Background

Guidelines recommend evaluation of cardiac function, valvular and ischemic heart disease, and thyroid, kidney, and liver function on initial diagnosis of atrial fibrillation (AF).

Hypothesis

We hypothesized that initial workup of patients with newly identified AF would vary by age, sex, and burden of comorbid illness.

Methods

In a retrospective analysis of a large sample of commercially insured patients 18 to 64 years old (n = 40 245) and a nationally representative 5% cohort of Medicare beneficiaries 65 years or older (n = 204 676), we measured claims for guideline-recommended services for initial evaluation of AF among patients with a new diagnosis between 2000 and 2008.

Results

From 30 days before through 90 days after AF diagnosis, basic evaluation, including physician visit, electrocardiogram, and echocardiography, was completed in up to 66.6% of patients. Completion rates for all guideline-recommended evaluations were 17.4% in the commercially insured sample and 18.5% in the Medicare cohort in 2007. Evaluation rates increased over time. Blood tests assessing thyroid function were documented for approximately one-third of patients in each cohort. Increasing the observation period to 1 year before through 3 months after the AF diagnosis markedly increased completion rates, but rates of thyroid function testing remained low (50%-60%). There were minor differences in evaluation completeness by sex, race, and geographic region.

Conclusions

Differences in guideline-recommended evaluation rates by demographic characteristics after a new diagnosis of AF were of minor clinical importance. Basic evaluation had satisfactory completion rates; however, rates of laboratory testing were low.