Treatment indications and potential off‐label use of antidepressants among older adults: A population‐based descriptive study in Denmark

OBJECTIVES: Off‐label prescriptions of antidepressants may be of special concern in older‐adults. We aimed to study the potential off‐label use of antidepressants among adults ≥65 years by describing the patterns, trends, and factors associated with missing and unspecified treatment indications. METHODS: We used registry data to describe indications of all antidepressant prescriptions (N = 13.8 million) redeemed by older‐adults in 2006–2019. We investigated factors associated with off‐label use by considering prescriptions with missing and unspecified indications of the first antidepressant prescription using a multinomial logistic regression with the ‘depression’ indication as a reference category and reported odds ratios (ORs) with 95% confidence intervals (CI). RESULTS: Overall, 18.1% of all antidepressant prescriptions had missing indications, and 9.9% had unspecified indications. The proportion of potential off‐label use based on missing and unspecified prescriptions remained mostly consistent during 2006–2019. We identified similar associations in user characteristics whether considering missing or unspecified first prescription. ORs with 95% CI were raised in non‐western ethnicity (vs. Danish, 1.12 (0.99–1.26) for missing indication and 1.28 (1.11–1.48) for unspecified indication) and female sex (vs. male, 1.05 (1.02–1.07) and 1.05 (1.02–1.07) respectively). ORs were reduced for shorter educational attainment (vs. long, 0.90 (0.87–0.94) and 0.92 (0.88–0.96)), older age (≥81 vs. 67–70 years, 0.66 (0.65–0.71) and 0.73 (0.70–0.76)) and hospital psychiatric diagnosis (per diagnosis 0.76 (0.73–0.78) and 0.88 (0.86–0.91)). CONCLUSIONS: Nearly one‐third of all antidepressant prescriptions redeemed by older‐adults in Denmark had either missing or unspecified treatment indications. Whether these prescriptions were actual off‐label use needs to be validated. Clinicians should pay special attention to patients' characteristics linking missing and unspecified indications and maintain adequate documentation while prescribing medication.