Identification of a threshold for biomass exposure index for chronic bronchitis in rural women of Mysore district, Karnataka, India.

Background & objectives: Exposure to air pollution due to combustion of biomass fuels remains one of the significant risk factors for chronic respiratory diseases such as chronic bronchitis. There is a need to identify the minimum threshold level of biomass index that is significantly associated with chronic bronchitis. This study was undertaken to identify a threshold for biomass exposure index in a rural women population in Mysore district, south India. Methods: A cross-sectional survey was conducted in a representative population of Mysore and Nanjangud taluks. Eight villages each from Mysore and Nanjangud were randomly selected based on the list of villages from census 2001. A house-to-house survey was carried out by trained field workers using the Burden of Obstructive Diseases questionnaire, which evaluated the biomass smoke exposure and chronic bronchitis. All the women aged above 30 yr were included in the study. Results: A total of 2011 women from Mysore and 1942 women from Nanjangud participated in the study. All women were non-smoking and used biomass fuels as the primary fuel for cooking. A threshold of biomass fuel exposure of 60 was identified on multivariate analysis in Mysore district after adjusting for age, passive smoking and working in a occupational exposure to dust, as the minimum required for a significant association with chronic bronchitis. One in every 20 women in Mysore district exposed to biomass fuel exposure index of 110 or more developed chronic bronchitis. Interpretation & conclusions: The minimum threshold of biomass exposure index of 60 is necessary to have a significant risk of developing chronic bronchitis in women. The number needed to harm to develop chronic bronchitis reduces with increasing biomass exposure index and women residing in rural Nanjangud have a higher risk for developing chronic bronchitis as compared to women in Mysore.

Factors affecting 30-month survival in lung cancer patients.

Background & objectives: Age adjusted incidence rate of lung cancer in India ranges from 7.4 to 13.1 per 100,000 among males and 3.9 to 5.8 per 100,000 among females. The factors affecting survival in lung cancer patients in India are not fully understood. The current study was undertaken to evaluate the factors affecting survival in patients diagnosed with lung cancer attending a tertiary care cancer institute in Bangalore, Karnataka, India. Methods: Consecutive patients with primary lung cancer attending Bangalore Institute of Oncology, a tertiary care centre at Bangalore, between 2006 and 2009 were included. Demographic, clinical, radiological data were collected retrospectively from the medical records. Results: A total of 170 consecutive subjects (128 males, 42 females) diagnosed to have lung cancer; 151 non-small cell lung cancer (NSCLC) and 19 small cell lung cancer (SCLC) were included. A higher proportion of never-smokers (54.1%) were observed, mostly presenting below the age of 60 yr. Most subjects were in stage IV and III at the time of diagnosis. More than 50 per cent of patients presented with late stage lung cancer even though the duration of symptoms is less than 2 months. The 30-month overall survival rates for smokers and never-smokers were 32 and 49 per cent, respectively. No significant differences were observed in 30 month survival based on age at presentation, gender and type of lung cancer. Cox proportional hazards model identified never-smokers and duration of symptoms less than 1 month as factors adversely affecting survival. Interpretation & conclusions: Our results showed that lung cancer in Indians involved younger subjects and associated with poorer survival as compared to other ethnic population. Studies on large sample need to be done to evaluate risk factors in lung cancer patients.

Prevalence of chronic cough, chronic phlegm & associated factors in Mysore, Karnataka, India.

Background & objectives: Chronic cough and chronic phlegm are important indicators of respiratory morbidity, accelerated lung function decline, increased hospitalization and mortality. This study was planned to estimate the prevalence of chronic cough and phlegm in the absence of dyspneoa and wheezing and to study its associated factors in a representative population of Mysore district. Methods: A cross-sectional survey was planned in a representative population of Mysore taluk. Eight villages were randomly selected based on the list of villages from census 2001. Trained field workers using the Burden of Obstructive Diseases questionnaire carried out a house-to-house survey. Results: A total of 4333 adult subjects were enrolled in the study with 2333 males and 2000 females. The prevalence of chronic cough in the community was 2.5 per cent and that of chronic phlegm was 1.2 per cent. A significant association was observed between chronic cough and age, gender, occupation and smoking and chronic phlegm with age, gender, occupation, indoor animals and smoking. A multivariate analysis confirmed independent association of age, occupation and smoking for chronic cough and age and smoking for chronic phlegm. On sub-group analysis of males, heavy smokers had higher prevalence of chronic cough and chronic phlegm as compared to light smokers and non smokers. Interpretation & conclusions: The prevalence of chronic cough was 2.5 per cent and chronic phlegm was 1.2 per cent in the general population in Mysore which is lower than that observed in other studies. Heavy smoking was an important preventable risk factor identified in this study and efforts towards smoking cessation are crucial to achieve good respiratory health in the community.