Projecting corporate health plan utilization and charges from annual ICD-9-CM diagnostic rates: a value-added...

To develop an allocation method for corporate health plan resources and expenditures based on annual International Classification of Disease, 9th revision, Clinical Modification (ICD-9-CM) diagnostic rate stratification as a surrogate for disease incidence.

A data-mining process was applied to a self-insured corporate health plan database. Annual membership rates of Current Procedural Terminology (CPT) procedure utilization and charges between 1990 and 1994 for a cohort of 7216 continuously employed plan members were stratified according to the annual rates of the 19 major ICD-9-CM diagnostic classifications. The stratified annual CPT utilization and charge rates were analyzed by correlation analysis and one-tailed t test.

Laboratory and pathology procedure utilization and charge rates were highly correlated with specific rankings of ICD-9-CM diagnostic classifications. The health plan diagnostic rate, laboratory utilization rate, and all charge rates increased significantly during the 5 study years.

Although all procedure utilization and charge rates in this health plan increased each year, their proportionality consistently was maintained among diagnostically related groups of patients. By restraining global expenditures, managed health plans conflict with historical utilization and charge patterns. Treating ICD-9-CM diagnostic groups as disease management services within a managed care plan allows procedures and expenses to be allocated according to medical necessity in the context of total membership benefits. For pathologists, who recently were mandated by the Health Care Financing Administration and the Office of Inspector General of the Department of Health and Human Services to become stewards of ICD-9-CM coding, this is a unique opportunity to lead an initiative to perfect managed care. The process will require permanent patient numbers, computerized longitudinal patient records, and standardized coded medical terminology.