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Editor's Notes

• #26: CORE GENERIC SLIDE There is now sufficient evidence to link smoking to TB infection, TB diseases and TB mortality. The meta-analysis conducted by Bates et al. (2007) showed no evidence of heterogeneity among studies conducted to assess the association between smoking and TB infection and TB diseases. There were more heterogeneities among studies to assess smoking and TB mortality, mainly due to different methods to derive cause-of-death data in developing countries (death certificates which is more unreliable and verbal autopsy). ? With a higher risk of smokers to get TB infection (defined as a minimum tuberculin skin test indurations diameter of 10 mm), the proportion of smokers who are infected and are at risk of TB disease will increase. If smoking increases the risk of TB disease in those already infected, this will increase the proportion of smokers at risk of TB mortality. The independent RR for TB disease can be estimated by dividing the study derived RR for TB disease (2.3-2.7) by the RR for TB infection (1.7). This gives an estimated RR for development of TB disease in an infected population of 1.4 to 1.6. Ex-patients are more than 3 times more likely to relapse if they smoke following short course TB treatment. ? Smoking, which increases the incidence of clinical tuberculosis, is a cause of half the male tuberculosis deaths in India, and of a quarter of all male deaths in middle age (plus smaller fractions of the deaths at other ages). At current death rates, about a quarter of cigarette or bidi smokers would be killed by tobacco at ages 25¨C69 years, those killed at these ages losing about 20 years of life expectancy. Overall, smoking currently causes about 700 000 deaths per year in India, chiefly from respiratory or vascular disease: about 550 000 men aged 25¨C69 years, about 110 000 older men, and much smaller numbers of women (since few women smoke). ? The relative risk for death from tuberculosis was 4¡¤5 (95% CI 4¡¤0¨C5¡¤0). Of the 1840 deaths from tuberculosis among men aged 25¨C69 years, 79% involved smokers. For other respiratory diseases, chief among which was chronic obstructive lung disease, the relative risk was 2¡¤9 and the smoking-associated proportion was 45%. Overall, tuberculosis and other respiratory diseases accounted for a substantial proportion of all smoking associated mortality. ? Reference: Bates MN, Khalakdina A, Pai M, Chang L, Lessa F, Smith KR. Risk of tuberculosis from exposure to tobacco smoke: a systematic review and meta-analysis. Arch Intern Med. 2007;167(4):335-42. Gajalakshmi V, Peto R, Kanaka TS, Jha P. Smoking and mortality from tuberculosis and other diseases in India: retrospective study of 43 000 adult male deaths and 35000 controls. Lancet 2003; 362: 507¨C15
• #27: CORE GENERIC SLIDE Even though more researches are needed, there are some patterns of dose-response relationships between exposure intensity to passive smoking and the risk of TB infection. The meta-analysis conducted by Lin et al. (2007) showed that the risk of getting pulmonary TB was 3.3 times (95% OR = 1.93 ¨C 5.72) than that of non-smoker. The risk of getting TB from second-hand smoking exposure was higher among children than adults, with case control study in Thailand reported ORs as high as 9.3, and another case-control study in Spain reported an OR of 5.4 (95%CI=2.44-11.9). The meta-analysis also confirms a dose-response relationship between passive smoking and the risk of TB infection. The probability of TB infection increases with the number of daily cigarettes smoked by family member, as well as with the proximity of contact with smoking household member. The adjusted OR for those who were in close contact was 9.3 (95%CI=3.14-27.6). Reference: Lin HH, Ezzati M, Murray M. Tobacco Smoke, Indoor Air Pollution and Tuberculosis: A Systematic Review and Meta-Analysis. PLoS Med 2007 Jan 16;4(1):e20.
• #28: GENERIC OPTIONAL SLIDE A study in Hongkong found out that smokers have less possibility to experience extra-pulmonary TB. Most of the TB patients who smoked have pulmonary TB, with a more severe clinical and radiological appearance (more cough, dyspnea, cavitary lesions), and are more likely to have positive sputum-smears. Smoking is however proven not related to sputum conversion two months after treatment, however, it prolongs the sputum conversion time among smokers than among non-smokers. A study in South India which follow-up cured TB patients up to 18 months identified that TB relapse was associated with irregular treatment, drug-resistance and smoking. The relapse rate among smoker is higher compared to non-smoker who comply to the treatment. Reference: Chiang CY, Slama K, Enarson DA. Associations between tobacco and tuberculosis. Int J Tuberc Lung Dis 2007 Mar;11(3):258-62.
• #29: OPTIONAL SUPPORT SLIDE ? All patients in this study conducted in Kerala, India were asked if any health professional had inquired about their smoking habits at any of their TB-related clinic visits since diagnosis. All of those who smoked in the months before diagnosis were then asked whether they had received any cessation advice from any health professional. Those who reported receiving smoking cessation advice were asked what messages they had received. All 153 study patients except one reported that they had been asked about tobacco use by health staff. ? A content analysis of messages received by smokers at the time of diagnosis revealed that only about half contained TB-specific messages¡ªmessages that smoking aggravates TB, smoking reduces the effectiveness of TB treatment and smoking can cause relapse of TB. The five most common TB-specific messages reported were: 1) ¡®Smoking is bad for this disease. Stop it¡¯; 2) ¡®Because you have TB, give up smoking¡¯; 3) ¡®Smoking will prevent cure, so stop it¡¯; 4) ¡®This disease is due to smoking, so stop it¡¯; 5) ¡®Smoking will reduce the effect of drugs, so give up smoking¡¯. Fifty per cent of study patients who received messages stated that they were only given general advice to quit smoking without any explanation. The four most common general messages were: 1) ¡®You should quit smoking¡¯; 2) ¡®Don¡¯t smoke again¡¯; 3) ¡®Give up smoking¡¯; 4) ¡®Stopping smoking is good for your health¡¯. ? Most patients reported receiving only one brief message from a doctor at the time of diagnosis, a time when they were quite ill, and being told many things about their medication. Two fifths of DOTS providers were health staff and three fifths were non-health staff (mostly anganwadi workers, grass root workers in the integrated child development services scheme). When the DOTS provider was a health staff member, only 30% of TB patients received a cessation message. When non-health staff were the DOTS providers, more than three quarters of TB patients reported being told to quit smoking while taking treatment. ? Reference: ? Pradeepkumar AS, Thankappan KR, Nichter M: Smoking among tuberculosis patients in Kerala, India: proactive cessation efforts are urgently needed. Int J Tuberc Lung Dis 2008;12:1139-45. Add speakers notes to help explain information on the slide..