Cost-effectiveness of thrombolytic therapy for acute myocardial infarction.

OBJECTIVE: To estimate the cost-effectiveness of thrombolytic therapy versus no thrombolytic therapy for patients following acute myocardial infarction, focusing on the impact of time to treatment on outcome. METHODS: A decision model was developed to assess the benefits, risks, and costs associated with thrombolytic therapy for treatment of acute myocardial infarction compared with standard nonthrombolytic therapy. The model used pooled data from a recent study of nine large randomized, controlled clinical trials and 12-month outcome data from a recently published meta-analysis of thrombolytic therapy trial data. Outcomes were expressed in terms of survival to hospital discharge and survival to 1 year after discharge. The risks of treatment that led to death, morbidity, or added costs were estimated. The model determined excess and marginal costs per death averted to hospital discharge and at 1 year. Results were also estimated in terms of cost per year of life saved. Sensitivity analyses included variations in time to treatment and drug cost. RESULTS: The marginal cost of thrombolytic therapy per death averted at 1 year was $222,344, or $14,438 per year of life saved. For patients treated within 6 hours of acute myocardial infarction, the marginal cost per death averted was $181,536 at 1 year, or $11,788 per year of life saved. CONCLUSIONS: Thrombolytic therapy is significantly more cost-effective than many other cardiovascular interventions and compares favorably with other forms of medical therapy. Results suggest that shortening the time to treatment has a critical impact on the cost-effectiveness of thrombolytic therapy.

The cost effectiveness of three programs to increase use of bicycle helmets among children.

Each year in the United States, 280 children die from bicycle crashes and 144,000 are treated for head injuries from bicycling. Although bicycle helmets reduce the risk of head injury by 85 percent, few children wear them. To help guide the choice of strategy to promote helmet use among children ages 5 to 16 years, the cost effectiveness of legislative, communitywide, and school-based approaches was assessed. A societal perspective was used, only direct costs were included, and a 4-year period after program startup was examined. National age-specific injury rates and an attributable risk model were used to estimate the expected number of bicycle-related head injuries and deaths in localities with and without a program. The percentage of children who wore helmets increased from 4 to 47 in the legislative program, from 5 to 33 in the community program, and from 2 to 8 in the school program. Two programs had similar cost effectiveness ratios per head injury avoided. The legislative program had a $36,643 cost and the community-based one, $37,732, while the school-based program had a cost of $144,498 per head injury avoided. The community program obtained its 33 percent usage gradually over the 4 years, while the legislative program resulted in an immediate increase in usage, thus, considering program characteristics and overall results, the legislative program appears to be the most cost-effective. The cost of helmets was the most influential factor on the cost-effectiveness ratio. The year 2000 health objectives call for use of helmets by 50 percent of bicyclists. Since helmet use in all these programs is less than 50 percent, new or combinations of approaches may be required to achieve the objective.

Cost effectiveness of antiviral treatment with zalcitabine plus zidovudine for AIDS patients with CD4+ counts less than 300/microliters in 5 European countries.

A cost-effectiveness model was developed on the basis of early clinical trial results from the US reporting sustained CD4+ cell response in patients receiving zalcitabine in addition to zidovudine. This model was then adapted and applied to 5 European countries to assess the comparative cost effectiveness of adding zalcitabine to antiviral treatment for AIDS patients. The countries included in the modelling effort were Switzerland, France, Italy, Germany and the UK. The model used a Markov state-transition process to estimate the rate of acute opportunistic disease episodes, lifetime medical treatment costs, and survival for populations of AIDS patients with baseline CD4+ counts of less than 300/microliters. Physician panels in each country developed standard treatment algorithms and adjusted the epidemiological data to reflect the AIDS profile of each country. Economic consultants provided cost data. Results from this exploratory data analysis show that if CD4+ counts correlate with the incidence of opportunistic disease episodes as expected, the combined use of zalcitabine and zidovudine for a 1-year period should be cost effective.

Cost utility of maintenance treatment of recurrent depression with sertraline versus episodic treatment with dothiepin.

The objective of this study was to model, for patients at risk of recurrent depression, the cost-utility of maintenance therapy with sertraline compared with treatment of acute episodes with dothiepin ('episodic treatment'). Using clinical decision analysis techniques, a Markov state-transition model was constructed to estimate the lifetime costs and quality-adjusted life-years (QALYs) of the 2 therapeutic strategies. The model follows 2 cohorts of 35-year-old women at high risk for recurrent depression over their lifetimes. Model construction and relevant data (probabilities) for performing the analysis were based on existing clinical knowledge. Two physician panels were used to obtain estimates of recurrence probabilities not available in the literature, health utilities, and resource consumption. Costs were obtained from published sources. The baseline analysis showed that it costs 2172 British pounds sterling ($US3692, 1991 currency) to save an additional QALY with sertraline maintenance treatment. Sensitivity analysis showed that the incremental cost-utility ratio ranged from 557 British pounds sterling to 5260 British pounds sterling per QALY. Overall, the resulting ratios are considered to be well within the range of cost-utility ratios that support the adoption and appropriate utilisation of a technology. Based on the study assumptions, long term maintenance treatment with sertraline appears to be clinically and economically justified choice for patients at high risk of recurrent depression.

Patient adherence to prescribed potassium supplement therapy.

We have investigated whether patient adherence ratios calculated from prescription refill data for potassium supplement medications differ depending on the type of supplement. By using automated pharmacy claims records from a large managed care organization, an index of adherence to prescribed therapy was calculated for each patient as a ratio of total days of drug supplied to the total number of days between prescription refills. The mean patient adherence to prescribed therapy ratios were compared among different potassium drug regimens. There were 2289 patients eligible for analysis; 65.9% were women, and the mean age was 57.6 years. The mean patient adherence ratio for one brand of extended-release tablet, K-DUR, was 0.81 (a majority of the patients were receiving 20 mEq/day). This was higher than the combined mean patient adherence ratio for all other supplements (0.73); the combined mean ratio for all other extended-release tablets (0.74); the combined mean ratio for all other tablets and capsules (0.74); the combined mean ratio for liquids (0.50); the combined mean ratio for liquids and powders (0.63); and equivalent to the ratio for another extended tablet, Micro-K (0.82). Regression analysis showed that increased patient adherence was seen among patients taking K-DUR tablets as compared with those taking other potassium supplements. Increased adherence among patients taking K-DUR remained statistically significant after controlling for number of prescriptions filled, dose, age, sex, and health plan location. Pharmacy claims data can be used effectively to measure patient adherence with potassium supplement therapy. Future research should relate patient adherence ratios to clinical outcomes.

Cost-effectiveness of hepatitis-B vaccine in Greece. A country of intermediate HBV endemicity.

We evaluated the cost-effectiveness of (a) a vaccination program for the prevention of hepatitis B; and (b) the two commercially available vaccines (Merck Sharp and Dohme; Pasteur Institute) in Greece, a country of intermediate endemicity. We examined cases of hepatitis-B infection prevented and the expected medical costs among the high-risk groups of medical and nursing students, hospital personnel, and the general population. Employing a vaccination program reduces considerably the risk of infection, especially in the high-risk groups, while it increases the total cost. The vaccines are very comparable in terms of both health and economic outcomes. Sensitivity analysis indicated that vaccine cost, incidence of hepatitis B, and compliance were the key factors for the choice of (a) whether to undertake an extensive program to prevent hepatitis-B infection and its chronic sequelae; and (b) which vaccine to administer.

Trends in smoking by age and sex, United States, 1974-1987: the implications for disease impact.

Using data from the 1974-1987 National Health Interview Surveys, we report trends in current smoking prevalence and quit ratios (the proportion of those who have ever smoked who no longer smoke) for men and women in the age groups 20-24, 25-44, 45-64, and 65 years and older. Current smoking prevalence decreased linearly for men in all age subgroups except 65 and older and for women ages 25-44 and 45-64 years only. The quit ratios increased linearly within each age/sex subgroup except for men and women ages 20-24 years. Overall, there were about 1.4 million fewer male smokers and over 1 million more female smokers in 1987 than there were in 1974. Between 1974 and 1987, the population ages 25-44 years increased by approximately 47%, and the population 65 years and older increased by approximately 34%. As a result, between 1974 and 1987, the actual number of smokers increased among men ages 25-44 years (8% increase), women ages 25-44 years (15% increase), and women ages 65 years and older (50% increase). These data suggest that even with favorable recent changes in the overall smoking prevalence of the U.S. population, the disease impact of smoking will increase for decades, especially among women. This scenario will be mitigated if increased attention is given to cessation among women in general and to the post-World War II generation of both male and female smokers.

Quitting smoking in the United States in 1986.

In an analysis of recent behavior with regard to quitting smoking, detailed histories were obtained on a representative sample of 5,623 Americans who had smoked in the year preceding the 1986 Adult Use of Tobacco Survey. An estimated 55.8 million Americans smoked regularly for some period during the year prior to the survey. Approximately one third (34.8%) quit for at least a day during the year prior to the survey, 28.3% quit for at least 7 days during the year prior to the survey, and 16.2% were still not smoking at the time of the survey. Of those who quit for a day, 54% had relapsed by the time of the survey. Demographic characteristics, such as age, sex, race, marital status, and education, were evaluated as predictors of making a major attempt to quit for 7 days or more. Among those who had made a major attempt, a similar analysis was done predicting success in maintaining cessation for 3 months or more. Ordinal logistic regression analyses showed that younger age and higher education predicted a major attempt to quit. There was only one group who differed markedly from all others: those who were younger and were more highly educated. Older age and being white predicted those who abstained for 3 months or longer.

Methods used to quit smoking in the United States. Do cessation programs help?

Using data from the 1986 Adult Use of Tobacco Survey, we analyzed smoking-cessation methods used by adult smokers in the United States who tried to quit. About 90% of successful quitters and 80% of unsuccessful quitters used individual methods of smoking cessation rather than organized programs. Most of these smokers who quit on their own used a "cold turkey" approach. Multivariate analysis showed that women, middle-aged persons, more educated persons, persons who had made more quit-smoking attempts, and, particularly, heavier smokers were most likely to use a cessation program. Daily cigarette consumption, however, did not predict whether persons would succeed or fail during their attempts to quit smoking. Rather, the cessation method used was the strongest predictor of success. Among smokers who had attempted cessation within the previous 10 years, 47.5% of persons who tried to quit on their own were successful whereas only 23.6% of persons who used cessation programs succeeded. We conclude that cessation programs serve a small, but important, population of smokers that includes heavier smokers, those most at risk for tobacco-related morbidity and mortality.

The reliability of self-reported cigarette consumption in the United States.

To investigate the possibility that self-reported smoking is not a valid measure for assessing trends in smoking prevalence, we compared total self-reported cigarette consumption with the adjusted consumption data from cigarette excise taxes as reported by the US Department of Agriculture (USDA) for the period 1974 through 1985. Self-reported consumption was calculated by using data from the National Health Interview Surveys (NHIS) for adults and from the National Household Surveys on Drug Abuse for adolescents. For this period, the average ratio of self-reported cigarette consumption to the USDA estimate of consumption was 0.72 (range = 0.69 to 0.78). There was no statistical difference in this consumption ratio from year to year, indicating no apparent increase in the underreporting of cigarette smoking in these surveys. We conclude that cross-sectional surveys of self-reported smoking status remain a reliable surveillance tool for monitoring changes in population smoking behavior.

Trends in cigarette smoking in the United States. The changing influence of gender and race.

Trends in the prevalence, initiation, and cessation of cigarette smoking are reported for the US population using weighted and age-standardized data from seven National Health Interview Surveys (1974 to 1985). The decline in prevalence was linear, with the prevalence for men decreasing at 0.91 percentage points per year to 33.5% in 1985 and the prevalence for women decreasing at 0.33 percentage points per year to 27.6% in 1985. For whites the rate of decline (percentage points per year) was 0.57, to 29.4% in 1985, and for blacks the decline was 0.67, to 35.6% in 1985. Smoking cessation increased among all gender-race groups from 1974 to 1985, with the yearly rate of increase (in percentage points per year) about equivalent for blacks (0.75) and whites (0.77), while it was higher in women (0.90) than in men (0.67). Smoking initiation decreased among young men (-1.03), while it remained about the same in young women (+0.11). Initiation decreased at a more rapid rate in blacks (-1.02) than in whites (-0.35). We conclude that smoking prevalence is decreasing across all race-gender groups, although at a slower rate for women than men, and that differences in initiation, more than cessation, are primarily responsible for the converging of smoking prevalence rates among men and women.

Trends in cigarette smoking in the United States. Educational differences are increasing.

National trends in smoking prevalence by educational category from 1974 through 1985 show that education has replaced gender as the major sociodemographic predictor of smoking status. Smoking prevalence has declined across all educational groups but the decline has occurred five times faster among the higher educated compared with the less educated. From 1974 to 1985, smoking prevalence among persons with less than a high school diploma declined to 34.2% (0.19 percentage points per year) whereas prevalence for persons with four years or more of college education declined to 18.4% (0.91 percentage points per year). Smoking cessation activity increased across all educational groups, but the rate of increase among the higher educated was twice that of lower-educated groups. Initiation of smoking among more-educated men decreased rapidly to 15% in 1985 but leveled off by 1987. Until 1985, less-educated young females were the only group in which smoking initiation was increasing. However, in 1987 a sudden and large decline in initiation among less-educated females occurred. The apparent recent changes in initiation patterns by educational level suggest that the converging of smoking prevalence between the genders may not continue. The large and widening educational gap in smoking suggests that health promotion priorities need to be reassessed.

Trends in cigarette smoking in the United States. Projections to the year 2000.

Data from National Health Interview Surveys from 1974 through 1985 are used to project cigarette smoking prevalence to the year 2000. Smoking prevalence in the United States has declined at a linear rate since 1974. If this trend continues, in the year 2000, 22% of the adult population (40 million Americans) will be smokers. By the year 2000, the major inequalities in prevalence will occur among educational categories. At least 30% of those who have not proceeded beyond a high school education will be smokers, whereas less than 10% of college graduates will smoke. Among the other sociodemographic subgroups, smoking prevalence is expected to decrease by the year 2000 to 20% among men, to 23% among women, to 25% among blacks, and to 21% among whites. Between 1974 and 1985, approximately 1.3 million persons per year became former smokers, indicating considerable success in public health efforts to encourage people to stop smoking. However, in the early 1980s, approximately 1 million new young persons per year were recruited to the ranks of regular smokers. This is equivalent to about 3000 new smokers each day. Public health efforts need to focus more on preventing young people from starting to smoke, and such prevention efforts should particularly target less educated socioeconomic groups.