Research integrity in randomized clinical trials: A scoping umbrella review.

BACKGROUND: Randomized clinical trials (RCTs) are experiencing a crisis of confidence in their trustworthiness. Although a comprehensive literature search yielded several reviews on RCT integrity, an overarching overview is lacking. OBJECTIVES: The authors undertook a scoping umbrella review of the research integrity literature concerning RCTs. SEARCH STRATEGY AND SELECTION CRITERIA: Following prospective registration (https://osf.io/3ursn), two reviewers independently searched PubMed, Scopus, The Cochrane Library, and Google Scholar, without language or time restrictions, until November 2021. The authors included systematic reviews covering any aspect of research integrity throughout the RCT lifecycle. DATA COLLECTION AND ANALYSIS: The authors assessed methodological quality using a modified AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) tool and collated the main findings. MAIN RESULTS: A total of 55 relevant reviews, summarizing 6001 studies (median per review, 63; range, 8-1106) from 1964 to 2021, had an overall critically low quality of 96% (53 reviews). Topics covered included general aspects (15%), design and approval (22%), conduct and monitoring (11%), reporting (38%), postpublication concerns (2%), and future research (13%). The most common integrity issues covered were ethics (18%) and transparency (18%). CONCLUSIONS: Low-quality reviews identified various integrity issues across the RCT lifecycle, emphasizing the importance of high ethical standards and professionalism while highlighting gaps in the integrity landscape. Multistakeholder consensus is needed to develop specific RCT integrity standards.

Misoprostol as an adjunct to standard uterotonics for treatment of post-partum haemorrhage: a multicentre, double-blind randomised trial.

BACKGROUND: Post-partum haemorrhage is a leading cause of global maternal morbidity and mortality. Misoprostol, a prostaglandin analogue with uterotonic activity, is an attractive option for treatment because it is stable, active orally, and inexpensive. We aimed to assess the effectiveness of misoprostol as an adjunct to standard uterotonics compared with standard uterotonics alone for treatment of post-partum haemorrhage. METHODS: Women delivering vaginally who had clinically diagnosed post-partum haemorrhage due to uterine atony were enrolled from participating hospitals in Argentina, Egypt, South Africa, Thailand, and Vietnam between July, 2005, and August, 2008. Computer-generated randomisation was used to assign women to receive 600 microg misoprostol or matching placebo sublingually; both groups were also given routine injectable uterotonics. Allocation was concealed by distribution of sealed and sequentially numbered treatment packs in the order that women were enrolled. Providers and women were masked to treatment assignment. The primary outcome was blood loss of 500 mL or more within 60 min after randomisation. Analysis was by intention to treat. This study is registered, number ISRCTN34455240. FINDINGS: 1422 women were assigned to receive misoprostol (n=705) or placebo (n=717). The proportion of women with blood loss of 500 mL or more within 60 min was similar between the misoprostol group (100 [14%]) and the placebo group (100 [14%]; relative risk 1.02, 95% CI 0.79-1.32). In the first 60 min, an increased proportion of women on misoprostol versus placebo, had shivering (455/704 [65%] vs 230/717 [32%]; 2.01, 1.79-2.27) and body temperature of 38 degrees C or higher (303/704 [43%] vs 107/717 [15%]; 2.88, 2.37-2.50). INTERPRETATION: Findings from this study do not support clinical use of 600 microg sublingual misoprostol in addition to standard injectable uterotonics for treatment of post-partum haemorrhage. FUNDING: Bill & Melinda Gates Foundation, and UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction.

Comparison of treatment effects between animal experiments and clinical trials: systematic review.

OBJECTIVE: To examine concordance between treatment effects in animal experiments and clinical trials. Study design Systematic review. DATA SOURCES: Medline, Embase, SIGLE, NTIS, Science Citation Index, CAB, BIOSIS. STUDY SELECTION: Animal studies for interventions with unambiguous evidence of a treatment effect (benefit or harm) in clinical trials: head injury, antifibrinolytics in haemorrhage, thrombolysis in acute ischaemic stroke, tirilazad in acute ischaemic stroke, antenatal corticosteroids to prevent neonatal respiratory distress syndrome, and bisphosphonates to treat osteoporosis. Review methods Data were extracted on study design, allocation concealment, number of randomised animals, type of model, intervention, and outcome. RESULTS: Corticosteroids did not show any benefit in clinical trials of treatment for head injury but did show a benefit in animal models (pooled odds ratio for adverse functional outcome 0.58, 95% confidence interval 0.41 to 0.83). Antifibrinolytics reduced bleeding in clinical trials but the data were inconclusive in animal models. Thrombolysis improved outcome in patients with ischaemic stroke. In animal models, tissue plasminogen activator reduced infarct volume by 24% (95% confidence interval 20% to 28%) and improved neurobehavioural scores by 23% (17% to 29%). Tirilazad was associated with a worse outcome in patients with ischaemic stroke. In animal models, tirilazad reduced infarct volume by 29% (21% to 37%) and improved neurobehavioural scores by 48% (29% to 67%). Antenatal corticosteroids reduced respiratory distress and mortality in neonates whereas in animal models respiratory distress was reduced but the effect on mortality was inconclusive (odds ratio 4.2, 95% confidence interval 0.85 to 20.9). Bisphosphonates increased bone mineral density in patients with osteoporosis. In animal models the bisphosphonate alendronate increased bone mineral density compared with placebo by 11.0% (95% confidence interval 9.2% to 12.9%) in the combined results for the hip region. The corresponding treatment effect in the lumbar spine was 8.5% (5.8% to 11.2%) and in the combined results for the forearms (baboons only) was 1.7% (-1.4% to 4.7%). CONCLUSIONS: Discordance between animal and human studies may be due to bias or to the failure of animal models to mimic clinical disease adequately.

Methodological quality of systematic reviews of animal studies: a survey of reviews of basic research.

BACKGROUND: Systematic reviews can serve as a tool in translation of basic life sciences research from laboratory to human research and healthcare. The extent to which reviews of animal research are systematic and unbiased is not known. METHODS: We searched, without language restrictions, Medline, Embase, bibliographies of known reviews (1996-2004) and contacted experts to identify citations of reviews of basic science literature which, as a minimum, performed search of a publicly available resource. From these we identified reviews of animal studies where laboratory variables were measured or where treatments were administered to live animals to examine their effects, and compared them with reviews of bench studies in which human or animal tissues, cell systems or organ preparations were examined in laboratories to better understand mechanisms of diseases. RESULTS: Systematic reviews of animal studies often lacked methodological features such as specification of a testable hypothesis (9/30, 30%); literature search without language restriction (8/30, 26.6%); assessment of publication bias (5/30, 16.6%), study validity (15/30, 50%) and heterogeneity (10/30, 33.3%); and meta-analysis for quantitative synthesis (12/30, 40%). Compared to reviews of bench studies, they were less prone to bias as they specified the question (96.6% vs. 80%, p = 0.04), searched multiple databases (60% vs. 26.6%, p = 0.01), assessed study quality (50% vs. 20%, p = 0.01), and explored heterogeneity (33.3% vs. 2.2%, p = 0.001) more often. CONCLUSION: There seems to be a gradient of frequency of methodological weaknesses among reviews: Attempted systematic reviews of whole animal research tend to be better than those of bench studies, though compared to systematic reviews of human clinical trials they are apparently poorer. There is a need for rigour when reviewing animal research.

Mapping the theories of preeclampsia: the need for systematic reviews of mechanisms of the disease.

Preeclampsia, a major cause of morbidity in pregnancy, is still a disease of unknown cause, despite considerable research in recent times. We believe that progress in understanding the disorder would be enhanced if the systematic review methodology, similar to that used to assess data from clinical trials, is applied to studies that investigate the many theories advanced to explain its cause. This article discusses the need for and a frame work of such an endeavor. The systematic review approach helps to determine where research should be focused, to prioritize the use of resources, to understand, and then hopefully to conquer a disease that still kills mothers and infants each year, worldwide.

Mapping the theories of preeclampsia: the role of homocysteine.

OBJECTIVE: We conducted a systematic review to examine the hypothesized mechanism through which homocysteine could lead to preeclampsia. DATA SOURCES: We searched MEDLINE, EMBASE, BIOSIS, SciSearch, and bibliographies of primary and review articles, and we contacted experts. METHODS OF STUDY SELECTION: Of the 25 relevant primary articles, 8 studies measured total serum homocysteine concentrations before the clinical onset of preeclampsia (1,876 women), whereas 17 measured it afterward (1,773 women). Meta-analytic techniques were used to examine consistency, strength, temporality, dose-response, and plausibility of the disease mechanisms implicating folate, vitamin B(6), vitamin B(12), genetic polymorphisms, oxidative stress, and endothelial dysfunction in the pathway linking hyperhomocysteinemia to preeclampsia. TABULATION, INTEGRATION, AND RESULTS: Overall, there were higher serum homocysteine concentrations among pregnant women with preeclampsia than among those with uncomplicated pregnancies, but the results were heterogeneous (P = .12; I(2) = 38.8%). Among studies with temporality, the size of association was smaller than that among those without (weighted mean difference 0.68 mumol/L versus 3.36 mumol/L; P < .006). There was no dose-response relationship between homocysteine concentration and severity of preeclampsia. The mechanisms underlying hyperhomocysteinemia (folate and vitamin B(12) deficiency and genetic polymorphisms) were not found to be plausible, but markers of oxidative stress and endothelial dysfunction were higher in hyperhomocysteinemia. CONCLUSION: Homocysteine concentrations are slightly increased in normotensive pregnancies that later develop preeclampsia and are considerably increased once preeclampsia is established. However, because of a lack of consistency in data, dose-response relationship, and biologic plausibility, the observed association cannot be considered causal from the current literature.