Resurvey of symptomatics of the Jaipur district population and suggestion for alternative diagnostic criteria of asthma for epidemiological surveys

INTRODUCTION: The prevalence of asthma in Jaipur district of Rajasthan was reported as 0.96% in an earlier survey. It was far below the national average of 2.38%. It was reasoned then that this could be due to under diagnosis of asthma in the Jaipur population. MATERIAL AND METHODS: A resurvey of the symptomatics, not diagnosed as asthma at time of the original survey was, therefore, undertaken. The resurvey data were analysed and those who now fulfilled the twin criteria for diagnosis of asthma, as used in the original survey, were diagnosed as having asthma. The original data of these newly diagnosed asthma patients were reanalyzed in search for an alternative diagnostic criterion. RESULTS: Of the 382 symptomatics, 344 (90%) could be resurveyed and of them, 85 now fulfilled the twin diagnostic criteria for asthma. The reanalysis of the original survey data of these patients revealed that presence of shortness of breath (SOB) had the highest sensitivity, the presence of allergic symptoms in self or the family had the highest specificity and the presence of wheezing had the highest odds ratio (OR) for diagnosing asthma. Further, the OR for diagnosing asthma increased further and was highest with the presence of SOB and 2 additional symptoms. With the use of the “symptom criteria” for diagnosis of asthma i.e. the presence of SOB with 2 additional symptoms, it would have been possible to diagnose majority of the missed cases at the time of the original survey itself. CONCLUSIONS: Based on this study data it can be concluded that (a) the twin criteria for diagnosing asthma as used in earlier surveys led to under diagnosis of asthma and (b) the use of symptom criteria alone effectively checks the problem of under diagnosis of asthma. The symptom criteria are being suggested as an alternative method for use in future epidemiological surveys on asthma.