The controller-to-total asthma medication ratio is associated with patient-centered as well as utilization outcomes.
BACKGROUND
The ratio of controller medication to total asthma medications has been related to asthma utilization outcomes, but its relationship to patient-centered outcomes has not been explored.


METHODS
Surveys that included validated asthma quality-of-life, control, and symptom severity tools were completed by a random sample of 2,250 health maintenance organization members aged 18 to 56 years who had persistent asthma. Linked computerized pharmacy data provided dispensing information on beta-agonist canisters and asthma controller medication. The ratio was calculated as the number of controller medications dispensed during the year of the survey divided by the total number medications (ie, inhaled beta-agonist plus controller medications) dispensed. The relationships of the optimal ratio cutoff to patient-centered outcomes and to subsequent acute asthma exacerbations were determined.


RESULTS
Mean asthma quality-of-life, asthma control, and symptom severity scale scores were significantly (p < 0.0001) more favorable in patients with ratios of > or = 0.5. After adjusting for demographic characteristics, patients with ratios of > or = 0.5 were significantly less likely to have adverse results regarding asthma quality of life (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.52 to 0.80), asthma control (OR, 0.62; 95% CI, 0.50 to 0.77), and symptom severity (OR, 0.53; 95% CI, 0.43 to 0.65), and were also less likely to experience subsequent asthma hospitalizations or emergency department visits (OR, 0.44; 95% CI, 0.26 to 0.74) than patients with lower ratios.


CONCLUSIONS
A higher controller medication/total asthma medication ratio is associated with better patient-centered asthma outcomes as well as with reduced emergency hospital utilization. This adds further support to the use of the medication ratio as an asthma quality-of-care measure.
Schatz
Michael
M
Department of Allergy, Kaiser-Permanente Medical Center Program, 7060 Clairemont Mesa Blvd, San Diego, CA 92111, USA. michael.x.schatz@kp.org
Zeiger
Robert S
RS
Vollmer
William M
WM
Mosen
David
D
Mendoza
Guillermo
G
Apter
Andrea J
AJ
Stibolt
Thomas B
TB
Leong
Albin
A
Johnson
Michael S
MS
Cook
E Francis
EF
D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001249:Asthma / Q000145:classification / Q000188:drug therapy*; D005260:Female; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D018802:Patient-Centered Care; D012372:ROC Curve; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents