Asthma-Related Health Care Resource Use Among Asthmatic Children With and Without Concomitant Allergic Rhinitis

Purpose of the Study. To determine the incremental effect of allergic rhinitis on health care resource use in children with asthma. Study Population. Children (aged 6–15 years) with asthma and >1 asthma-related encounter with a general practitioner (GP) during a 12-month follow-up period were included from the United Kingdom medical plus general-practice database, including 2 million office patient visits per year to >500 GPs. Methods. This was a population-based historical cohort investigation. Asthma and allergic rhinitis were determined by diagnosis codes and drug codes for appropriate medications. Results. Of 9522 children with asthma, 1879 (19.7%) had allergic rhinitis recorded in the GP medical charts. Compared with children with asthma alone, children with comorbid allergic rhinitis experienced more GP visits (4.4 vs 3.4) and more of them were hospitalized for asthma (1.4% vs 0.5%) during the 12-month follow-up period. In multivariable regression analyses, comorbid allergic rhinitis was an independent predictor of hospitalization for asthma (odds ratio: 2.34; 95% confidence interval [CI]: 1.41–3.91) and was associated with increases in the number of asthma-related GP visits (mean increase: 0.53; 95% CI: 0.52–0.54) and asthma drug costs (mean increase [British pounds]: £6.7; 95% CI: £6.5–£7.0). The association between allergic rhinitis and higher costs of prescriptions for asthma drugs was independent of asthma severity, measured indirectly by the intensity of use of asthma drugs. Conclusions. Children with comorbid allergic rhinitis incurred greater prescription drug costs and experienced more physician visits and hospitalizations for asthma than did children with asthma alone. A unified treatment strategy for asthma and allergic rhinitis, as recommended by the Allergic Rhinitis and Its Impact on Asthma initiative, might reduce the costs of treating these conditions. Reviewer Comments. This is a useful study emphasizing the impact of allergic rhinitis on asthma, with implications for better therapeutic approaches. The study may have actually underestimated the impact of allergic rhinitis, because the data are retrospective and diagnosed allergic rhinitis was estimated at only 19.7%, compared with rates as high as 50% among children with asthma in other studies.