Factors Influencing Mammography Use Among Women in Medicare Managed Care

Health Care Financing Review, Summer, 2001 by Judith K. Barr, Susan Reisine, Yun Wang, Eric F. Holmboe, Karin L. Cohen, Thomas J. Van Hoof, Thomas P. Meehan

INTRODUCTION

In the continuing effort to understand factors that facilitate or act as barriers to older women's use of mammography screening, especially under managed care, and to develop interventions that will address these concerns, a mail survey of Medicare beneficiaries was conducted. Based on the literature, this study was designed to assess health beliefs that act as facilitators or barriers to the use of mammography, while controlling for the effects of demographic and health plan characteristics. In addition, because this is a Medicare population of older women who might not receive mammograms due to other health considerations, we included a measure of health status. This article presents the findings about mammography use based on the beneficiary survey data.

OLDER WOMEN, BREAST CANCER, AND MAMMOGRAPHY

Older age is the single greatest risk factor for breast cancer in women. According to the American Cancer Society (1999), breast cancer risk increases from 1 in 67 at age 40 to 1 in 25 at age 70, and the incidence continues increasing to age 80. More than one-half of all breast cancers occur in women age 65 or over. Mammography screening has been demonstrated to reduce breast cancer mortality (Shapiro et al., 1982), especially among women in the age group 50-74 compared with those without mammography (Kerlikowske et al., 1995). While prospective trials have typically not included women age 70 or over, two recent reports addressed the efficacy of mammography in older women. The researchers found that, compared with younger women, women age 70 or over benefit from screening in terms of early diagnosis (Hwang and Cody, 1998). In the other study, the age group 70-79 would have a small increase in life expectancy from biennial mammograms, compared with the gains from screening at age 65-69 (Kerlikowske et al., 1999).

Guidelines for the use of screening mammography from the American Cancer Society, the American College of Radiology, the U.S. Preventive Services Task Force, and the American College of Preventive Medicine, among various authorities, generally agree on mammograms every 1 to 2 years for women up to age 70 (National Guideline Clearinghouse, 2000. The National Committee on Quality Assurance (NCQA) measures performance of managed care plans according to the standard of a screening mammogram in the past 2-year measurement period for women in the age group 52-69 (National Committee on Quality Assurance, 2000). Most of the guidelines do not specify the continuation of mammography for those age 70 or over, because gains in life expectancy from mammograms may be limited by comorbidities (Kerlikowske et al., 1999). However, some of the guidelines do not specify an upper age limit, and mammography has been recommended for women age 75 or over who have good general health and life expectancy (Blustein and Weiss, 1998).

Yet, biennial mammogram rates remain lower among women age 70 or over (Blackman, Bennett, and Miller, 1999). Based on data from the Behavioral Risk Factor Surveillance System from 1989-1997, women age 70 or over are considerably less likely to report having a mammogram within the past 2 years (66.7 percent) than women age 60-69 (77.1 percent) or age 50-59 (78.0 percent). This differential between these age groups was larger in 1997 than in the previous 2 years (Blackman, Bennett, and Miller, 1999). A similar differential for women age 75 or over was found for 1-year mammogram rates on the 1992 National Health Interview Survey and in 1992 Medicare claims data, although the self-reported rates were higher than those based on claims (May and Trontell, 1998). Blustein and Weiss (1998), based on an analysis of data from the Medicare Current Beneficiary Survey, concluded that advanced age and impaired functional status were related to reduced likelihood of mammography among women age 75 or over; women age 85 or over were less likely to have a mammogram regardless of health and functional status, and several comorbid conditions were unrelated to mammography use.

Studies have consistently shown that the major facilitating factor is a physician's recommendation or referral (Rimer, Trock, and Engstrom, 1991; Lerman et al., 1990; Friedman et al., 1995). Barriers that may deter older women from getting mammography screening have been documented. In addition to the lack of a physician's recommendation (National Cancer Institute Breast Cancer Screening Consortium, 1990; Rimer, 1993), other barriers include: concerns about cost and lack of knowledge about the Medicare benefit; lack of transportation and/or time; belief that breast cancer is not a problem; concerns about the effects of radiation; embarrassment and anxiety or fear of cancer (Lerman et al., 1990; Rimer, Trock, Engstrom, 1991; Glockner et al., 1992; Friedman et al., 1995; Rubenstein, 1994). Older women may not realize that age places them at greater risk of breast cancer (Rubenstein, 1994; Friedman, et al., 1998). More than one-third of older women responding to a National Cancer Institute Survey (1999) said they were not as concerned about getting breast cancer as they had been at younger ages.