Medical practice variation: shifting the paradigm toward the clinicians’ perspective: Enabling physicians to reduce unwarranted practice variation

Medical practice variation refers to differences in healthcare processes or outcomes when compared to peers or a gold standard such as evidence-based guidelines. It can be categorized into warranted and unwarranted practice variation. Practice variation is unwarranted when it cannot be explained by patient characteristics or preferences. Research on medical practice variation has three main objectives: to identify, explain, or reduce unwarranted variation. Reducing unwarranted practice variation involves adapting the clinical behavior of healthcare professionals. Audit and Feedback (A&F) can be utilized as a tool for this purpose. An A&F cycle measures professional performance against standards and provides this feedback to healthcare professionals. This thesis aims to improve practice variation research for immediate use in A&F cycles to reduce unwarranted practice variation.

This thesis is divided into four sections. Section A focused on how practice variation is currently studied. A scoping review (Chapter 2) of studies on medical practice variation in cesarean section rates concluded that future research should better account for patient characteristics and provide feedback on clinical performance using lower aggregation levels to facilitate use in A&F cycles. Section B focused on how practice variation studies could be improved to be suitable for A&F. An analysis of Dutch General Practitioners' (GPs) experiences with the Primary Care Practice Report (PCPR) (Chapter 3) showed that GPs desired more specific feedback related to clinical outcomes and actionable data on disease patterns and interventions. Chapter 4 examined healthcare substitution for intrauterine device (IUD) insertions from secondary to primary care in the Netherlands. It found that 74% of IUDs were inserted in primary care, with regional variation from 58% to 82%. This study suggested that better collaboration among healthcare providers could enhance care substitution, reducing costs and improving patient care. The fourth study (Chapter 5) assessed whether hysterectomy rates for women with bleeding disorders or fibroids were substituted by less invasive techniques. The study suggested that, except perhaps for the embolization technique, at the regional level, minimally invasive techniques were used in daily practice as additional methods and not solely as a substitute for hysterectomy. The fifth study (Chapter 6) analyzed variation in the stepped-care model for women with idiopathic heavy menstrual bleeding. It found substantial variation in treatment approaches across hospitals. The findings suggested that women often received suboptimal care, neglecting the least invasive options initially. Section C assessed how data linkage of existing datasets could improve practice variation analysis. The sixth study (Chapter 7) aimed to identify guideline deviations in cervical cancer screening in Dutch hospitals by linking insurance and pathology data. It found instances of overtreatment and undertreatment. Providing hospital-level data to healthcare professionals could enhance feedback utilization and improve care quality. In the final section D, the focus was on additional policy measures when the reduction of unwarranted practice variation fell short. The seventh study (Chapter 8) involved interviews with key stakeholders to identify measures to reduce unwarranted medical practice variation and proposed four strategic measures to enhance the integration of scientific evidence into daily medical practice.

This thesis concludes that to effectively reduce unwarranted practice variation, indicators must be adjusted for case-mix factors, offer insight into healthcare outcomes, and be presented at the lowest aggregation level. These indicators should use explicit targets to empower healthcare professionals. Using secondary data and integrating existing datasets can help develop informative A&F indicators without imposing additional administrative burdens. Future research should incorporate these A&F indicators as key performance indicators (KPIs) in healthcare contracting, aligning financial incentives with reducing unwarranted practice variation and improving appropriate healthcare implementation.