Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 1620 Tremont St (Ste 3030), Boston, MA 02120, USA. email@example.com
To evaluate the effects of patient copayment and coinsurance policies on adherence to therapy with beta-adrenergic blocking agents (beta-blockers) and on the rate of initiation of beta-blocker therapy after acute myocardial infarction (MI) in a population-based natural experiment.
Three sequential cohorts included British Columbia residents age 66 years and older who initiated beta-blocker therapy during time intervals with full drug coverage (2001), a $10 or $25 copayment (2002), and 25% coinsurance (2003-2004). We used linked data on all prescription drug dispensings, physician services, and hospitalizations. Follow-up of each cohort was 9 months after the policy changes.
We measured the proportion of subjects in each cohort who were adherent to beta-blocker therapy over time, with adherence defined as having >80% of days covered. We also measured the proportion of patients initiating beta-blocker therapy after acute MI. Policy effects were evaluated using multivariable regression.
Adherence to beta-blocker therapy was marginally reduced as a consequence of the copayment policy (-1.3 percentage points, 95% confidence interval [CI] = -2.5 , -0.04) or the coinsurance policy (-0.8 percentage points, 95% CI = -2.0, 0.3). The proportion of patients initiating beta-blockers after hospitalization for acute MI remained steady at about 61% during the study period, similar to that observed in a control population of elderly Pennsylvania residents with full drug coverage.
Fixed patient copayment and coinsurance policies had little negative effect on adherence to relatively inexpensive beta-blocker therapy, or initiation of beta-blockers after acute MI.
Cites: N Engl J Med. 1991 Oct 10;325(15):1072-71891009
To compare the results of a randomised and an observational evaluation of the same policy that restricted reimbursement for nebulised respiratory medications in adult patients in a community setting.
Cluster randomised controlled trial and observational time series with historical controls.
Pharmacare, the government funded drug benefits plan for elderly people and patients receiving social assistance in British Columbia, Canada.
In the randomised controlled trial 104 clusters of medical practices, pair matched by geography and approximately by practice size, were randomised to the intervention group (449 patients affected by the policy on 1 March 1999), and the control group (offered a six month exemption, affecting 386 patients). The observational analysis included all Pharmacare beneficiaries (excluding the 386 exempt patients) who had used any nebulised drugs six months before the policy (4624 patients).
Pharmacare restricted reimbursement for nebulised bronchodilators, steroids, and cromoglycate to patients whose doctors applied for an individual patient's exemption, giving an appropriate clinical reason.
Number of contacts with doctors and services, emergency admissions to hospital, and utilisation of and expenditure for respiratory drugs in databases of British Columbia's Ministry of Health.
Contacts with doctors or emergency admissions to hospital did not increase in association with the restriction, regardless of the analytical approach. In the observational analysis, we found a reduction of C24 dollars per patient month in all nebulised drug use (95% confidence interval 19 to 29) and an increase of C3 dollars per patient month in all expenditure for inhalers (1.4 to 4.5). The randomised evaluation found savings of C8 dollars per patient month for nebulisers (P = 0.24) and no increase in spending on inhalers (P = 0.79). Correcting for 60% non-compliance by exempt doctors in a sensitivity analysis yielded similar results as the observational evaluation.
Observational as well as randomised analyses found moderate net savings and no increase in unintended healthcare outcomes after restricting reimbursement for nebulised respiratory drugs. Randomised policy trials are feasible and, if carefully implemented, likely to be concordant with observational evaluations.
Rapid growth in prescription drug costs has compelled insurers to require increased patient cost-sharing.
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.
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.
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]).
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.
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Cites: J Am Geriatr Soc. 2002 Mar;50(3):521-511943050
Antidepressant therapies are underused among older adults and could be further curtailed by patient cost-sharing requirements. The authors studied the effects of two sequential cost-sharing policies in a large, stable population of all British Columbia seniors: change from full prescription coverage to 10-25 dollars copayments (copay) in January 2002 and replacement with income-based deductibles and 25% coinsurance in May 2003.
PharmaNet data were used to calculate monthly dispensing of antidepressants (in imipramine-equivalent milligrams) among all British Columbia residents age 65 and older beginning January 1997 through December 2005. Monthly rates of starting and stopping antidepressants were calculated. Population-level patterns over time were plotted, and the effects of implementing cost-sharing policies on antidepressant use, initiation, and stopping were examined in segmented linear regression models.
Implementation of the copay policy was not associated with significant changes in level of antidepressant dispensing or the rate of dispensing growth. Subsequent implementation of the income-based deductible policy also did not lead to a significant change in dispensing level but led to a significant (p=.02) decrease in the rate of growth of antidepressant dispensing. The copay policy was associated with a significant (p=.01) drop in the frequency of antidepressant initiation among persons with depression. Income-based deductibles reduced the rate of increase in antidepressant initiation over time. Implementation of the copay and income-based deductible policies did not have significant effects on stopping rates.
Introducing new forms of medication cost sharing appears to have the potential to reduce some use and initiation of antidepressant therapy by seniors. The clinical consequences of such reduced use need to be clarified.
Divison of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Ave (BLI-341), Boston, MA 02115, USA. firstname.lastname@example.org
A causal relation between drug benefit policy change and the increase in adverse outcomes can be tested by comparing the experience of a group of patients affected by the policy vs. the (counterfactual) experience of the same patients if the policy had not been implemented. Because counterfactual experiences cannot be observed, it must be assumed that the counterfactual is correctly described by extrapolating from the same population's previous experience. The null hypothesis of no policy effect can be empirically tested using quasi-experimental longitudinal designs with repeated measures. If compliance to a policy is low, results may be biased towards the null, but a subgroup analysis of compliers may be biased by nonignorable treatment selection. Using the example of reference drug pricing in British Columbia we discuss assumptions for causal interpretations of such analyses, and provide supplementary analyses to assess and improve the validity of findings. Results from nonrandomized comparisons of subgroups defined by their compliance to a policy change should generally be interpreted cautiously, and several biases should be explored.