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ICD Code: 493. Asthma

ICD Code: 493. Article Review
Title: Aggarwal AN et al; "Prevalence and Risk Factors for Bronchial Asthma in Indian Adults: A Multicentre Study." Indian Journal of Chest Disease and Allied Sciences; V.48; 2006; p13
      ASTHMA IN INDIA: There is very limited data on asthma epidemiology from the developing world, including India. The overall burden of asthma in India is estimated at more than 15 million patients. However, India is a vast country with immense geographical, economical, racial, religious, and socio-political diversity. There are obvious differences in prevalence of disease and approach to management of health problems.
      STUDY DESIGN: The authors have adapted a questionnaire to assist in field diagnosis of asthma for epidemiological purposes and have estimated prevalence of disease in the local population, both in children and adults. Prevalence of asthma in adults age 15 and older was studied in different parts of the country with a multicentric design using uniform methodology. The questionnaire envisaged for use in this study had two components. The first part was aimed at collecting information on respiratory symptoms and establishing a diagnosis of asthma based on this data. The second component was aimed at collecting information on possible demographic and environmental exposure factors influencing the prevalence of asthma.
      Data from a total of 73,605 respondents were included in the final analysis. There were 37,682 (52%) men and 35,923 (48%) women. While about half of the subjects were aged between 15 and 34 years, about 10% of individuals were aged 65 years or more at each center.
      TOBACCO AND COOKING HABITS: In general, 1% or fewer women in urban areas had ever smoked tobacco in the past; figures for rural women were higher. About 25% to 40% of men in rural areas and 20% to 30% of men in urban areas had ever smoked tobacco in the past. Cigarette and bidi were the most common forms of smoked tobacco, and only a small minority of smokers had quit smoking in the past. About 40% of subjects studied were regularly involved in cooking food at home; the vast majority of these subjects were women. Liquefied petroleum gas was the most common cooking fuel used at all urban areas and rural Delhi; in other rural areas, solid fuels (e.g., wood, dung, etc.) were more commonly used.
      PREVALENCE (INDIA): As per the definition used in the survey, asthma was present in 2.28%, 1.69%, 2.05%, and 3.47% of respondents, respectively, at Chandigarh, Delhi, Kanpur, and Bangalore, with an overall prevalence of 2.38% (men, 2.21%; women, 2.56%). Overall prevalence was reported as 2.55% in urban areas (men, 2.29%; women, 2.81%) and 2.18% in rural areas (men, 2.12%; women, 2.24%). Prevalence was relatively higher among female respondents of urban areas at Delhi, Chandigarh, and Bangalore.
      RISK FACTORS: Compared to Chandigarh, the odds ratio (OR) for asthma was reported as follows by location: Delhi, 1.026; Kanpur, 1.153; Bangalore, 1.707. Compared to males, females had an OR of 1.435 for asthma. Compared to ages 15-24 years, the OR for asthma was reported as follows by age: ages 25-34 years, 1.618; ages 35-44 years, 2.819; ages 45-54 years, 4.838; ages 55-64 years, 7.504; ages 65-74 years, 11.332; ages 75 and older, 13.472. Compared to rural residence, the OR for asthma was reported as 1.342 for urban residence and 1.282 for mixed residence. Compared to low socioeconomic status, the OR was reported as 0.831 for middle and 0.717 for high socioeconomic status. Compared to nonsmokers, the OR was reported as 1.534 for cigarette smokers, 1.599 for bidi smokers, and 2.227 for smokers of hookah or other products. Compared to those with no self cooking, the OR was reported as follows by usual cooking habit: liquefied petroleum gas, 0.853; kerosene, 0.869; solid fuel, 1.035.
      DISCUSSION: There is very limited information on prevalence of asthma among adults in India. Nevertheless, the present estimates are close to the figure of 2.78% reported three decades ago in a middle-aged urban population. These results are also similar to the asthma prevalence (3.5%) reported in Mumbai more recently using a "clinician diagnosis" based on the European Community Respiratory Health Survey protocol. As stressed earlier, the largest obstacle in comparing prevalence estimates across two or more fields studies relates to methodological differences in study design, disease definition, and data analysis.
      A particularly interesting observation from the present data is the importance of tobacco smoking in relationship to the prevalence of asthma.
      Another important finding from the data is that the study population at Bangalore had a higher prevalence of asthma as compared to the other three north Indian cities, even after adjustment of other risk factors associated with asthma. While this data is insufficient to draw any definite conclusions regarding north-south differences in asthma prevalence in India, it certainly opens new areas for looking into ethnic variations in disease prevalence, severity, and morbidity in this country with such great heterogeneity.

Search Criteria: Text - Indian Journal of Chest Disease and Allied Sciences; V.48; 2006; p13