Sex and Gender in Randomized Controlled Trials of Adults Receiving Maintenance Dialysis: A Meta-epidemiologic Study

Systematic Review of Women Leading and Participating in Nephrology Randomized Clinical Trials

Introduction

Women are underrepresented in the leadership of and participation in randomized controlled trials (RCTs). We conducted a bibliometric review of nephrology RCTs to examine trial leadership by women and participation of women in nephrology RCTs.

Methods

A bibliometric review of RCTs published in top medical, surgical, or nephrology journals was conducted using MEDLINE and EMBASE from January 2011 to December 2021. Leadership by women as corresponding authors, women trial participation, and trial characteristics were examined with duplicate independent data extraction. Logistic regression was used to examine associations between trial characteristics and women leadership and trial participation.

Results

A total of 1770 studies were screened and 395 RCTs met eligibility criteria. The number (%) of women in corresponding, first, and last authorship positions were as follows: 89 (22%), 109 (28%), and 74 (19%), respectively, without change over time (P = 0.94). The median percentage (interquartile range [IQR]) of women trial participants was 39.0% (13.5%) with no difference between women or men lead authors (P = 0.15). Men lead authors were statistically less likely to enroll women in RCTs. Women lead authors were less likely to be funded by industry (odds ratio [OR]: 0.30; 95% confidence interval [CI]: 0.14-0.63; P = 0.002) or lead international trials (OR: 0.11; 95% CI: 0.01-0.83; P = 0.03). Trials with sex-specific eligibility criteria were more likely to have women leaders (OR: 2.56; 95% CI: 1.19-5.49; P = 0.02) than those without.

Discussion

Gender inequalities in RCT leadership and RCT participation exist in nephrology and did not improve over time. Strategies to improve inequalities need to be implemented and evaluated.

Sex- and Gender-Based Reporting in Antihypertensive Medication Literature Informing Hypertension Guidelines

BACKGROUND

Hypertension is the leading modifiable cardiovascular risk factor with recognized sex- and gender-based differences. We assessed the incorporation of sex and gender reporting in the antihypertensive medication literature informing hypertension guidelines.

METHODS AND RESULTS

Literature cited in the International Society of Hypertension (2020), European Society of Cardiology/European Society of Hypertension (2018), American College of Cardiology/American Heart Association (2017), Latin American Society of Hypertension (2017), Pan-African Society of Cardiology (2020), and Hypertension Canada (2020) guidelines was systematically reviewed. Observational studies, randomized controlled trials, and systematic reviews involving antihypertensive medications were included. Studies with participants of a single sex, guidelines, and commentaries were excluded. Data on study participation-to-prevalence ratio by sex, analysis of baseline demographics and study outcomes by sex, and stratification of adverse events by sex were extracted. Of 1659 unique citations, 331 studies met inclusion criteria. Of those, 81% reported the sex of participants, and 22% reported a male-to-female participation-to-prevalence ratio of 0.8 to 1.2. Three percent of studies stratified baseline characteristics by sex, and 20% considered sex during analysis through statistical adjustment or stratification. Although 32% of studies reported adverse events, only 0.6% stratified adverse events by sex. Most (58%) studies reporting sex/gender used sex and gender terms interchangeably.

CONCLUSIONS

Incorporation of sex- and gender-based considerations in study population, analysis, or reporting of results and adverse events is not common in the antihypertensive medication literature informing international hypertension guidelines. Greater attention to sex- and gender-based factors in research is required to optimally inform management of hypertension.

Sex or Gender Reporting in Ophthalmology Clinical Trials Among US Food and Drug Administration Approvals, 1995 to 2022

Importance

As critical determinants of scientific rigor, reproducibility, and equity, sex and gender should be considered in clinical trial design and reporting.

Objective

To evaluate the accuracy of sex and gender reporting and extent of sex- and gender-based analysis in clinical trials associated with US Food and Drug Administration (FDA) drug approvals between January 1, 1995, and December 31, 2022.

Design, Setting, and Participants

In this cross-sectional study of participants enrolled in FDA ophthalmology trials, the following trial documents were reviewed by pairs of independent reviewers in decreasing order of priority: peer-reviewed publication, ClinicalTrials.gov report, and FDA medical and statistical reviews. Trial protocols and supplementary materials were also reviewed.

Main Outcome and Measures

The proportion of trials that correctly applied sex and gender terminology, reported the method of assessing sex or gender, and conducted sex- or gender-based data analysis; incorrect application of sex and gender terminology was defined as interchangeable use of sex- and gender-related terms without a clear justification.

Results

Between 1995 and 2022, 34 ophthalmic drugs corresponding to 85 trials (34 740 participants) received FDA approval, of which 16 drugs (47.1%) corresponding to 32 trials (18 535 participants [37.6%]) were associated with peer-reviewed publications. Sixteen trials used sex and gender terminology correctly (19.5%). No trial reported how sex and gender were collected nor enrolled participants from sexual and gender identity minority populations. Most trials reported sex- and gender-disaggregated demographic data (96.5%), but few conducted sex- or gender-based analysis for data on dropout (1.2%), primary outcomes (28.2%), secondary outcomes (2.4%), and adverse events (9.4%). Erroneous sex and gender reporting was associated with later publication year (2008.5 vs 2001.0; median difference, 7.5; 95% CI, -6.0 to 11.0; P < .001) and higher journal influence metrics, including 2022 journal impact factor (13.7 vs 5.9; median difference, 7.8; 95% CI, -1.4 to 152.4, P < .001) and 2022 journal citation indicator (4.9 vs 2.1; median difference, 2.9; 95% CI, 0-20.0, P < .001).

Conclusions and Relevance

In this observational study, over three-quarters of ophthalmology trials associated with FDA drug approvals conflated sex and gender and over two-thirds lacked sex- and gender-based analyses. More rigorous integration of sex and gender appears warranted for FDA, and presumably other trials, to improve their validity, reproducibility, and equity.