Tobacco smoking in Tanzania, East Africa: population based smoking prevalence using expired alveolar carbon monoxide as a validation tool.

OBJECTIVES To describe the prevalence of tobacco smoking in an urban East African population while using a simple validation procedure to examine the degree of under reporting in men and women. DESIGN A cross sectional population based study in adults (15 years and over) with sampling from a well maintained census register. SETTING Ilala Ilala, a middle income district of Dar es Salaam, Tanzania. SUBJECTS An age and sex stratified random sample of 973 men and women. MAIN OUTCOME MEASURES Self reported smoking status with correction by exhaled alveolar carbon monoxide (EACO). RESULTS From the 605 participants (response rate 67.9%) age standardised (new world population) smoking prevalence, based on questionnaire and EACO, was 27.0% (95% confidence interval (CI) 20.8% to 33.2%) in males and 5.0% (95% CI 2.8% to 7.2%) in females. The age specific prevalence of smoking was highest in the age group 35-54 years (34.3%) for men and in the over 54 years group (16%) for women. Of those classified as smokers, 7.3% of men and 27.3% of women were reclassified as current smokers based on EACO (> or = 9 parts per million), after they had reported themselves to be an ex- or non-smoker in the questionnaire. CONCLUSIONS The data suggest: (1) high rates of smoking among men in an urban area of East Africa; and (2) the importance of validating self reports of smoking status, particularly among women.