Interventions aimed at providers can also improve screening use. Physician reminder systems, chart audit with feedback, and physician education about appropriate screening practices contribute to higher screening test use (Becker et al., 1989; Burack et al., 1997; Chambers et al., 1989; Cheney and Ramsdell, 1987; Cowan et al., 1992; Landis et al., 1992; McPhee et al., 1989, 1991; Nattinger et al., 1989; Ornstein et al., 1991; Tierney et al., 1986; Yarnall et al., 1993). However, in one study, written feedback and financial incentives were ineffective in improving physician compliance to cancer screening guidelines in primary care sites serving women age 50 and older cared for in a Medicaid HMO (Hillman et al., 1998).
Screening tests alone do not provide a diagnosis of cancer; this can be made only with further testing. In fact, most people with abnormal results from a single cancer screening test will not be found to have cancer, so definitive testing is essential if the benefits of screening are to be realized (Mandelblatt et al., 1997). Nonetheless, many individuals fail to receive timely, or any, follow-up of an abnormal screening test, with large variations in the rates of nonresolution across settings and populations. Different studies have reported that 20-99 percent of women who have abnormal mammograms receive appropriate diagnostic follow-up (Kerlikewske, 1996; Manelblatt et al., 1993b), and 20-74 percent of women with abnormal Pap smears receive appropriate follow-up (Lacey et al., 1993; Marcus et al., 1992; Mandelblatt et al., 1997; Michielutte et al., 1985).
In one study of the reasons for delays between the time of the initial medical consultation and the establishment of a diagnosis among women with breast cancer, providers and the health care systems were found to be responsible for 45 percent of cases with significant delays. Delays were attributed to difficulties in scheduling or physician inaction. In about 25 percent of the cases, the delay was attributed to patients, and the most common reason for inaction provided by women was that the problem was not perceived as important. In another 17 percent of cases, both the patient and system were determined to be responsible. For the balance of cases, no reason for the delay was ascertained (Caplan et al., 1996). Several patient characteristics are associated with inadequate follow-up of abnormal cancer screening results: rural residence (Fox et al., 1997), relatively less education (Michielutte et al., 1985), low income (McCarthy et al., 1996a), and being a member of a racial or ethnic minority group (Chang et al., 1996; Kerlikowske, 1996; Mandelblatt et al., 1996; Rojas et al., 1996), but these factors are not all independent predictors of follow-up. Some of the observed racial differences may, in part, be attributable to socioeconomic status, age, marital status, and history of previous mammogram. For instance, when these factors were controlled for in an analysis of the effect of race on screening follow-up, the effect of race diminished substantially (McCarthy et al., 1996a). It is unclear whether certain patients fail to heed advice about follow-up; whether personal characteristics predict the likelihood that a physician will make follow-up recommendations; whether certain institutions lack tracking systems; or whether certain patients have difficulties navigating the system.