Advancing Methods to Study Clinical Variation in Healthcare

Area of Science:

• Health Services Research
• Clinical Epidemiology
• Biostatistics

Background:

• Clinical variation, also known as medical practice variation, refers to differences in patient care and outcomes across various dimensions.
• Understanding unexplained clinical variation is crucial for identifying overuse, underuse, inefficiencies, and inequities in healthcare.
• Existing literature lacks a comprehensive characterization of methods used to study clinical variation.

Purpose of the Study:

• To provide non-technical methodological guidance for researchers on describing and quantifying clinical variation.
• To characterize and compare various methods for analyzing clinical variation.
• To serve as a resource for examining clinical variation in health services research.

Main Methods:

• Visualizations: Point and jitter plots, scatterplots, caterpillar plots, box plots, and funnel plots are presented to display clinical variation.
• Statistical Approaches: Basic measures like variance, standard deviation, coefficient of variation, and interquartile range are discussed.
• Multilevel Models: Advanced methods are described to measure variation magnitude, identify contributing levels, and explore explanatory factors using statistics like the intraclass correlation coefficient and odds ratios.

Main Results:

• Funnel plots can identify variation exceeding expected levels after adjusting for case-mix.
• Multilevel models quantify variation and identify factors at different levels (patient, provider, hospital) that explain it.
• Key considerations include appropriate measurement of care/outcomes, identifying warranted vs. unwarranted variation, and potential interventions.

Conclusions:

• This review offers an overview of techniques for describing and quantifying clinical variation.
• It aims to equip researchers with the knowledge to effectively analyze and understand differences in medical practice.
• The guidance supports efforts to improve healthcare quality by addressing unwarranted clinical variation.