Every year in Ontario, the records of over 42 million prescriptions dispensed to persons eligible for Ontario Drug Benefit (ODB) benefits are transmitted to a central database. The ODB database is the second largest database of medications in Canada, containing records on almost half of all medications dispensed in Ontario. There is no information about the reliability of the coding on the ODB drug claims database and, therefore, the objective of this study was to estimate the reliability of coding of the Drug Identification Number, and the date, quantity and duration of the dispensation on claims sent to the ODB.
To meet this objective, approximately 100 randomly selected prescriptions dispensed from each of 50 pharmacies in southern Ontario between July 1, 1998 and December 31, 1999 were audited. For each claim, the written information on the prescription was compared with the electronic information submitted to the ODB database. Logistic regression was used to test the association between coding errors and the location, owner affiliation, and productivity of each pharmacy (defined as the annual volume of dispensations divided by the annual number of hours worked by all pharmacists and pharmacy assistants).
Of the 183 pharmacies owners invited to participate, consent to abstract information was obtained in 50, yielding a participation rate of 27%. Of the 5155 dispensed prescriptions, 37 errors were found, yielding an overall error rate of 0.7% (95% CI 0.5% to 0.9%). None of the characteristics of pharmacies that were examined (location, owner affiliation, productivity) was associated with coding errors.
Pharmacists almost always dispense the medication that is prescribed and this information is reliably transmitted to the ODB drug claims database. This means that any conclusions drawn by researchers using these data are not likely to be compromised by low coding reliability.
Clinical trials of cost-effectiveness are often conducted in more than one country. The two most common ways of dealing with the multinational nature of the data are either to calculate a pooled estimate or to stratify results by country. Since the between-country heterogeneity in costs is potentially substantial, pooled estimates may be difficult to interpret for any one country. Policy decisions are often made at a national level, and so country-specific results are important. However, country-specific analyses will be based on fewer patients and will often fail to provide adequate precision for statistical analyses. Shrinkage estimation is a compromise between these two methods and has been used successfully in other fields. These estimates are country-specific yet less variable than those derived through a subgroup approach. Univariate and multivariate shrinkage estimators for costs and effects are proposed, then compared with one another and to the traditional methods in a simulation study. The methods are illustrated using data from a multinational trial evaluating the cost-effectiveness of three thrombolytic drug regimens in patients with acute myocardial infarction.
To compare the expected costs and outcomes of seven alternative long-term primary care strategies for the management of patients with moderate-to-severe heartburn over a 1-year period.
A decision-analytic model was developed to estimate costs and effects (weeks with heartburn symptoms and quality adjusted life years [QALYs]) for each strategy. Meta-analyses were used to synthesize acute treatment and maintenance studies and physician surveys to collect information on patient management. The impact of uncertainty on the base case results was assessed using probabilistic sensitivity analysis. Probability distributions were defined for key model parameters and techniques of Monte Carlo simulation were used to draw values from these distributions. Cost-effectiveness acceptability curves (CEACs) conditional on the monetary value decision makers are willing to pay for a symptom-free day or QALY were created for each strategy.
In the base case, no strategy was strictly dominated by any other strategy. However, two strategies (maintenance H2-receptor antagonists H2RA] and step-down proton pump inhibitor PPI]) were dominated through principles of extended dominance. The least costly and least effective strategy was intermittent H2RA, while maintenance PPI was the most costly and most effective.
This analysis showed that the best way of managing patients with heartburn depends on how much society is willing to pay to achieve health improvements. Based on the commonly quoted threshold of US 50,000 dollars per QALY, the optimal primary care strategy for managing patients with moderate-to-severe heartburn symptoms is to treat the symptoms with a PPI followed by maintenance therapy with an H2RA to prevent symptomatic recurrence.
The purpose of this study was to determine the cost-effectiveness of physiologic pacemakers.
The Canadian Trial of Physiologic Pacing (CTOPP) was a large randomized trial that evaluated the efficacy of physiologic pacing compared with ventricular pacing. CTOPP also included a prospective cost-effectiveness substudy.
Resource usage and costs were collected from a subset of 472 patients (of 1,094) who received a physiologic pacemaker and 586 (of 1,474) who received a ventricular pacemaker. Costs included initial pacemaker implantation and all health care follow-up costs over a follow-up of 5.2 years. Costs are reported in 2004 Canadian dollars (1 Canadian dollar = 0.76 US dollars), with adjustments for censoring. Incremental cost-effectiveness was estimated as the ratio of the difference (treatment-control) in mean cost to the difference in life expectancy (mean survival), with costs and effects discounted at 3% per year.
Over a mean follow-up of 3.1 years, physiologic pacing was associated with a gain of 0.01 life-years. This benefit increases to 0.25 life-years in the subgroup of patients with an intrinsic (unpaced) heart rate 60.
In the short term, a strategy of routine implantation of physiologic pacemakers is not cost-effective by currently accepted standards. The selective use of these devices in patients likely to be pacemaker dependent appears to be cost-effective. Further studies with longer follow-up and which consider the benefit of reducing nonfatal cardiac events would be valuable.
One barrier to economic evaluation alongside neonatal randomized controlled trials is the expense of collecting detailed patient resource information. To reduce this data collection burden, we identified the key resource items that predict daily ancillary costs for extremely low birth weight infants.
Participants were 385 infants enrolled in the Trial of Indomethacin Prophylaxis for Preterms in nine tertiary level neonatal intensive care units in Canada. Information on eighty-nine nonpersonnel resource items was abstracted from the hospital chart from admission to tertiary hospital discharge. Unit costs were derived from a provincially standardized cost accounting system. Using stepwise linear regression, models correlating total daily ancillary costs with key resource items were constructed for each of five periods of admission. Models were derived in a randomly split half of the total sample of patient days and validated against the remainder.
The 385 infants contributed resource information from 23,354 admission days. The regression model for weeks one to twelve included the covariates surfactant, chest radiograph, red blood cell transfusion, cranial ultrasound, abdominal radiograph, parenteral amino acid infusion, surgery, platelet transfusion, and echocardiogram and explained 91% of the variability in daily nonpersonnel costs (P
Two programs to reduce expenditures for common gastrointestinal drugs were introduced simultaneously by British Columbia (BC) Pharmacare in 1995. Reference-based pricing restricted reimbursement for all histamine-2 receptor antagonists (H2RAs) to the cost of the least expensive H2RA available, generic cimetidine. Special authority restricted reimbursement for proton pump inhibitors (PPIs) to patients who met certain eligibility criteria. We evaluated the effect of reference-based pricing for H2RAs and special authority for PPIs on dispensing and reimbursement for senior citizen beneficiaries of BC Pharmacare.
Itemized monthly claims data for upper gastrointestinal drugs were obtained from BC Pharmacare for all beneficiaries 65 years of age or older. Periods before and after implementation of reference-based pricing and special authority were compared with respect to defined daily doses dispensed per 100,000 beneficiaries, BC Pharmacare reimbursement per 100,000 beneficiaries, BC Pharmacare reimbursement per defined daily dose and beneficiary contributions per defined daily dose. We used regression models to project forward trends in expenditures observed before implementation of the new policies and hence to estimate accrued cost savings.
Before reference-based pricing and special authority, the numbers of defined daily doses that were dispensed and total BC Pharmacare reimbursements for H2RAs appeared to be declining gradually, whereas those for PPIs were rising. With reference-based pricing, the monthly defined daily dose of cimetidine dispensed increased more than 4-fold, to 116,257 per 100,000 beneficiaries, while those of other restricted H2RAs decreased by more than half, to 50,927 per 100,000 beneficiaries. Special authority immediately reduced the dispensed volumes of PPIs by one-fourth, but growth in volume then appeared to resume at its previous rate. The estimated annualized cost savings achieved by reference-based pricing and special authority were $1.8 million to $3.2 million for H2RAs (depending on the estimation method used) and $5.5 million for PPIs. However, beneficiary contributions for H2RAs increased from negligible amounts to approximately 16% of total drug expenditures.
Reference-based pricing and special authority appear to have been successful in altering prescribing habits and reducing provincial expenditures for upper gastrointestinal drugs, but they have increased the financial burden on senior citizen beneficiaries.
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To estimate the effect of reference pricing (RP) of nonsteroidal anti-inflammatory drugs (NSAIDs) on drug subsidy program and beneficiary expenditures on analgesic drugs.
Monthly claims data from Pharmacare, the public drug subsidy program for seniors in British Columbia, Canada, over the period of February 1993 to June 2001.
RP limits drug plan reimbursement of interchangeable medicines to a reference price, which is typically equal to the price of the lowest cost interchangeable drug; any cost above that is borne by the patient. Pharmacare introduced two different forms of RP to the NSAIDs, Type 1 in April 1994 and Type 2 in November 1995. Under Type 1 RP, generic and brand versions of the same NSAID are considered interchangeable, whereas under Type 2 RP different NSAIDs are considered interchangeable. We extrapolated average reimbursement per day of NSAID therapy over the months before RP to estimate what expenditures would have been without the policies. These counterfactual predictions were compared with actual values to estimate the impact of the policies; the estimated impacts on reimbursement rates were multiplied by the postpolicy volume of NSAIDS dispensed, which appeared unaffected by the policies, to estimate expenditure changes.
After Type 2 RP, program expenditures declined by $22.7 million (CAN), or $4 million (CAN), annually cutting expenditure by about half. Most savings accrued from the substitution of low-cost NSAIDs for more costly alternatives. About 20 percent of savings represented expenditures by seniors who elected to pay for partially reimbursed drugs. Type 1 RP produced one-quarter the savings of type 2 RP.
Type 2 RP of NSAIDs achieved its goal of reducing drug expenditures and was more effective than Type 1 RP. The effects of RP on patient health and associated health care costs remain to be investigated.
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Influenza is a common viral respiratory infection that is associated with significant morbidity. Oseltamivir (Tamiflu) is a neuraminidase inhibitor-a new class of antiviral treatment for influenza where efficacy and safety has been established but cost-effectiveness is unknown.
A decision analytic model was used to estimate the costs and effectiveness of two treatment scenarios for empiric management of otherwise healthy nonelderly patients, presenting with influenza-like illness (ILI) to primary care physicians in Canada: 1) where oseltamivir is reimbursed and on formulary for prescription; and 2) where oseltamivir is not on formulary. Outcomes are influenza-days averted and quality-adjusted life-years (QALYs) gained. Effectiveness, utility, and pneumonia complication risk estimates are by pooled analysis of patient-level data from four clinical trials. Unit cost information (Canadian dollars) was obtained from published sources in Ontario. Probabilistic sensitivity analysis was conducted using Monte Carlo simulation.
Of 2288 patients randomized, influenza was confirmed in 1575 (69%) and oseltamivir treatment reduced the mean time to symptom alleviation by 1.08 days (95% confidence interval CI] 0.58-1.59). Infected patients treated with oseltamivir had higher utility scores (quality of life) than placebo patients over the 7 days of follow-up (P
In the absence of major contraindications, treatment guidelines recommend that, following a major traumatic event, all patients receive low molecular weight heparin (e.g. enoxaparin) as thromboprophylaxis for the prevention of deep vein thrombosis (DVT).
To estimate the incremental cost-effectiveness of enoxaparin versus low dose unfractionated heparin (UH) for the prophylaxis of DVT following major trauma.
Using probabilistic decision-analytic modeling, we estimated the incremental cost-effectiveness of enoxaparin versus unfractionated heparin for the prophylaxis of DVT following moderate to severe trauma (injury severity score > or = 9) over a life-time time horizon from the perspective of the health care payer. Cost effectiveness was calculated based on both the incremental cost (ïC) per DVT averted and the ïC per life year gained (LYG).
The incremental cost of enoxaparin relative to UH was C$90, and the incremental effectiveness was 0.085 DVTs averted and -0.13 LYG. This resulted in an incremental cost-effectiveness ratio of C$1,059 per DVT averted, and the conclusion that UH is the dominant strategy in terms of LYG. In addition to the probabilistic analysis, one-way and two-way sensitivity analysis revealed that the model was most sensitive to variation in the discount rate (3-7%), but that UH remained the dominant strategy in terms of life years independent of the parameter estimates.
Although enoxaparin appears to be a cost-effective alternative when considering the intermediate endpoint of DVTs averted, it may be dominated by UH in terms of LYG due to the higher incidence of major bleeds in patients receiving enoxaparin versus UH.