PREVALENCE AND RELIABILITY OF ASTHMA SYMPTOMS IN PRIMARY-SCHOOL CHILDREN IN CAPE-TOWN

Background. Childhood asthma is believed to be a serious problem in Ca pe Town, South Africa. This study aimed to measure the prevalence and reliability of asthma symptoms and reported asthma in Cape Town school children:aged mainly 7 and 8 years, and to assess underdiagnosis. Meth od. A questionnaire was completed by parents of 1955 children, followe d by 620 personal interviews repeating the questions, Results. The pre valence of recent wheeze (previous 12 months) (26.8%) was high by inte rnational comparison, but not that of reported asthma (10.8%). Among c hildren with more than 12 recent attacks of wheeze, only 60% were repo rted as asthmatic and 55% as receiving regular treatment. Symptom prev alences varied with the respondent's familial relationship to the chil d. On some questions the interview produced higher wheeze prevalences than the self-administered questionnaire. Repeatability of questions v aried: asthma ever (kappa = 0.69), recent wheeze (kappa = 0.59), and r ecent sleep disturbance by wheeze (kappa = 0.56) were the most reliabl e. Conclusions. Prevalence based on symptom reports may vary with the respondent and between self- and interviewer-administered questionnair es. Also, certain questions currently proposed for childhood asthma qu estionnaires may be unreliable. Nevertheless, it can be concluded that the prevalence of wheeze is high in this population, and that underdi agnosis and undertreatment of asthma are a problem.