Additional analyses were conducted to examine the combined intervention effects for specific diverse populations (see Figures 4-3 and 4-4). The estimated intervention effect was greatest for older women—7.9 percent (95-percent CI: 10.5-25.4; 11 studies)—followed by an estimated effect of 12.7 percent (95-percent CI: 7.3-18.1; 26 studies) for comparisons consisting of more than 40 percent low-income women. When comparisons were made for intervention groups with more than 40 percent nonwhite women, the estimated effects were 12 percent (95-percent CI: 6.7-17.4; 24 studies) and 11.6 percent (95-percent CI: 6.4-16.7; 16 studies) if comparisons are limited to 40 percent or more African-American women. Again, significant heterogeneity between the studies was evident for each of these groupings.
As other Institute of Medicine reports (e.g., 2000, 2001) have recommended recently, the strongest interventions were those that increased access and addressed structural, economic, and geographic barriers to mammography use, along with intrapersonal and interpersonal factors (Skinner, Arfken, and Waterman, 2000; Skaer et al., 1996; Taylor et al., 1999; Rimer et al., 1992; Kiefe et al., 1994). That is, they combined communication interventions with others that were designed to enhance access. After all, mammography use does not occur in a vacuum. But individual-directed interventions in health care settings also showed impressive effects. Overall, the outcomes of combinations of certain kinds of interventions had the greatest impact on diverse women.
These results cannot be compared directly to studies conducted only among mainstream populations. However, the results can be compared to other mammography meta-analyses. Several meta-analyses of mammography-enhancing interventions previously have been reported. Although they all used different categories and inclusion/exclusion criteria, making direct comparisons impossible, the conclusions for general populations are consistent with, but not identical to, findings for diverse populations.
Wagner’s (1998) review focused on mammography reminders for general populations, and concluded that women who received reminders were more likely to be screened than those who did not