Undiagnosed atrial fibrillation (AF) can lead to avoidable strokes. However, in terms of AF screening recommendations, guidelines fluctuate. For a study, researchers sought to determine if using a portable single-lead ECG at primary care visits increased the number of AF diagnoses. During vital sign evaluations, they randomly assigned 16 primary care clinics to either AF screening or usual care using a portable single-lead ECG (AliveCor KardiaMobile). The patients involved in the study were all above the ages ≥ 65. At the meeting, primary care providers received screening results. The primary care provider made all confirmatory diagnostic tests and therapy choices. During the 1-year follow-up, new AF diagnoses were obtained electronically and manually. The proportions and rates of occurrence were computed. The effect heterogeneity was examined.

About 1.72% of persons in the screening group had new AF identified at 1 year vs 1.59% in the control group (risk difference, 0.13% [95% CI, –0.16 to 0.42]; P=0.38) of 30,715 patients without prevalent AF (n=15,393 screening [91% screened], n=15,322 control). New AF diagnoses in the screening and control groups were higher among individuals aged ≥85 years in prespecified subgroup analyses (5.56% versus 3.76%, respectively; risk difference, 1.80% [95% CI, 0.18 to 3.30]). The difference in newly diagnosed AF during the screening period and the preceding year was somewhat higher in the screening group than in the control group (0.32% versus –0.12%; risk difference, 0.43% [95% CI, –0.01 to 0.84]). The proportion of newly diagnosed AF patients who were started on oral anticoagulants did not change between the screening (n=194, 73.5%) and control (n=172, 70.8%) groups (risk difference, 2.7% [95% CI, –5.5 to 10.4]). When compared to usual care, screening for AF with a single-lead ECG during primary care visits had no effect on new AF diagnoses among all patients aged 65 years or older.