No single intervention for the promotion of repeat mammography use is best, as results of a meta-analysis published June 29 in the Journal of the National Cancer Institute found heterogeneity across both intensive strategies and reminder-only interventions in studies that reported estimates of repeat screening for intervention and control groups.
“Various interventions to promote repeat use of mammography have been evaluated, but the efficacy of such interventions is not well understood,” explained lead author Sally W. Vernon, MD, from the Center for Health Promotion and Prevention Research at the University of Texas in Houston, and colleagues.
Researchers reviewed various databases from 1990 through Aug. 15, 2009, extracting data to calculate unadjusted effect estimates and 95 percent confidence intervals. The 25 studies analyzed reported estimates of repeat screening for intervention and control groups. In addition, researchers performed stratified analyses and conducted influence analyses on meta-regression models for 15 selected explanatory variables.
The study intervention strategies were grouped into three categories: reminders, education/motivation and counseling. Authors also classified studies according to counseling protocols used and use of single or multiple interventions.
Despite some homogeneous subgroups discovered within some reviewed categories, including year(s) the study was conducted, age range of participants, race/ethnicity and study setting, heterogeneity was observed after stratification, noted the researchers. The summary odds ratio for the eight heterogeneous reminder-only studies was the largest observed and was determined to be statistically significantly greater than the summary odds ratio for the 17 studies that used more intensive strategies of education/motivation or counseling, which were found to be homogeneous.
This finding could be attributed to a lack of standardization among interventions or different populations or settings, offered Vernon and colleagues.
“A variety of approaches have been used to describe and classify intervention strategies, and no one approach is considered the gold standard,” the authors wrote. “Heterogeneity prevents firm conclusions about the effectiveness of more intensive vs. less intensive strategies…We also cannot conclude that reminder-only intervention strategies are more effective than alternate strategies.”
Additional studies with more consistent designs and well-defined intervention categories are needed to identify methods or strategies that could increase repeat mammography, concluded the study.
Strategies for action
In an accompanying editorial, Jeanne Mandelblatt, MD, from the Cancer Control Program at Georgetown University Medical Center, Lombardi Comprehensive Cancer Center in Washington, D.C., and Diana Buist, PhD, from the Group Health Research Institute in Seattle, offered several potential courses of action from a public health perspective in response to the study’s results. These include investment of more research to test additional interventions to improve repeat mammography rates, devotion of more resources to developing better screening tests and using risk status to match interventions and technology and target communications rather than employing a “one size fits all” approach.