Enrolment of women and reporting of sex-stratified results in clinical trials for Alzheimer's disease
Abstract
Aims Although women constitute two-thirds of Alzheimer's disease (AD) patients, it is currently not clear whether this proportion is reflected in clinical trials. In a pilot study, we aimed to ascertain the representation of women in clinical trials and the reporting of sex-stratified results.
Methods We searched the AlzForum Therapeutics Database (https://www.alzforum.org/therapeutics), selected drugs in phase III clinical trials for AD or mild cognitive impairment (Fig. 1) and compiled a list of 22 publications (Group 1, median publication year: 2013.5). Additionally, we identified previous phase III trials of approved AD drugs on www.accessdata.fda.gov (Group 2, 16 trials, median publication year: 2004).
Next, we collected data on the proportion (percentage) of women in the trials and on sex stratification. We calculated the significance of percentage difference between the two trial groups using Student's T-test.
Results In Group 1, the more recent trials, 12233 men and 15137 women participated overall, women constituted 55.3% participants. Only 3/22 (13.63%) of the trials published subgroup analysis by sex.
In Group 2, the older approved drug trials, 63% women participated. This constituted a significant (p<0.001, t=-4.16, df=33.42) difference between the two groups.
Conclusions Compared to prevalence of AD in general population, women might be less represented in recent clinical trials. This was specifically observed in recent clinical trials of investigational drugs.
Based on our findings, we are conducting a systematic review and meta-analysis in order to further elucidate the emerging temporal trends in male and female participation in clinical trials and to ascertain sex stratification in published clinical trials. In addition to presenting the results of the pilot analysis above, we also presented the preliminary results of a comprehensive systematic review.