The Effect of Area HMO Market Share on Cancer Screening

Authors

  • Laurence C. Baker,

    Search for more papers by this author
    • Address correspondence to Laurence Baker, Ph.D., Department of Health Research and Policy, HRP Redwood Building, Rm. 110, Stanford University School of Medicine, Stanford, CA. Dr. Baker is also with the National Bureau of Economic Research, Cambridge, MA. Kathryn A. Phillips, Ph.D., and Su-Ying Liang, Ph.D., are with the Institute for Health Policy Studies, University of California, and the School of Pharmacy, University of California, San Francisco. Jennifer S. Haas, M.D., M.S.P.H., is with the Division of General Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA. Dean Sonneborn, M.A., is with the Institute for Health Policy Studies, University of California, San Francisco.

  • Kathryn A. Phillips,

  • Jennifer S. Haas,

  • Su-Ying Liang,

  • Dean Sonneborn


  • This research was supported by the National Cancer Institute (R01 CA81130) and the Agency for Healthcare Research and Quality (AHRQ P01 HS10771, P01 HS10856, and R01 HS10925). The authors appreciate the comments of Dr. Harold Luft on previous versions of this manuscript.

Abstract

Objective. Managed care may have widespread impacts on health care delivery for all patients in the areas where they operate. We examine the relationship between area managed care activity and screening for breast, cervical, and prostate cancer among patients enrolled in more managed care plans and patients who are enrolled in less managed plans.

Data and Methods. Data on cancer screening from the 1996 Medical Expenditure Panel Survey (MEPS) were linked to data on health maintenance organization (HMO) and preferred provider organization (PPO) market share and HMO competition at the metropolitan statistical area (MSA) level. Logistic regression analysis was used to examine the relationship between area managed care prevalence and the use of mammography, clinical breast examination, Pap smear, and prostate cancer screening in the past two years, controlling for important covariates.

Results. Among all patients, increases in area-level HMO market share are associated with increases in the appropriate use of mammography, clinical breast exam, and Pap smear (OR for high relative to low managed care areas are 1.75, p<.01, for mammography, 1.58, p<.05, for clinical breast exam, and 1.71, p<.01, for Pap smear). In analyses of subgroups, the relationship is significant only for individuals who are enrolled in the nonmanaged plans; there is no relationship for individuals in more managed plans. No relationship is observed between area HMO market share and prostate cancer screening in any analysis. Neither the level of competition between area HMOs nor area PPO market share is associated with screening rates.

Conclusions. Area-level managed care activity can influence preventive care treatment patterns.

Ancillary