A randomized trial of early detection of asthma-related symptoms in pre-school children at preventive child health centers in The Netherlands
07 / 2002 - 07 / 2009
Database Zorg Onderzoek Nederland ZON
Aim: (1) To study the effectiveness of early detection of asthma-related symptoms at ages of 14, 24, 36 and 46 months in a randomized trial with 30 child health centers. Effects on "current" health at ages 18, 30 and 42 months will be evaluated as well as presence of asthma at the age of 5 years. Follow-up at the age of 7 and later will be prepared. (2) To evaluate the effects of early detection on care utilization/prescribed drugs (incl. costs) and the reported (dis)advantages of early detection by parents/professionals. Asthma is characterized by episodes of reversible airway obstruction resulting in attacks of shortness of breath with wheezing and coughing, on the basis of airway hypersensitivity for specific (allergic) and non-specific triggers, with a chronic inflammatory reaction in the bronchial walls as pathological substrate. The clinical diagnosis of asthma as such cannot be established in pre-school children. In the very young, shortness of breath often is not apparent, and allergic sensitization-blood-tests (e.g. multi-RAST) and lung function tests (e.g. peak-flow) are not yet appropriate/feasible. The current Dutch General Practitioners (GP's) evidence-based childhood-asthma-guidelines for 0-4 year olds are therefore based on the "symptom diagnosis" labeled as "recurrent cough, wheezing and/or chest congestion/phlegm". Young children with these symptoms have a relatively high chance (45%) to develop asthma in later life. Asthma-related symptoms in (young) children represent a very important community health problem: prevalence is 3-10%; impact on quality of life, family- and school functioning is high. In the absence of systematic detection there is considerable underdiagnosis/treatment (30-60%) due to underpresentation of symptoms by parents. Yet, asthmatic symptoms can be managed highly effectively by a package of measures including GP-monitoring, health education, non-pharmacological interventions (non-smoking, avoidance of allergenic/non-allergenic triggers in environment/food, flu vaccination), and (if indicated) bronchodilator and/or anti-inflammatory inhalation aerosols. Early and adequate treatment has a direct health effect and also appears to facilitate lung development with a better function and less symptoms in later life. Validated early detection procedures in very young children, based on medical history taking, are available. This is in principle identical to the diagnostic procedure for 0-4 year olds in primary/secondary care, as clinical tests as a rule are not appropriate at that age. Early diagnosis/treatment of adults with asthma-related symptoms has been proven to be cost-effective. No randomized trials of the effects of early detection in (pre-school) children have been carried out yet. This study evaluates a computer-assisted medical history module strictly based on the GP-guidelines, implemented as early detection instrument at age 14, 24, 36 and 46 months in a random half of all Rotterdam preventive child health centers (CHC's; "Consultatiebureaus Jeugdgezondheidszorg 0-4 years"; n=30). Short/medium-term health effects, effects on care utilization (and costs), and appreciation by parents/professionals will be evaluated. Secondary prevention, if effective, is part of an asthma prevention chain, also including primary (non-smoking, allergen impermeable mattress covers etc.) and tertiary prevention (flu vaccination etc.), studied in other ZON-projects. Prevention of childhood asthma is an important public health objective. Given highly effective modes of management/treatment, consensus (across preventive/primary/secondary care) in evidence-based guidelines, and validated early detection procedures in young children, Dutch experts recently assigned very high priority to an asthma-early-detection-trial in Dutch preventive youth care. Systematic early detection of asthma-related symptoms could overcome underdiagnosis/treatment, which is due to underpresentation by parents. This study, within the Generation-R cohort (n=10,000), evaluates the early detection of asthma-related symptoms at age 14, 24, 36 and 46 months in a trial with randomized child health centers (n=30). Detected cases will be managed in primary care in accordance with clinical guidelines. Primary goal of the intervention is short-term improvement of generic and respiratory health-related quality of life at age 0-4 years. Secondary goal is reducing the probability of doctor-diagnosed asthma at the age of 5 years. Short-term (0-4 yrs) and medium-term (age 5 yrs) health outcomes, (costs of) induced care utilization/prescribed drugs and perceived (dis)advantages by parents/professionals will be evaluated. Long-term follow-up at ages of 7 and later will be prepared, but are not included in this proposal. Secondary prevention, if effective, is part of an asthma prevention chain, also including primary and tertiary prevention (which is studied in other ZON-projects).