Smoking habits in patients with ulcerative colitis: evaluation of retrospective questionnaires

: We evaluated retrospective smoking data reported by 221 patients with ulcerative colitis in 1984 and repeated in an identical questionnaire in 1989. Reported years of smoking initiation or smoking cessation agreed to a high extent; the difference between the two questionnaires was in mean (± SD) -0.1 ± 1.5 (median, 0) years, and 96% of the differences were <±2 SD. Data on smoking habits and amount of cigarette consumption at the time of diagnosis were also consistent in the two questionnaires. In 197 cases (89.1%), the two questionnaires agreed completely, and in only five cases (2.3%), smoking reports disagreed. In nine cases (4.1%), reported smoking habits agreed, but reported number of cigarettes differed. In 10 cases (4.5%), the amount of consumption was incompletely reported in one of the two questionnaires, whereas reported smoking habits agreed.