Representation of people with comorbidity and multimorbidity in clinical trials of novel drug therapies: an individual-level participant data analysis.

Comorbidity and multimorbidity are less common in trials than in community populations with the same index condition. Comorbidity and multimorbidity are, nevertheless, common in trials. This suggests that standard, industry-funded clinical trials are an underused resource for investigating treatment effects in people with comorbidity and multimorbidity.