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Biomedical subjects

R Leidl

Publications and source records attributed to R Leidl.

At least 19 recordsLinked to original sources

A preference-based index for the SF-12.

BACKGROUND: The SF-12 is a widely used generic measure of subjective health. As the scoring algorithms of the SF-12 do not include preference values, different approaches to assign a preference-based index are available that should be tested regarding their feasibility and validity. OBJECTIVES: To develop a concept for a preference-based index for the SF-12 on the basis of multi-attribute decision analysis and to perform initial tests of its feasibility and validity in an empirical study. METHODS: A multi-attribute preference function for the SF-12 was developed, estimated and tested for validity. Two mail surveys (n = 100, 200) and an interview (n = 72) were conducted with women who had an operation for breast cancer. Visual analogue scale (VAS) and standard gamble (SG) measures elicited preference-based valuations. RESULTS: Eight attributes were identified in the SF-12. Validity tests showed an average difference of 8 VAS score points between directly measured and predicted values for given health states. CONCLUSION: The initial results show that this approach might allow the direct assignment of a preference-based valuation to the SF-12. The quality of the psychometric features of the multi-attribute value function is encouraging. Future studies should test this concept more extensively, especially by determining parameters for a representative sample of the general population and by comparing performance with other approaches to value the SF-12.

Algorithms↗

[Decisions in case of "problematic" cost-effectiveness ratios based on the example of a clinical trial in rehabilitation care].

PURPOSE: Economic assessment of an additional psychological intervention in the rehabilitation of patients with chronic low-back pain and evaluation of results by decision makers. METHODS: Piggy-back cost-utility analysis of a randomised clinical trial, including a bootstrap analysis. Costs were measured by using the cost accounting systems of the rehabilitation clinics and by surveying patients. Health-related quality of life was measured using the EQ-5D. Implications of different representations of the decision problem and corresponding decision rules concerning the cost-effectiveness plane are discussed. RESULTS: As compared with the 126 patients of the control arm, the 98 patients in the intervention arm gained 3.5 days in perfect health on average as well as 1219 euro cost saving. However, because of the uncertainty involved, the results of a bootstrap analysis cover all quadrants of the cost-effectiveness plane. Using maximum willingness-to-pay per effect unit gained, decision rules can be defined for parts of the cost-effectiveness plane. These have to be aggregated in a further valuation step. CONCLUSIONS: Study results show that decisions on stochastic economic evaluation results may require an additional valuation step aggregating the various parts of the cost-effectiveness plane.

Cost-Benefit Analysis↗

Validation of the EuroQol questionnaire in cardiac rehabilitation.

OBJECTIVE: To analyse the psychometric properties of the EuroQol questionnaire (EQ-5D) applied to patients with acute coronary syndromes (ACS). SETTING: Rehabilitation hospital. PATIENTS AND DESIGN: 106 consecutive patients with ACS (51% myocardial infarction, 42% coronary artery bypass grafting, 7% angina) completed the EQ-5D, the 36 item short form health survey (SF-36), and the MacNew questionnaire at admission, at discharge, and three months after inpatient cardiac rehabilitation. Acceptance, validity, reliability, and responsiveness of the EQ-5D were tested. RESULTS: The EQ-5D was highly accepted. The EQ-5D index showed substantial ceiling effects after rehabilitation. As expected the EQ-5D visual analogue scale (VAS) score (70.3 v 57.1) and EQ-5D index (77.8 v 64.5) were significantly better for patients with myocardial infarction than for patients who underwent surgery (both p < or = 0.001). Significant correlations were found between the EQ-5D VAS score, EQ-5D index, and domains of the SF-36 (r = 0.21 to r = 0.74). The correlation with the MacNew subscores and with the global score ranged between 0.55 and 0.78. With repeated measurement the EQ-5D showed reasonable reliability in stable patients with intraclass correlation ranging between 0.91 and 0.54. EQ-5D was responsive in patients who indicated improvement in health states between admission and discharge (effect size 0.74-0.82). CONCLUSION: The psychometric properties of the EQ-5D were satisfying. It is a reasonably valid, reliable, and responsive instrument for patients with ACS. It may be useful in clinical research and epidemiological studies to generate preference based valuations of health related quality life.

Adult↗

[Does co-operation research provide approaches to explain the changes in the German hospital market?].

UNLABELLED: The German hospital market faces an extensive process of consolidation. In this change hospitals consider cooperation as one possibility to improve competitiveness. AIM: To investigate explanations of changes in the German hospital market by theoretical approaches of cooperation research. METHOD: The aims and mechanism of the theories, their relevance in terms of contents and their potential for empirical tests were used as criteria to assess the approaches, with current and future trends in the German hospital market providing the framework. Based on literature review, six theoretical approaches were investigated: industrial organization, transaction cost theory, game theory, resource dependency, institutional theory, and co-operative investment and finance theory. In addition, the data needed to empirically test the theories were specified. RESULTS: As a general problem, some of the theoretical approaches set a perfect market as a precondition. This precondition is not met by the heavily regulated German hospital market. Given the current regulations and the assessment criteria, industrial organization as well as resource-dependency and institutional theory approaches showed the highest potential to explain various aspects of the changes in the hospital market. CONCLUSION: So far, none of the approaches investigated provides a comprehensive and empirically tested explanation of the changes in the German hospital market. However, some of the approaches provide a theoretical background for part of the changes. As this dynamic market is economically of high significance, there is a need for further development and empirical testing of relevant theoretical approaches.

Cooperative Behavior↗

[Costs of ambulant care for patients with inflammatory bowel disease in general practice].

BACKGROUND: Outpatient care managed by general practitioners plays an important role in diagnostic and treatment of inflammatory bowel diseases (IBD). The chronic recurrent course often requires intensive and costly medical care. OBJECTIVE: To measure the costs of outpatient care for patients with IBD provided by general practitioners (GPs). MATERIAL AND METHODS: The analysis is based on an electronic data base implemented in 100 general practices in different parts of Germany. 191 patients with altogether 705 consultations over a period of one year were included in the analysis. Costs of care were measured using German fee schedules for health care delivery and market prices for drugs. RESULTS: In a 12-months-period the mean number GP-contacts was 3.6. Mean costs were 23.61 euro; per visit and annual costs were 87.15 euro; per patient. Pharmacotherapy was used by 147 patients (77%) and caused costs of 613.40 euro; per year, with 64% due to the use of salicylates. 66 patients (35%) also had diagnostic services provided from specialists, 7 patients (4%) required psychotherapeutic care. CONCLUSION: The presented study is the first to analyse in detail the costs for medical care of IBD in general practices in Germany. Results can be used in economic assessment of the disease and in cost-effectiveness-analyses of intervention strategies. They may support treatment guidelines and treatment decisions from an economic point of view.

Adolescent↗

Overview of economic evaluation of positron-emission tomography.

Since the 1990s positron-emission tomography (PET) in Germany has been used increasingly in clinical diagnostics in the areas of oncology, cardiology, and neurology/ psychiatry. As the use of PET requires a complex and expensive infrastructure, analysis of the cost-effectiveness of PET compared to common diagnostic methods is becoming increasingly important. This contribution summarizes and discusses the results of a health technology assessment report on the cost-effectiveness of PET.

Journal Article↗

[Cost measurement based on a cost diary in patients with inflammatory bowel disease].

OBJECTIVE: Cost diaries administered by patients have been used as a method to measure costs for different diseases. Our aim was to test the application of a patient cost diary in patients with inflammatory bowel disease (IBD) and to measure disease specific resource utilization and costs. PATIENTS AND METHODS: A specific patient cost diary for IBD was developed and tested in a prospective pilot study. 105 outpatients with IBD of a University Hospital agreed to participate over a 4 week follow-up period. They were asked to report weekly their use of medical care and costs related to their illness. Visits to health care providers, hospitalizations, drug use, costs due to absence from paid and unpaid work, travel costs as well as out-of-pocket expenses were considered. RESULTS: The response rate was 90 %. Almost 70 % of the patients estimated the diary as easy to fill in. Compared with other data sources, the cost measurement using the cost diary showed good agreement regarding costs of drug therapy and outpatient hospital treatment. Mean costs due to illness were estimated to be 1,500 Euro per 4 weeks. This corresponds to total costs of about 20,000 Euro per year of care. 69 % of total costs were indirect costs due to illness-related absence from work, days of inactivity at home, and early retirement. Direct health care and direct non health care costs (e. g. travel costs) were responsible for 27 % and 4 % of costs, respectively. DISCUSSION AND CONCLUSION: The presented instrument offers a suitable and practical method of assessing IBD-related resource utilization. The prospectively obtained data for direct medical and non medical, as well as indirect costs allow a cost measurement from the societal perspective. The presented cost diary can be used for measuring costs for economic evaluations of medical interventions.

Adult↗

[Economic rehabilitation management among patients with chronic low back pain].

BACKGROUND AND STUDY PURPOSE: Back pain causes high costs to society. In Germany, these amount to an estimated total of 5 billion euro of direct costs per year and 13 billion euro of indirect costs, the latter being caused by incapacity to work. The purpose of this study is to develop a concept for economic rehabilitation management. This concept is based on the managed care approach and aims at improving efficiency of care. METHODS: The concept development consists of a theoretical and an empirical part. The method of the theoretical part is based on a systematic literature review on managed care (not included in this article), health systems research and the analysis of economic incentives. For the empirical investigation, long term effects and costs were calculated. For the evaluation of effects, we psychometrically tested and used the EuroQol (EQ-5D) as a measure of health-related quality of life (HRQL). The calculation of costs (both direct and indirect) is based on routine data of payers, a cost diary and the internal cost accounting systems of rehabilitation clinics. We statistically analysed the cost distribution and identified predictors of the management targets (e.g., costs of care) by means of regression analyses. RESULTS: The market-driven managed care approach is based on three tools: (1) a primary care system with case management and gatekeeping, (2) direct influence on providers by utilisation review and setting guidelines, and (3) indirect influence by setting supply-side economic incentives via the remuneration mode. The third managed care tool is most important when managing the rehabilitation of working age patients with chronic low back pain from an economic point of view. This concept consists of three components: (1) a case-based budget for direct costs; this is a prospective remuneration mode for an integrated primary care network including a rehabilitation facility, (2) retrospective bonus payments which are related to savings of indirect costs, and (3) retrospective bonus payments which are related to the effectiveness of rehabilitation, i.e. gains in HRQL. Common features of the three management components are a long-term perspective (e.g., from admission to a rehabilitation clinic until six months after discharge) and risk-adjustment of the three management targets (i.e., direct and indirect costs and gains in HRQL) in order to avoid selection and to limit the financial risk for providers. The EuroQol instrument shows acceptable psychometric properties in the rehabilitation setting for back pain patients. This instrument may yield two kinds of preference-based index values, one reflecting the preferences of the general population and one those of the patient. The Pearson correlation of these two approaches is fair, but there is a systematic difference. Empirical investigation shows that the distribution of both direct and indirect costs is skewed to the right. Statistically relevant predictors of the management targets are incapacity to work and HRQL at admission. CONCLUSIONS: Economic rehabilitation management might help to save money and to improve health outcomes, thus increasing the efficiency of care. The results of our empirical studies show the feasibility of tools for the economic management of rehabilitation. Risk adjustment of the management components is of paramount importance.

Chronic Disease↗

[Cost evaluation by a patient questionnaire: pilot study of a weekly cost diary].

Weekly cost diaries are instruments to measure direct and indirect costs prospectively by using patient data. First we searched MEDLINE for information concerning the use of diaries in health care and their methodological evaluation. Based on a Dutch weekly cost diary we developed an instrument for patients with acute or chronic back pain to be completed following participation in an inpatient rehabilitation measure. Its use was tested in an explorative pilot study. We asked for all costs and resource use due to back pain (all direct medical and non medical costs as well as indirect costs) occurring in a 4-week follow-up period, irrespective of the cost carrier. The total response rate was 58%. Patients spent an average 13 minutes a week for completing the questionnaire, without reporting any major methodological difficulties. Some 30% percent of overall costs were direct costs, the majority being non-recurring costs for assistive devices such as mattresses and mattress frames. Excluding these, monthly direct costs per patient were 270 DM on average. Indirect costs, mainly due to absence from salaried work, amounted to an average 1634 DM per patient, with marked variation. Our study results show that this instrument is basically useful and feasible in this indication. Further studies with larger and representative samples are needed to evaluate data quality. It is suggested that weekly cost diaries can be useful tools in particular in decentralized health care systems to measure costs from the societal perspective.

Adult↗

[Radiologic diagnosis of fistulas and abscesses in Crohn's disease: cost-effectiveness analysis of 2 different imaging strategies].

PURPOSE: To analyze cost-effectiveness of magnetic resonance imaging and conventional enteroclysis in the assessment of fistulas and abscesses in patients with Crohn's disease (CD). METHODS: A decision analytic model was used to compare enteroclysis with MRI, performing a cost-effectiveness analysis of both diagnostic strategies. Data from 84 patients undergoing a clinical trial were used. Primary outcome was defined as one correctly diagnosed patient regarding Crohn's disease, fistulas, and abscesses, including true-positive and true-negative cases. Costs of the two procedures were estimated in German Marks (DM) using fee schedules. The influence of different definitions of effects was calculated. For all variables single and multiple sensitivity analyses were performed. RESULTS: Incremental cost effectiveness of MRI vs. enteroclysis was 3,119.33 DM per one additional correctly diagnosed patient. The results of sensitivity analyses suggest that MRI use in certain patient subgroups (patients at higher prevalence of CD, fistulas, and abscesses) even becomes more cost-effective. In this case one additional effect could be gained below 1,650 DM. CONCLUSIONS: From an economic perspective, decision makers should consider the use of MRI in the work-up of patients with Crohn's disease as an efficient procedure under certain conditions. To support treatment policies for physicians or insurance coverage of certain diagnostic strategies the costs possibly saved with MRI should also be considered.

Abdominal Abscess↗

[Cost analysis of the treatment of patients with multiple trauma].

Current clinical management after multiple trauma is expensive. The aim of the present study was to quantify the actual costs of inpatient treatment after multiple trauma in a German university hospital, to compare the actual costs with the reimbursement rates, and to identify important determinants of costs. Routine documentation of hospital costs at a patient level was not available. Therefore a method for calculating the costs of resource utilization during clinical treatment of patients was developed. The concept was based on financial and utilization data provided by the hospital administration and patient-specific data. The average costs per case in the study group (mean ISS = 37) were 73.613 DM, maximal costs were up to 292.490 DM. The most costly components were intensive care, accounting for 60%, followed by procedures in the operating room (24%). A comparison with the reimbursement rates resulted in an average loss of 23.211 DM per case. Factors significantly associated with the costs of acute care hospitalization were outcome, injury severity, pattern of injury, blood volume replacement, length of mechanical ventilation, and number of operations. Whereas patient age, CNS state, mechanism of injury, pre-hospital care, and time between accident and hospital admission revealed no effect. Given the current reimbursement rates, multiple trauma care clearly belongs to those categories of care which have to be subsidized within the hospital. Any challenge to the optimal level of care resulting from this should be avoided.

Acute Disease↗

Primary staging of lymphomas: cost-effectiveness of FDG-PET versus computed tomography.

The objective of this study was to measure the incremental cost-effectiveness of 2-(fluorine-18) fluorodeoxyglucose positron emission tomography (FDG-PET) versus computed tomography (CT) as diagnostic procedures in the primary staging of malignant lymphomas. The study was based on 22 patients of a clinical study who underwent the diagnostic procedures at Ulm University Hospital between April 1997 and May 1998. Direct costs of FDG-PET and CT, including staff, materials, investment, maintenance and overheads, were valued using a micro-costing approach. The effectiveness of both diagnostic procedures was measured as the percentage of correctly staged patients, given a gold standard for staging. The incremental cost-effectiveness ratio was the main outcome measure. Costs per patient of FDG-PET were 257 euros for FDG production and 704 euros for the FGD-PET scan, thus totalling 961 euros (in 1999 prices). The cost per patient of CT scans was found to be 391 euros. Verified PET findings induced an upstaging in four patients such that the effectiveness was 81.8% (18/22) for CT and 100% (22/22) for PET. Incremental cost-effectiveness ratios (interpreted as the additional costs of a more effective diagnostic strategy per additional unit of effectiveness, i.e. additionally correctly staged patient, achieved) were 478 euros per correctly staged patient for CT versus "no diagnostics" and 3133 euros for FDG-PET versus CT. Great potential for cost saving was identified in sensitivity analyses for FDG-PET. It is concluded that diagnostic accuracy and the costs of the diagnostic procedures could be measured precisely. FDG-PET was more accurate than CT. Decision-makers who consider savings in treatment costs significant may find the cost-effectiveness ratio of PET to lie within an acceptable range. However, more research is needed to assess the long-term treatment and cost effects of more accurate staging. There is significant potential to improve the technical efficiency of PET.

Adolescent↗

[Cost effectiveness of mass orthoptic screening in kindergarten for early detection of developmental vision disorders].

PURPOSE: Orthoptic screening in the kindergarten is one option to improve early detection of amblyopia in children aged 3 years. The purpose of this study was to analyse the cost-effectiveness of such a screening programme in Germany. METHODS: Based on data from the literature and own experience gained from orthoptic screening in kindergarten a decision-analytic model was developed. According to the model, all children in kindergarten, aged 3 years, who had not been treated for amblyopia before, were subjected to an orthoptic examination. Non-cooperative children were reexamined in kindergarten after one year. Children with positive test results were examined by an ophthalmologist for diagnosis. Effects were measured by the number of newly diagnosed cases of amblyopia, non-obvious strabismus and amblyogenic refractive errors. Direct costs were estimated from a third-party payer perspective. The influence of uncertain model parameters was tested by sensitivity analysis. RESULTS: In the base analysis the cost per orthoptic screening test was DM 15.39. Examination by an ophthalmologist cost DM 71.20. The total cost of the screening programme in all German kindergartens was DM 6.1 million. With a 1.5% age-specific prevalence of undiagnosed cases, a sensitivity of 95% and a specificity of 98%, a total of 4,261 new cases would be detected. The cost-effectiveness ratio was DM 1,421 per case detected. Sensitivity analysis showed considerable influence of prevalence and specificity on the cost-effectiveness ratio. It was more cost-effective to re-screen non-cooperative children in kindergarten than to have them examined by an ophthalmologist straight-away. CONCLUSIONS: The decision-analytic model showed stable results which may serve as a basis for discussion on the implementation of orthoptic screening and for planning a field study.

Amblyopia↗

Cost-effectiveness of screening programs for Chlamydia trachomatis: a population-based dynamic approach.

BACKGROUND: Models commonly used for the economic assessment of chlamydial screening programs do not consider population effects. GOAL: To develop a novel dynamic approach for the economic evaluation of chlamydial prevention measures and to determine the cost-effectiveness of a general practitioner-based screening program. STUDY DESIGN: The dynamic approach was used to estimate the cost-effectiveness of a screening program for the first 10 years of screening in The Netherlands. Screening involved a ligase chain reaction test on urine followed by standardized therapies and partner referral. Eligible persons were sexually active, 15 to 24 years, visited a general practitioner, and had no symptoms of sexually transmitted diseases. The heterosexual model population, which consisted of persons 15 to 64 years, had a total chlamydial prevalence of 4.1% before screening. Screening effects on chlamydial incidence were computed by using a population-based stochastic simulation model. Incidence data were connected with a decision analysis model to determine the health effects of the program. The net costs of the program were calculated (investment costs minus averted costs, in 1997 US$) from a societal perspective and expressed per major outcome averted (symptomatic pelvic inflammatory disease, chronic pelvic pain, ectopic pregnancy, infertility, neonatal pneumonia). RESULTS: Unlike the standard static approach, our model adequately addresses dynamic processes such as chlamydial transmission and the impact of screening programs on chlamydial incidence in the population. During the first 10 years of screening, the investigated program yields savings of US $492 or US $1,086 per major outcome averted, excluding or including indirect costs, respectively. These results depend on chlamydial prevalence and partner referral. CONCLUSIONS: The cost-effectiveness of chlamydial screening programs seems best to be determined by using dynamic modeling on a population basis. In addition to preventing negative health outcomes, the investigated screening program may save costs.

Adolescent↗

Cost-effectiveness of orthoptic screening in kindergarten: a decision-analytic model.

PURPOSE: The purpose of this study was to analyze the cost-effectiveness of orthoptic screening for amblyopia in kindergarten. METHODS: A decision-analytic model was used. In this model all kindergarten children in Germany aged 3 years were examined by an orthoptist. Children with positive screening results were referred to an ophthalmologist for diagnosis. The number of newly diagnosed cases of amblyopia, amblyogenic non-obvious strabismus and amblyogenic refractive errors was used as the measure of effectiveness. Direct costs were measured form a third-party payer perspective. Data for model parameters were obtained from the literature and from own measurements in kindergartens. A base analysis was performed using median parameter values. The influence of uncertain parameters was tested in sensitivity analyses. RESULTS: According to the base analysis, the cost of one orthoptic screening test was 7.87 euro. One ophthalmologic examination cost 36.40 euro. The total cost of the screening program in all kindergartens was 3.1 million euro. A total of 4,261 new cases would be detected. The cost-effectiveness ratio was 727 euro per case detected. Sensitivity analysis showed considerable influence of the prevalence rate of target conditions and of the specificity of the orthopic examination on the cost-effectiveness ratio. CONCLUSIONS: This analysis provides information which is useful for discussion about the implementation of orthoptic screening and for planning a field study.

Amblyopia↗

[Common effect measures in medical and health economics studies? Results of an exploratory survey of physicians].

BACKGROUND: In economic evaluation studies quality-adjusted life years (QALYs) are often used as measure of effects. QALYs are calculated by weighting survival time with a valuation of health-related quality of life (HRQoL). The results may support clinical decisions for patient groups provided that physicians consider QALYs acceptable and clinically relevant. This study investigates whether physicians accept the various methodological steps of the calculation of QALYs and whether effect measures that result from these steps are useful in clinical studies, too. METHODS: In summer 1998, 41 physicians (21 principal investigators of clinical studies in oncology, 12 surgeons, 8 primary care physicians) completed a questionnaire. RESULTS: 90% of the physicians considered HRQoL a relevant measure of clinical effectiveness but only 54% were familiar with the concept of HRQoL. 80% accepted the creation of an index of HRQoL, 68% accepted the integration of HRQoL and survival time into a single effect measure, but only 44% accepted the multiplicative way of calculating QALYs. According to most physicians, HRQoL should be valued either by study patients or health care professionals rather than general population samples. 92% of the physicians considered identical effect measures in clinical and economic studies necessary or desirable. CONCLUSIONS: QALYs are not generally rejected by the responding physicians. The integration of HRQoL is largely accepted. The multiplicative way of combining survival time and HRQoL values is rejected by many physicians. The findings can be used to define a starting point for the development of common effect measures in medicine and health economics.

Attitude of Health Personnel↗

Current and future medical costs of asthma and chronic obstructive pulmonary disease in The Netherlands.

The aim of this study was to estimate the healthcare costs of asthma and chronic obstructive pulmonary disease (COPD), in the Netherlands, in 1993. Also studied was the future development of these costs, as a result of ageing and possible changes in smoking behavior. A prevalence-based cost-of-illness approach was used to estimate direct medical costs. Age- and gender-specific data were obtained from representative national registries and large, representative surveys. To model future costs, cost estimates were linked to an epidemiological model based on a dynamic multi-state lifetable. It describes 1 yr changes, from one state to another, that result from ageing, birth, migration, incidence, recovery from asthma and death due to asthma, COPD or other causes, and starting or quitting smoking. Three different scenarios were modelled: 1) a reference scenario which primarily predicts the impact of ageing. 2) an 'attainable' smoking reduction scenario and 3) an 'extreme' smoking reduction scenario. Direct medical costs were estimated to be $US 346 million in 1993. With increasing age, the relative importance of asthma in total asthma and COPD costs decreased from 91% to less than 4%. Annual costs per patient were estimated to be $US 499 for asthma and $US 876 for COPD. The breakdown of costs differed considerably between asthma and COPD. The reference scenario predicted the costs to increase by 60% to reach $US 555 million by 2010, COPD prevention as modelled in the second and the third scenario reduced the projected cost increase from 60%, to 57% and 48%, respectively. Together, the direct costs of asthma and COPD represent 1.3% of the Dutch health care budget. The breakdown of the costs shows different patterns for asthma and COPD. The costs of these diseases are expected to increase by 60% in the near future. In the short run the impact of smoking reduction on reducing this increase is relatively small, but it will be greater in the long run.

Adolescent↗

Real world designs in economic evaluation. Bridging the gap between clinical research and policy-making.

This paper identifies the information that economic evaluation should provide to adequately inform policy-makers. First, policy-makers need cost-effectiveness information that is both internally and externally valid. The latter aspect is often ignored and refers to the relevance of the results of economic trials to the specific decision-making context of the policy-maker. Second, policy-makers, like purchasers of care, may want assessments of the overall budget and health impacts of adopting an intervention in a disease or treatment area. This requires more of an aggregate analysis than the current approaches to economic evaluation (which are typically individual-orientated). There are 3 main conceptual approaches to economic evaluation: the use of randomised controlled trials (RCTs), observational studies and modelling. The RCT can be considered as the gold standard in economic evaluation because of its high internal validity, but results should be interpreted with caution because of its low external validity. There a number of options to enhance external validity; of these, additional modelling and observational data seem to be the most promising. To address issues at the system level, disease modelling or public health modelling is suggested. A 3-step approach, comprising successive assessment of internal validity, external validity (real world relevance) and net impact at the system level, can enhance the informative value of economic analyses. For example, this approach has been used to assess the informative value to decision-makers of an RCT in benign prostatic hyperplasia. The analysis emphasised the feasibility and importance of additional modelling beyond the results from an RCT-based economic analysis and provided important information of relevance for policy-making. Because of the need to increase the real world relevance of pharmacoeconomic analyses, there is potentially a large role for modelling in economic evaluation; however, in order to enhance its credibility, more attention should be paid to validity aspects.

Cost-Benefit Analysis↗