Long-term adherence to anti-osteoporosis medication and determinants of adherence in the population-based screening trial ROSE

UNLABELLED: Screening initiatives for osteoporosis must facilitate treatment of those at elevated fracture risk. In a randomized controlled trial of 24,229 women, those in the screening group with FRAX ≥ 15% were invited for DXA with AOM treatment offered as per national guidelines. Treatment initiation in the following year was 9.5 times higher compared with controls.

PURPOSE: To determine if screened individuals have lower adherence to anti-osteoporotic medication (AOM) than unscreened and to examine determinants for low treatment adherence.

METHOD: In 2010/2011, women aged 65-80 (N = 34,229) in the Region of Southern Denmark were invited to the risk-stratified osteoporosis strategy evaluation (ROSE) randomized study. Women in the screening group with moderate to high 10-year fracture risk (FRAX® ≥ 15%) were invited for dual-energy x-ray absorptiometry with AOM treatment as per national guidelines. Screened, controls, and an age-matched general population sample were compared for adherence to AOM using 10-year follow-up data on prescription and hospital records.

RESULTS: Among ROSE participants with FRAX ≥ 15%, 5864 screened and 5790 controls were eligible for analysis, along with an equal number from the general population. AOM initiation in the first year was 9.5 times higher in screened compared to controls (HR 9.50, 7.16; 12.61). There was no difference in implementation assessed as medication possession ratio. The 5-year persistence rates were similar in screened and controls (51-52%), but lower in the general population (44%). FRAX risk factors partly influenced AOM initiation in the screened, with different patterns in other groups. Immobilization, comorbidities, and co-medications were key determinants of discontinuation in both the short and long term.

CONCLUSION: The ROSE screening programme significantly increased treatment initiation in postmenopausal women. Screened women showed similar treatment adherence levels to non-screened once they started medication. However, frail women were more prone to treatment discontinuation, highlighting the need for targeted support in this subgroup.

TRIAL REGISTRATION: The original ROSE trial is registered at ClinicalTrials.gov (NCT01388244). The study protocol has been published in Rubin et al. The risk-stratified osteoporosis strategy evaluation study (ROSE): a randomized prospective population-based study. Design and baseline characteristics. Calcif Tissue Int. 2015;96(2):167-79.