SELECTED ARTICLES FROM THE RECENT LITERATURE 2003

10/15/03

Minimizing attrition in long-term asthma studies

Summary
It has been increasingly recognized that long-term follow-up observation is needed for meaningful studies of clinical events in asthma, including findings in therapeutic trials. However, high subject dropout rates have threatened the success of numerous studies. In an attempt to find ways to identify factors associated with patient attrition, with an eye towards reducing it, Bender et al of the National Jewish Medical and Research Center evaluate characteristics of the asthma and demographic and psychologic factors associated with individuals missing scheduled visits and dropping out of the study. Predictors of attrition were examined within the Childhood Asthma Management Program (CAMP), a multicentral clinical trial that followed up 1,041 asthmatic children for 4-6 years. The overall dropout rate was 42 patients (4%) lower than reported in any previous clinical asthma trial of that duration. The dropout patients had milder asthma, lower cognitive, academic and social competence skills, and more family conflict and distress than seen in the 82% of the children who attended all study visits. The 49 children who had erratic attendance in scheduled visits but did not drop out of the study also had lower intellectual and academic skills and less family social support.

Reference
Ann Allergy Asthma Immunol 2003; 91:168-76

Editor's Comments
The overall 4% dropout rate in this CAMP project was very low after a 4-6 year duration of such a large multicenter study. The characteristics of patient/families that missed appointments or even dropped out are not surprising to me based on my personal experience treating chronic asthma. Individuals from lower socio-economic groups with lower educational levels and attainments tend to be more "crisis oriented" in their approach to their health care particularly when there is much social upheaval in the household. There are more tendencies by such individuals to miss appointments when asthma is mild/under apparent control. It is frequently difficult to convince the parents of such asthmatic children that follow-up visits for preventive care is very important.

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