EFFECT OF FECAL OCCULT BLOOD TESTING ON COLORECTAL MORTALITY - RESULTS OF A POPULATION-BASED CASE-CONTROL STUDY IN THE DISTRICT OF FLORENCE, ITALY

The aim of our case-control study was to estimate the effect on mortal ity from colorectal cancer (CRC) of a population-based screening with a faecal occult blood test started in 1982 in a rural area of the dist rict of Florence, We examined the relationship between mortality and t he interval since the most recent screening. The cases in the study we re 206 individuals who had died from CRC after the age of 41 years. Fi ve controls were selected randomly from the list of individuals alive at the time of diagnosis of the corresponding case and were matched by sex, age and place and length of residence. After adjustment for pote ntially confounding factors, the odds ratio (OR) for death from CRC fo r screened persons vs. those not screened was 0.60 [95% confidence int erval (CI), 0.4-0.9]. The OR was lowest in the first 3 years after the most recent test (OR = 0.54; 95% CI, 0.3-0.9) and increased towards u nity subsequently. Our results suggest that screening for CRC by bienn ial faecal occult blood testing can reduce mortality from the disease. (C) 1997 Wiley-Liss, Inc.