Abstract
BACKGROUND: Comprehensiveness in primary care is defined as the breadth of services provided by a health care clinician team and is an important metric related to patient outcomes and care delivery. We describe a novel measure of comprehensiveness based on ICD-10 codes. METHODS: We compare the distribution of ICD-10 codes from the care of a large population at a regional academic health system to the distribution of codes from the National Ambulatory Medical Care Survey (NAMCS) using linear regression and the mathematical inner product. RESULTS: The linear regression between the pattern of ICD-10 codes for the selected population and the NAMCS has a slope 1.00, 95% CI 0.57:1.43, P = .0002, R(2) 0.62. When considering specific specialty areas of practice, primary care is distinct from specialty care based on the inner product between the distribution of care for a given specialty independent of whether a regional or national reference population is used. CONCLUSION: The distribution of care based on ICD-10 codes provides a stable and possibly generalizable reference for comprehensive care. The inner product of an ICD-10 care distribution and a reference provides a quantitative estimate of comprehensiveness that distinguishes primary care from specialty care.