Health Care Costs and Financing

Immunization rates in New Mexico have fallen significantly since the introduction of Medicaid managed care

The 1996 introduction of Medicaid managed care (MMC) in New Mexico, a State with a predominantly rural, poor, and multiethnic population, did not improve immunization coverage in that State. In fact, after 1996, New Mexico's immunization rates fell to among the lowest in the United States, according to a study supported by the Agency for Healthcare Research and Quality (HS09703).

Reduced funding for State-run public health clinics (PHCs) and increased informal referrals of patients to clinics for immunization by private physicians and managed care organizations may have contributed to this decline, explains Howard Waitzkin, M.D., Ph.D., of the University of New Mexico. Dr. Waitzkin and his colleagues recommend that future policies consider the effects of Medicaid reform on safety net institutions like community health centers (CHCs), which are responsible for immunizations and other necessary preventive services.

The researchers studied trends in immunization based on data from the National Immunization Survey. To help explain changes in New Mexico's immunization rates in relation to MMC, they analyzed data gathered through ethnographic observations at safety net institutions, including welfare offices, CHCs, hospital emergency departments, private physicians' offices, mental health institutions, managed care organizations, and State agencies.

Immunization coverage decreased significantly after implementation of MMC, from 80 percent in 1996 to 73 percent in 2001 for the 4:3:1 vaccination series (four doses of diphtheria, tetanus, and pertussis vaccine; three doses of polio vaccine; and one dose of measles vaccine). New Mexico dropped in rank among States from 30th for this vaccination series in 1996 to 50th in 2001. Ethnographic observations revealed conditions that might have contributed to decreased immunization rates. These include reduced funding for immunizations at public health clinics and difficulties in gaining access to MMC providers, informal referral from managed care organizations and contracting physicians to CHCs and State-run health clinics, and increased workloads and delays at CHCs, linked partly to these informal referrals for immunization.

See "Immunization coverage and Medicaid managed care in New Mexico: A multimethod assessment," by Michael A. Schillaci, Ph.D., Dr. Waitzkin, E. Ann Carson, M.S., and others, in the January 2004  Annals of Family Medicine 2(1), pp. 13-21.

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