Prevention Science

, Volume 14, Issue 2, pp 144–156 | Cite as

Methods for Synthesizing Findings on Moderation Effects Across Multiple Randomized Trials

  • C. Hendricks BrownEmail author
  • Zili Sloboda
  • Fabrizio Faggiano
  • Brent Teasdale
  • Ferdinand Keller
  • Gregor Burkhart
  • Federica Vigna-Taglianti
  • George Howe
  • Katherine Masyn
  • Wei Wang
  • Bengt Muthén
  • Peggy Stephens
  • Scott Grey
  • Tatiana Perrino
  • Prevention Science and Methodology Group


This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design.


Meta-analysis Parallel data analysis Integrative data analysis Variation in impact Subgroup analyses 



We would like to thank our colleagues in the Prevention Science and Methodology Group (PSMG) for their suggestions in the development of this paper. This project was funded by a National Institute on Drug Abuse supplement to the Prevention Science and Methodology Group for the US-EU Drug Abuse Prevention Project (R01MH040859; Brown, Sloboda, Muthén, Masyn, Wang), Robert Wood Johnson Foundation (No. 039223, 040371) for Sloboda, Stephens, Grey, Teasdale. The EU-Drug Abuse Prevention Project is funded by the European Commission (European Public Health programme 2002 grant # SPC 2002376, Faggiano, Vigna-Taglianti), and the parallel data analyses supported by the European Monitoring Centre for Drugs and Drug Addiction (Burkhart, CT.09.RES.005.1.0: Keller). We would also like to thank J G Perpich LLC for their support in the use of the NIDA International Virtual Collaboratory funded through N44DA000000-00409, for their logistical support in developing our international collaboration. A version of this paper was presented by the first author at the “Foundational Issues in Examining Subgroup Effects in Experiments” Interagency Federal Methodological Meeting: Subgroup Analysis in Prevention and Intervention Research, Washington, DC.


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Copyright information

© Society for Prevention Research 2011

Authors and Affiliations

  • C. Hendricks Brown
    • 1
    Email author
  • Zili Sloboda
    • 2
  • Fabrizio Faggiano
    • 3
  • Brent Teasdale
    • 4
  • Ferdinand Keller
    • 5
  • Gregor Burkhart
    • 6
  • Federica Vigna-Taglianti
    • 7
  • George Howe
    • 8
  • Katherine Masyn
    • 9
  • Wei Wang
    • 10
  • Bengt Muthén
    • 11
  • Peggy Stephens
    • 12
  • Scott Grey
    • 13
  • Tatiana Perrino
    • 1
  • Prevention Science and Methodology Group
  1. 1.University of MiamiMiller School of MedicineMiamiUSA
  2. 2.JBS InternationalRockvilleUSA
  3. 3.Avogadro UniversityNovaraItaly
  4. 4.Georgia State UniversityAtlantaUSA
  5. 5.University of UlmUlmGermany
  6. 6.European Monitoring Centre for Drugs and Drug AddictionLisbonPortugal
  7. 7.Piedmont Centre for Drug Addiction EpidemiologyGrugliascoItaly
  8. 8.George Washington UniversityWashingtonUSA
  9. 9.Harvard UniversityCambridgeUSA
  10. 10.University of South FloridaTampaUSA
  11. 11.UCLALos AngelesUSA
  12. 12.Akron UniversityAkronUSA
  13. 13.Kent State UniversityKentUSA

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