The reliability of smoking history amongst survivors of myocardial infarction.

Summary and Conclusions One hundred and seventeen survivors of a first attack of acute coronary heart disease had blood carboxy-haemoglobin levels checked and smoking histories recorded. All were participants in a longterm follow-up and secondary prevention programme. At last follow-up, four to eighteen years after the initial attack, 35 stated that they were still smoking, 57 claimed to be ex-smokers, 6 were non-smokers and 19 were pipe or cigar smokers. Thirty-one of the 35 current smokers had a COHb concentration which exceeded 1.6 %. Five of the ex-smokers had concentrations between 1.6 and 2.3%. There was a low and possibly zero deception rate amongst the ex-smokers. This may reflect a high degree of rapport achieved between patients and medical staff during an exceptionally long and regular follow-up period.