A population-based estimate of the extent of colorectal cancer screening in Ontario.
OBJECTIVE
The incidence and mortality rates for colorectal cancer (CRC) in Canada are among the highest in the world. For individuals >/=50 yr, CRC screening is effective in reducing both CRC incidence and mortality. The goal of this research was to conduct a Canadian population-based study of the use of tests and procedures to evaluate the large bowel to estimate the extent of CRC screening.


METHODS
We identified an inception cohort of all residents of Ontario aged 50-59 on January 1, 1995, without a previous history of CRC or large-bowel evaluation by five tests or procedures: fecal occult blood test (FOBT), barium enema, rigid sigmoidoscopy, flexible sigmoidoscopy, and colonoscopy. We followed these individuals to December 31, 2000, identified all tests received, and determined the proportion that received one or more tests or procedures of each type. Data were obtained from three sources: the Ontario Health Insurance Plan (OHIP) database, the Canadian Institute for Health Information-Discharge Abstract Database (CIHI-DAD), and the Registered Persons Database (RPDB).


RESULTS
We identified 982,443 individuals in our inception cohort without prior CRC or large bowel evaluation. The proportion that had at least one test or procedure was less than 10% for each type. The largest proportion (9.3%) had one or more FOBTs. Classified according to the initial test received, 14.5% had a non-endoscopic test (FOBT, barium enema) and 6% had an endoscopic test (rigid sigmoidoscopy, flexible sigmoidoscopy, colonoscopy). The majority (79.5%) had no test or procedure to evaluate the large bowel.


CONCLUSIONS
An extraordinarily low proportion (<20.5%) of screen-eligible 50-59-yr-old men and women in Ontario were screened for CRC during a 6-yr follow-up. Given the high burden of CRC in Canada a major opportunity exists to improve the health of Canadians by increasing our screening efforts.
Rabeneck
Linda
L
Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
Paszat
Lawrence F
LF
D017677:Age Distribution; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D016001:Confidence Intervals; D019723:Endoscopes; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009780:Occult Blood; D009864:Ontario / Q000453:epidemiology; D011159:Population Surveillance; D011237:Predictive Value of Tests; D011336:Probability; D018570:Risk Assessment; D017678:Sex Distribution; D012812:Sigmoidoscopy; D016019:Survival Analysis