Is oscillometric ankle pressure reliable in leg vascular disease?

The objective of the study was to evaluate the validity of oscillometric systolic ankle pressure in symptomatic leg arterial occlusive disease. Ankle pressure measurements using oscillometric curves obtained using a standard 12-cm cuff with a specially designed device for signal processing were validated against the continuous wave (CW) Doppler technique. Thirty-four subjects without signs or symptoms of peripheral vascular disease (68 legs) and 47 patients with leg ischaemia (85 legs) varying from moderate claudication to critical ischaemia were examined. The oscillometric curves were analysed using several algorithms reported in the literature, based on the assumption that maximum oscillations are recorded near mean arterial pressure. In normals, reasonable agreement between CW Doppler and oscillometric methods was seen. When an algorithm that determined the lowest cuff pressure at which maximum oscillations occurred, and a characteristic ratio for systolic pressure of 0.52 was used, the mean difference between CW Doppler and oscillometry was 1.7 mmHg [range -19 to +27, limits of agreement (2 SD) 21.1 mmHg]. In ischaemic legs, oscillometry overestimated systolic ankle pressure by a mean of 28.8 mmHg [range -126 to +65, limits of agreement 82.8 mmHg]. The difference was more pronounced among patients with critical ischaemia compared with claudicants, and also more evident among diabetics. The error of oscillometric pressure determination in subjects with leg arterial disease inversely increased with CW Doppler ankle pressure. In 39% of the recordings in legs with a CW Doppler systolic pressure below 100 mmHg, the oscillometric mean arterial pressure was higher than the recorded CW Doppler systolic pressure. In conclusion, the oscillometric method to determine systolic ankle pressure, based on the concept of maximum cuff oscillations occurring near mean arterial pressure, is not reliable in leg arterial disease, usually overestimating ankle pressure.

Cost-utility analysis of interferon beta-1b in secondary progressive multiple sclerosis

OBJECTIVES

Interferon beta-1b has recently become available for the treatment of secondary progressive multiple sclerosis (SPMS). This study aims at estimating the cost-effectiveness of this new treatment that has been shown in a clinical trial to reduce the progression of the disease. Effectiveness is measured as the number of quality-adjusted life-years (QALYs) gained from the reduction in progression. Because the clinical trial period will only capture part of the treatment's effect in terms of QALYs gained, since benefits achieved during the trial will have an effect beyond it, the cost-effectiveness analysis involves modeling over the longer term using complementary data.

METHODS

A Markov model with states based on disability expressed by EDSS scores was used. Transition probabilities were calculated directly from clinical trial data for the first 3 years and then extrapolated to 10 years. Mean costs and utilities for each Markov state were calculated from a population-based cross-sectional study in Sweden.

RESULTS

The incremental cost per QALY is SEK 342,700 (US $39,250; US $1 = SEK 8.73, March 10, 2000) when all costs (direct, informal care, and indirect) are included (discounted 3%). When indirect costs are excluded, the cost per QALY is SEK 542,000 ($62,100).

CONCLUSIONS

Cost-effectiveness analysis in SPMS requires that the effect of treatment beyond clinical trials be included. Also, analysis should be done from a societal perspective, since many of the costs occur outside the healthcare system. The cost-utility ratios estimated in this analysis are at or below the mean threshold value indicated in a recent survey of health economists ($60,000).

Costs and benefits of laparoscopic surgery--a review of the literature

The purpose of this paper is to look at the cost-effectiveness of laparoscopic surgery in relation to conventional open surgery. It focuses both on the results and the methods, and aims to identify the need for further studies as well as the appropriate methods of economic evaluation. We searched the literature and identified studies in which "cost" or "cost-effectiveness" was mentioned in relation to open and laparoscopic surgery. Laparoscopic and open surgery were compared for gallbladder disease, inguinal hernia and gastro-oesophageal reflux disease (GORD). Finally, we reviewed studies that focused on cost comparisons of disposable compared with reusable instruments in laparoscopic surgery. We found that the evidence on whether laparoscopic surgery results in lower costs for the health care system than open operations is not conclusive. There are, however, indications that it results in savings in indirect costs from reduced periods of sick leave. There is also an indication that reusable instruments resulted in lower costs for each operation than disposable instruments. We conclude that a prospective, randomised study is the preferred study design in the early stage of the development of a new technique, when it is not fully obvious what the indications for the new technique are. This should be considered when doing economic evaluations of new indications for laparoscopic surgery, for example appendicectomy and non-inguinal hernia repair.

Costs, quality of life and disease severity in multiple sclerosis: a cross-sectional study in Sweden

This study assessed the cost to society of multiple sclerosis (MS) in Sweden in 1998. The cost-of-illness method, based on the human capital theory, was used as the theoretical framework. The study used a cross-sectional approach, in which resource utilization data and quality-of-life data (utilities) were collected at a single time point. The total cost of MS was estimated at 4868 MSEK, or 586 MEUR, giving an annual cost of 442 500 SEK, or 53 250 EUR, per patient (1USD = 9.73 SEK, 1 EUR = 8.31 SEK, as of 21 September 2000). Direct costs accounted for about 67% of total cost, and they were dominated by the cost of personal assistants and drugs. Indirect costs (loss of production) accounted for about 33% of total costs. To these economic costs, intangible costs of 2702 MSEK (325 MEUR) should be added as well. Direct, indirect and informal care costs all rose significantly with increased disability and were higher during a relapse. Quality of life declined substantially with increased disability and was lower during a relapse. Multiple sclerosis was found to be associated with much higher costs to society than has been ascertained by former studies. The study also revealed a strong correlation between severity of the disease and quality of life. These results are crucial for further studies on the cost-effectiveness of new treatments aimed at preventing relapses and reducing progression of the disease.

Cost effectiveness of bisoprolol in the treatment of chronic congestive heart failure in Sweden: analysis using data from the Cardiac Insufficiency Bisoprolol Study II trial

OBJECTIVE

To investigate the cost effectiveness of adding the beta-blocker bisoprolol to standard treatment in patients with congestive heart failure (CHF).

DESIGN AND SETTING

A cost-effectiveness study was based on the Cardiac Insufficiency Bisoprolol Study II (CIBIS-II), a randomised clinical trial investigating the efficacy of adding bisoprolol to standard therapy of CHF. The cost-effectiveness analysis was carried out from a societal perspective.

METHODS

Health effects were measured in terms of years of life gained. On the cost side, treatment costs for pharmaceuticals and hospitalisations were included. Data on healthcare resource consumption from CIBIS-II were used and were combined with average Swedish retail prices for medicines, and average costs for hospitalisations based on hospital admissions, in the base case. The costs of added years of life, i.e. consumption net of production during life-years gained were also included.

RESULTS

If costs of added years of life were not included, then bisoprolol therapy increased life expectancy at an incremental cost of Swedish kronor (SEK) 13 094 (1999 values) per year of life gained. If costs of added years of life were included, then the incremental cost-effectiveness ratio of bisoprolol therapy was SEK 168 858 per year of life gained.

CONCLUSIONS

For patients with CHF with the characteristics of those in CIBIS-II, the cost effectiveness of bisoprolol therapy compares favourably with that of other cardiovascular therapies.

Challenges for model-based economic evaluations of postmenopausal osteoporosis interventions

Assessing the cost-effectiveness of long-term treatment for osteoporosis requires use of mathematical models to estimate health effects and costs for competing interventions. The primary motivations for model-based analyses include the lack of long-term clinical trial outcome data and the lack of data comparing all relevant treatments within randomized clinical trials. We report on specific modeling challenges that arose in the development of a model of the natural history of postmenopausal osteoporosis that is suitable for assessing the cost-effectiveness of osteoporosis interventions among various population subgroups in diverse countries. These include choice of modeling changes in bone mineral density (BMD) or in fracture rate, definition of health states, modeling mortality and costs of long-term care following fracture, incorporation of health utility, and model validation. This report should facilitate future postmenopausal osteoporosis model development and provide insight for decision-makers who must evaluate model-based economic analyses of postmenopausal osteoporosis interventions.

[Vaccination of the elderly against pneumococcal disease is cost-efficient. Mass vaccination of all aged 65 and over is recommended]

The pneumococcal vaccine has been shown to be about 70 percent efficacious in preventing invasive pneumococcal disease in elderly persons. In a European multicenter study, pneumococcal vaccination was moderately cost-effective in preventing hospital admission due to invasive pneumococcal disease in persons 65 years of age or above. In Sweden the cost was approximately 300,000 SEK per quality adjusted life years (QALY) gained, but only about 60,000 SEK per QALY in a two-way sensitivity analysis making reasonable assumptions regarding the incidence and mortality of invasive pneumococcal disease in this age group. On the basis of these findings, pneumococcal vaccination should be recommended for all persons 65 years of age or older.

Direct medical costs for patients with type 2 diabetes in Sweden

OBJECTIVES

To estimate the total direct medical costs to society for patients with type 2 diabetes in Sweden and to investigate how different factors, for example diabetic late complications, affect costs.

DESIGN

Cross-sectional data regarding health care utilization, clinical characteristics and quality of life, were collected at a single time-point. Data on resource use cover the 6-month period prior to this time point.

SETTING

Patient recruitment and data collection were performed in nine primary care centres in three main regions in Sweden.

SUBJECTS

Only patients with an age at diabetes diagnosis >/= 30 years (type 2 diabetes) were included (n = 777).

RESULTS

The total annual direct medical costs for the Swedish diabetes type 2 population were estimated at about 7 billion SEK (Swedish Kronor) in 1998 prices, which is about 6% of the total health care expenditures and more than four times higher than the former Swedish estimate obtained when using diabetes as main diagnosis for calculating costs. The annual per patient cost was about 25 000 SEK. The largest share of this cost was hospital inpatient care. Costs increased with diabetes duration and were higher for patients treated with insulin compared to those treated with oral hypoglycaemic drugs or with life style modification only. Patients with both macro- and microvascular complications had more than three times higher costs compared with patients without such complications.

CONCLUSIONS

Type 2 diabetes is a serious and expensive disease and the key to reducing costs seems to be intensive management and control in order to prevent and delay the associated late complications.

Cost-effectiveness of pneumococcal vaccination of older people: a study in 5 western European countries

Pneumococcal vaccination of older persons is thought to be cost-effective in preventing pneumococcal pneumonia, but evidence of clinical protection is uncertain. Because there is better evidence of vaccination effectiveness against invasive pneumococcal disease, we determined the cost-effectiveness of pneumococcal vaccination of persons aged > or =65 years in preventing hospital admission for both invasive pneumococcal disease and pneumococcal pneumonia in 5 western European countries. In the base case analyses, the cost-effectiveness ratios for preventing invasive disease varied from approximately 11,000 to approximately 33,000 European currency units (ecu) per quality-adjusted life year (QALY). Assuming a common incidence (50 cases per 100,000) and mortality rate (20%-40%) for invasive disease, the cost-effectiveness ratios were <12,000 ecu per QALY in all 5 countries. For preventing pneumococcal pneumonia, vaccinating all elderly persons would be highly cost-effective to cost saving. Public health authorities should consider policies for encouraging pneumococcal vaccination for all persons aged > or =65 years.

Second International Pharmacoeconomic Conference on Alzheimer' s Disease

The Second International Pharmacoeconomic Conference on Alzheimer's Disease was held in Stockholm, Sweden, on April 4, 2000. The presentations focused on the role of cognition in pharmacoeconomic evaluations, the costs and consequences of behavioral disturbances, quality of life, disease progression models, and methods for valuing informal care. The results from individual studies will be published separately. Cognition has been used as the sole measure of disease severity in economic evaluations in dementia. However, behavioral disturbances are an important determinant of both cost and quality of life and should also be considered when appraising the effect of treatment. Quality-of-life assessment constitutes a single measure of the total impact of the disease, as well as a way of quantifying the benefits of treatment with antidementia drugs so that they can be compared with interventions in other disease areas. Measuring the quality of life of patients with dementia is associated with methodologic difficulties related to the difficulties for some patients in completing usual assessment processes. Disease progression models may be helpful in extrapolating the results from clinical trials to longer time periods and more representative populations. Modeling is an unavoidable part of the economic evaluation of antidementia drugs, and efforts should be made to increase transparency and comparability among models. Informal care constitutes a large percentage of the total care for patients with dementia, and the valuation of these services has a large impact on the results of pharmacoeconomic evaluations. Difficulties lie in quantifying the time spent on caring for the elderly and in attaching the correct price to each unit of time. The contingent valuation method is an alternative way of valuing informal care that so far has not been used in the field of dementia.

Diffusion of lysozyme in gels and liquids. A general approach for the determination of diffusion coefficients using holographic laser interferometry

A study on diffusion measurements of the protein lysozyme in liquids and agarose gels, at different pH and ionic strengths, has been performed using holographic laser interferometry. The measurements showed that the diffusive flux was very dependent on pH and ionic strength when the protein was not at its isoelectric point or when the charge of the lysozyme molecules was not screened by ions in the solution. Evaluation of the experimental data with Fick's law, resulted in diffusion coefficients for lysozyme that are strongly dependent on pH and ionic strength. Evaluation of the experimental data using a more general transport model, based on chemical potential gradients instead of concentration gradients resulted in lysozyme diffusion coefficients that are independent of pH and ionic strength. The chemical potential was estimated by using the Poisson-Boltzmann equation.

Changing pattern of histological type, location, stage and outcome of surgical treatment of gastric carcinoma

BACKGROUND

There are indications that some features of gastric carcinoma are changing, with a possible impact on prognosis. The aim of this study was to examine any changes in type, location, stage, resection rate, postoperative mortality rate or prognosis for patients with gastric carcinoma in a well defined population.

METHODS

During 1974-1991, 1161 new cases of gastric adenocarcinoma were diagnosed in Ostergötland County, Sweden. Tumour location, Laurén histological type, tumour node metastasis (TNM) stage, radicality of tumour resection and postoperative complications were recorded after histological re-evaluation of tissue specimens and examination of all patient records. Dates of death were obtained from the Swedish Central Bureau of Statistics. Time trends were studied by comparing the intervals 1974-1982 (period 1) and 1983-1991 (period 2).

RESULTS

The proportion of diffuse type of adenocarcinoma increased (from 27 to 35 per cent), while that of mixed type decreased (from 16 to 9 per cent) and that of intestinal type was unchanged. The proportion of tumours located in the proximal two-thirds of the stomach increased (from 32 to 42 per cent) and the proportion of patients with tumours in TNM stage IV decreased (from 32 to 25 per cent). Overall tumour resection rates were unchanged, although the proportion of radical total gastrectomies increased (from 36 to 50 per cent). Excluding tumours of the cardia or gastric remnant after previous ulcer surgery, the 5-year relative survival rate after radical resection increased from 25 to 36 per cent and the postoperative mortality rate decreased for both radical (from 11 to 4 per cent) and palliative (from 18 to 6 per cent) resection.

CONCLUSION

The patterns of tumour histology, location and stage of gastric carcinoma have changed in the authors' region. These changes were paralleled by a significant improvement in survival and postoperative mortality rates.

The determinants of health expenditure in the OECD countries: a pooled data analysis

This paper uses international health expenditure and the latest OECD data to investigate the determinants of aggregate health expenditure. The study differs from most previous studies in two principal ways. First, it uses a somewhat larger sample for estimation, with pooled time-series, cross-section data for 22 OECD countries for a 20-year period. Most previous work has used a purely cross-section approach: in this case, the small sample size reduced the statistical reliability of results and limited the number of hypotheses that can be tested simultaneously. Second, and following from this, a more extensive range of hypotheses is tested, with particular emphasis on those relating to the contractual relations between payers, providers and patients. The findings show, for example, that the use of primary care "gatekeepers" seems to result in lower health expenditure and also that the way of remunerating physicians in the ambulatory care sector appears to influence health expenditure; capitation systems tend to lead to lower expenditure than fee-for-service systems.

The cost-effectiveness of lipid lowering in patients with diabetes: results from the 4S trial

AIMS/HYPOTHESIS

The purpose of this study is to investigate the cost-effectiveness of simvastatin in diabetic patients, using prospectively collected outcomes data from the Scandinavian Simvastatin Survival Study.

METHODS

Diabetic patients were identified using two different classifications schemes: Clinical history (diabetic, non-diabetic) and the new American Diabetes Association definition (diabetic, impaired fasting glucose, normal fasting glucose). The analysis is based on prospectively collected data from the trial on hospitalization for cardiovascular problems, study drug utilization and mortality. The incremental cost per life year saved with simvastatin is estimated using costs from Sweden (primary) and other European countries.

RESULTS

Hospitalizations for cardiovascular problems were considerably reduced with simvastatin therapy, with the greatest differences in the diabetic subgroups. Reductions in hospitalizations in the diabetic group resulted in substantial hospital cost savings that offset 67 to 76 % of the drug cost (depending on the classification used). For the diabetic patients, the estimates of the cost per life-year gained ranged from 1600 Euros (based on clinical history) to 3200 Euros (based on American Diabetes Association) using Swedish costs. In the other evaluated European countries treatment with simvastatin showed a favourable cost-effectiveness ratio independent of differences in local health care unit costs.

CONCLUSION/INTERPRETATION

For all subgroups in the diabetic classification schemes, treatment with simvastatin resulted in estimates of cost per life-year gained that were well within the range generally considered to be cost effective. Based on the Scandinavian Simvastatin Survival Study, simvastatin therapy provides good value for money in both diabetic and non-diabetic patients with cardiovascular disease. [Diabetologia (1999) 42: 1293-1301]

A computer model to analyze the cost-effectiveness of hormone replacement therapy

This paper gives a detailed presentation of a computer model for evaluating the cost-effectiveness (CE) of hormone replacement therapy (HRT), describing the model's design, structure, and data requirements. The model needs data specified for costs, quality of life, risks, and mortality rates. As an illustration, the CE of HRT in Sweden is calculated. Two treatment strategies are evaluated for asymptomatic women: estrogen-only therapy and estrogen combined with a progestin. The model produces similar results compared with earlier studies. The CE ratios improve with the size of the risk reduction and generally with age. Further, estrogen-only therapy is associated with a lower cost per gained effectiveness unit compared with combined therapy. Uncertainty surrounding the long-term effects of HRT means that the CE estimates should be interpreted carefully. The model permits the inclusion of indirect costs and costs in added life-years, allowing the analysis to be made from a societal perspective, which is an improvement relative to previous studies.

Costs of Mini Mental State Examination-related cognitive impairment

OBJECTIVE

To investigate the relationship between cognitive impairment, measured with the Mini Mental State Examination (MMSE), and the cost of care.

DESIGN

The study uses data from the Kungsholmen project, a population-based study in Sweden in which people 75 years and older were observed over time. The initial study population (n = 1810) was divided into 4 health states based on the MMSE. A Markov model was constructed from the transition probabilities between different states between the first and second phases of the study. The expected cost of cognitive impairment for a period of 10 years was estimated for the cohort of patients studied.

MAIN OUTCOME MEASURES AND RESULTS

There was a strong correlation between cognitive impairment in terms of the MMSE and the annual cost of care. A multivariate statistical analysis showed that a decrease in the MMSE by 1 point was associated with an increase in the cost of care of 15,000 Swedish kronor (SEK) [$US2000; 1995 values].

CONCLUSIONS

The results show that large savings are possible if the decline in cognitive functioning can be prevented. The model developed can be used to estimate the impact on cost of care of treatments which reduce the cognitive decline in patients with Alzheimer's disease.

Ionization behavior of acidic residues in calbindin D(9k)

The ionization state of seven glutamate residues, one aspartate, and the C-terminal alpha-COOH group in bovine apo calbindin D(9k) has been studied by measurement and modeling of the pH titration curves and apparent pK(a) values. The observed pK(a) ranged from 3.0 to 6.5. Most of the observed acidic groups were half-ionized at lower pH values than those in unstructured proteins. As a rule, the ionization equilibria extended over a wider pH range than in the case of unperturbed single titrations, indicating a complex influence of protein charges on the charge state of each individual residue. Glu17, which is a backbone Ca(2+)-ligand in the N-terminal binding loop of calbindin D(9k), was half-protonated at pH 3.6 but manifested biphasic titration with apparent pK(a) values of 3.2 and 6.5. Complementary Monte Carlo simulations of the titration process and pK(a) values of the acidic groups in calbindin D(9k) reproduce the experimentally observed titration features, except for the pronounced double titration of Glu17. Discrepancies between the results from direct measurement and from modeling may be partly caused by changes in the protein structure when the net charge changes from -8 to +11 over the isoelectric point at pH 5. Proteins 1999;37:106-115.

[Health economics analysis of diabetes is necessary. It facilitates decision-making and international comparison]

Cost-of-illness studies have shown diabetes to be associated with substantial direct and indirect costs, accounting for 5-6 percent of total health care expenditure. In a Swedish study, where total costs were divided into costs due to management of diabetes and costs due to complications, the total annual cost to the community was estimated to be SEK 5.7 billion in 1994, costs due to complications being the major item, accounting for over 75 per cent of the total. There have been few other Swedish studies of costs for diabetes or diabetes-related complications. The most widely studied category of complications is diabetes-related foot ulcers, with an estimated annual cost of SEK 1-2 billion. However, earlier studies were marred by shortcomings: costs estimated for the main diagnosis only, without breakdown into categories or distinction between type 1 and type 2 diabetes, sources of data other than official data-bases ignored, etc. Diabetes care in Sweden is of high quality, and substantial clinical, epidemiological and health economics research has been carried out. It is important that Sweden contributes to international research on health economics aspects of diabetes.

Costs of coronary heart disease and stroke: the case of Sweden

OBJECTIVES

To estimate the annual costs in Sweden of coronary heart disease (CHD) and stroke, and the potential cost savings if these clinical 'events' are avoided. The analysis is undertaken from a societal perspective, including both direct and indirect costs. Costs are calculated for five clinical conditions: (i) acute myocardial infarction (AMI), (ii) angina pectoris (AP), (iii) unstable angina (UA), (iv) congestive heart failure (CHF), and (v) stroke.

DESIGN

A retrospective study including patients admitted to the Department of Medicine at Södertälje Hospital during the period January 1993 to March 1995 with CHD or a stroke. Each patient was followed for 1 year after admission to the hospital. To estimate potential cost savings, the patient was used as his or her own control. The potential savings in direct costs if CHD or a stroke is avoided were estimated as the difference between costs for 1 year after and 1 year before the event. The indirect costs were calculated as the difference between the values of market production of goods and services the year before the event and the year after.

SETTING

The Department of Medicine at Södertälje Hospital, Södertälje, Sweden.

SUBJECTS

The patients included in the study were patients at the Department of Medicine at Södertälje Hospital in Sweden. The inclusion criterion was that the patients should have been admitted for the first time for CHD or stroke during the year 1994. To obtain 25 patients for each clinical category we first had to expand the inclusion period to cover January 1993 to March 1995. Secondly, we also had to include 36 patients with an earlier established uncomplicated CHD or stroke. Despite this, no more than 22 patients with UA were found.

INTERVENTIONS

Patients were followed in medical practice.

MAIN OUTCOME MEASURES

Costs, direct and indirect costs, and potential savings.

RESULTS

The mean direct costs during the year after a clinical event range between Swedish kronor (SEK) 41 000 for CHF and SEK 96 000 for stroke, whereas the mean potential savings in direct costs range from SEK 36 000 for CHF to SEK 91 000 for UA. The potential mean savings in indirect costs range between SEK 24 000 for CHF and SEK 102 000 for AMI. The direct costs for first-time patients are lower than those for patients with an earlier established CHD or stroke. No systematic differences have been found in potential direct cost savings and indirect costs between the two patient groups.

CONCLUSIONS

CHD and stroke are associated with high costs during the year after admission to the Department of Medicine. There are also large potential cost savings from the prevention of CHD and stroke. However, further studies, including more patients and costs arising in the municipality, are needed to establish more precise and complete estimates of the costs related to CHD and stroke.

The cost-effectiveness of donepezil therapy in Swedish patients with Alzheimer's disease: a Markov model

This study compared the cost-effectiveness of donepezil, a new cholinesterase inhibitor indicated for the treatment of mild-to-moderate probable Alzheimer's disease (AD), with no treatment. A Markov state transition model was employed to simulate treatment costs based on Swedish epidemiologic data. The Markov states used in the model were defined according to cognitive function, as assessed by the Mini-Mental State Examination. Data on costs and baseline transition probabilities were taken from the Kungsholmen Project, an observational, population-based study of persons aged >75 years in Sweden. Data on the treatment effect were taken from a clinical trial comparing donepezil to placebo over 24 weeks and were applied to the baseline transition probabilities to assess the effect of treating the clinical manifestations of AD in Swedish patients. Also, a within-trial analysis was performed for comparison, using transition probabilities taken from the clinical study. Both models were run for 5 years in half-year cycles, and both demonstrated various degrees of cost savings and improved effectiveness, as measured by increased time in nonsevere disease states. Thus donepezil had superior cost-effectiveness compared with no treatment.

Cost-effectiveness of prolonged administration of a low molecular weight heparin for the prevention of deep venous thrombosis following total hip replacement

Recently there has been discussion on the value of prolonged thromboprophylaxis after elective hip surgery to prevent thromboembolic complications up to one month. Continuing low molecular weight heparin for one month can significantly reduce the frequency of venographically-proven deep vein thrombosis (DVT). How this will influence health economics has hitherto not been evaluated. Data on costs and effect from a randomized comparison between 10 and 30 days of once daily low molecular weight heparin (enoxaparin) were used in a cost-effectiveness study. Data on treatment costs were based on patients actually treated for DVT within the randomized study. Various sensitivity analyses were performed. In the study both phlebographically detected and clinically manifested venous thromboembolism were registered. By using costs from the health care system in Sweden it could be shown that the cost was 6,075 Swedish Krona (SEK) per phlebographic DVT avoided and 13,184 Swedish Krona (SEK) per clinical DVT avoided. If more than 50% of the patients managed to self-administer the low molecular weight heparin injections, the use of prolonged prophylaxis is cost-effective. Prolonged prophylaxis with the low molecular weight heparin enoxaparin after elective hip arthroplasty is cost-effective provided that at least 50% of the patients can administer the subcutaneous injections themselves.