Worldwide, tobacco-use continues to be one of the leading causes of preventable death and has been estimated to kill more than five million people annually (1). In recent times, the epidemic of tobacco-use has shifted from developed to developing countries (2). According to estimates, 10 million people will die from tobacco-use per year by 2030, with 70% of these deaths occurring in developing countries (1). India, a major developing country, accounts for one-sixth of the tobacco-related illnesses worldwide and is estimated to face an exponential increase in tobacco-related mortality from 1.4% of all deaths in 1990 to 13.3% in 2020 (3). To reduce the burden of morbidity and mortality due to tobacco-use in population, it is essential that effective policies for tobacco control be implemented.
To formulate an effective strategy for tobacco control, it is very essential to know how the habit of tobacco-use gets initiated so that this can be prevented at the initial stages. One of the essential questions is whether one learns tobacco consumption at home or outside home. We hypothesize that tobacco consumption is primarily learnt at home. Therefore, for tobacco control to be efficient, the home environment should be the primary target. No earlier study has focussed on this issue in this geographical area. With this background, we studied the pattern of tobacco-use in families of tobacco-users and non-users and their potential influence on the habit of tobacco consumption in siblings and their children.
MATERIALS AND METHODS
This prospective cohort study was performed in a tertiary-care hospital in Delhi. The study was initiated in November 2010 and included new patients who were registered in a tobacco-cessation clinic run for coronary artery disease patients with history of smoking. Fifty consecutive patients over the next three months were enrolled. The approval for the study was obtained from the Ethics Committee of the hospital. The patients with coronary artery disease, with history of tobacco-use (smoking and/or tobacco-chewing), were enrolled in Group I. Prevalence of the use of tobacco among the parents, siblings, and children were found out by creating pedigree profile of such patients. Another 50 age- and gender-matched controls who did not use tobacco in any form were enrolled in Group II. These included healthy relatives of patients visiting outpatients department and the hospital staff. They were similarly evaluated for history of the use of tobacco in family by creating pedigree profiles for these patients since pedigree profiles provide detailed information about smoking, psychosocial factors (conflicts in family/stress), family history of premature cardiovascular disease, hypertension, and diabetes. Pedigree assessment gives us an opportunity for early lifestyle intervention in young asymptomatic siblings (4). Prevalence of the use of tobacco among both groups was compared and analyzed using SPSS (version 17.1) and any statistically-significant difference noted. For the purpose of the study, p values <0.05 were considered statistically significant.
There were 50 patients with CAD in Group I and 50 age- and gender-matched healthy controls in Group II. Both cases and controls had an average age of 44.2 [+ or -] 16.3 years. There were 12 females (24%) and 38 males (76%) among the cases and 12 females (24%) and 38 males (76%) among the controls.
In Group I, both mother and father were using tobacco in the case of 12 tobacco-users with CAD. Among tobacco-users, 42 patients (84%) had history of tobacco-use by fathers and 14 patients (28%) had history of tobacco-use by mothers compared to only 1 subject (2%) with history of tobacco-use by fathers and none (0%) by mothers of the nonusers (Table). The use of tobacco among parents in Group I was higher than in Group II, and it was statistically significant with p<0.001.
The siblings of 35 patients (70%) in Group I used tobacco in multiple forms compared to 0% in Group II controls. …