Long-term results from a randomized controlled trial to increase cancer screening among attendees of community health centers

Ann Fam Med. 2005 Mar-Apr;3(2):109-14. doi: 10.1370/afm.240.


Purpose: We assessed whether increased cancer screening rates that were observed with Cancer Screening Office Systems (Cancer SOS) could be maintained at 24 months' follow-up, a period in which clinics were expected to be largely self-sufficient in maintaining the intervention.

Methods: Eight primary care clinics serving disadvantaged populations in Hills-borough County, Fla, agreed to take part in a cluster-randomized experimental trial. Charts of independent samples of established patients aged 50 to 75 years were abstracted, with data collected at baseline (n = 1,196) and at 24 months' follow-up (n = 1,296). Papanicolaou (Pap) smears, mammography, and fecal occult blood testing were assessed.

Results: At 24 months of follow-up, intervention patients had received a greater number of cancer screening tests (mean 1.17 tests vs 0.94 tests, t test = 4.42, P <.0001). In multivariate analysis that controlled for baseline screening rates, secular trends, and other patient and clinic characteristics, the intervention increased the odds of mammograms slightly (odds ratio [OR]) = 1.26; 95% confidence interval [CI], 1.02-1.55; P = .03) but had no effect on fecal occult blood tests (OR = 1.17; 95% CI, 0.92-1.48; P =0.19) or Pap smears (OR = 0.88; 95% CI, 0.0.68-1.15; P = .34).

Conclusions: The Cancer SOS intervention had persistent, although modest, effects on screening at 24 months' follow-up, an effect that had clearly diminished from results reported at 12 months' follow-up. Further study is needed to develop successful intervention strategies that are either self-sustaining or that are able to produce long-term changes in screening behavior.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Community Health Centers
  • Female
  • Follow-Up Studies
  • Humans
  • Mass Screening / statistics & numerical data
  • Middle Aged
  • Neoplasms / diagnosis*
  • Randomized Controlled Trials as Topic
  • Time Factors