Serious adverse events reported in placebo randomised controlled trials of oral naltrexone: a systematic review and meta-analysis.

BACKGROUND: Naltrexone is an opioid antagonist used in many different conditions, both licensed and unlicensed. It is used at widely varying doses from 3 to 250 mg. The aim of this review was to extensively evaluate the safety of oral naltrexone by examining the risk of serious adverse events and adverse events in randomised controlled trials of naltrexone compared to placebo. METHODS: A systematic search of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, other databases and clinical trials registries was undertaken up to May 2018. Parallel placebo-controlled randomised controlled trials longer than 4 weeks published after 1 January 2001 of oral naltrexone at any dose were selected. Any condition or age group was included, excluding only studies in opioid or ex-opioid users owing to possible opioid/opioid antagonist interactions. The systematic review used the guidance of the Cochrane Handbook and Preferred Reporting Items for Systematic Reviews and Meta-analyses harms checklist throughout. Numerical data were independently extracted by two people and cross-checked. Risk of bias was assessed with the Cochrane risk-of-bias tool. Meta-analyses were performed in R using random effects models throughout. RESULTS: Eighty-nine randomised controlled trials with 11,194 participants were found, studying alcohol use disorders (n = 38), various psychiatric disorders (n = 13), impulse control disorders (n = 9), other addictions including smoking (n = 18), obesity or eating disorders (n = 6), Crohn's disease (n = 2), fibromyalgia (n = 1) and cancers (n = 2). Twenty-six studies (4,960 participants) recorded serious adverse events occurring by arm of study. There was no evidence of increased risk of serious adverse events for naltrexone compared to placebo (risk ratio 0.84, 95% confidence interval 0.66-1.06). Sensitivity analyses pooling risk differences supported this conclusion (risk difference -0.01, 95% confidence interval -0.02-0.00) and subgroup analyses showed that results were consistent across different doses and disease groups. Secondary analysis revealed only six marginally significant adverse events for naltrexone compared to placebo, which were of mild severity. CONCLUSIONS: Naltrexone does not appear to increase the risk of serious adverse events over placebo. These findings confirm the safety of oral naltrexone when used in licensed indications and encourage investments to undertake efficacy studies in unlicensed indications. TRIAL REGISTRATION: PROSPERO 2017 CRD42017054421 .

When to include clinical study reports and regulatory documents in systematic reviews.

Reporting bias is a major threat to the validity and credibility of systematic reviews. This article outlines the rationale for accessing clinical study reports and other regulatory documents (regulatory data) as a means of addressing reporting bias and identifies factors that may help decide whether (or not) to include regulatory data in systematic reviews. The article also describes the origins and current state of regulatory data access and summarises a survey of current systematic reviewers' practices in considering regulatory data for inclusion in systematic reviews. How to access and extract regulatory data is not addressed. Organisations and other stakeholders such as Cochrane should encourage the use of data from clinical study reports as an important source of data in reviews of pharmaceutical interventions particularly when the intervention in question is of high importance and the risk of reporting bias is great.

The use of clinical study reports to enhance the quality of systematic reviews: a survey of systematic review authors.

BACKGROUND: Clinical study reports (CSRs) are produced for marketing authorisation applications. They often contain considerably more information about, and data from, clinical trials than corresponding journal publications. Use of data from CSRs might help circumvent reporting bias, but many researchers appear to be unaware of their existence or potential value. Our survey aimed to gain insight into the level of familiarity, understanding and use of CSRs, and to raise awareness of their potential within the systematic review community. We also aimed to explore the potential barriers faced when obtaining and using CSRs in systematic reviews. METHODS: Online survey of systematic reviewers who (i) had requested or used CSRs, (ii) had considered but not used CSRs and (iii) had not considered using CSRs was conducted. Cochrane reviewers were contacted twice via the Cochrane monthly digest. Non-Cochrane reviewers were reached via journal and other website postings. RESULTS: One hundred sixty respondents answered an open invitation and completed the questionnaire; 20/160 (13%) had previously requested or used CSRs and other regulatory documents, 7/160 (4%) had considered but not used CSRs and 133/160 (83%) had never considered this data source. Survey respondents mainly sought data from the European Medicines Agency (EMA) and/or the Food and Drug Administration (FDA). Motivation for using CSRs stemmed mainly from concerns about reporting bias 11/20 (55%), specifically outcome reporting bias 11/20 (55%) and publication bias 5/20 (25%). The barriers to using CSRs noted by all types of respondents included current limited access to these documents (43 respondents), the time and resources needed to obtain and include these data in evidence syntheses (n = 25) and lack of guidance about how to use these sources in systematic reviews (n = 26). CONCLUSIONS: Most respondents (irrespective of whether they had previously used them) agreed that access to CSRs is important, and suggest that further guidance on how to use and include these data would help to promote their use in future systematic reviews. Most respondents who received CSRs considered them to be valuable in their systematic review and/or meta-analysis.

Evaluating progestogens for prevention of preterm birth international collaborative (EPPPIC) individual participant data (IPD) meta-analysis: protocol.

BACKGROUND: Preterm birth is the most common cause of death and harm to newborn babies. Babies that are born early may have difficulties at birth and experience health problems during early childhood. Despite extensive study, there is still uncertainty about the effectiveness of progestogen (medications that are similar to the natural hormone progesterone) in preventing or delaying preterm birth, and in improving birth outcomes. The Evaluating Progestogen for Prevention of Preterm birth International Collaborative (EPPPIC) project aims to reduce uncertainty about the specific conditions in which progestogen may (or may not) be effective in preventing or delaying preterm birth and improving birth outcomes. METHODS: The design of the study involves international collaborative individual participant data meta-analysis comprising systematic review, re-analysis, and synthesis of trial datasets. Inclusion criteria are as follows: randomized controlled trials comparing progestogen versus placebo or non-intervention, or comparing different types of progestogen, in asymptomatic women at risk of preterm birth. Main outcomes are as follows; fetal/infant death, preterm birth or fetal death (<=37 weeks, <=34 weeks, <= 28 weeks), serious neonatal complications or fetal/infant death, neurosensory disability (measured at 18 months or later) or infant/child death, important maternal morbidity, or maternal death. In statistical methods, IPD will be synthesized across trials using meta-analysis. Both 'two-stage' models (where effect estimates are calculated for each trial and subsequently pooled in a meta-analysis) and 'one-stage' models (where all IPD from all trials are analyzed in one step, while accounting for the clustering of participants within trials) will be used. If sufficient suitable data are available, a network meta-analysis will compare all types of progesterone and routes of administration extending the one-stage models to include multiple treatment arms. DISCUSSION: EPPPIC is an international collaborative project being conducted by the forming EPPPIC group, which includes trial investigators, an international secretariat, and the research project team. Results, which are intended to contribute to improvements in maternal and child health, are expected to be publicly available in mid 2018. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017068299.

Reporting of harms outcomes: a comparison of journal publications with unpublished clinical study reports of orlistat trials.

BACKGROUND: The quality of harms reporting in journal publications is often poor, which can impede the risk-benefit interpretation of a clinical trial. Clinical study reports can provide more reliable, complete, and informative data on harms compared to the corresponding journal publication. This case study compares the quality and quantity of harms data reported in journal publications and clinical study reports of orlistat trials. METHODS: Publications related to clinical trials of orlistat were identified through comprehensive literature searches. A request was made to Roche (Genentech; South San Francisco, CA, USA) for clinical study reports related to the orlistat trials identified in our search. We compared adverse events, serious adverse events, and the reporting of 15 harms criteria in both document types and compared meta-analytic results using data from the clinical study reports against the journal publications. RESULTS: Five journal publications with matching clinical study reports were available for five independent clinical trials. Journal publications did not always report the complete list of identified adverse events and serious adverse events. We found some differences in the magnitude of the pooled risk difference between both document types with a statistically significant risk difference for three adverse events and two serious adverse events using data reported in the clinical study reports; these events were of mild intensity and unrelated to the orlistat. The CONSORT harms reporting criteria were often satisfied in the methods section of the clinical study reports (70-90 % of the methods section criteria satisfied in the clinical study reports compared to 10-50 % in the journal publications), but both document types satisfied 80-100 % of the results section criteria, albeit with greater detail being provided in the clinical study reports. CONCLUSIONS: In this case study, journal publications provided insufficient information on harms outcomes of clinical trials and did not specify that a subset of harms data were being presented. Clinical study reports often present data on harms, including serious adverse events, which are not reported or mentioned in the journal publications. Therefore, clinical study reports could support a more complete, accurate, and reliable investigation, and researchers undertaking evidence synthesis of harm outcomes should not rely only on incomplete published data that are presented in the journal publications.

Reporting of harms data in RCTs: a systematic review of empirical assessments against the CONSORT harms extension.

OBJECTIVE: To determine the standard of reporting of harms-related data, in randomised controlled trials (RCTs) according to the Consolidated Standards of Reporting Trials (CONSORT) statement extension for harms. DESIGN: Systematic review. DATA SOURCES: The Cochrane library, Ovid MEDLINE, Scopus and ISI Web of Knowledge were searched for relevant literature. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included publications of studies that used the CONSORT harms extension to assess the reporting of harms in RCTs. RESULTS: We identified 7 studies which included between 10 and 205 RCTs. The clinical areas of the 7 studies were: hypertension (1), urology (1), epilepsy (1), complimentary medicine (2) and two not restricted to a clinical topic. Quality of the 7 studies was assessed by a risk of bias tool and was found to be variable. Adherence to the CONSORT harms criteria reported in the 7 studies was inadequate and variable across the items in the checklist. Adverse events are poorly defined, with 6 studies failing to exceed 50% adherence to the items in the checklist. CONCLUSIONS: Readers of RCT publications need to be able to balance the trade-offs between benefits and harms of interventions. This systematic review suggests that this is compromised due to poor reporting of harms which is evident across a range of clinical areas. Improvements in quality could be achieved by wider adoption of the CONSORT harms criteria by journals reporting RCTs.