Medication adherence in rheumatoid arthritis patients: Older is wiser

OBJECTIVES: To create a profile of individuals nonadherent to their medicat ions in an age-stratified sample (ages 34-84) of community-dwelling rheumat oid arthritis patients. The relative contributions of age, cognitive functi on, disability, emotional state, lifestyle, and beliefs about illness to no nadherence were assessed. DESIGN: A direct-observation approach was used in conjunction with structur al equation modeling. All participants were administered a preliminary asse ssment battery. Medications were then transferred to vials with microelectr onic caps that recorded medication events for all medications for the next 4 weeks. PARTICIPANTS AND SETTING: A volunteer sample of 121 community-dwelling rheu matoid arthritis (RA) patients were recruited from newspaper ads, posters, and via informal physician contact from private rheumatology practices in A tlanta and Athens, Georgia. Written verification of the RA diagnosis and a disease severity rating were obtained from personal physicians before patie nts were enrolled in the study. Patients were tested in a private physician 's office, and their medication adherence was monitored electronically for a month in their every-day work and home settings. MEASUREMENTS AND RESULTS: Structural equation modeling techniques were used to develop a model of adherence behavior. Cognitive and psychosocial measu res were used to construct latent variables to predict adherence errors. Th e model of medication adherence explained 39% of the variance in adherence errors. The model demonstrated that older adults made the fewest adherence errors, and middle-aged adults made the most. A busy lifestyle, age, and co gnitive deficits predicted nonadherence, whereas coping with arthritis-rela ted moods predicted adherence. Illness severity, medication load, and physi cal function did not predict adherence errors. Omission of medication accou nted for nearly all errors. CONCLUSION: Despite strong evidence for normal, age-related cognitive decli ne in this sample, older adults had sufficient cognitive function to manage medications. A busy lifestyle and middle age were more determinant of who was at risk of nonadherence than beliefs about medication or illness. Thus, practicing physicians should not assume that older adults have insufficien t cognitive resources to manage medications and that they will be the most likely to make adherence errors. Very busy middle-aged adults seem to be at the greatest risk of managing medications improperly.