Reliability of information on cigarette smoking and beverage consumption provided by hospital controls.

We compared data from interviews of patients admitted to hospital and interviews repeated at home for 400 hospital controls. Of these, 294 (73.5%) could be re-interviewed (responders). Never smoking was reported by 44% of subjects in the in-hospital interviews and by 40% in the repeat at-home interviews. Among those interviewed in hospital, 38% claimed to be nondrinkers, as did 38% of responders, but only 28% characterized themselves as nondrinkers in the repeat interview. For consumption of regular coffee, 15% reported none in the selected sample, 14% among responders, but only 6% in the repeat at-home interview. Agreement was good for decaffeinated coffee and tea consumption.