Stage at diagnosis and treatment patterns among older women with breast cancer: an HMO and fee-for-service comparison.

CONTEXT Few studies have compared patterns of care in health maintenance organization (HMO) and fee-for-service (FFS) settings. OBJECTIVE To examine breast cancer stage at diagnosis and, for those at an early stage, treatment patterns for elderly women in HMO and FFS settings. DESIGN Cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) program linked to Medicare enrollment records. SETTINGS AND PARTICIPANTS Women aged 65 years or older residing in 11 geographic areas who were newly diagnosed as having breast cancer between 1988 and 1993. MAIN OUTCOME MEASURES Standardized percentage of cases diagnosed at late stages for HMO vs FFS; standardized percentage of early-stage cases undergoing initial treatment with breast-conserving surgery (BCS); and, among BCS cases, standardized percentage receiving adjuvant radiation therapy. Standardization was achieved through logistic regression, controlling for patient demographics, cancer history, county of residence, year of diagnosis, and educational attainment at the census tract level. Analyses of treatment patterns were controlled for stage at diagnosis and tumor size. RESULTS The HMO enrollees were less likely to have breast cancer diagnosed at late stages than FFS patients (HMO, 7.6%; FFS, 10.8%; difference, -3.2% [95% confidence interval (CI), -4.2% to -2.2 %]). Among early-stage cases, the percentages undergoing BCS were similar in HMO and FFS settings overall (HMO, 38.4%; FFS, 36.8%; difference, 1.6% [95% CI, 0.0%-3.2%]); percentages varied markedly at the individual plan level. Among women undergoing BCS, HMO enrollees were significantly more likely to receive radiation therapy but, again, results varied by plan (HMO, 69.0%; FFS, 63.7%; difference, 5.3% [95% CI, 2.9%-7.7%]). In general, use of BCS and radiation therapy was substantially higher than that found in an earlier study examining cases diagnosed between 1985 and 1989. CONCLUSIONS Treatment of early-stage breast cancer in HMOs often differs from local FFS patterns, but not in a consistent way. During the period of our study, elderly HMO enrollees did not appear to have systematic access problems with adjuvant radiation therapy following BCS compared with women in an FFS setting.