Choosing wisely in daily practice: a mixed methods study on determinants of antinuclear antibody testing by...

To explore the relationship between antinuclear antibody (ANA) overuse and rheumatologist-related factors before and after an intervention aimed at reducing ANA overuse.

In this mixed methods study we performed surveys among rheumatologists (n = 20) before and after the ANA intervention (education and feedback). We identified clinician-related determinants of ANA overuse (demographic characteristics, cognitive bias, numeracy, personality, thinking styles, and knowledge) by multivariate analysis. Two focus group meetings with rheumatologists were held 6 months after the intervention to explore self-reported determinants.

Questionnaires were completed by all rheumatologists and eight participated in the focus groups. Rheumatologists with more work experience and a less extravert personality ordered more ANA tests before the intervention [β = 0.01, 95% confidence interval (CI) 0.003 to 0.02, p = 0.01 and β = -0.11, 95% CI -0.21 to -0.01, p = 0.04, respectively; R² = 47%]. After the intervention, female rheumatologists changed less than their male colleagues with regard to the number of ANA tests ordered (β = 0.15, 95% CI 0.03-0.26, p = 0.02; R^{2 =} 25%). During the focus groups, seven themes were identified that influenced improvement in ANA overuse: determinants related to the intervention and the study, individual health professionals, patients, professional interactions, incentives and resources, capacity for organizational change, and social, political, and legal factors.

We identified several determinants that together explained a sizable part of the variance observed in the ANA outcomes at baseline and in the change in ANA outcomes afterwards. Furthermore, the focus groups yielded additional factors suggesting a complex interplay of determinants influencing rheumatologists' ANA ordering behaviour.