The impact of a psychosocial support program on survival with breast cancer: The importance of selection bias in program evaluation Journal Articles uri icon

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  • A retrospective follow-up study was conducted to assess the impact of a psychosocial support program on survival with breast cancer. One-hundred and two nonparticipants were individually matched to 34 participants on several prognostic factors, and both groups were followed from date of cancer diagnosis (1971-1980) until December, 1981. Preliminary findings suggest a strong beneficial effect of the program on survival, which is statistically significant. However, this observed effect is due largely to a selection bias caused by the failure to match on the duration of the lag period between cancer diagnosis and program entry. Correcting for this bias in the analysis results in a small, nonsignificant program effect. We are not able to rule out a possible effect, however, because of the relative lack of statistical power and because of a modest, though nonsignificant benefit observed for women who entered the program shortly after diagnosis. Furthermore, the program might have other beneficial effects on the quality of life.


  • Morgenstern, Hal
  • Gellert, George A
  • Walter, Stephen
  • Ostfeld, Adrian M
  • Siegel, Bernard S

publication date

  • January 1984