Original Article Tobacco Smoking in India: Prevalence, Quit-rates and Respiratory Morbidity S.K. Jindal 1, A.N. Aggarwal 1, K. Chaudhry 2, S.K. Chhabra 3, G.A. D Souza 4, D. Gupta 1, S.K. Katiyar 5, R. Kumar 1, B. Shah 2, V.K. Vijayan 3 for Asthma Epidemiology Study Group Postgraduate Institute of Medical Education and Research 1, Chandigarh; Indian Council of Medical Research 2, New Delhi; Vallabhbhai Patel Chest Institute 3, Delhi; St. John s Medical College Hospital 4 Bangalore; G.S.V.M. Medical College 5, Kanpur, India ABSTRACT Background. Population prevalence of tobacco smoking especially with reference to detailed habits such as the amount smoked, the smoking forms, quit-rates and relationship with demographic variables were studied at four different centres in India along with the study on epidemiology of asthma and chronic obstructive pulmonary disease. Methods. The study population included adults of over 15 years of age selected with two-stage stratified random sample design. A specifically designed questionnaire was used for the study. Results. There were 11496 (15.6%) ever smokers in the study sample of 73605 subjects. Among 37682 males, 10756 (28.5%) were ever smokers and among 35923 females, 740 (2.1%) were ever smokers. Bidi was the commonest form of smoking, more so in the rural areas. The mean number of cigarettes/bidis smoked per day was 14 (± 11.5) and the mean age of starting smoking was 20.5 (± 20.0) years. Increasing age, low socio-economic status and rural residence were important factors associated with smoking. Vigorous anti-tobacco measures under the tobacco control programmes yielded only a quit-rate of 10 percent. Nearly 14% of ever smokers had some respiratory symptoms. Conclusions. A substantial proportion of population in India has current or past smoking habit with higher prevalence among males than females. The quit-rates have been low in spite of the various anti-tobacco measures. There is a significant respiratory morbidity associated with smoking. [Indian J Chest Dis Allied Sci 2006; 48: 37-42] Key words: Smoking, Cigarettes, Bidis, Hookah, Respiratory morbidity, Population prevalence. INTRODUCTION Tobacco use including both the smoking and the nonsmoking forms of tobacco is common in India. The few reports of tobacco use in different population groups report its prevalence from about 15% to over 50% among men 1-7. Differences in its prevalence are rather wide for the nonsmoking forms. Tobacco smoking in most parts of India except Punjab, Maharashtra and Sikkim is reported in about one fourth to half of adult men of over 15 years of age 8. Amongst women, smoking was more common in the North Eastern states, Jammu & Kashmir and Bihar, while most other parts of India had prevalence rates of about 4 percent or less 8. In other reports, ever smoking among the school going youth of 13-15 years age, studied as a part of the Global Youth Tobacco Survey (GYTS) study was reported on an average in upto about 10 percent individuals 9-12. All these reports clearly indicate a higher prevalence of tobacco smoking in adult men. Detailed information on the type of smoking forms, amount smoked, quitrates and relationship with different demographic variables is relatively small. A multicentric study was undertaken to investigate the epidemiology of chronic airway obstruction such as chronic obstructive pulmonary disease (COPD) and bronchial asthma in the adult population 13. The present report provides information on the population prevalence of smoking habits at four different centres studied with the help of question items included in the questionnaire for the above mentioned study. MATERIAL AND METHODS The study reported here formed an essential component of the comprehensive report on epidemiology of asthma and COPD 13. Information on smoking habits, demographic and exposure variables was collected with the help of a single, pre-validated respiratory symptom questionnaire at Bangalore, Chandigarh, Delhi and Kanpur employing a two-stage stratified sampling [Received: September 29, 2005; accepted: October 28, 2005] Correspondence and reprint requests: Dr S.K. Jindal, Professor and Head, Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh-160012, India; Tele.: 91-0172-2756821; Telefax: 91-0172-2745959; E-mail: skjindal@indiachest.org.
38 Smoking in India S.K. Jindal et al design. Both rural and urban samples were studied with a village or an urban locality as the first stage unit and a household as the second stage unit. A specifically written computer programme using the software Epi info (V.6) which operated in DOS mode, was used for analysis. RESULTS The study population of 73605 in total consisted of 37682 male and 35923 female subjects of over 15 years of age. The distribution of subjects from each centre for both the urban and the rural populations showed a little higher preponderance of males except from Bangalore where there was a larger number of female subjects of urban residence (Table 1). Ever smoking habit was present in 28.5% of men and 2.1% of women (Table 2). In spite of some differences between the urban and the rural populations, the overall prevalences were similar at all the four centres; the lowest was reported form Kanpur (22%) and the highest from Bangalore (33.6%) amongst men (Table 2). Smoking was seen in 3.1% and 4.2% of women at Chandigarh and Delhi respectively, while only 1% at Kanpur and very few (only two ) at Bangalore had reported the smoking history (Table 2). Tobacco smoking was further analysed for the type of smoking product and the amount of smoking. Considering together the data from all the four centres, cigarettes were smoked by 47.5% of urban and 12.5% in rural smokers while bidis were smoked by 51.7% and 81.2% of urban and rural smokers respectively (Table 3). The rest of the smokers smoked hookah alone or along with other smoking products. The average number of cigarettes/bidis smoked daily were similar in the rural and urban smokers i.e. 15.0 and 12.4 respectively (Table 3). Hookah smoking could not be quantified on the basis of numbers/day in the absence of a standard unit for a hookah smoke. Interestingly, the mean age of starting smoking was similar in both rural and urban subjects, i.e. 20.2 and 21.0 years respectively (Table 3). Differences in the smoking prevalence on the basis of different variables were assessed by calculation of crude and adjusted odds ratio (OR) for different smoking products (Table 4). Both the crude and the adjusted ORs for smoking any product were the highest for the male sex. Other important variables important for smoking were an increasing age, rural (or mixed) residence and lower socio-economic status (Table 4). The data on subjects who had quit smoking in the past were analysed separately. Of 11496 ever smokers, about 10 percent had quit in the past; 928(8.1%) for more than 1 year and 153(1.3%) for less than 1 year (Table 5). The important variables favouring abstinence from smoking for more than a year were the increase in age and a higher socio-economic status, male sex, and presence of respiratory symptoms (Table 6). The ORs were higher for Bangalore and Chandigarh versus Delhi or Kanpur. Table 1. Centre-wise distribution of study population categorised according to the gender and current residence Urban Rural Total Total Male Female Male Female Male Female Bangalore 4527 4800 4111 4003 8638 8803 17441 Chandigarh 5717 5638 5333 4976 11050 10614 21664 Delhi 4033 3927 3933 3749 7966 7676 15642 Kanpur 6107 5552 3921 3278 10028 8830 18858 Total 20384 19917 17298 16006 37682 35923 73605 Table 2. Distribution of prevalence of smoking habit (current or former) in men and women respectively at the four centres Men Women Total Chandigarh Rural 2159 (40.5%) 275 (5.5%) 2434 (23.6%) Urban 1144 (20.0%) 54 (1.0%) 1198 (10.6%) Total 3303 (29.9%) 329 (3.1%) 3632 (16.8%) Delhi Rural 1629 (41.4%) 280 (7.5%) 1909 (24.9%) Urban 720 (17.9%) 42 (1.1%) 762 (9.6%) Total 2349 (29.5%) 322 (4.2%) 2671 (17.1%) Kanpur Rural 1032 (26.3%) 52 (1.6%) 1084 (15.1%) Urban 1170 (19.2%) 36 (.6%) 1206 (10.3%) Total 2202 (22.0%) 88 (1.0%) 2290 (12.1%) Bangalore Rural 1427 (34.7%) 0 (.0%) 1427 (17.6%) Urban 1475 (32.6%) 1 (.0%) 1476 (15.8%) Total 2902 (33.6%) 1 (.0%) 2903 (16.6%) Total Rural 6247 (36.1%) 607 (3.8%) 6854 (20.6%) Urban 4509 (22.1%) 133 (0.7%) 4642 (11.5%) Total 10756 (28.5%) 740 (2.1%) 11496 (15.6%)
2006; Vol. 48 The Indian Journal of Chest Diseases & Allied Sciences 39 Table 3. Distribution of smokers with the type of product used, number of cigarettes/bidis smoked per day and the age of starting smoking (at the 4 centres combined) Rural Urban Total Type of smoking product Cigarettes 857 (12.5%) 2204 (47.5%) 3061 (26.6%) Bidis 5568 (81.2%) 2402 (51.7%) 7970 (69.3%) Hookah and others 429 (6.3%) 36 (0.8%) 465 (4.0%) No. smoked per day Mean 15.0 12.4 14.0 S.D 12.0 10.7 11.5 Median 12.0 10.0 12.0 Age of starting smoking (year) Mean 20.2 21.0 20.5 S.D. 8.4 7.3 20.0 Median 20.0 20.0 20.0 Table 4. Crude and adjusted odds ratio (with 95% confidence intervals) of smoking in relation to various factors Cigarette Smoking Bidi Smoking Any Tobacco Smoking Crude odds ratio Adjusted odds ratio Crude odds ratio Adjusted odds ratio Crude odds ratio Adjusted odds ratio Centre Chandigarh* 1.000 1.000 1.000 1.000 1.000 1.000 Delhi 0.735 (0.658-0.822) 0.675 (0.600-0.761) 1.047 (0.983-1.116) 0.781 (0.722-0.844) 1.022 (0.968-1.080) 0.817 (0.764-0.874) Kanpur 0.634 (0.569-0.706) 0.593 (0.523-0.673) 0.747 (0.700-0.797) 0.384 (0.351-0.420) 0.686 (0.649-0.726) 0.446 (0.413-0.481) Bangalore 1.455 (1.329-1.592) 1.876 (1.695-2.076) 0.889 (0.834-0.948) 0.724 (0.668-0.784) 0.991 (0.940-1.046) 0.946 (0.885-1.011) Usual residence Urban* 1.000 1.000 1.000 1.000 1.000 1.000 Rural 0.601 (0.556-0.650) 0.632 (0.580-0.688) 2.979 (2.831-3.135) 3.592 (3.383-3.814) 1.999 (1.918-2.083) 2.243 (2.135-2.356) Mixed 1.510 (1.239-1.839) 1.029 (0.821-1.289) 1.213 (0.990-1.485) 1.517 (1.201-1.916) 1.342 (1.159-1.554) 1.445 (1.212-1.722) Gender Female* 1.000 1.000 1.000 1.000 1.000 1.000 Male 70.116 (53.803-91.375) 83.269 (63.846-108.601) 18.954 (17.309-20.755) 27.499 (25.007-30.238) 18.992 (17.600-20.495) 25.882 (23.909-28.017) Age 15-24 years* 1.000 1.000 1.000 1.000 1.000 1.000 25-34 years 4.134 (3.543-4.823) 4.570 (3.906-5.346) 6.286 (5.561-7.105) 7.147 (6.297-8.112) 5.431 (4.932-5.981) 6.068 (5.491-6.707) 35-44 years 6.133 (5.259-7.153) 7.685 (6.565-8.996) 11.087 (9.824-12.512) 15.553 (13.704-17.652) 9.189 (8.351-10.112) 12.154 (10.993-13.438) 45-54 years 8.559 (7.330-9.994) 11.041 (9.407-12.960) 15.348 (13.585-17.339) 25.974 (22.816-29.569) 12.817 (11.635-14.120) 19.292 (17.400-21.390) 55-64 years 8.183 (6.908-9.693) 12.142 (10.171-14.494) 16.762 (14.747-19.053) 31.316 (27.255-35.981) 14.073 (12.700-15.594) 23.928 (21.390-26.767) 65-74 years 8.530 (7.062-10.304) 12.958 (10.618-15.813) 19.374 (16.903-22.207) 33.641 (28.926-39.124) 16.841 (15.081-18.805) 26.747 (23.647-30.255) >=75 years 6.675 (5.108-8.722) 8.717 (6.586-11.536) 16.639 (14.013-19.757) 23.306 (19.186-28.331) 16.858 (14.690-19.346) 21.981 (18.775-25.736) Socio-economic Status High* 1.000 1.000 1.000 1.000 1.000 1.000 Medium 0.856 (07.758-0.967) 1.281 (1.123-1.463) 3.392 (2.894-3.977) 3.827 (3.234-4.529) 1.709 (1.555-1.879) 2.101 (1.889-2.336) Low 0.515 (0.450-0.590) 1.151 (0.986-1.344) 5.125 (4.369-6.011) 11.138 (9.365-13.247) 2.002 (1.817-2.205) 4.161 (3.717-4.658) *Reference category.
40 Smoking in India S.K. Jindal et al Table 5. Current smoking habit among ever smokers and those who had quit smoking Men Women Total Current Quit Smoking Current Quit Smoking Current Quit Smoking <1 year >1 year <1 year >1 year < 1 year >1 year Chandigarh Rural 1990 (92.2%) 27 (1.3%) 142 (6.6%) 247 (89.8%) 3 (1.1%) 25 (9.1%) 2237 (91.9%) 30 (1.2%) 167 (6.9%) Urban 965 (84.4%) 21 (1.8%) 158 (13.8%) 46 (85.2%) 2 (3.7%) 6 (11.1%) 1011 (84.4%) 23 (1.9%) 164 (13.7%) Total 2955 (89.5%) 48 (1.5%) 300 (9.1%) 293 (89.1%) 5 (1.5%) 31 (9.4%) 3248 (89.4%) 53 (1.5%) 331 (9.1%) Delhi Rural 1528 (93.8%) 23 (1.4%) 78 (4.8%) 262 (93.6%) 2 (.7%) 16 (5.7%) 1790 (93.8%) 25 (1.3%) 94 (4.9%) Urban 668 (92.8%) 9 (1.3%) 43 (6.0%) 39 (92.9%) 1 (2.4%) 2 (4.8%) 707 (92.8%) 10 (1.3%) 45 (5.9%) Total 2196 (93.5%) 32 (1.4%) 121 (5.2%) 301 (93.5%) 3 (.9%) 18 (5.6%) 2497 (93.5%) 35 (1.3%) 139 (5.2%) Kanpur Rural 976 (94.6%) 10 (1.0%) 46 (4.5%) 49 (94.2%) 0 (.0%) 3 (5.8%) 1025 (94.6%) 10 (.9%) 49 (4.5%) Urban 1053 (90.0%) 23 (2.0%) 94 (8.0%) 32 (88.9%) 2 (5.6%) 2 (5.6%) 1085 (90.0%) 25 (2.1%) 96 (8.0%) Total 2029 (92.1%) 33 (1.5%) 140 (6.4%) 81 (92.0%) 2 (2.3%) 5 (5.7%) 2110 (92.1%) 35 (1.5%) 145 (6.3%) Bangalore Rural 1260 (88.3%) 10 (.7%) 157 (11.0%) 0 (.0%) 0 (.0%) 0 (.0%) 1260 (88.3%) 10 (.7%) 157 (11.0%) Urban 1299 (88.1%) 20 (1.4%) 156 (10.6%) 1 (100.0%) 0 (.0%) 0 (.0%) 1300 (88.1%) 20 (1.4%) 156 (10.6%) Total 2559 (88.2%) 30 (1.0%) 313 (10.8%) 1 (100.0%) 0 (.0%) 0 (.0%) 2560 (88.2%) 30 (1.0%) 313 (10.8%) Total Rural 5754 (92.1%) 70 (1.1%) 423 (6.8%) 558 (91.9%) 5 (.8%) 44 (7.2%) 6312 (92.1%) 75 (1.1%) 467 (6.8%) Urban 3985 (88.4%) 73 (1.6%) 451 (10.0%) 118 (88.7%) 5 (3.8%) 10 (7.5%) 4103 (88.4%) 78 (1.7%) 461 (9.9%) Total 9739 (90.5%) 143 (1.3%) 874 (8.1%) 676 (91.4%) 10 (1.4%) 54 (7.3%) 10415 (90.6%) 153 (1.3%) 928 (8.1%) Table 6. Crude and adjusted odds ratio (with 95% confidence intervals) of having quit smoking for more than a year, in relation to various factors Crude Odds Ratio Adjusted Odds Ratio Centre Chandigarh* 1.000 1.000 Delhi 0.547 (0.446-0.672) 0.476 (0.384-0.590) Kanpur 0.674 (0.551-0.826) 0.718 (0.565-0.914) Bangalore 1.205 (1.024-1.418) 1.085 (0.905-1.302) Usual residence Urban* 1.000 Rural 0.705 (0.615-0.809) 0.559 (0.480-0.652) Mixed 1.743 (1.192-2.547) 1.328 (0.876-2.013) Gender Female* 1.000 Male 1.124 (0.844-1.495) 1.359 (1.004-1.840) Age 15-24 years* 1.000 25-34 years 1.132 (0.618-2.072) 1.175 (0.639-2.159) 35-44 years 1.960 (1.099-3.495) 2.014 (1.125-3.607) 45-54 years 3.433 (1.944-6.061) 3.399 (1.916-6.029) 55-64 years 5.528 (3.128-9.770) 5.710 (3.211-10.156) 65-74 years 9.154 (5.178-16.183) 9.030 (5.065-16.098) >=75 years 10.201 (5.636-18.465) 10.435 (5.702-19.096) Socio-economic status High * 1.000 Medium 0.491 (0.385-0.627) 0.322 (0.240-0.430) Low 0.270 (0.207-0.352) 0.548 (0.420-0.715) Any respiratory symptom No* 1.000 1.000 Yes 3.113 (2.677-3.621) 2.180 (1.850-2.568) *: Reference category. We also analysed the presence of individual respiratroy symptoms in ever smokers, nonsmokers exposed to environmental tobacco smoke and the individuals exposed to exhaust of solid fuel combustion. In ever smokers, almost all respiratory symptoms were two to three times as commonly seen as in never smokers, but the symptoms in the other two groups were similar to those amongst the never smokers (Table 7). DISCUSSION The present study conducted at four different centres in India primarily to look into the population prevalence of chronic respiratory diseases such as bronchial asthma and COPD provides useful information on tobacco smoking especially with reference to different smoking forms and relationship with demographic variables. The prevalence of smoking in 28.5% of men and 2.1% of women reported in this study is generally similar to the median prevalence of 30.6% reported in a cross sectional household survey from 26 states of India 8. There was, however a wide range of the prevalence rate from the lowest of 13.9% in Punjab to the highest of 49.4% in Mizoram 8. There are quite a few reports on the smoking habit in India published in the past decade. In particular, the habit has been studied amongst the school going youth of 13 to 15 years age as a part of the Global Youth Tobacco Survey (GYTS) sponsored by the Centre for Disease Control (CDC), USA and the World Health Organization (WHO) 9-12 under the same programme, the smoking habit was also studied amongst adults working in the schools, i.e., the Global School Personnel Survey (GSPS) 14,15. There was a large variation in current daily smoking from 14.4% in Rajasthan to over 50% in the North Eastern states 14,15. The prevalence of ever any tobacco use' was much higher. Bidi, the hand rolled form of tobacco, wrapped in the dried tendu leaf, was the most common smoking product in this study especially in the rural population. This is quite consistent with reports of the earlier
2006; Vol. 48 The Indian Journal of Chest Diseases & Allied Sciences 41 Table 7. Respiratory symptoms in relation to smoking status, and comparison with exposure to solid fuel combustion and ever exposure to household environmental tobacco smoke (ETS) Never Smoker Ever Smoker Exposed to Ever Exposed Solid Fuel to ETS* Combustion* Wheezing 1610 (2.6%) 598 (5.2%) 280 (3.1%) 781 (2.8%) Morning chest tightness/breathlessness 1431 (2.3%) 573 (5.0%) 225 (2.5%) 698 (2.5%) Dyspnea on exertion 3145 (5.1%) 1101 (9.6%) 502 (5.6%) 1441 (5.1%) Dyspnea without exertion 1159 (1.9%) 496 (4.3%) 202 (2.3%) 549 (1.9%) Breathlessness at night 1221 (2.0%) 485 (4.2%) 190 (2.1%) 590 (2.1%) Cough at night 1480 (2.4%) 869 (7.6%) 223 (2.5%) 729 (2.6%) Cough in morning 1428 (2.3%) 915 (8.0%) 241 (2.7%) 677 (2.4%) Phlegm in morning 1301 (2.1%) 851 (7.4%) 207 (2.3%) 613 (2.2%) Breathlessness-always 427 (.7%) 189 (1.6%) 62 (.7%) 171 (.6%) usually 1584 (2.6%) 625 (5.4%) 256 (2.9%) 726 (2.6%) Tightness in chest with dust exposure 2309 (3.7%) 688 (6.0%) 245 (2.7%) 983 (3.5%) Dyspnea with dust exposure 2489 (4.0%) 762 (6.6%) 279 (3.1%) 1088 (3.8%) Ever asthma 1267 (2.0%) 437 (3.8%) 182 (2.0%) 637 (2.3%) Attack of asthma 753 (1.2%) 245 (2.1%) 123 (1.4%) 401 (1.4%) Inhaler use 1159 (1.9%) 400 (3.5%) 142 (1.6%) 513 (1.8%) Any of the above 3945 (6.4%) 1602 (13.9%) 615 (6.9%) 1801 (6.4%) *: Data only for never smokers. studies 16,17. Hookah smoking, the more traditional way in which tobacco is kept in a earthen pot (chillum) along with the burning coal and smoked through a watercontainer with the help of a long pipe was present in about 6% of rural and less than 1% of urban smokers. Apparently, this traditional form of smoking is largely extinct in the cities. Even in the villages, the hookah is gradually giving place to bidi and/or cigarette smoking. On an average the number of cigarettes or bidis smoked daily was similar in both rural (15±17) and urban (12.4 ±10.7) areas. Similarly, the mean age of starting smoking was similar in both the populations. Male sex, poverty and low education are the more frequently reported factors of importance among smokers. In the National Sample Survey in 1995-96 amongst subjects of over 10 years of age, the regular use of both tobacco and alcohol increased significantly with each diminishing income quintile 18. In Mumbai, both education and occupation were found to have simultaneous and independent relationship with tobacco use 19. Similar observations are made in Western literature, people with low income were reported to more than twice as likely to smoke in the United States 20. It is quite noteworthy that about 14 percent of subjects reported the presence of one or the other respiratory symptoms. About half this number among nonsmokers exposed to environmental tobacco smoke from the smoker parents, spouses or colleagues, reported similar symptoms. Similarly, exposure to the exhausts from combustion of solid fuels was responsible for respiratory symptoms in about 7 percent of symptoms. It can be indirectly concluded that the magnitude of respiratory morbidity caused by exposure to either ETS or solid fuel combustion in nonsmokers is similar and that smokers are twice as likely to suffer from respiratory symptoms. We have reported similar findings on the subject in our earlier studies 21. Another important observations in this study was made with reference to the ex-smokers. About 10 percent smokers among both the men and women had quit smoking for about a year or more. This was more so in the urban population, those belonging to the higher socio-economic group and those who had developed respiratory symptoms (and possibly other tobacco related problems, which were not included in the study). This may also partly reflect a trend of a positive outcome of the vigorous anti-tobacco measures under the tobacco control programmes adopted in the last few years by India, a signatory to the Framework Convention on Tobacco Control. ACKNOWLEDGEMENTS The study was supported by a financial grant from the Indian Council of Medical Research, New Delhi. Authors also express their gratitude to members of the Asthma Task Force of Indian Council of Medical Research for their suggestions and help. REFERENCES 1. Reddy KS, Gupta PC, editors. Prevalence of tobacco use. Report on Tobacco Control in India. New Delhi: Ministry of Health and Family Welfare, Govt. of India 2004; pp 49-56. 2. Malaowalla AM, Silverman S, Mani NJ, Billimoria KF, Smith LW. Oral cancer in 57, 518 industrial workers of Gujarat, India: a prevalence and follow-up survey. Cancer 1976; 37: 1882-6. 3. Behera D, Malik SK. Chronic respiratory disease in Chandigarh teachers. Indian J Chest Dis Allied Sci 1987; 29: 25-8. 4. Pandey GK, Raut DK, Hazra S, Vajpayee A, Pandey A, Chatterjee P. Patterns of tobacco use amongst school teachers. Indian J Pub Health 2001; 45: 82-7.
42 Smoking in India S.K. Jindal et al 5. Sarkar D, Dhand R, Malhotra A, Malhotra S, Sharma BK, Perceptions and attitude towards tobacco smoking among doctors in Chandigarh. Indian J Chest Dis Allied Sci 1990; 32: 1-9. 6. Kumar A, Mohan U, Jain VC. Influence of some sociodemographic factors on smoking status of academicians. Indian J Chest Dis Allied Sci 1997; 39: 5-12. 7. Ghosal AG, Ghosh A, Debnath NB, Saha AK. Smoking habits and respiratory symptoms: observations among college students and professionals. J Indian Med Assoc 1996; 94: 55-7. 8. Rani M, Bonu S, Jha P, Nguyen SN, Jamjoum L. Tobacco use in India: prevalence and predictors of smoking and chewing in a national cross-sectional household survey. Tobacco Control 2003; 12: e4. 9. The Global Youth Tobacco Survey Collaborating Group. Tobacco use among youth: a cross-country comparison. Tobacco Control 2002; 11: 252-70. 10. Gupta PC, Ray C. Tobacco and youth in the South-East Asian region. Indian J Cancer 2002; 39: 5-33. 11. Sinha DN. Exposure vs targeting youth in north and east of India. Health for the Millions 2003; 29-30: 15-22. 12. Jindal SK, Aggarwal AN, Gupta D, Kashyap S, Chaudhary D. Prevalence of tobacco use among school going youth in North Indian states. Indian J Chest Dis Allied Sci 2005; 47: 161-6. 13. Aggarwal AN, Chaudhry K, Chhabra SK, D'Souza GA, Gupta D, Jindal SK, et al. Prevalence and risk factors for bronchial asthma in Indian Adults: a multicentre study. Indian J Chest Dis Allied Sci 2006; 48: 13-22. 14. Sinha DN, Gupta PC, Pednekar MS. Tobacco use among school personnel in eight North-eastern states of India. Indian J Cancer 2003; 40: 3-14. 15. Sharma R, Pednekar MS, Rehman AU, Gupta R. Tobacco use among school personnel in Rajasthan, India. Indian J Cancer 2004; 41: 162-6. 16. Chhabra SK, Rajpal S, Gupta R. Patterns of smoking in Delhi and comparison of chronic respiratory morbidity among bidi and cigarette smokers. Indian J Chest Dis Allied Sci 2001; 43: 19-26. 17. Reddy KS, Gupta PC, editors. Prevalence of tobacco use. Report on Tobacco Control in India. New Delhi: Ministry of Health and Family Welfere, Govt. of India 2004; pp 43-48. 18. Neufeld KJ, Peters DH, Rani M, Bonu S, Brooner RK. Regular use of alcohol and tobacco in India and its association with age, gender, and poverty. Drug Alcohol Depend 2005; 77: 283-91. 19. Sorensen G, Gupta PC, Pednekar MS. Social disparities in tobacco use in Mumbai, India: the roles of occupation, education and gender. Am J Pub Health 2005; 95: 1003-8. 20. Ahrens D, Bandi P, Ullsvik J, Moberg DP. Who smokes?: a demographic analysis of Wisconsin smokers. WMJ 2005; 104: 18-22. 21. Jindal SK, Gupta D. Tobacco smoking, exposure to environmental tobacco smoke and respiratory disease. In Gupta PC, Hammer JE (III), Murti PR, editors. Control of Tobacco Related Cancers and Other Diseases. International Symposium 1990. Bombay: Oxford University Press, 1992; pp 187-90.