204326 Statistical techniques for assessing and increasing external validity

Wednesday, November 11, 2009: 12:30 PM

Elizabeth A. Stuart, PhD , Departments of Mental Health and Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
There has recently been increased emphasis on the identification of evidence-based services in a number of fields, including the National Registry of Evidence-based Programs and Practices in mental health, the Cochrane Collaboration in health care, and the Campbell Collaboration in the social, education, and behavioral fields. Efficacy and effectiveness trials are critical steps in establishing that an intervention merits use and dissemination in these registries. A next step is to consider the generalizability of the effectiveness results when the intervention is disseminated more widely. To this point, emphasis has been on internal validity–obtaining unbiased effect estimates for the subjects in a trial—rather than on external validity—addressing whether those subjects are representative of the population and whether the effects generalize. This talk will discuss design and analysis options for assessing and increasing external validity. Design options include the enrollment of representative samples in clinical trials, as exemplified by the recent push towards “practical clinical trials.” Analysis techniques include meta-analysis and research synthesis approaches that combine information from multiple studies, as well as newer methods that combine population-level data with data from randomized trials. The talk will discuss methodological and practical challenges in this area and highlight recent developments and applications. Motivating examples will primarily come from mental health, including both prevention and treatment. The methods have the potential to help policy makers, service providers, advocates, and consumers use available data to determine which programs and practices will be most beneficial in terms of improving public health.

Learning Objectives:
Describe methods for assessing and increasing the external validity of studies that aim to estimate program effectiveness.

Keywords: Statistics, Mental Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have written the abstract and will prepare and deliver the presentation.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.