Asthma prevalence in lower Manhattan public primary schools

Asthma is commonly undiagnosed chronic condition in childhood. Schools provide unique settings for accessing almost all children for asthma screening. While several methods, including pulmonary function testing and exercise challenges, have been proposed for school-based asthma screening, the multi-center validated School-Based Asthma and Allergy Questionnaires (Redline, S. et al. 2004) prove to be the least invasive, inexpensive, and easiest to implement, with good sensitivity of 80% and specificity of 70%. In our screening program, on-site pulmonary function tests for all children scored positive on the questionnaires were performed.

From January 2005 to June 2006, a total of 476 second-grade students from four public primary schools were screened. Because 95% of the participants were ethnic Chinese, the questionnaires were translated into Chinese, and given to students' families with the English questionnaires to increase the response rate, as well as minimize screening errors due to language barrier.

A total of 88 (18.5%) of respondents had previously established diagnosis of asthma at the time of screening. 229 (48.1%) children without prior asthma diagnosis responded positive to the questionnaires, which falls within the range of 35% to 49% reported in the original validation studies from 4 inner-city schools in different metropolitan areas. In addition, our data showed a possible increase in asthma prevalence, both in form of established diagnosis of asthma - 16.7% in 2005 and 21.6% in 2006 (5% increase), as well as positive responses to the questionnaires without prior asthma diagnosis - 46.1% in 2005 and 52.0% in 2006 (6% increase).