Subacute lack of asthma control as a predictor of subsequent acute asthma exacerbation in a managed care population.
OBJECTIVE
To evaluate whether an assessment of subacute lack of asthma control (SALAC) predicts subsequent acute asthma exacerbation (AAE).


METHODS
This retrospective administrative claims study used medical and pharmacy claims from the HealthCore Integrated Research Database to identify patients aged 6 to 64 years with asthma and having 3 years' continuous enrollment from January 1, 2003, through December 31, 2005.


METHODS
Study inclusion criteria were at least 2 outpatient visits or at least 1 hospitalization or emergency department (ED) visit with an asthma diagnosis (International Classification of Diseases, Ninth Revision, Clinical Modification code 493.xx) in at least 1 of 3 years (2003-2005). SALAC was defined as more than 4 asthma outpatient visits or more than 5 short-acting beta2-agonist (SABA) prescriptions per year, and AAE was defined as at least 1 hospitalization or ED visit with a primary asthma diagnosis or an oral corticosteroid burst prescription. Generalized estimating equations modeled the risk of subsequent-year AAE as a function of 2 sets of variables to determine the independent effect of prior-year SALAC and its components on subsequent-year AAE. The first set included age, sex, geographic region, prior year AAE, and prior-year SALAC. The second set included age, sex, geographic region, prior-year AAE, high prior-year SABA use, and frequent prior-year asthma outpatient visits.


RESULTS
Of 35,806 patients with asthma, 46.6% were male, and 35.8% were younger than 18 years. The mean annual prevalence of SALAC was 12.1%. Controlling for all other variables, the generalized estimating equation results indicate that prior-year SALAC is associated with a 60% increased risk of subsequent-year AAE (P <.001). Increased prior-year asthma outpatient visits and SABA use are associated with 34% and 85%, respectively, greater risks of subsequent-year AAE (P <.001 for both).


CONCLUSIONS
SALAC and its components can aid in predicting patients at risk for AAE.
HealthCore, Inc, 800 Delaware Ave, 5th Fl, Wilmington, DE 19801-1366, USA. jstephenson@healthcore.com
Judith J
JJ
Stephenson
Ralph A
RA
Quimbo
Benjamin
B
Gutierrez
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D002648:Child; D015331:Cohort Studies; D019468:Disease Management; D018450:Disease Progression; D005260:Female; D005544:Forecasting; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D008329:Managed Care Programs; D008875:Middle Aged; D012189:Retrospective Studies; D014481:United States; D055815:Young Adult