Presentation (CTI)

OBJECTIVES: Unnecessary diagnostic testing remains common and may contribute to rising healthcare costs and patient harm. However, few studies have examined this issue from the perspective of physician-level determinants. This study examined the association between physician human capital and diagnostic test-ordering decisions, with particular attention to the mediating role of information-processing efficiency and the moderating effect of diagnostic uncertainty.
METHODS: A vignette-based behavioral experiment was conducted among 213 physicians from nine hospitals in China. Participants completed standardized clinical scenarios involving asthma and bronchiectasis under different levels of diagnostic uncertainty. Moderated mediation analyses were conducted using Hayes' PROCESS macro.
RESULTS: 88.73% of participants ordered at least one unnecessary diagnostic test, and 29.11% failed to order clinically necessary tests. Physician human capital was negatively associated with the number of unnecessary tests (β = -0.204) and positively associated with the likelihood of ordering clinically necessary tests (β = 0.520). Information-processing efficiency mediated both associations, accounting for 20.9% of the total effect on unnecessary testing and 57.8% of the total effect on necessary testing. Diagnostic uncertainty moderated the indirect pathway, with stronger effects under lower uncertainty and attenuated effects under higher uncertainty.
CONCLUSIONS: These findings suggest that information-processing efficiency mediates the association between physician human capital and diagnostic test-ordering decisions, and that this mediation is moderated by the level of diagnostic uncertainty. Strengthening physicians' information-processing capacity, together with efforts to reduce diagnostic uncertainty in clinical practice, may promote more appropriate diagnostic testing.