Medication adherence in older people with rheumatoid arthritis is lower according to electronic monitoring than according to pill count

Objectives. Suboptimal medication adherence is a serious problem in the treatment of chronic inflammatory diseases. To measure medication adherence, electronic monitoring is regarded as superior to pill count. GLORIA is an ongoing two-year trial on the addition of low-dose (5 mg/d) prednisolone or placebo to standard care in older people (65+ years) with RA. During the entire trial, adherence is measured with electronic caps, and with pill counts. The objective is to describe medication adherence patterns, and to compare the adherence results of the two methods. Methods. The recorded adherence patterns of patients (blinded for treatment group) were classified according to descriptive categories. The cutoff for good adherence was set at 80% of prescribed pills taken. Results. Trial inclusion closed in 2018 at 451 patients, but trial follow-up is ongoing; the current dataset contains adherence data of 371 patients. Mean number of recorded 90-day periods per patient was 4 (range 1-8). Based on pill count over all periods, 90% of the patients had good adherence; based on cap data, only 20%. Cap data classified 30% of patients as non-user (