Study designs for effectiveness and translation research :identifying trade-offs.

BACKGROUND: Practitioners and policymakers need credible evidence of effectiveness to justify allocating resources to complex, expensive health programs. Investigators, however, face challenges in designing sound effectiveness and translation research with relevance for "real-world" settings. METHODS: Research experts and federal and foundation funders (n= approximately 120) prepared for and participated in a symposium, held May 4-5, 2004, to weigh the strengths, limitations, and trade-offs between alternate designs for studying the effectiveness and translation of complex, multilevel health interventions. RESULTS: Symposium attendees acknowledged that research phases (hypothesis generating, efficacy, effectiveness, translation) are iterative and cyclical, not linear, since research in advanced phases may reveal unanswered questions in earlier phases. Research questions thus always need to drive the choice of study design. When randomization and experimental control are feasible, participants noted that the randomized controlled trial with individual random assignment remains the gold standard for safeguarding internal validity. Attendees highlighted trade-offs of randomized controlled trial variants, quasi-experimental designs, and natural experiments for use when randomization or experimental control or both are impossible or inadequately address external validity. Participants discussed enhancements to all designs to increase confidence in causal inference while accommodating greater external validity. Since no single study can establish causality, participants encouraged replication of studies and triangulation using different study designs. Participants also recommended participatory research approaches for building population relevance, acceptability, and usefulness. CONCLUSIONS: Consideration of the study design choices, trade-offs, and enhancements discussed here can guide the design, funding, completion, and publication of appropriate policy- and practice-oriented effectiveness and translational research for complex, multilevel health interventions.

Effectiveness of interventions to increase screening for breast, cervical, and colorectal cancers: nine updated systematic reviews for the guide to community preventive services.

CONTEXT: Screening reduces mortality from breast, cervical, and colorectal cancers. The Guide to Community Preventive Services previously conducted systematic reviews on the effectiveness of 11 interventions to increase screening for these cancers. This article presents results of updated systematic reviews for nine of these interventions. EVIDENCE ACQUISITION: Five databases were searched for studies published during January 2004-October 2008. Studies had to (1) be a primary investigation of one or more intervention category; (2) be conducted in a country with a high-income economy; (3) provide information on at least one cancer screening outcome of interest; and (4) include screening use prior to intervention implementation or a concurrent group unexposed to the intervention category of interest. Forty-five studies were included in the reviews. EVIDENCE SYNTHESIS: Recommendations were added for one-on-one education to increase screening with fecal occult blood testing (FOBT) and group education to increase mammography screening. Strength of evidence for client reminder interventions to increase FOBT screening was upgraded from sufficient to strong. Previous findings and recommendations for reducing out-of-pocket costs (breast cancer screening); provider assessment and feedback (breast, cervical, and FOBT screening); one-on-one education and client reminders (breast and cervical cancer screening); and reducing structural barriers (breast cancer and FOBT screening) were reaffirmed or unchanged. Evidence remains insufficient to determine effectiveness for the remaining screening tests and intervention categories. CONCLUSIONS: Findings indicate new and reaffirmed interventions effective in promoting recommended cancer screening, including colorectal cancer screening. Findings can be used in community and healthcare settings to promote recommended care. Important research gaps also are described.