Subgroup Analysis in Pulmonary Hypertension-Specific Therapy Clinical Trials: A Systematic Review

Subgroup analyses in venous thromboembolism trials reporting pharmacological interventions: A systematic review

INTRODUCTION

Randomized controlled trials (RCTs) that conduct subgroup analyses have the potential to provide information on treatment decisions in specific groups of patients from heterogeneous populations. Although we understand several factors can modify the incidence of venous thromboembolism (VTE) and the benefit/risk ratio of anticoagulation treatments, further evidence is warranted to show the heterogeneity of treatment effects in different subgroups of patients.

AIMS

The primary purpose was to evaluate the appropriateness and interpretation of subgroup analysis performed on VTE RCTs reporting pharmacological interventions.

MATERIALS AND METHODS

A systematic review of RCTs published between January 2017 and January 2022 was conducted. Claims of subgroup effects were evaluated with predefined criteria. High-quality claims of subgroup effect were further analyzed and discussed.

RESULTS

Overall, 28 RCTs with a generally low bias risk were included. The purposes of the treatments included pharmacologic thromboprophylaxis (17), therapeutic dose anticoagulation (9), and catheter-directed pharmacologic thrombolysis (2). The evaluated subgroup analyses generally presented: a high number of subgroup analyses reported, a lack of prespecification, and a lack of usage of statistical tests for interaction. The authors reported 13 claims of subgroup effect; only two were considered potentially reliable to represent heterogeneity in the direction or magnitude of treatment effect.

CONCLUSIONS

Subgroup analyses of VTE RCTs reporting pharmacologic interventions are generally methodologically poor. Most claims of subgroup effect did not meet critical criteria and lacked credibility. Clinicians in this field may proceed with scepticism when assessing claims of subgroup effects due to methodological concerns and misleading interpretations.

Racial and ethnic subgroup reporting in diabetes randomized controlled trials published from 2000 to 2020: A survey

BACKGROUND

It remained unknown about the status of and trends in racial/ethnic subgroup reporting in the diabetes trials over the past two decades.

OBJECTIVES

In this survey, we aimed to evaluate the current state of and temporal trends in subgroup reporting by race/ethnicity regarding the effects of interventions in diabetes randomized controlled trials (RCTs) from year 2000-2020 and to explore the potential trial factors in relation to racial/ethnic subgroup reporting.

METHODS

We searched electronic databases for eligible diabetes RCTs. The outcome was whether the trials had the event of racial/ethnic subgroup reporting regarding the intervention effects on trial primary outcomes. Poisson regression was used to assess the temporal trends in racial/ethnic subgroup reporting, and univariable logistic regression models were employed for evaluating trial factors related to racial/ethnic subgroup reporting.

RESULTS

A total of 405 diabetes RCTs were eligible for inclusion. There were 26 (6.42%) trials with racial/ethnic subgroup reporting. A chronological trend towards increased rates of racial/ethnic subgroup reporting was observed; however, the trend was not statistically significant (p = 0.07). Advanced patients' age (Odds ratio [OR] = 2.92, 95% confidence interval [CI]: 1.24-6.88), follow-up duration (OR = 3.53, 95% CI: 1.13-11.00), and BIPOC (Black, Indigenous, and People of Colour) enrolment (OR = 2.39, 95% CI: 1.01-5.62) were found to positively relate with racial/ethnic subgroup reporting, while the industrial funding was associated with decreased reporting (OR = 0.43, 95% CI: 0.19-0.97). Less than one fourth of the trials with racial/ethnic subgroup reporting predefined the subgroup analysis.

CONCLUSIONS

The majority of diabetes RCTs did not report intervention effects by racial/ethnic subgroup, which was not temporally improved over the past two decades. More efforts and strategies are needed to improve the racial/ethnic subgroup consideration and reporting in diabetes trials.