Research Designs for Intervention Research with Small Samples II: Stepped Wedge and Interrupted Time-Series Designs
- 907 Downloads
The stepped wedge design (SWD) and the interrupted time-series design (ITSD) are two alternative research designs that maximize efficiency and statistical power with small samples when contrasted to the operating characteristics of conventional randomized controlled trials (RCT). This paper provides an overview and introduction to previous work with these designs and compares and contrasts them with the dynamic wait-list design (DWLD) and the regression point displacement design (RPDD), which were presented in a previous article (Wyman, Henry, Knoblauch, and Brown, Prevention Science. 2015) in this special section. The SWD and the DWLD are similar in that both are intervention implementation roll-out designs. We discuss similarities and differences between the SWD and DWLD in their historical origin and application, along with differences in the statistical modeling of each design. Next, we describe the main design characteristics of the ITSD, along with some of its strengths and limitations. We provide a critical comparative review of strengths and weaknesses in application of the ITSD, SWD, DWLD, and RPDD as small sample alternatives to application of the RCT, concluding with a discussion of the types of contextual factors that influence selection of an optimal research design by prevention researchers working with small samples.
KeywordsResearch design Small samples Stepped wedge design Interrupted time-series design
Conflicts of Interest
The authors declare that they have no conflict of interest.
- Campbell, D. T., Stanley, J. C., & Gage, N. L. (1963). Experimental and quasi-experimental designs for research. Boston, MA: Houghton, Mifflin and Company.Google Scholar
- Centers for Disease Control and Prevention (2013). Antibiotic resistance threats in the United States, 2013. http://www.cdc.gov/features/antibioticresistancethreats/.
- Dumsha, J. Z., DiTomasso, R. A., Gomez, F. C., Melucci, N. J., & Stouch, B. C. (2011). Changes in self-reported drinking behaviors among US teenagers associated with the introduction of flavored malt beverages: An interrupted time series quasi-experiment. Addiction Research and Theory, 19, 199–212. doi: 10.3109/16066359.2010.500064.CrossRefGoogle Scholar
- Franson, P. (2002). Fast-growing malternatives threaten grape expectations. Wine Business Online. Retrieved from http:/ /www.winebusiness.com/SalesMarketing /Webarticle. cfm?AID = 64002&IssueId = 63975.
- Gerritsen, D. L., Smalbrugge, M., Teerenstra, S., Adang Leontjevas, E. M., Vernooij-Dassen, M. J., & Koopmans, R. T. C. M. (2011). Act in case of depression: The evaluation of a care program to improve the detection and treatment of depression in nursing homes. Study protocol. BMC Psychiatry, 11(91), 1–7. doi: 10.1186/1471-244X-11-91.Google Scholar
- Glass, G. V. (1997). Interrupted time-series quasi-experiments. In R. M. Jaeger (Ed.), Complementary methods for research in education (pp. 589–608). Washington D. C: American Educational Research Association.Google Scholar
- Grant, A. D., Charalambous, S., Fielding, K. L., Day, J. H., Corbett, E. L., Chaisson, R. E., & Churchyard, G. J. (2005). Effect of routine isoniazid preventative therapy on tuberculosis incidence among HIV-infected men in South Africa: a novel randomized incremental recruitment study. Journal of the American Medical Association, 22, 2719–2725.CrossRefGoogle Scholar
- Hayden, M.K., Lin, M. K. Lolans, K., Blom, D., Weiner, S., Lyles, R. Weinstein, R. A. (2014). Prevention of colonization and infection by Klebsiella Pneumoniae Carbapenemase-Producing Enterobacteriaceae in long term acute care hospitals. Manuscript submitted for publication.Google Scholar
- Hussey, M. A., & Hughes, J. P. (2007). Design and analysis of stepped wedge cluster randomized trials. Contemporary Clinical Trials, 28, 182–191. Retrieved from http://faculty.washington.edu/peterg/Vaccine2006/articles/HusseyHughes.2007.pdf.
- Keane, R. (2003). Malternative maximization. Adams Beverage Group. Retrieved from http://www.beveragenet.net/bd/2003/0307/0307mlt.asp.Google Scholar
- Mdege, N. D., Man, M. S., Taylor Nee Brown, C. A., & Torgerson, D. J. (2011). Systematic review of stepped wedge cluster randomized trials shows that design is particularly used to evaluate interventions during routine implementation. Journal of Clinical Epidemiology, 64, 936–948.CrossRefPubMedGoogle Scholar
- Pridemore, A. W. A., Trahan, A., & Chamlin, M. B. (2009). No evidence of suicide increase following terrorist attacks in the United States: An interrupted time-series analysis of September 11 and Oklahoma City. Suicide and Life Threatening Behavior, 39, 659–670. doi: 10.1521/suli.2009.39.6.659.CrossRefPubMedGoogle Scholar
- The Gambia Hepatitis Study Group. (1987). The Gambia hepatitis intervention study. Cancer Research, 47, 5782–5787.Google Scholar
- Wyman, P. A., Brown, C. H., Inman, J., Cross, W., Schmeelk-Cone, K., Guo, J., & Pena, J. B. (2008). Randomized trial of a gatekeeper program for suicide prevention: 1-year impact on secondary school staff. Journal of Consulting and Clinical Psychology, 76(1), 104–115. doi: 10.1037/0022-006X.76.1.104.PubMedCentralCrossRefPubMedGoogle Scholar
- Wyman, P. A., Brown, C. H., LoMurray, M., Schmeelk-Cone, K., Petrova, M., Yu, Q., & Wang, W. (2010). An outcome evaluation of the Sources of Strength suicide prevention program delivered by adolescent peer leaders in high schools. American Journal of Public Health, 100(9), 1653–1661. doi: 10.2105/AJPH.2009.190025.PubMedCentralCrossRefPubMedGoogle Scholar
- Wyman, P. A., Henry, D., Knoblauch, S., Brown, C. H. (2015). Designs for testing group-based interventions with limited numbers of social units: The dynamic wait-listed and regression point displacement designs. Prevention Science. Google Scholar