Treating hyperlipidemia for the primary prevention of coronary disease. Are higher dosages of lovastatin cost-effective?

OBJECTIVE: To compare the average and marginal life-time cost-effectiveness of increasing dosages of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, such as lovastatin, for the primary prevention of coronary heart disease (CHD). METHODS: We estimated the lifelong costs and benefits of the modification of lipid levels achieved with lovastatin based on published studies and a validated CHD prevention computer model. Patients were middle-aged men and women without CHD, with mean total serum cholesterol levels of 6.67, 7.84, and 9.90 mmol/L (258, 303, and 383 mg/dL), and high-density lipoprotein cholesterol levels of 1.19 mmol/L (46 mg/dL), as described in clinical trials. We estimated the cost per year of life saved for dosages of lovastatin ranging from 20 to 80 mg/d that reduced the total cholesterol level between 17% and 34%, and increased high-density lipoprotein cholesterol level between 4% and 13%. RESULTS: After discounting benefits and costs by 5% annually, the average cost-effectiveness of lovastatin, 20 mg/d, ranged from $11,040 to $52,463 for men and women. The marginal cost-effectiveness of 40 mg/d vs 20 mg/d remained in this range ($25,711 to $60,778) only for persons with baseline total cholesterol levels of 7.84 mmol/L (303 mg/dL) or higher. However, the marginal cost-effectiveness of lovastatin, 80 mg/d vs 40 mg/d, was prohibitively expensive ($99,233 to $716,433 per year of life saved) for men and women, irrespective of the baseline total cholesterol level. CONCLUSIONS: Assuming that $50,000 per year of life saved is an acceptable cost-effectiveness ratio, treatment with lovastatin at a dosage of 20 mg/d is cost-effective for middle-aged men and women with baseline total cholesterol levels of 6.67 mmol/L (258 mg/dL) or higher. At current drug prices, treatment with 40 mg/d is also cost-effective for total cholesterol levels of 7.84 mmol/L (303 mg/dL) or higher. However, treatment with 80 mg/d is not cost-effective for primary prevention of CHD.

Estimating surgical volume--outcome relationships applying survival models: accounting for frailty and hospital fixed effects.

This paper investigates the surgical volume-outcome relationship for patients undergoing hip fracture surgery in Quebec between 1991 and 1993. Using a duration model with multiple destinations which accounts for observed and unobserved (by the researcher) patient characteristics, our initial estimates show that higher surgical volume is associated with a higher conditional probability of live discharge from the hospital. However, these results reflect differences between hospitals rather than differences within hospitals over time: when we also control for differences between hospitals that are fixed over time, hospitals performing more surgeries in period t + 1 than in period t experience no significant change in outcomes, as would be predicted by the 'practice makes perfect' hypothesis. The volume-outcome relationship for hip fracture patients thus appears to reflect quality differences between high and low volume hospitals.

Down and out: estimating the relationship between mental health and unemployment.

We utilized a unique dataset of Montreal residents to estimate the relationship between employment and mental health, controlling for endogeneity. We applied a maximum likelihood, simultaneous equation generalized probit model to estimate jointly the determinants of an individual's latent index of employability and their mental health as measured by the Psychiatric Symptom Index (PSI). The likelihood function was adjusted to account for the fact that individuals were sampled based on their employment status, and also for the fact that repeated observations of individuals in different periods were used in the analysis. We found tangible beneficial effects of mental health on employability. In addition, employment appears to improve mental health. The ML estimates of the endogenous relationship between employment and mental health indicate that OLS estimates are biased upwards, but the effects of unemployment on deteriorating mental health are not spurious.

A head-to-head comparison of the cost effectiveness of HMG-CoA reductase inhibitors and fibrates in different types of primary hyperlipidemia.

The objective of this study was to compare the lifetime cost-effectiveness of HMG-CoA reductase inhibitors and fibrates for the treatment of hyperlipidemia. Estimates of lipid modification achieved due to drug therapy were based on published head-to-head comparisons of specific HMG-CoA reductase inhibitors and fibrates in randomized, double-blind studies. We used a validated coronary heart disease (CHD) prevention computer model to estimate the costs and benefits of lifelong lipid modification. The patients were middle-aged men and women who were free of CHD, with either primary type IIa or IIb hyperlipidemia. The intervention used were specific HMG-CoA reductase inhibitors and fibrates at several dosages, which reduced total cholesterol 11-34% and increased high-density lipoprotein cholesterol 1-29%. The main outcome measure was the cost per year of life saved after discounting benefits and costs by 5% annually. The lifetime cost effectiveness of HMG-CoA reductase inhibitors (fluvastatin, lovastatin, pravastatin, simvastatin) and fibrates (bezafibrate, fenofibrate, gemfibrozil) for the treatment of primary hyperlipidemia varied according to patient population, the effectiveness of each drug in modifying lipid levels, and the price of each drug. The estimates of cost per year of life saved for HMG-CoA reductase inhibitors range from $19,886 to $73,632, and $16,955 to $59,488 for fibrates according to gender and type of primary hyperlipidemia. Fluvastatin 20 mg/day was significantly more cost effective than gemfibrozil 1200 mg/day for male patients with type IIa hyperlipidemia. Simvastatin 17.3 mg/day or 20 mg/day yielded similar cost-effectiveness ratios compared with fibrates among type II hyperlipidemic patients. However, micronized fenofibrate was more cost effective than simvastatin 20 mg/day among type IIb patients. The cost effectiveness of lipid therapy varies widely and can be maximized by selecting specific drugs for specific lipid abnormalities.

The effect of tobacco tax cuts on cigarette smoking in Canada.

OBJECTIVE: To assess the effect of the tobacco tax cuts made in 1994 on the smoking habits of Canadians. DESIGN: Population-based retrospective cohort study. DATA: Data from the Survey on Smoking in Canada conducted by Statistics Canada on 11,119 respondents 15 years of age and older, who were interviewed about their smoking habits on 4 occasions, approximately every 3 months from January 1994 to February 1995. OUTCOME MEASURES: Changes in smoking prevalence, incidence, quit rates and mean number of cigarettes smoked per day in the provinces where tobacco taxes were cut and in those where taxes were not cut. RESULTS: During the survey, smoking prevalence decreased in all provinces, whether or not cigarette taxes had been cut. However, the prevalence of smoking was greater in the provinces where tobacco taxes had been cut than in those where they had not, and this difference increased from 2.0% at the beginning of the survey to 3.4% by the end (p < 0.001). In addition, rates of starting cigarette smoking were higher and smoking quit rates were lower in the provinces where taxes had been cut than in those where taxes had not been cut. CONCLUSION: Although smoking rates are declining in Canada, tobacco tax cuts appear to have slowed the rate of decline by inducing more nonsmokers to take up smoking and leading fewer smokers to quit.

Why health care costs more in the US: comparing health care expenditures between systemic lupus erythematosus patients in Stanford and Montreal.

OBJECTIVE: Recent studies to identify the causes of higher health care expenditure in the US versus Canada have relied on population-based measures of health care utilization and have restricted their analysis to one sector, such as physician or hospital expenditures. We present a detailed comparative analysis of the direct costs (health services utilized) of treating systemic lupus erythematosus (SLE) patients in Stanford, CA and Montreal, Quebec. METHODS: Using the self-report Stanford Health Assessment Questionnaire, we assessed 6-month direct costs incurred by 174 American and 164 Canadian SLE patients. We explored 3 potential reasons for the differential expenditure. These were 1) higher prices for health care inputs, 2) more severe disease in the patient case mix, and 3) greater resource utilization. RESULTS: The direct health care costs for the American SLE patients exceeded those for the Canadian patients by almost 2-fold ($10,530 versus $5,271, expressed in 1991 US dollars). The higher direct costs were explained by the higher price of health services in the US and the more severe disease mix. In fact, for all health resources categories studies, Canadians utilized at least as many services as their American counterparts. Canadians had longer hospital stays, made more emergency room visits, and used more medications. CONCLUSION: Despite significantly greater per capita health care expenditure in the US, our data show that Canadian SLE patients actually receive more medical services.

What are the costs of queuing for hip fracture surgery in Canada?

This paper investigates the effect of wait time for hip fracture surgery in Canada on post-surgery length of stay in hospital and inpatient mortality. After controlling for observed and unobserved patient and hospital characteristics, pre-surgery delay has little effect on either of the two outcome variables. Patients from higher income postal-codes experience only slightly shorter delays, and income has no substantial effect on post-surgery outcomes. For hip fracture patients surgery delay may lead to greater pre-surgery inpatient costs and more patient discomfort, but we find no evidence of a detrimental impact on post-surgery outcomes.

The cost-effectiveness of HMG-CoA reductase inhibitors to prevent coronary heart disease. Estimating the benefits of increasing HDL-C.

OBJECTIVE: To evaluate the lifetime cost-effectiveness of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors for treatment of high blood cholesterol levels. DESIGN: We added cost data to a validated coronary heart disease (CHD) prevention computer model that estimates the benefits of lifelong risk factor modification. The updated model takes into account the costs of cholesterol reduction, the savings in CHD health care costs attributable to intervention, the additional non-CHD costs resulting from patients' living longer, and the beneficial effects of reducing CHD risk by reducing total cholesterol and increasing high-density lipoprotein cholesterol (HDL-C). PATIENTS: Men and women aged 30 to 70 years who were free of CHD, had total cholesterol levels equal to the 90th percentile of the US distribution in their age and sex group, had HDL-C levels equal to the mean of the US distribution in their age and sex group, and were either with or without additional CHD risk factors. INTERVENTION: Use of 20 mg of lovastatin per day, which on average reduces total serum cholesterol by 17% and increases HDL-C by 7%. MAIN OUTCOME MEASURES: Cost per year of life saved after discounting benefits and costs by 5% annually. RESULTS: The increase in HDL-C associated with lovastatin lowered cost-effectiveness ratios by approximately 40%, such that the treatment of hypercholesterolemia was relatively cost-effective for men (as low as $20,882 per year of life saved at age 50 years) and women ($36,627 per year of life saved at age 60 years) with additional risk factors. Non-CHD costs resulting from longer life expectancy after intervention added at most 23% to the cost-effectiveness ratios for patients who began treatment at age 70 years, and as little as 3% for patients at age 30 years. CONCLUSION: The cost-effectiveness of HMG-CoA reductase inhibitors varied widely by age and sex and was sensitive to the presence of non-lipid CHD risk factors. The additional non-CHD costs due to increased life expectancy may be significant for the elderly. Accounting for the drug effects of raising HDL-C levels increased the proportion of the population for which medication treatment was relatively cost-effective.