Emergency hospital admissions after income-based deductibles and prescription copayments in older users of inhaled medications.
BACKGROUND
Rapid growth in prescription drug costs has compelled insurers to require increased patient cost-sharing.


OBJECTIVE
The aim of this study was to compare the effects of 2 recent cost-sharing policies on emergency hospitalizations due to chronic obstructive pulmonary disease, asthma, or emphysema (CAE), and on physician visits.


METHODS
We analyzed data from a large-scale natural experiment in British Columbia (BC), Canada. The cost-sharing policies were a fixed copayment policy (fixed copay policy) and an income-based deductible (IBD) policy with 25% coinsurance (IBD policy). Prescription, physician billing, and hospitalization records were obtained from the BC Ministry of Health. From the total population of BC residents > or = 65 years of age, we extracted data from all patients dispensed an inhaled corticosteroid, beta(2)-agonist, or anticholinergic from June 30, 1997, to April 30, 2004. Poisson regression was used to evaluate the impact of the policies in a cohort of patients receiving long-term inhaler treatment. An identically defined historical control group unaffected by the policy changes was used for comparison.


RESULTS
The study population included 37,320 users of long-term inhaled medications from the BC population of 576,000 persons > or = 65 years of age. During the IBD period but not the fixed copay period, emergency hospitalizations for CAE increased 41% (95% CI for adjusted rate ratio [RR], 1.24-1.60) in patients > or = 65 years of age. There was also a significant increase in physician visits of 3% (95% CI for adjusted RR, 1.01-1.05). No significant increases were observed during the fixed copay period. In a secondary analysis using a concurrent control group, we estimated a smaller but significant increase in emergency CAE hospitalizations of 29% (95% CI for adjusted RR, 1.09-1.52). This analysis also showed increases in physician visits (fixed copay period RR, 1.03 [95% CI for adjusted RR, 1.01-1.05]; IBD period RR, 1.07 [95% CI for adjusted RR, 1.05-1.08]).


CONCLUSIONS
The results suggest that the IBD policy was likely associated with an increased risk for emergency hospitalization and physician visits in these users of inhaled medications who were aged > or = 65 years.
Dormuth
Colin R
CR
Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA. colin.dormuth@ti.ubc.ca
Maclure
Malcolm
M
Glynn
Robert J
RJ
Neumann
Peter
P
Brookhart
Alan M
AM
Schneeweiss
Sebastian
S
D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000191:economics* / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000188:drug therapy; D002170:Canada; D018680:Cholinergic Antagonists / Q000191:economics* / Q000627:therapeutic use; D015331:Cohort Studies; D003669:Deductibles and Coinsurance / Q000191:economics*; D004363:Drug Utilization; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004646:Emphysema / Q000188:drug therapy; D005260:Female; D005938:Glucocorticoids / Q000191:economics* / Q000627:therapeutic use; D006291:Health Policy; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D007345:Insurance Claim Review; D008171:Lung Diseases / Q000188:drug therapy*; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy; D013221:State Health Plans / Q000191:economics
D000318:Adrenergic beta-Agonists; D018680:Cholinergic Antagonists; D005938:Glucocorticoids