively registered (Prospero registration CRD42018116364). RESULTS: Eleven trials of 2165 patients were included. Primary tumour sites investigated included lung, colorectal, gastro-oesophageal, pancreatic and liver. Most trials recruited patients with advanced malignancy and used sub-maximal statin doses for relatively short durations. Aside from one trial which demonstrated benefit with allocation to pravastatin 40 mg in hepatocellular carcinoma, the remaining ten trials did not demonstrate efficacy with statins. The pooled hazard ratio for all-cause mortality with allocation to pravastatin in patients with hepatocellular carcinoma in two trials was 0.69 (95% confidence interval CI 0.30-1.61). Study estimates were imprecise. There were no clinically important differences in statin-related adverse events between groups. Overall, included trials were deemed low risk of bias. CONCLUSION: The trial evidence is not sufficiently robust to confirm or refute the efficacy and safety of statins in patients with solid malignant tumours. Study and patient characteristics may explain this uncertainty. The potential role of high-dose statins in adjuvant settings deserves further research.

Anticholinergic drugs and incident dementia, mild cognitive impairment and cognitive decline: a meta-analysis.

BACKGROUND: the long-term effect of the use of drugs with anticholinergic activity on cognitive function remains unclear. METHODS: we conducted a systematic review and meta-analysis of the relationship between anticholinergic drugs and risk of dementia, mild cognitive impairment (MCI) and cognitive decline in the older population. We identified studies published between January 2002 and April 2018 with ≥12 weeks follow-up between strongly anticholinergic drug exposure and the study outcome measurement. We pooled adjusted odds ratios (OR) for studies reporting any, and at least short-term (90+ days) or long-term (365+ days) anticholinergic use for dementia and MCI outcomes, and standardised mean differences (SMD) in global cognition test scores for cognitive decline outcomes. Statistical heterogeneity was measured using the I2 statistic and risk of bias using ROBINS-I. RESULTS: twenty-six studies (including 621,548 participants) met our inclusion criteria. 'Any' anticholinergic use was associated with incident dementia (OR 1.20, 95% confidence interval [CI] 1.09-1.32, I2 = 86%). Short-term and long-term use were also associated with incident dementia (OR 1.23, 95% CI 1.17-1.29, I2 = 2%; and OR 1.50, 95% CI 1.22-1.85, I2 = 90%). 'Any' anticholinergic use was associated with cognitive decline (SMD 0.15; 95% CI 0.09-0.21, I2 = 3%) but showed no statistically significant difference for MCI (OR 1.24, 95% CI 0.97-1.59, I2 = 0%). CONCLUSIONS: anticholinergic drug use is associated with increased dementia incidence and cognitive decline in observational studies. However, a causal link cannot yet be inferred, as studies were observational with considerable risk of bias. Stronger evidence from high-quality studies is needed to guide the management of long-term use.

Association between different methods of assessing blood pressure variability and incident cardiovascular disease, cardiovascular mortality and all-cause mortality: a systematic review.

BACKGROUND: Blood pressure variability (BPV) is a possible risk factor for adverse cardiovascular outcomes and mortality. There is uncertainty as to whether BPV is related to differences in populations studied, measurement methods or both. We systematically reviewed the evidence for different methods to assess blood pressure variability (BPV) and their association with future cardiovascular events, cardiovascular mortality and all-cause mortality. METHODS: Literature databases were searched to June 2019. Observational studies were eligible if they measured short-term BPV, defined as variability in blood pressure measurements acquired either over a 24-hour period or several days. Data were extracted on method of BPV and reported association (or not) on future cardiovascular events, cardiovascular mortality and all-cause mortality. Methodological quality was assessed using the CASP observational study tool and data narratively synthesised. RESULTS: Sixty-one studies including 3,333,801 individuals were eligible. BPV has been assessed by various methods including ambulatory and home-based BP monitors assessing 24-hour, "day-by-day" and "week-to-week" variability. There was moderate quality evidence of an association between BPV and cardiovascular events (43 studies analysed) or all-cause mortality (26 studies analysed) irrespective of the measurement method in the short- to longer-term. There was moderate quality evidence reporting inconsistent findings on the potential association between cardiovascular mortality, irrespective of methods of BPV assessment (17 studies analysed). CONCLUSION: An association between BPV, cardiovascular mortality and cardiovascular events and/or all-cause mortality were reported by the majority of studies irrespective of method of measurement. Direct comparisons between studies and reporting of pooled effect sizes were not possible.

Can cardiovascular risk management be improved by shared care with general practice to prevent cognitive decline following stroke/TIA? A feasibility randomised controlled trial (SERVED memory).

BACKGROUND: Cognitive impairment and dementia following cerebrovascular disease are increasingly common in the UK. One potential strategy to prevent post-stroke cognitive decline is multimodal vascular risk factor management. However, its efficacy remains uncertain and its application in vulnerable patients with incident cerebrovascular disease and early cognitive impairment has not been assessed. The primary aim of this study was to assess the feasibility of recruitment and retention of patients with early cognitive impairment post-stroke or transient ischaemic attack (TIA) to a trial of enhanced vascular risk factor management combining primary and secondary care. METHODS: In this single centre, open label trial adults with a recent stroke or TIA and mild cognitive impairment (MCI) were randomised 1:1 to a three-monthly multimodal vascular risk factor intervention jointly delivered by the trial team and General Practitioner (GP), or control (defined as usual care from the GP). Chosen risk factors were blood pressure (BP), total cholesterol, blood glucose (HbA1C) in those with diabetes, and heart rate and adequacy of anticoagulation in those with atrial fibrillation (AF). Similar patients with normal cognition were enrolled in an embedded observational cohort and also received usual care from the GP. Repeat cognitive screening was undertaken in all participants after 12 months. RESULTS: Seventy three participants were recruited to the randomised trial and 94 to the observational cohort (21.8% of those screened). From the randomised trial 35/73 (47.9%) dropped out before final follow-up. In all groups guideline based rates of risk factor control were mostly poor at baseline and did not significantly improve during follow-up. The observational cohort demonstrated greater decline in cognitive test scores at 12 months, with no difference between the randomised groups. CONCLUSIONS: Recruitment to such a study was feasible, but retention of participants was difficult and generally poor rates of risk factor control suggested insufficient application of the intervention. Consequently, successful scaling up of the trial would require protocol changes with less reliance on primary care services. Any future trial should include participants with normal cognition post-stroke as they may be at greatest risk of cognitive decline. TRIAL REGISTRATION: ISRCTN, ISRCTN42688361 . Registered 16 April 2015.

Increasing prevalence of anticholinergic medication use in older people in England over 20 years: cognitive function and ageing study I and II.

BACKGROUND: Anticholinergic medication use is linked with increased cognitive decline, dementia, falls and mortality, and their use should be limited in older people. Here we estimate the prevalence of anticholinergic use in England's older population in 1991 and 2011, and describe changes in use by participant's age, sex, cognition and disability. METHODS: We compared data from participants aged 65+ years from the Cognitive Function and Ageing Studies (CFAS I and II), collected during 1990-1993 (N = 7635) and 2008-2011 (N = 7762). We estimated the prevalence of potent anticholinergic use (Anticholinergic Cognitive Burden [ACB] score = 3) and average anticholinergic burden (sum of ACB scores), using inverse probability weights standardised to the 2011 UK population. These were stratified by age, sex, Mini-Mental State Examination score, and activities of daily living (ADL) or instrumental ADL (IADL) disability. RESULTS: Prevalence of potent anticholinergic use increased from 5.7% (95% Confidence Interval [CI] 5.2-6.3%) of the older population in 1990-93 to 9.9% (9.3-10.7%) in 2008-11, adjusted odds ratio of 1.90 (95% CI 1.67-2.16). People with clinically significant cognitive impairment (MMSE [Mini Mental State Examination] 21 or less) were the heaviest users of potent anticholinergics in CFAS II (16.5% [95% CI 12.0-22.3%]). Large increases in the prevalence of the use medication with 'any' anticholinergic activity were seen in older people with clinically significant cognitive impairment (53.3% in CFAS I to 71.5% in CFAS II). CONCLUSIONS: Use of potent anticholinergic medications nearly doubled in England's older population over 20 years with some of the greatest increases amongst those particularly vulnerable to anticholinergic side-effects.

History of Benzodiazepine Prescriptions and Risk of Dementia: Possible Bias Due to Prevalent Users and Covariate Measurement Timing in a Nested Case-Control Study.

Previous estimates of whether long-term exposure to benzodiazepines increases dementia risk are conflicting and are compromised by the difficulty of controlling for confounders and by reverse causation. We investigated how estimates for the association between benzodiazepine use and later dementia incidence varied based on study design choices, using a case-control study nested within the United Kingdom's Clinical Practice Research Datalink. A total of 40,770 dementia cases diagnosed between April 2006 and July 2015 were matched on age, sex, available data history, and deprivation to 283,933 control subjects. Benzodiazepines and Z-drug prescriptions were ascertained in a drug-exposure period 4-20 years before dementia diagnosis. Estimates varied with the inclusion of new or prevalent users, with the timing of covariate ascertainment, and with varying time between exposure and outcome. There was no association between any new prescription of benzodiazepines and dementia (adjusted odds ratio (OR) = 1.03, 95% confidence interval (CI): 1.00, 1.07), whereas an inverse association was observed among prevalent users (adjusted OR = 0.91, 95% CI: 0.87, 0.95), although this was likely induced by unintentional adjustment for colliders. By considering the choice of confounders and timing of exposure and covariate measurement, our findings overall are consistent with no causal effect of benzodiazepines or Z-drugs on dementia incidence.

The effects of hypoglycaemia and dementia on cardiovascular events, falls and fractures and all-cause mortality in older individuals: A retrospective cohort study.

AIMS: Older individuals with diabetes are susceptible to harm as the result of hypoglycaemia; however, the consequences of hypoglycaemia in older individuals with dementia are not known. We aimed to test the association between hypoglycaemia and serious adverse events in older patients with diabetes and dementia, and whether the consequences of hypoglycaemia were affected by the presence of dementia. MATERIALS AND METHODS: This was a cohort study using the Clinical Practice Research Datalink in England (1997-2016). We selected participants, intervention (exposure) and follow-up to mirror two hypothetical target randomized controlled trials. The exposure of target trial 1 was hypoglycaemia in patients with dementia. Target trial 2 examined adverse effects of hypoglycaemia according to dementia status. We used Cox proportional hazard regression to estimate adjusted hazard ratios (aHR) for falls, fractures, cardiovascular events and mortality. RESULTS: In target trial 1, hypoglycaemia was associated with increased risk during a 12-month follow-up period for falls and fractures (aHR, 1.94 [95% CI, 1.67-2.24]), for cardiovascular events (aHR, 2.00 [95% CI, 1.61-2.48]) and for mortality (aHR, 2.36 [95% CI, 2.09-2.67]). In target trial 2, the presence of dementia was associated with increased risk of adverse events, following hypoglycaemia, during a 12-month follow-up period for falls and factures (aHR, 1.72 [95% CI, 1.51-1.96]) and for mortality (aHR, 1.27 [95% CI, 1.15-1.41]), but dementia had no effect on cardiovascular events (aHR, 1.14 [95% CI, 0.95 to 1.36]). CONCLUSIONS: Hypoglycaemia is associated with early increased risk of serious adverse events in older individuals with diabetes and dementia.

Anticholinergic and benzodiazepine medication use and risk of incident dementia: a UK cohort study.

BACKGROUND: Studies suggest that anticholinergic medication or benzodiazepine use could increase dementia risk. We tested this hypothesis using data from a UK cohort study. METHODS: We used data from the baseline (Y0), 2-year (Y2) and 10-year (Y10) waves of the Medical Research Council Cognitive Function and Ageing Study. Participants without dementia at Y2 were included (n = 8216). Use of benzodiazepines (including nonbenzodiazepine Z-drugs), anticholinergics with score 3 (ACB3) and anticholinergics with score 1 or 2 (ACB12) according to the Anticholinergic Cognitive Burden scale were coded as ever use (use at Y0 or Y2), recurrent use (Y0 and Y2), new use (Y2, but not Y0) or discontinued use (Y0, but not Y2). The outcome was incident dementia by Y10. Incidence rate ratios (IRR) were estimated using Poisson regression adjusted for potential confounders. Pre-planned subgroup analyses were conducted by age, sex and Y2 Mini-Mental State Examination (MMSE) score. RESULTS: Dementia incidence was 9.3% (N = 220 cases) between Y2 and Y10. The adjusted IRRs (95%CI) of developing dementia were 1.06 (0.72, 1.60), 1.28 (0.82, 2.00) and 0.89 (0.68, 1.17) for benzodiazepines, ACB3 and ACB12 ever-users compared with non-users. For recurrent users the respective IRRs were 1.30 (0.79, 2.14), 1.68 (1.00, 2.82) and 0.95 (0.71, 1.28). ACB3 ever-use was associated with dementia among those with Y2 MMSE> 25 (IRR = 2.28 [1.32-3.92]), but not if Y2 MMSE≤25 (IRR = 0.94 [0.51-1.73]). CONCLUSIONS: Neither benzodiazepines nor ACB12 medications were associated with dementia. Recurrent use of ACB3 anticholinergics was associated with dementia, particularly in those with good baseline cognitive function. The long-term prescribing of anticholinergics should be avoided in older people.

Statistical reporting of clinical pharmacology research.

Research in clinical pharmacology covers a wide range of experiments, trials and investigations: clinical trials, systematic reviews and meta-analyses of drug usage after market approval, the investigation of pharmacokinetic-pharmacodynamic relationships, the search for mechanisms of action or for potential signals for efficacy and safety using biomarkers. Often these investigations are exploratory in nature, which has implications for the way the data should be analysed and presented. Here we summarize some of the statistical issues that are of particular importance in clinical pharmacology research.

The effect of co-trimoxazole on serum potassium concentration: safety evaluation of a randomized controlled trial.

AIMS: Co-trimoxazole maintains a well-established role in the treatment of Pneumocystis jirovecii and Toxoplasma gondii, as well as urinary tract infections. Observational studies report hyperkalaemia to be associated with co-trimoxazole, which may stem from an amiloride-like potassium-sparing effect. The current study investigated changes in serum potassium in patients without acute infections, and the influence of concomitant antikaliuretic drugs on this effect. METHODS: A post hoc analysis was carried out of a randomized controlled trial in patients with interstitial lung disease who were assigned to placebo or 960 mg co-trimoxazole twice daily. Serum potassium and creatinine were measured at baseline, 6 weeks, and 6, 9 and 12 months. The primary outcome was the difference in mean serum potassium concentrations between co-trimoxazole and placebo at 6 weeks. RESULTS: Mean serum potassium levels were similar at baseline: 4.24 (± 0.44) mmol l-1 in the 87 co-trimoxazole group participants and 4.25 (± 0.39) mmol l-1 in the 83 control participants. Co-trimoxazole significantly increased mean serum potassium levels at 6 weeks, with a difference between means compared with placebo of 0.21 mmol l-1 [95% confidence interval (CI) 0.09, 0.34; P = 0.001). This significant increase in serum potassium was detectable even after exclusion of patients on antikaliuretic drugs, with a difference between means for co-trimoxazole compared with placebo of 0.23 mmol l-1 (95% CI 0.09, 0.38; P = 0.002). There were 5/87 (5.7%) patients on co-trimoxazole whose serum potassium concentrations reached ≥5.5 mmol l-1 during the study period. CONCLUSIONS: Co-trimoxazole significantly increases serum potassium concentration, even in participants not using antikaliuretic drugs. While the magnitude of increase was often minor, a small proportion in our outpatient cohort developed hyperkalaemia of clinical importance.

Overview of systematic reviews of therapeutic ranges: methodologies and recommendations for practice.

BACKGROUND: Many medicines are dosed to achieve a particular therapeutic range, and monitored using therapeutic drug monitoring (TDM). The evidence base for a therapeutic range can be evaluated using systematic reviews, to ensure it continues to reflect current indications, doses, routes and formulations, as well as updated adverse effect data. There is no consensus on the optimal methodology for systematic reviews of therapeutic ranges. METHODS: An overview of systematic reviews of therapeutic ranges was undertaken. The following databases were used: Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts and Reviews of Effects (DARE) and MEDLINE. The published methodologies used when systematically reviewing the therapeutic range of a drug were analyzed. Step by step recommendations to optimize such systematic reviews are proposed. RESULTS: Ten systematic reviews that investigated the correlation between serum concentrations and clinical outcomes encompassing a variety of medicines and indications were assessed. There were significant variations in the methodologies used (including the search terms used, data extraction methods, assessment of bias, and statistical analyses undertaken). Therapeutic ranges should be population and indication specific and based on clinically relevant outcomes. Recommendations for future systematic reviews based on these findings have been developed. CONCLUSION: Evidence based therapeutic ranges have the potential to improve TDM practice. Current systematic reviews investigating therapeutic ranges have highly variable methodologies and there is no consensus of best practice when undertaking systematic reviews in this field. These recommendations meet a need not addressed by standard protocols.

Communication skills training for mental health professionals working with people with severe mental illness.

BACKGROUND: Research evidence suggests that both mental health professionals and people with severe mental health illness such as schizophrenia or schizoaffective disorder find it difficult to communicate with each other effectively about symptoms, treatments and their side effects so that they reach a shared understanding about diagnosis, prognosis and treatment. Effective use of communication skills in mental health interactions could be associated with increased patient satisfaction and adherence to treatment. OBJECTIVES: To review the effectiveness of communication skills training for mental health professionals who work with people with severe mental illness. SEARCH METHODS: We searched the Cochrane Schizophrenia Trials Register (latest search 17 February, 2016) which is compiled by systematic searches of major resources (including AMED, BIOSIS, CINAHL, Embase, MEDLINE, PsycINFO, PubMed, and registries of clinical trials) and their monthly updates, handsearches, grey literature, and conference proceedings. There are no language, date, document type, or publication status limitations for inclusion of records into the register. SELECTION CRITERIA: All relevant randomised clinical trials (RCTs) that focused on communication skills training (CST) for mental health professionals who work with people with severe mental illness compared with those who received standard or no training. We sought a number of primary (patient adherence to treatment and attendance at scheduled appointments as well as mental health professionals' satisfaction with the training programme) and secondary outcomes (patients' global state, service use, mental state, patient satisfaction, social functioning, quality of life). RCTs where the unit of randomisation was by cluster (e.g. healthcare facility) were also eligible for inclusion. We included one trial that met our inclusion criteria and reported useable data. DATA COLLECTION AND ANALYSIS: We independently selected studies, quality assessed them and extracted data. For binary outcomes, we planned to calculate standard estimates of the risk ratio (RR) and their 95% confidence intervals (CI) using a fixed-effect model. For continuous outcomes, we planned to estimate the mean difference (MD) between groups, or obtain the adjusted mean difference (aMD) where available for cluster-randomised trials. If heterogeneity had been identified, we would have explored this using a random-effects model. We used GRADE to create a 'Summary of findings' table and we assessed risk of bias for the one included study. MAIN RESULTS: We included one pilot cluster-RCT that recruited a total of 21 psychiatrists and 97 patients. The psychiatrists were randomised to a training programme in communication skills, compared to a no specific training (NST) programme. The trial provided useable data for only one of our prestated outcomes of interest, patient satisfaction. The trial did not report global state but did report mental state and, as global state data were not available, we included these mental state data in the 'Summary of findings' table. There was high risk of bias from attrition because of substantial losses to follow-up and incomplete outcome data.Patient satisfaction was measured as satisfaction with treatment and 'experience of therapeutic relationship' at medium term (five months). Satisfaction with treatment was similar between the CST and NST group using the Client Satisfaction Questionnaire (CSQ-8) (1 RCT, n = 66/97*, aMD 1.77 95% CI - 0.13 to 3.68, low-quality evidence). When comparing patient experience of the therapeutic relationship using the STAR-P scale, participants in the CST group rated the therapeutic relationship more positively than participants in the NST group (1 RCT, n = 63/97, aMD 0.21 95% CI 0.01 to 0.41, low-quality evidence).Mental state scores on the Positive and Negative Syndrome Scale (PANSS) were similar between treatment groups for general symptoms (1 RCT, n = 59/97, aMD 4.48 95% CI -2.10 to 11.06, low-quality evidence), positive symptoms (1 RCT, n = 59/97, aMD -0.23, 95% CI -2.91 to 2.45, low-quality evidence) and negative symptoms (1 RCT, n = 59/97, aMD 3.42, 95%C CI -0.24 to 7.09, low-quality evidence).No data were available for adherence to treatment, service use or quality of life.* Of the total of 97 randomised participants, 66 provided data. AUTHORS' CONCLUSIONS: The evidence available is from one pilot cluster-randomised controlled trial, it is not adequate enough to draw any robust conclusions. There were relatively few good quality data and the trial is too small to highlight differences in most outcome measures. Adding a CST programme appears to have a modest positive effect on patients' experiences of the therapeutic relationship. More high-quality research is needed in this area.

Closure methods of the appendix stump for complications during laparoscopic appendectomy.

BACKGROUND: Laparoscopic appendectomy is amongst the most common general surgical procedures performed in the developed world. Arguably, the most critical part of this procedure is effective closure of the appendix stump to prevent catastrophic intra-abdominal complications from a faecal leak into the abdominal cavity. A variety of methods to close the appendix stump are used worldwide; these can be broadly divided into traditional ligatures (such as intracorporeal or extracorporeal ligatures or Roeder loops) and mechanical devices (such as stapling devices, clips, or electrothermal devices). However, the optimal method remains unclear. OBJECTIVES: To compare all surgical techniques now used for appendix stump closure during laparoscopic appendectomy. SEARCH METHODS: In June 2017, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 6) in the Cochrane Library, MEDLINE Ovid (1946 to 14 June 2017), Embase Ovid (1974 to 14 June 2017), Science Citation Index - Expanded (14 June 2017), China Biological Medicine Database (CBM), the World Health Organization International Trials Registry Platform search portal, ClinicalTrials.gov, Current Controlled Trials, the Chinese Clinical Trials Register, and the EU Clinical Trials Register (all in June 2017). We searched the reference lists of relevant publications as well as meeting abstracts and Conference Proceedings Citation Index to look for additional relevant clinical trials. SELECTION CRITERIA: We included all randomised controlled trials (RCTs) that compared mechanical appendix stump closure (stapler, clips, or electrothermal devices) versus ligation (Endoloop, Roeder loop, or intracorporeal knot techniques) for uncomplicated appendicitis. DATA COLLECTION AND ANALYSIS: Two review authors identified trials for inclusion, collected data, and assessed risk of bias independently. We performed the meta-analysis using Review Manager 5. We calculated the odds ratio (OR) for dichotomous outcomes and the mean difference (MD) for continuous outcomes, with 95% confidence intervals (CIs). MAIN RESULTS: We included eight randomised studies encompassing 850 participants. Five studies compared titanium clips versus ligature, two studies compared an endoscopic stapler device versus ligature, and one study compared an endoscopic stapler device, titanium clips, and ligature. In our analyses of primary outcomes, we found no differences in total complications (OR 0.97, 95% CI 0.27 to 3.50, 8 RCTs, very low-quality evidence), intraoperative complications (OR 0.93, 95% CI 0.34 to 2.55, 8 RCTs, very low-quality evidence), or postoperative complications (OR 0.80, 95% CI 0.21 to 3.13, 8 RCTs, very low-quality evidence) between ligature and all types of mechanical devices. However, our analyses of secondary outcomes revealed that use of mechanical devices saved approximately nine minutes of total operating time when compared with use of a ligature (mean difference (MD) -9.04 minutes, 95% CI -12.97 to -5.11 minutes, 8 RCTs, very low-quality evidence). However, this finding did not translate into a clinically or statistically significant reduction in inpatient hospital stay (MD 0.02 days, 95% CI -0.12 to 0.17 days, 8 RCTs, very low-quality evidence). Available information was insufficient for reliable comparison of total hospital costs and postoperative pain/quality of life between the two approaches. Overall, evidence across all analyses was of very low quality, with substantial potential for confounding factors. Given the limitations of all studies in terms of bias and the low quality of available evidence, a clear conclusion regarding superiority of any one particular type of mechanical device over another is not possible. AUTHORS' CONCLUSIONS: Evidence is insufficient at present to advocate omission of conventional ligature-based appendix stump closure in favour of any single type of mechanical device over another in uncomplicated appendicitis.

Reporting of Adverse Events in Published and Unpublished Studies of Health Care Interventions: A Systematic Review.

BACKGROUND: We performed a systematic review to assess whether we can quantify the underreporting of adverse events (AEs) in the published medical literature documenting the results of clinical trials as compared with other nonpublished sources, and whether we can measure the impact this underreporting has on systematic reviews of adverse events. METHODS AND FINDINGS: Studies were identified from 15 databases (including MEDLINE and Embase) and by handsearching, reference checking, internet searches, and contacting experts. The last database searches were conducted in July 2016. There were 28 methodological evaluations that met the inclusion criteria. Of these, 9 studies compared the proportion of trials reporting adverse events by publication status. The median percentage of published documents with adverse events information was 46% compared to 95% in the corresponding unpublished documents. There was a similar pattern with unmatched studies, for which 43% of published studies contained adverse events information compared to 83% of unpublished studies. A total of 11 studies compared the numbers of adverse events in matched published and unpublished documents. The percentage of adverse events that would have been missed had each analysis relied only on the published versions varied between 43% and 100%, with a median of 64%. Within these 11 studies, 24 comparisons of named adverse events such as death, suicide, or respiratory adverse events were undertaken. In 18 of the 24 comparisons, the number of named adverse events was higher in unpublished than published documents. Additionally, 2 other studies demonstrated that there are substantially more types of adverse events reported in matched unpublished than published documents. There were 20 meta-analyses that reported the odds ratios (ORs) and/or risk ratios (RRs) for adverse events with and without unpublished data. Inclusion of unpublished data increased the precision of the pooled estimates (narrower 95% confidence intervals) in 15 of the 20 pooled analyses, but did not markedly change the direction or statistical significance of the risk in most cases. The main limitations of this review are that the included case examples represent only a small number amongst thousands of meta-analyses of harms and that the included studies may suffer from publication bias, whereby substantial differences between published and unpublished data are more likely to be published. CONCLUSIONS: There is strong evidence that much of the information on adverse events remains unpublished and that the number and range of adverse events is higher in unpublished than in published versions of the same study. The inclusion of unpublished data can also reduce the imprecision of pooled effect estimates during meta-analysis of adverse events.