Impact of non-adherence to direct oral anticoagulants amongst Swedish patients with non-valvular atrial fibrillation: results from a real-world cost-utility analysis

AIMS: A third of non-valvular atrial fibrillation (NVAF) patients are non-adherent to direct oral anticoagulants (DOACs). Estimates of the economic value of full adherence and the cost of two types of adherence improving interventions are important to healthcare planners and decision-makers. METHODS: A cost-utility analysis estimated the impact of non-adherence over a 20-year horizon, for a patient cohort with a mean age of 77 years, based on data from the Stockholm Healthcare database of NVAF patients with incident stroke between 2011 and 2018. Adherence was defined using a medication possession ratio (MPR) cut-off of 90%; primary outcomes were the number of ischemic strokes and associated incremental cost-utility ratio. RESULTS: Hypothetical comparisons between cohorts of 1,000 patients with varying non-adherence levels and full adherence (MPR >90%) predicted an additional number of strokes ranging from 117 (MPR = 81-90%) to 866 (MPR <60%), and years of life lost ranging from 177 (MPR = 81- 90%) to 1,318 (MPR < 60%; discounted at 3%). Chronic disease co-management intervention occurring during each DOAC prescription renewal and patient education intervention at DOAC initiation will be cost-saving to the health system if its cost is below SEK 143 and SEK 4,655, and cost-effective if below SEK 858 and SEK 28,665, respectively. CONCLUSION: Adherence improving interventions for NVAF patients on DOACs such as chronic disease co-management and patient education can be cost-saving and cost-effective, within a range of costs that appear reasonable to the Swedish healthcare system.