Predicting asthma in preschool children at high risk presenting in primary care: development of a clinical asthma prediction score.

Background: A setting-specific asthma prediction score for preschool children with wheezing and/or dyspnoea presenting in primary healthcare is needed since existing indices are mainly based on general populations.

Aims: To find an optimally informative yet practical set of predictors for the prediction of asthma in preschool children at high risk who present in primary healthcare.

Methods: A total of 771 Dutch preschool children at high risk of asthma were followed prospectively until the age of six years.

The effect of two lottery-style incentives on response rates to postal questionnaires in a prospective cohort study in preschool children at high risk of asthma: a randomized trial.

Background: In research with long-term follow-up and repeated measurements, quick and complete response to questionnaires helps ensure a study's validity, precision and efficiency. Evidence on the effect of non-monetary incentives on response rates in observational longitudinal research is scarce.

Objectives: To study the impact of two strategies to enhance completeness and efficiency in observational cohort studies with follow-up durations of around 2 years.

Prediction and treatment of asthma in preschool children at risk: study design and baseline data of a prospective cohort study in general practice (ARCADE).

Background: Asthma is a difficult diagnosis to establish in preschool children. A few years ago, our group presented a prediction rule for young children at risk for asthma in general practice. Before this prediction rule can safely be used in practice, cross-validation is required.

Two simple strategies (adding a logo or a senior faculty's signature) failed to improve patient participation rates in a cohort study: randomized trial.

Background: Patient participation in research studies is often difficult to achieve, and efforts to increase participation rates fail frequently. Given the paucity of evidence on interventions aimed at improving patient participation, we conducted a randomized trial.

Objectives: The first was to assess the effect of the logo of the funding agency on the willingness to consider participation in a prospective cohort study in general practice.