Polypharmacy among people with rheumatoid arthritis: the role of age, disease duration and comorbidity.

BACKGROUND

People with rheumatoid arthritis (RA) often have comorbidities with associated disability and complex medication regimens. Little published evidence exists about why people with RA require so many medications, although it is logical to hypothesize that this may relate to older age, longer duration of RA, more active RA, worse functional disability and a greater number of comorbidities.

OBJECTIVES

We set out to quantify polypharmacy in RA and identify its predictors in an observational cohort.

METHODS

The case notes of 348 people receiving secondary care for RA were reviewed to record polypharmacy. The 28-joint Disease Activity Score (DAS28) was calculated and the Health Assessment Questionnaire (HAQ) and the Self-administered Comorbidity Questionnaire (SCQ) were completed.

RESULTS

The mean total number of medications was 5.39, with a maximum of 16; of these, a mean of 2.41 medications were directly for RA. A mediational relationship was identified: older age and longer RA duration were significant predictors of a greater total number of medications, but these relationships were explained by the greater number of comorbidities in older participants and those with longer RA duration. Polypharmacy was not related to RA activity or functional disability.

CONCLUSIONS

Polypharmacy is common among people with RA and associates with older age and longer RA duration through a greater number of comorbidities. Regular review of the full treatment plan of individuals with RA by pharmacists and other health professionals specializing in rheumatology, to weigh the benefits and risks of each medication and their interactions in light of RA activity and comorbidities, is advocated.