Cancer Causes & Control

, Volume 22, Issue 9, pp 1233–1241 | Cite as

Alternative approaches to assessing intervention effectiveness in randomized trials: application in a colorectal cancer screening study

  • Annette E. Maxwell
  • Catherine M. Crespi
  • Leda L. Danao
  • Cynthia Antonio
  • Gabriel M. Garcia
  • Roshan Bastani
Original Paper



Previous analysis of a randomized community-based trial of a multi-component intervention to increase colorectal cancer (CRC) screening among Filipino Americans (n = 548) found significantly higher screening rates in the two intervention groups compared to the control group, when using intent-to-treat analysis and self-reported screening as the outcome. This report describes more nuanced findings obtained from alternative approaches to assessing intervention effectiveness to inform future intervention implementation.


The effect of the intervention on CRC screening receipt during follow-up was estimated using methods that adjusted for biases due to missing data and self-report and for different combinations of intervention components. Adjustment for self-report used data from a validation substudy. Effectiveness within demographic subgroups was also examined.


Analyses accounting for self-report bias and missing data supported the effectiveness of the intervention. The intervention was also broadly effective across the demographic characteristics of the sample. Estimates of the intervention effect were highest among participants whose providers received a letter as part of the intervention.


The findings increase confidence that the intervention could be broadly effective at increasing CRC screening in this population. Subgroup analyses and attempts to deconstruct multi-component interventions can provide important information for future intervention development, implementation, and dissemination.


Colorectal cancer Cancer screening Immigrants Validation of self-report Subgroup analysis 



We would like to thank the members of the Filipino American community who participated in this study. This work was supported by Grant RSGT-04-210-01-CPPB from the American Cancer Society. CMC was supported by NIH/NCI grant P30 CA 16042.

Conflict of interest

The authors declare that there are no conflicts of interest.


  1. 1.
    Maxwell AE, Crespi CM (2009) Trends in colorectal cancer screening utilization among ethnic groups in California: are we closing the gap? Cancer Epidemiol Biomarkers Prev 18(3):752–759PubMedCrossRefGoogle Scholar
  2. 2.
    Maxwell AE, Danao LL, Crespi CM, Antonio C, Garcia GM, Bastani R (2008) Disparities in the receipt of fecal occult blood test versus endoscopy among Filipino American immigrants. Cancer Epidemiol Biomarkers Prev 17(8):1963–1967PubMedCrossRefGoogle Scholar
  3. 3.
    Maxwell AE, Bastani R, Danao LL, Antonio C, Garcia GM, Crespi CM (2010) Results of a community-based randomized trial to increase colorectal cancer screening among Filipino Americans. Am J Public Health 100(11):2228–2234PubMedCrossRefGoogle Scholar
  4. 4.
    Kruse RL, Alper BS, Reust C, Stevermer JJ, Shannon S, Williams RH (2002) Intention-to-treat analysis: who is in? Who is out? J Fam Pract 51(11):969–971PubMedGoogle Scholar
  5. 5.
    Gluud LL (2006) Bias in clinical intervention research. Am J Epidemiol 163(6):493–501PubMedCrossRefGoogle Scholar
  6. 6.
    Bastani R, Glenn BA, Maxwell AE, Jo AM (2007) Hepatitis B among Korean Americans: finding ways to improve testing, vaccination, and better health outcomes. Ethn Dis 17(2):416–417 SpringPubMedGoogle Scholar
  7. 7.
    Bastani R, Maxwell AE, Bradford C, Das IP, Yan KX (1999) Tailored risk notification for women with a family history of breast cancer. Prev Med 29(5):355–364PubMedCrossRefGoogle Scholar
  8. 8.
    Bastani R, Glenn BA, Taylor VM, Chen MS Jr, Nguyen TT, Stewart SL et al (2010) Integrating theory into community interventions to reduce liver cancer disparities: The health behavior framework. Prev Med 50(1–2):63–67PubMedCrossRefGoogle Scholar
  9. 9.
    Schueler KM, Chu PW, Smith-Bindman R (2008) Factors associated with mammography utilization: a systematic quantitative review of the literature. J Women’s Health (2002) 17(9):1477–1498CrossRefGoogle Scholar
  10. 10.
    Maxwell AE, Bastani R, Warda US (1997) Breast cancer screening and related attitudes among Filipino-American women. Cancer Epidemiol Biomarkers Prev 6(9):719–726PubMedGoogle Scholar
  11. 11.
    Little RJA, Rubin DB (2002) Statistical analysis with missing data, 2nd edn. Wiley, HobokenGoogle Scholar
  12. 12.
    Moye LA (2003) Multiple analyses in clinical trials. Springer, New YorkGoogle Scholar
  13. 13.
    Rosenbaum PR, Rubin DB (1983) The central role of the propensity score in observational studies for causal effects. Biometrika 70:41–55CrossRefGoogle Scholar
  14. 14.
    Harder VS, Stuart FA, Anthony JC (2010) Propensity score techniques and the assessment of measured covariate balance to test causal associations in psychological research. Psychol Methods 15:234–249PubMedCrossRefGoogle Scholar
  15. 15.
    Bastani R, Glenn BA, Maxwell AE, Ganz PA, Mojica CM, Chang LC (2008) Validation of self-reported colorectal cancer (CRC) screening in a study of ethnically diverse first-degree relatives of CRC cases. Cancer Epidemiol Biomarkers Prev 17(4):791–798PubMedCrossRefGoogle Scholar
  16. 16.
    Marcus AC, Mason M, Wolfe P, Rimer BK, Lipkus I, Strecher V et al (2005) The efficacy of tailored print materials in promoting colorectal cancer screening: results from a randomized trial involving callers to the National Cancer Institute’s Cancer Information Service. J Health commun 10(Suppl 1):83–104PubMedCrossRefGoogle Scholar
  17. 17.
    Walsh JM, Kaplan CP, Nguyen B, Gildengorin G, McPhee SJ, Perez-Stable EJ (2004) Barriers to colorectal cancer screening in Latino and Vietnamese Americans. Compared with non-Latino white Americans. J Gen Intern Med 19(2):156–166PubMedCrossRefGoogle Scholar
  18. 18.
    Ioannou GN, Chapko MK, Dominitz JA (2003) Predictors of colorectal cancer screening participation in the United States. Am J Gastroenterol 98(9):2082–2091PubMedCrossRefGoogle Scholar
  19. 19.
    Zapka JG, Puleo E, Vickers-Lahti M, Luckmann R (2002) Healthcare system factors and colorectal cancer screening. Am J Prev Med 23(1):28–35PubMedCrossRefGoogle Scholar
  20. 20.
    Vernon SW, Tiro JA, Vojvodic RW, Coan S, Diamond PM, Greisinger A et al (2008) Reliability and validity of a questionnaire to measure colorectal cancer screening behaviors: does mode of survey administration matter? Cancer Epidemiol Biomarkers Prev 17(4):758–767PubMedCrossRefGoogle Scholar
  21. 21.
    Rauscher GH, Johnson TP, Cho YI, Walk JA (2008) Accuracy of self-reported cancer-screening histories: a meta-analysis. Cancer Epidemiol Biomarkers Prev 17(4):748–757PubMedCrossRefGoogle Scholar
  22. 22.
    Taylor VM, Hislop TG, Tu SP, Teh C, Acorda E, Yip MP et al (2009) Evaluation of a hepatitis B lay health worker intervention for Chinese Americans and Canadians. J Community Health 34(3):165–172PubMedCrossRefGoogle Scholar
  23. 23.
    Taylor VM, Hislop TG, Jackson JC, Tu SP, Yasui Y, Schwartz SM et al (2002) A randomized controlled trial of interventions to promote cervical cancer screening among Chinese women in North America. J Natl Cancer Inst 94(9):670–677PubMedGoogle Scholar
  24. 24.
    Lipkus IM, Skinner CS, Dement J, Pompeii L, Moser B, Samsa GP et al (2005) Increasing colorectal cancer screening among individuals in the carpentry trade: test of risk communication interventions. Prev Med 40(5):489–501PubMedCrossRefGoogle Scholar
  25. 25.
    Maxwell AE, Jo AM, Crespi CM, Sudan M, Bastani R (2010) Peer navigation improves diagnostic follow-up after breast cancer screening among Korean American women: results of a randomized trial. Cancer Causes Control 21(11):1931–1940PubMedCrossRefGoogle Scholar
  26. 26.
    Jo AM, Maxwell AE, Wong WK, Bastani R (2008) Colorectal cancer screening among underserved Korean Americans in Los Angeles County. J Immigr Minor Health 10(2):119–126PubMedCrossRefGoogle Scholar
  27. 27.
    Seeff LC, Nadel MR, Klabunde CN, Thompson T, Shapiro JA, Vernon SW et al (2004) Patterns and predictors of colorectal cancer test use in the adult US population. Cancer 100(10):2093–2103PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Annette E. Maxwell
    • 1
  • Catherine M. Crespi
    • 1
  • Leda L. Danao
    • 1
  • Cynthia Antonio
    • 1
  • Gabriel M. Garcia
    • 2
  • Roshan Bastani
    • 1
  1. 1.School of Public Health and Jonsson Comprehensive Cancer CenterUniversity of California, Los AngelesLos AngelesUSA
  2. 2.College of Health and Social Welfare, Department of Health SciencesUniversity of Alaska AnchorageAnchorageUSA

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