Barriers and facilitators to reducing overuse of thyroid function testing: a mixed-methods study.

Background: Thyroid function laboratory testing is often overused. Tailored de-implementation interventions require an understanding of underlying barriers and facilitators contributing to overuse.

Methods: We performed a mixed-methods study exploring barriers and facilitators of appropriate thyroid function testing using surveys and focus groups conducted between June and October 2023 in British Columbia, Canada. Quantitative survey data were summarised using simple statistics, and open-ended survey questions were summarised using summative content analysis. Focus group transcripts were analysed using thematic analysis. Key themes were mapped onto the combined Theoretical Domains Framework and Capability, Opportunity, Motivation-Behaviour model.

Results: 230 practitioners completed the survey (1.4% response rate), and 53 practitioners attended a total of six focus groups. Three themes emerged around barriers from synthesising the results: patient expectations, practitioner knowledge gaps and health system factors. Patient expectations were linked to non-specific symptoms, recommendations from alternate care providers, increased interest in hormone testing and internet searches, leading to patient requests for more testing and/or referrals to specialists. Knowledge gaps included use of specialised tests, interpretation of free hormone results, frequency of thyroid testing and screening in asymptomatic, pregnant and postpartum patients. Health system barriers included lack of practitioner time, lack of family doctors leading more patients to seek care from alternative providers, existing order sets and ordering processes, and existing culture of ordering practices. Identified facilitators of behaviour change towards appropriate thyroid testing included educational resources for practitioners and patients, leveraging of health information systems for seamless viewing of prior test results, reflexive testing and provision of personalised practitioner feedback.

Conclusions: Interventions to reduce overutilisation of thyroid testing should include easily accessible physician educational and feedback resources, patient educational materials and changes to laboratory ordering processes and information systems. Future studies should develop and evaluate the use of these intervention elements in British Columbia.