Exclusion of older adults from randomized controlled trials in rheumatoid arthritis

To assess eligibility criteria that either explicitly or implicitly exclude older patients from randomized controlled trials (RCTs) in RA.

Our analysis included RCTs of pharmacological interventions registered with ClinicalTrials.gov and started between 2013 and 2022. Co-primary outcomes were proportions of trials with an upper age limit and the eligibility criteria indirectly increasing risk of the exclusion of older adults.

A total of 143/290 (49%) trials had an upper age limit of 85 years or less. Multivariable analysis showed that the odds of an upper age limit were significantly lower in trials performed in the USA [adjusted odds ratio (aOR), 0.34; CI, 0.12-0.99; P = 0.04] and intercontinental trials (aOR, 0.4; CI, 0.18-0.87; P = 0.02). In total, 154/290 (53%) trials had at least one eligibility criterion implicitly excluding older adults. These included specific comorbidities (n = 114; 39%), compliance concerns (n = 67; 23%), and broad and vague exclusion criteria (n = 57; 20%); however, we found no significant associations between these criteria and trial characteristics. Overall, 217 (75%) trials either explicitly or implicitly excluded older patients; we also noted a trend towards increasing proportion of these trials over time. Only one trial (0.3%) enrolled solely patients aged 65 and older.

Older adults are commonly excluded from RCTs in RA based on both age limits and other eligibility criteria. This seriously limits the evidence base for the treatment of older patients in clinical practice. Given the growing prevalence of RA in older adults, relevant RCTs should be more inclusive to them.