Stage of cancer at diagnosis for Medicare HMO and fee-for-service enrollees.

OBJECTIVES: Health maintenance organizations (HMOs) with Medicare contracts often provide cancer screening and preventive services not covered under fee-for-service. This study compared cancer patients in HMOs and fee-for-service on stage at diagnosis.
METHODS: The study examined stage at diagnosis for aged Medicare enrollees in HMOs and fee-for-service, using information from the Surveillance, Epidemiology, and End Results program, linked with Medicare enrollment files. Twelve cancer sites were investigated, and demographics, area of residence, year of diagnosis (1985 to 1989), and education at the census tract level were controlled.
RESULTS: HMO enrollees were diagnosed at earlier stages for cancers of the female breast, cervix, colon, and melanomas and at later stages for stomach cancer. There were no differences for cancers of the prostate, rectum, buccal cavity and pharynx, bladder, uterus, kidney, and ovary. HMO effects were strongest in areas with large, mature HMOs.
CONCLUSIONS: Compared with fee-for-service enrollees, HMO enrollees were diagnosed at earlier stages for cancer sites for which effective screening services are available. The earlier detection of certain cancers among HMO enrollees may result from coverage of screening services and, perhaps, promotion by HMOs of such services.