Neurocognitive functioning in children with mild and moderate asthma in the childhood asthma management program. The Childhood Asthma Management Program (CAMP) Research Group

BACKGROUND

The Childhood Asthma Management Program (CAMP) is a multicenter double-blind, randomized, placebo-controlled, clinical trial of two anti-inflammatory agents and placebo in children with mild and moderate asthma.

OBJECTIVE

The interrelationship between asthma severity and neurocognitive functioning among 1041 children (age range, 5-12 years) enrolled in the CAMP trial was examined.

METHODS

Asthma severity was established at baseline with a clinical history of asthma symptomatology and measures of lung function (spirometry and methacholine challenge). Diary cards were used in a screening to record nighttime awakenings and doctor contacts caused by asthma symptoms, symptom severity, and number of puffs from a rescue inhaler. All children received a comprehensive neurocognitive assessment at the end of the 28-day screening period (before randomization), including measures of intelligence, attention, memory, and academic achievement.

RESULTS

Significant differences were found between children with mild and moderate asthma on lung function and symptom outcome variables (log(e)FEV(1)PC(20), DeltaFEV(1) percent predicted, change in peak flow percent predicted, nighttime awakenings caused by asthma, average symptom severity score, and average daily number of puffs from a rescue inhaler) but not on neurocognitive variables. Multiple regression analyses revealed that asthma outcomes could not be predicted by neurocognitive variables despite controlling for socioeconomic status. The prevalence of neurocognitive dysfunction, as indicated by the use of psychostimulant medication, was found to be consistent with that found in the existing literature.

CONCLUSION

Mild and moderate asthma symptoms are not related to neurocognitive functioning in the children enrolled in CAMP. Mean performance on neurocognitive variables was found to be similar to that of national normative data.

Neuropsychological and behavioral changes in asthmatic children treated with beclomethasone dipropionate versus theophylline

OBJECTIVE

Results from previous investigations that examined the psychological side effects of theophylline have been inconsistent, and none have reported about inhaled corticosteroids. The objective of this study was to assess the relative psychological side effects of theophylline and beclomethasone in asthmatic children.

METHODS

This was a multicenter, randomized, double-blind, parallel-groups study in which 102 asthmatic patients were assigned to one of two treatments: beclomethasone three times daily or theophylline twice daily. At baseline, 1 month, and 1 year, parents completed standardized behavioral questionnaires while the children received psychometric testing of attention and concentration, memory and learning, and problem-solving.

RESULTS

Although power was sufficient to detect meaningful mean score changes, no consistent differential treatment effects were observed. Two significant treatment-by-period interactions were discordant, with one suggesting slightly better attention in the theophylline group, whereas the other indicated a small advantage in attention scores in the beclomethasone group. Numerous significant period effects revealed that behavior and cognitive test performance improved over the 1-year period, regardless of treatment, and confirmed a well established practice effect resulting from repeated administrations of such tests.

CONCLUSIONS

Neither theophylline nor beclomethasone should be avoided out of concern for significant psychological side effects. The possibility remains that a subset of asthmatic children may be susceptible to such medication-induced changes; investigators have suggested that preschool children may be at particular risk, although no controlled studies with this age group have been conducted. Parental perceptions of medication side effects can be influenced by temporary effects present at initiation of treatment or by erroneous attribution of the psychological effects of the chronic illness. Reports of psychological changes in response to asthma medications must be addressed respectfully but objectively, with due consideration of available evidence and an awareness of other potential explanations.

Retention of asthmatic patients in a longitudinal clinical trial

BACKGROUND

Prevention of study patient attrition and assessment of its impact on outcome data are problems that receive little attention despite their obvious importance in asthma research.

OBJECTIVE

The medical, demographic, and psychologic characteristics of asthmatic children and adults who dropped out of a yearlong medication trial were assessed to determine whether this group differed from those who completed the study, potentially introducing bias into the data set and interfering with completion of the study's objectives.

METHODS

Profiles of 362 adult and pediatric asthmatic patient dropouts from the multicenter trial were contrasted with profiles of those who completed the study. Despite a 1-month prerandomization screening, 24% of patients failed to complete the trial for varied reasons, which largely included noncompliance and treatment dissatisfaction.

RESULTS

Although attrition rates were equal among adults and children, dropout-completer differentiation was not. Adult completers did not differ from dropouts in any variables. However, pediatric dropouts were more likely than completers to be female (67% and 36%, p = 0.008) and to have more reactive airways (PD20, 2.29 +/- 1.32 and 5.2 +/- 1.23, p = 0.05), to have reduced scores on tests of intelligence (Full Scale IQ, 102.2 +/- 2.6 and 112.5 +/- 1.6, p = 0.002) and problem solving (Wisconsin Card Sorting Test Error Scores, 39.8 +/- 4.1 and 29.1 +/- 2.0, p = 0.01), and to have increased behavioral problems (Child Behavior Checklist Total Problem Score, 60.7 +/- 2.5 and 53.6 +/- 1.1, p = 0.003).

CONCLUSION

These findings demonstrate the potential of patient attrition to bias outcome in clinical trials and underscore the necessity of: (1) preventing its occurrence, (2) correctly assessing its causes, and (3) determining its ultimate impact on study results. Strategies for each of these three tasks should be implemented at the study's initial planning stages.