Preventing Hospital Admissions for Asthma

Abstract

To the Editor. The article by Lieu et al1 describes early intervention by parents at home and written management plans provided to the family being strongly associated with reduced risk of adverse outcomes among children with asthma. However, examination of their data suggests that neither was highly predictive for preventing hospitalization. The magnitude of the difference between cases and controls receiving a written asthma plan was quantitatively small, 43.5 versus 49.3%, respectively, and that difference was similar for asthma severity identified as moderate, moderately severe, and severe. The magnitude of differences in early intervention was even smaller.Lieu et al state the aim of their study was to suggest priority areas for intervention by identifying outpatient management practices associated with increased or decreased risk of adverse outcomes, eg, hospitalization. However, not adequately examined by Lieu was the potential for outcome to be influenced by apparent differences in medical practice among specialists and generalists as suggested in several studies.2-5 Despite the high level of acuity described among these patients, only 7% of cases and <5% of controls were identified as having an asthma specialist.What are the measures that specialists use to ensure a major impact on asthma outcome that could be applied in a primary care setting?6 In addition to providing instruction in effectively using an age-appropriate method of delivering an inhaled β2-agonist, early identification of bronchodilator subresponsiveness and early intervention with a short course of high-dose oral corticosteroids reliably prevents progression of asthma,7 prevents hospitalizations in patients seeking emergency care,8-11 and decreases by 90% the frequency of hospitalization among young children with asthma induced by viral respiratory infections,12 which probably constitutes the largest single age group and trigger for hospital admissions. Specialists will, of course, also evaluate the need for maintenance medication and assess the role of environmental factors in the disease, but treatment of acute exacerbations with inhaled β2-agonists and a short course of high-dose oral corticosteroids for patients likely to require emergency care and/or hospitalization is reliable and effective when applied early. Unfortunately, the report by Lieu addressed neither the timing nor the nature of intervention for the acute symptoms that led to hospitalization.The authors of the publication concluded correctly that early intervention for asthma flare-ups by parents at home can reduce the risk of adverse outcomes. However, “early intervention” cannot be perceived as generic. The specific nature, timing, and dosage of the intervention makes the difference between success and failure, and specialized programs have been demonstrated to be highly successful at implementing effective early intervention measures.2-5Until generalists regard every episode of emergency care and every episode of hospitalization for asthma as a serious treatment failure and either provide intervention measures shown to be effective6 or refer to an appropriate subspecialty care program for future management, the current endemic nature of asthma emergency care and hospitalization will continue despite the best intention of comprehensive guidelines.13In Reply. We appreciate Dr Weinberger's interest in our study. However, his interpretation of the raw magnitude of the difference between cases and controls is statistically misguided. It is most appropriate to judge the association between having a written plan and the risk of hospitalization or emergency department (ED) visits not from the raw percentages, but from the multivariate analyses, which adjusted for other important predictors including socioeconomic status and severity of illness. The adjusted odds ratios of 0.54 for hospitalization and 0.45 for ED visits show a twofold reduction in risk for each outcome. In addition, the unadjusted differences between parents of hospitalized patients and their controls who reported that their children had mild (24.0% vs 44.6%) or moderate (31.4% vs 53.4%) asthma were striking.We acknowledge that our study was limited in its ability to evaluate the effects of specialist versus generalist care on adverse outcomes due to the small proportion of patients referred to specialists. However, we believe that the more important question is what providers and parents of all educational backgrounds can do to prevent asthma adverse outcomes. In that regard, Dr Weinberger's comments referring to studies that focused specifically on early oral corticosteroids to prevent severe asthma flare-ups are well-taken as stronger evidence for this practice than can be found in our study.