The Behavioral Economics of Alcohol Demand in French and American University Students.

BACKGROUND: Behavioral economic approaches have revealed several characteristics of alcohol demand (e.g., intensity, elasticity, and essential value) in university students; however, these approaches have not yet examined alcohol demand among students outside of the United States. The current study examined alcohol demand among student samples in the United States and France using a hypothetical alcohol purchase task (APT) and a novel APT Choice task, in which nonalcoholic beverages were concurrently available at a fixed low price. METHODS: Participants at each site (United States, n = 132; France, n = 132) were asked to complete an Internet-based survey including the APT, APT Choice, Alcohol Use Disorders Identification Test, Daily Drinking Questionnaire, and Drinking Motives Questionnaire-Revised Short Form. Group demand functions were produced for each of the 2 samples in both country-specific and standardized drink units, and the exponential demand equation was fitted to each of the APT and APT Choice demand curves. Slope analyses were performed on the Non-Alcoholic Cross-Price demand to assess substitutability. RESULTS: APT data revealed that in both samples, alcohol price and consumption were inversely related and demand measures were significantly associated with other alcohol measures. In addition, the availability of a nonalcoholic alternative reduced alcohol demand in both samples, with evidence of substitutability revealed by increases in cross-price consumption. CONCLUSIONS: Low-cost alcohol is associated with increased alcohol consumption in both French and U.S. university students, and concurrent availability of a nonalcoholic beverage within the APT both reduces alcohol demand and demonstrates behavioral economic substitutability. These findings will inform future studies investigating behavioral and environmental factors underlying transcultural differences and specific prevention efforts.

An assessment of fixed interval timing in free-flying honey bees (Apis mellifera ligustica): an analysis of individual performance.

Interval timing is a key element of foraging theory, models of predator avoidance, and competitive interactions. Although interval timing is well documented in vertebrate species, it is virtually unstudied in invertebrates. In the present experiment, we used free-flying honey bees (Apis mellifera ligustica) as a model for timing behaviors. Subjects were trained to enter a hole in an automated artificial flower to receive a nectar reinforcer (i.e. reward). Responses were continuously reinforced prior to exposure to either a fixed interval (FI) 15-sec, FI 30-sec, FI 60-sec, or FI 120-sec reinforcement schedule. We measured response rate and post-reinforcement pause within each fixed interval trial between reinforcers. Honey bees responded at higher frequencies earlier in the fixed interval suggesting subject responding did not come under traditional forms of temporal control. Response rates were lower during FI conditions compared to performance on continuous reinforcement schedules, and responding was more resistant to extinction when previously reinforced on FI schedules. However, no "scalloped" or "break-and-run" patterns of group or individual responses reinforced on FI schedules were observed; no traditional evidence of temporal control was found. Finally, longer FI schedules eventually caused all subjects to cease returning to the operant chamber indicating subjects did not tolerate the longer FI schedules.

Sample size calculation in economic evaluations.

A simulation method is presented for sample size calculation in economic evaluations. As input the method requires: the expected difference and variance of costs and effects, their correlation, the significance level (alpha) and the power of the testing method and the maximum acceptable ratio of incremental effectiveness to incremental costs. The method is illustrated with data from two trials. The first compares primary coronary angioplasty with streptokinase in the treatment of acute myocardial infarction, in the second trial, lansoprazole is compared with omeprazole in the treatment of reflux oesophagitis. These case studies show how the various parameters influence the sample size. Given the large number of parameters that have to be specified in advance, the lack of knowledge about costs and their standard deviation, and the difficulty of specifying the maximum acceptable ratio of incremental effectiveness to incremental costs, the conclusion of the study is that from a technical point of view it is possible to perform a sample size calculation for an economic evaluation, but one should wonder how useful it is.

[Costs of diagnosis and treatment for pulmonary embolism lower due to application of consensus strategy]. / Kosten van diagnostiek en behandeling wegens longembolie lager door toepassing van de consensusstrategie.

OBJECTIVE: To compare the costs of diagnosis and treatment of patients clinically suspected of pulmonary embolism, before and after the adoption of the Dutch consensus for the diagnosis of pulmonary embolism. DESIGN: Study of the records, followed by a prospective study with a follow-up lasting 6 months. SETTING: Academic Medical Centre and Slotervaart Hospital, Amsterdam, the Netherlands. METHOD: Data were collected on 120 patients from the preconsensus period and on 452 patients examined according to the consensus strategy. This established the average patterns of medical consumption of patients before and after adoption of consensus. The mean costs per patient were then estimated. RESULTS: Diagnosis and treatment of a patient according to the consensus strategy on the basis of our estimates were considerably less expensive than non-protocolled diagnosis and treatment (Dfl. 4,413 as against Dfl. 5,115 per patient). This difference mainly resulted from shorter hospital stays owing to more rapid completion of the diagnosis. Considering the large number of annual hospital admissions in the Netherlands in connection with this diagnosis, savings of up to Dfl. 26 million would appear possible if the consensus were followed nationwide. CONCLUSION: Considerable amounts are involved in the diagnosis and treatment of pulmonary embolism in the Netherlands. Accordingly, further research into possibilities to make these more efficient would appear advisable.

The cost effectiveness of diclofenac plus misoprostol compared with diclofenac monotherapy in patients with rheumatoid arthritis.

The objective of our study was to estimate the cost effectiveness of treatment with a fixed-dose combination of diclofenac and misoprostol compared with diclofenac monotherapy in the prevention of nonsteroidal anti-inflammatory drug (NSAID)-induced ulcers in rheumatoid arthritis (RA) patients. A model was used to incorporate estimates of costs, incidence of ulcers and their complications, death rates and the efficacy of misoprostol. The costs per ulcer-free period gained and costs per additional survivor were calculated. Cost effectiveness was calculated for the treatment of all RA patients, and of risk groups only. All costs were measured in 1995 Netherlands guilders (NLG; exchange rate at the time of the study: NLG1 = $US0.60). The analysis showed that if 100 RA patients receive 3 months of treatment with diclofenac plus misoprostol, instead of diclofenac alone, this will lead to overall additional costs of NLG773, while 0.82 symptomatic ulcers and 0.019 deaths will be prevented. If misoprostol is given only to patients at high risk for NSAID-induced ulcer, cost savings will occur instead of additional costs. Univariate sensitivity analysis showed that the outcomes are sensitive to changes in: (i) the percentage of ulcers treated in the ambulatory setting; (ii) the price difference between diclofenac and the fixed-dose diclofenac-misoprostol combination; (iii) the percentage of ulcers with complications; and (iv) the efficacy of misoprostol. In conclusion, it can be stated that treatment with diclofenac-misoprostol is cost saving in RA patients at high risk for NSAID-induced ulcers. For RA patients in general, the cost-effectiveness of this intervention compares favourably with that of other prophylactic treatments.

The cost-effectiveness of diagnostic strategies in patients with suspected pulmonary embolism.

The cost-effectiveness of various diagnostic strategies in patients with clinically suspected pulmonary embolism (PE) was analysed using a modelling approach. In 451 consecutive patients with clinically suspected PE data on the performance of diagnostic tests were collected prospectively in two large teaching hospitals in Amsterdam, The Netherlands. The ventilation-perfusion lung scan was used as the primary diagnostic test in all patients. In patients with a non-diagnostic lung scan result the performance of a clinical decision rule, a D-dimer test, and ultrasonography of the leg veins was evaluated with pulmonary angiography as the gold standard. It was estimated that the strategy recommended by a 1992 Dutch consensus meeting costs about Dfl 4400 per patient and that 97.02% of the patients can be expected to survive the first 6 months after the primary PE. The nation-wide annual costs for the diagnosis and treatment of patients by this strategy were estimated at 163 million Dutch Guilders. Subsequently, the costs and effects of alternative strategies were evaluated in a modelling approach, and compared with those of the consensus strategy. One strategy was selected that produces the best results in terms of survival and leads to considerable savings as compared with the consensus strategy. In this strategy subsequently a ventilation-perfusion scan, a clinical decision rule, a D-dimer test, a pulmonary angiography and leg ultrasonography are performed. Patients with a high probability ventilation-perfusion scan, an abnormal angiography or leg ultrasound test are treated, whereas treatment is withheld in patients with a normal ventilation-perfusion scan, a normal clinical decision rule, a negative D-dimer test, a normal angiography, or a normal leg ultrasound test. This strategy will have to prove its value and usefulness in clinical practice in a subsequent prospective validation phase.

Economic aspects of treatment with captopril for patients with asymptomatic left ventricular dysfunction in The Netherlands.

OBJECTIVE: To estimate the costs and effects of preventive treatment with captopril compared with the current treatment policy in patients with asymptomatic left ventricular dysfunction after a myocardial infarction. METHODS: Estimates of effects are based on the results of the SAVE trial. Costs are estimated on the basis of current treatment patterns in four Dutch hospitals. All knowledge is incorporated in a mathematical model extrapolating the SAVE results to 20 years. RESULTS AND CONCLUSIONS: Captopril treatment is expected to increase survival at certain costs. The average additional costs per patient are estimated at DF1 2,491 in 4 years and at DF1 8,723 in 20 years of treatment. Costs per additional survivor after 4 years are estimated at DF1 69,126. After extrapolation of the results of the SAVE trial to 20 years, costs per life-year gained can be estimated at DF1 15,799. From univariate sensitivity analysis it appears that the results are highly sensitive for the costs of treatment with captopril and the occurrence and prevention of clinical heart failure. Varying all estimates randomly between upper and lower limits-in 5,000 simulations-an estimate of costs per life-year gained of DF1 15,729 is made for 20 years of treatment, with 95% of all estimates between DF10 and DF1 50, 000. On a national level, undiscounted costs are expected to increase up to approximately DF1 42 million annually during the first 40 years after introduction of the preventative strategy.

The role of plasma D-dimers concentration in the exclusion of pulmonary embolism.

OBJECTIVE: To determine the role of four ELISA D-dimer assays in the exclusion of pulmonary embolism. DESIGN: Blinded comparison using pulmonary angiography and/or lung scintigraphy as a reference method. SETTING: A secondary and tertiary referral centre. PATIENTS AND METHODS: Consecutive patients with suspected pulmonary embolism underwent lung scintigraphy, followed by angiography if a non-diagnostic result was obtained. Comorbid conditions resulting in elevated plasma D-dimer levels were defined a priori. Cut-off levels for 100% sensitivity was determined. A decision-analytic model was used to determine effectiveness and costs in the management pulmonary embolism. MAIN OUTCOME MEASURES: The exclusion efficacy of the various assays at a sensitivity of 100% and cost-effectiveness. RESULTS: A total of 179 patients were included (78 inpatients and 101 outpatients; 74 patients had comorbid conditions). Pulmonary embolism could be adequately excluded in between 8% and 18% of all patients, an in between 3% and 7% and 11% and 27% of inpatients and outpatients, respectively, depending on the assay used. D-dimer assays could exclude pulmonary embolism in <5% of patients with comorbid conditions, whereas this increased to 14-32% in outpatients without comorbid conditions. A cost-effectiveness analysis showed a cost reduction of 10% at a specificity of 30%, largely due to a 28% decrease in angiography requirements. Furthermore, for every 2% decrease to sensitivity, one per 1000 evaluated patients would die as a result of inadequately treated pulmonary embolism. CONCLUSION: D-dimer ELISA assays may have a role in the exclusion of pulmonary embolism in symptomatic outpatients, where the application may reduce angiography by 30% and costs by 10%.

Societal perspective on the burden of migraine in The Netherlands.

This study presents a comprehensive overview of the societal burden of migraine in The Netherlands. We assessed the direct and indirect costs of this disease, and the health status of patients with migraine. We developed the 'illness and labour' (I&L) questionnaire to collect data on the effect of illness on labour performance. 846 migraine patients and 834 controls were selected from the general population. Participants completed an I&L questionnaire as well as generic health status questionnaires. The direct costs of migraine amounted to 134 million Netherlands guilders (NLG) [$US1 = NLG1.68, October 1994]. Conservative calculations of the costs of absence from work and reduced productivity at work were NLG264 and NLG277 million per year, respectively. Our study did not indicate that migraine caused household productivity losses. The baseline estimate of the total societal costs of migraine in The Netherlands was NLG675 million per year. The assessment of health status showed considerable impairment of psychological and social functioning in migraine patients.

[Is the use of helicopters with a trauma team in severely injured accident victims in The Netherlands cost effective? A modelling approach]. / Is het inzetten van helikopters met een traumateam bij ernstig gewonde ongevalsslachtoffers in Nederland kosteneffectief? Een modelmatige benadering.

OBJECTIVE: The assessment of the cost-effectiveness of helicopter medical crews for patients with major trauma in the Dutch situation. DESIGN: A modelling approach, combining available information with plausible assumptions. SETTING: Institute for Medical Technology Assessment, Rotterdam. METHODS: First, a baseline scenario was developed, implementing information that was available in the literature and a few assumptions. The sensitivity of the cost-effectiveness for the various assumptions was evaluated in alternative scenarios. END-POINTS. The relation between the costs per life year gained and the expected increase in the number of patients surviving an accident is established for the separate scenarios. RESULTS: In the baseline scenario the number of victims with a trauma score < or = 12 is estimated at 4500 per year, it is assumed that victims who die at the scene of the accident are unsalvageable and that hospital treatment costs Dfl. 27,000.--per patient. As a result costs per life year saved are only under Dfl. 50,000.--when more than 29 patients per year (9.23% gain in survival) are additionally saved. Sensitivity analysis shows that the cost-effectiveness depends highly on the expected gain in survival and on the estimate of the costs of hospital treatment. Both variables are surrounded with a lot of uncertainty. CONCLUSIONS: Relying on the information that is available at this moment, no definite conclusions can be drawn on the cost-effectiveness of this facility, because too many essential data are missing. Empirical research is necessary.

Assessing the benefits of transplant services.

This chapter presents some methods for the assessment of transplant benefits, using the example of liver transplantation. An independent assessment of the benefits of medical technology is especially important for evaluation of the balance between the costs and benefits involved. To enable comparison with other health-care facilities, benefits are defined in terms of a combination of life-years gained and quality of life. The number of life-years gained can be calculated by comparing the survival expected with and without transplantation. Survival with transplantation is estimated on the basis of observed survival, acknowledging that the probability of survival may have changed over time, owing to changes in therapy and selection criteria. To estimate survival without transplantation, several techniques are available. Prognostic models, correcting for stage of disease, are often used. Pitfalls in the use of these models are discussed. The number of life-years gained can be corrected for quality of life by weighing survival with and without transplantation with an index representing quality of life. A method for the calculation of such an index is given. Finally, some cost estimates are presented and the results are discussed.

[Cost-effectiveness analysis of long-term liver transplantation; the liver transplantation program of Groningen 1979-1991]. / Kosten-effectiviteitsanalyse van levertransplantatie op lange termijn; het Groningse levertransplantatieprogramma 1979-1991.

A medical technology assessment of the liver transplantation programme of Groningen University Hospital, which was commissioned by the Dutch National Health Insurance Board, is discussed. The results of all 152 liver transplantations performed between 1979 and November 1990 were analysed. The main objective of the study was to evaluate the long-term effects of liver transplantation. Five years after transplantation 59% of the adult patients were still alive. The survival probability depended greatly on the primary liver disease. Mortality and morbidity occurred mainly within the first year after transplantation. Thereafter the prospects for the patients were excellent, with regard to both the probability of survival and the quality of life. The costs of liver transplantation could be calculated only for patients with primary biliary cirrhosis and other forms of biliary cirrhosis, not caused by hepatitis B infection or alcohol abuse. For these patients the costs of a liver transplantation were estimated at HFl. 263,000--(with a 10% margin), 10 years of follow-up included and corrected for the costs that would have been made for the treatment of the liver disease. For this population of patients a liver transplantation costs between Hfl. 64,000--and Hfl. 79,000--per life year gained, 10 years of follow-up included. Costs of cyclosporin still take up a major part of the costs. The need for liver transplantation in the Netherlands was estimated at between 35 and 126 transplantations per year, depending on indications, contraindications, referral policy and the percentage of retransplantations.