Evaluation of risk factors and health outcomes among persons with asthma.
OBJECTIVE
To examine risk factors associated with healthcare utilization in Arizona Medicaid patients with asthma.


METHODS
Data were obtained from Arizona Medicaid between 1/1/2002 and 12/31/2003. Inclusion criteria consisted of persons with an asthma diagnosis (ICD9-CM 493.XX), 5 to 62 years of age; and were new users of inhaled-corticosteroids (ICS), combination ICS+long-acting beta-agonist, or leukotriene-modifiers. Factors examined included age, geographic location (urban/rural), race/ethnicity (White, non-Hispanic Black, Hispanic, other), medication adherence, pre-period short-acting beta-agonist use (SABA), and co-morbidities. Utilization measures examined included SABA use; exacerbations measured by hospital visits; and asthma-related and total healthcare costs. Analyses for utilization measures were performed using negative binomial, logistic regression, and generalized linear modeling gamma-family, log-link, respectively.


RESULTS
A total of 3,013 subjects met inclusion/exclusion criteria and had a mean age (+/-SD) of 24.7 +/-13.7 years. Urban residents were 55% more likely to have an exacerbation than rural residents (odds ratio-OR 0.45, 95%CI: 0.27-0.78). Age (years 18 to 62) was a significant predictor for SABA use (incidence rate ratio-IRR 1.22, 95% CI: 1.06-1.41); and exacerbations (OR 2.07, 95% CI: 1.28-3.38). Mean predicted asthma cost was $530 (95% CI: $461-608) for ages 5 to 17, $702 (95% CI $600-822) for ages 18 to 39), and $583 (95% CI $468-726) for ages 40 to 62. Males were 46% less likely to have an exacerbation than females (OR 0.54, 95% CI: 0.31-0.94). Exacerbations were not different between race/ethnicity categories. Predicted mean asthma-related costs were not different between Whites ($591, 95% CI: $509-686), Blacks ($638, 95% CI: $499-815), or Hispanics ($535, 95% CI: $466-614).


CONCLUSIONS
Results of these analyses found urban areas had higher rates of asthma-related hospital visits compared to rural counties, but no difference in asthma-costs between urban and rural areas which may suggest rural exacerbations may be more costly or severe. Persons with asthma aged 18 to 62 had higher rates of asthma-related emergency-room visits/hospitalizations than those aged 5 to 18. Persons 18 to 39 years of age had higher costs than person 5 to 17 or 40 to 62. Race/ethnicity in this population was not a significant predictor of outcomes or asthma-related costs.
Smith
Karen
K
Arizona Health Care Cost Containment System, Tucson, Arizona, USA. ksmith@pharmacy.arizona.edu
Warholak
Terri
T
Armstrong
Edward
E
Leib
Marc
M
Rehfeld
Rick
R
Malone
Daniel
D
D000293:Adolescent; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000328:Adult; D000367:Age Factors; D018927:Anti-Asthmatic Agents / Q000191:economics / Q000627:therapeutic use*; D001130:Arizona; D001249:Asthma / Q000188:drug therapy* / Q000191:economics* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D017048:Health Care Costs; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D020024:Leukotriene Antagonists / Q000627:therapeutic use; D008297:Male; D008484:Medicaid / Q000706:statistics & numerical data; D008875:Middle Aged; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D012737:Sex Factors; D016896:Treatment Outcome; D014481:United States; D014505:Urban Population / Q000706:statistics & numerical data
D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D005938:Glucocorticoids; D020024:Leukotriene Antagonists