Do clinical investigations predict long-term outcome? A follow-up of paediatric respiratory outpatients

Abstract Introduction The contribution of clinical investigations to prediction of long-term outcomes of children investigated for asthma is unclear. Aim We performed a broad range of clinical tests and investigated whether they helped to predict long-term wheeze among children referred for evaluation of possible asthma. Methods We studied children aged 6-16 years referred to two Swiss pulmonary outpatient clinics with a history of wheeze, dyspnoea, or cough in 2007. The initial assessment included spirometry, body plethysmography, fractional exhaled nitric oxide, skin prick tests, and bronchial provocation tests (BPT) by exercise, methacholine, and mannitol. Respiratory symptoms were assessed with questionnaires at baseline and at follow-up seven years later. Associations between baseline factors and wheeze at follow-up were investigated by logistic regression. Results At baseline, 111 children were examined in 2007. Seven years after baseline, 85 (77%) completed the follow-up questionnaire, among whom 61 (72%) had wheeze at baseline, while at follow-up 39 (46%) reported wheeze. Adjusting for age and sex, the following characteristics predicted wheeze at adolescence: wheeze triggered by pets (odds ratio 4.2, 95% CI 1.2-14.8), pollen (2.8, 1.1-7.0), and exercise (3.1, 1.2-8.0). Of the clinical tests, only a positive exercise test (3.2, 1.1-9.7) predicted wheeze at adolescence. Conclusion Reported exercise-induced wheeze and wheeze triggered by pets or pollen were important predictors of wheeze persistence into adolescence. None of the clinical tests predicted wheeze more strongly than reported symptoms. Clinical tests might be important for asthma diagnosis but medical history is more helpful in predicting prognosis in children referred for asthma.