OBJECTIVES: Individuals with undiagnosed atrial fibrillation (AF) are at an increased stroke risk but are not afforded the protection of oral anticoagulants (OAC). AF awareness campaigns, such as Heart Rhythm Week (HRW), may lead to earlier diagnoses and treatment. This study investigated whether AF-related consultation rates changed post-HRW in the years 2012-2016.

METHODS: An interrupted time series design was used to evaluate whether underlying weekly rates of AF-related diagnoses, tests and prescriptions were impacted by HRW. The study population included adults without prior AF in the Clinical Practice Research Datalink (CPRD) which comprises primary care records for a representative subset of the UK population. Poisson regression was used to model weekly event rates over time adjusting for seasonal trends. Incidence rate ratios and 95% confidence intervals (IRR [95% CI]) describing the relative difference in rates pre- and post-HRW were calculated. The impact of HRW was hypothesised to result in a temporary rate increase lasting 8 weeks. Subgroup analyses were performed by sex.

RESULTS: After adjustment for seasonal trends, higher IRR [95% CI] were shown for AF diagnoses (1.09 [1.01,1.19]), pulse checks (1.13 [1.05,1.21]) and OAC prescriptions (1.10 [1.00,1.22]) post HRW. In analyses by sex, higher IRR [95% CI] were shown for AF diagnoses in women (1.14 [1.00,1.32]), but not in men (1.05 [0.93,1.19]).

CONCLUSIONS: This study demonstrates a novel use of real-world data to evaluate the impact of population-level health interventions. Overall AF diagnoses, pulse checks and OAC prescriptions increased 8 weeks following HRW but there were differences by sex. These findings show the impact of awareness campaigns in helping identify undiagnosed patients and may help inform future campaigns to target specific groups.