Clinician Attitudes and Beliefs Associated with More Aggressive Diagnostic Testing

Background: Variation in clinicians’ diagnostic test utilization is incompletely explained by demographics and likely relates to cognitive characteristics. We explored clinician factors associated with diagnostic test utilization. Methods: We used a self-administered survey of attitudes, cognitive characteristics, and reported likelihood of test ordering in common scenarios; frequency of lipid and liver testing in patients on statin therapy. Participants were 552 primary care physicians, nurse practitioners, and physician assistants from practices in 8 US states across 3 regions, from June 1, 2018 to November 26, 2019. We measured Testing Likelihood Score: the mean of 4 responses to testing frequency and self-reported testing frequency in patients on statins. Results: Respondents were 52.4% residents, 36.6% attendings, and 11.0% nurse practitioners/physician assistants; most were white (53.6%) or Asian (25.5%). Median age was 32 years; 53.1% were female. Participants reported ordering tests for a median of 20% (stress tests) to 90% (mammograms) of patients; Testing Likelihood Scores varied widely (median 54%, interquartile range 43%-69%). Higher scores were associated with geography, training type, low numeracy, high malpractice fear, high medical maximizer score, high stress from uncertainty, high concern about bad outcomes, and low acknowledgment of medical uncertainty. More frequent testing of lipids and liver tests was associated with low numeracy, high medical maximizer score, high malpractice fear, and low acknowledgment of uncertainty. Conclusions: Clinician variation in testing was common, with more aggressive testing consistently associated with low numeracy, being a medical maximizer, and low acknowledgment of uncertainty. Efforts to reduce undue variations in testing should consider clinician cognitive drivers.