Denise F. Johnson, MPH, MBA LaShaunda L. Malone, MSPH Catherine M. Stein, PhD American Public Health Association Meeting November 5, 2013 Boston, MA. The impact of tobacco smoking on tuberculosis recurrence in Uganda

Background Many countries with the highest burden of tuberculosis (TB) also have high smoking rates. Smoking increases the risk of becoming infected with TB, developing active form of the disease, and dying from TB 1. Passive smoking increases risk of TB infection, especially among children.

Background Previous research has identified tobacco smoking as a risk factor for tuberculosis (TB) recurrence 2-4. Compared to nonsmokers with TB, smokers are more likely to be diagnosed at a later or more severe stage of the disease. less likely to adhere to treatment. more likely to have a recurrence after completing TB treatment 1-3. For these reasons, it is essential to examine the impact of smoking on TB recurrence.

Objective The purpose of this analysis is to evaluate the association between smoking and TB recurrence among patients who completed TB treatment at an urban clinic in Kampala, Uganda.

Methods We conducted a retrospective review of records of adult TB patients who participated in the Kawempe District Household Contact Study from 2002–2009. TB recurrence was defined as a positive culture of M. tuberculosis from a patient who completed treatment after his/her initial TB episode and was declared cured. We examined o The associations between smoking and other risk factors for TB recurrence. o Survival estimates during the first 2 years after treatment completion based on smoking history.

Results Of the 538 index cases who completed TB treatment, 98 (18.2%) had ever smoked. The factors significantly associated with smoking were o Male gender o Age 30+ o Ever used alcohol o Employed o HIV positive status o TB strain A total of 33 patients (6.1%) had recurrent TB. Of those who smoked, 13.3% had TB recurrence compared to 4.6% of those who had never smoked (P = 0.001).

Characteristics of Subjects by Smoking Status n=538 *Some responses were missing.

Factors Associated with TB Recurrence n=538 *Some responses were missing.

Kaplan-Meier Survival Estimates Stratified by Smoking History

Discussion Patients who ever smoked were significantly more likely to have recurrent TB. The probability of surviving without TB recurrence among non-smokers was greater than for smokers in the first 2 years after treatment completion. Further research is warranted as tobacco consumption is increasing in developing countries. Smoking cessation during and after TB treatment is necessary to help prevent TB recurrence.

References 1.The deadly pairing of tuberculosis and smoking. World Lung Foundation 2011; 2(2). 2.D’Arc Lyra Batista J, et al. Smoking increases the risk of relapse after successful tuberculosis treatment. Int J Epidemiol 2008; 37(4): Thomas A, Gopi PG, Santha T, et al. Predictors of relapse among pulmonary tuberculosis patients treated in a DOTS programme in South India. Int J Tuberc Lung Dis 2005; 9: Chiang C-Y, Slama K, Enarson A. Associations between tobacco and tuberculosis. Int J Tuberc Lung Dis 2007; 11(3):