Are clinical trials a cost-effective investment?

To assess the economic attractiveness of clinical research, this study measures the cost-effectiveness of seven selected randomized trials. The model considers the cost of performing a trial and the benefits to the health status of a target population one could expect before the trial was performed. The incremental cost-effectiveness for performing the trials ranged from a low of $2 to $3 per life-year saved for a trial of aspirin in unstable angina to a high of $396 to $685 per life-year saved for the randomized trial portion of the Coronary Artery Surgery Study. These ratios were substantially lower (ie, more economically attractive) than the cost-effectiveness ratios associated with performing interventions of proved effectiveness. This study shows that a selected group of clinical trials, some of which were controversial and expensive, were indeed a good investment. This information may be helpful to policymakers who consider allocating funds to biomedical research.     

Cholesterol-lowering therapy with pravastatin in patients with average cholesterol levels and established ischaemic heart disease: is it cost-effective?

OBJECTIVE: To measure the cost-effectiveness of cholesterol-lowering therapy with pravastatin in patients with established ischaemic heart disease and average baseline cholesterol levels. DESIGN: Prospective economic evaluation within a double-blind randomised trial (Long-Term Intervention with Pravastatin in Ischaemic Disease [LIPID]), in which patients with a history of unstable angina or previous myocardial infarction were randomised to receive 40 mg of pravastatin daily or matching placebo. PATIENTS AND SETTING: 9014 patients aged 35-75 years from 85 centres in Australia and New Zealand, recruited from June 1990 to December 1992. MAIN OUTCOME MEASURES: Cost per death averted, cost per life-year gained, and cost per quality-adjusted life-year gained, calculated from measures of hospitalisations, medication use, outpatient visits, and quality of life. RESULTS: The LIPID trial showed a 22% relative reduction in all-cause mortality (P < 0.001). Over a mean follow-up of 6 years, hospital admissions for coronary heart disease and coronary revascularisation were reduced by about 20%. Over this period, pravastatin cost $A4913 per patient, but reduced total hospitalisation costs by $A1385 per patient and other long-term medication costs by $A360 per patient. In a subsample of patients, average quality of life was 0.98 (where 0 = dead and 1 = normal good health); the treatment groups were not significantly different. The absolute reduction in all-cause mortality was 3.0% (95% CI, 1.6%-4.4%), and the incremental cost was $3246 per patient, resulting in a cost per life saved of $107 730 (95% CI, $68 626-$209 881) within the study period. Extrapolating long-term survival from the placebo group, the undiscounted cost per life-year saved was $7695 (and $10 938 with costs and life-years discounted at an annual rate of 5%). CONCLUSIONS: Pravastatin therapy for patients with a history of myocardial infarction or unstable angina and average cholesterol levels reduces all-cause mortality and appears cost effective compared with accepted treatments in high-income countries.     

Hepatitis C: an economic evaluation of extended treatment with interferon.

OBJECTIVES: To re-evaluate the cost effectiveness of treating hepatitis C virus (HCV) infection with interferon alfa (IF alpha) in Australia, taking into account changes in clinical practice. DESIGN: A decision-analytic method (Markov model) was used to simulate the costs and effects of 6 months and 12 months of treatment with IF alpha versus no treatment (conventional management). Both costs and effects were modelled over 30 years. DATA SOURCES: Published meta-analysis of the effectiveness of treatment, professional judgement about treatment protocols, scheduled medical fees, diagnosis-related costs for hospital admission, and a literature search for quality-of-life weights. PATIENTS: A hypothetical cohort of 1000 patients with chronic HCV infection aged 40 years at the start of treatment. MAIN OUTCOME MEASURES: Incremental costs per life-year gained and per quality-adjusted life-year (QALY) gained. RESULTS: Compared with no treatment, IF alpha treatment for 6 months results in an extra 94.2 life-years or 320.1 QALYs at an extra cost of $1.8 million (after discounting at 3%) in a cohort of 1000 patients. Discounted cost per life-year gained is $19,110, which is about a quarter of the cost reported in 1994. The discounted cost per QALY gained is $5625. Extended treatment for another 6 months results in an additional 89.0 life-years saved or 170.8 QALYs gained at an incremental discounted cost of $15,835 per life-year gained and $8250 per QALY gained. CONCLUSIONS: The cost effectiveness of IF alpha treatment for HCV infection has improved as a result of better patient selection, cost reductions and enhanced effectiveness of extended treatment. The results are sensitive to assumptions made about quality of life and the discount rate.     

The prevalence of venous thromboembolism after hip and knee replacement surgery

OBJECTIVE: To determine the prevalence of venous thromboembolism (VTE) after total hip replacement (THR), total knee replacement (TKR) or bilateral TKR in a large sample of patients in a major hospital orthopaedic unit. DESIGN, SETTING AND PATIENTS: The Mater Misericordiae Hospital, North Sydney, NSW, a 195-bed private hospital. All patients who had THR, TKR or bilateral TKR at the hospital between 1 April 1995 and 31 December 2001 had physical prophylaxis (graduated compression elastic stockings or intermittent pneumatic compression, or both) and chemical prophylaxis (anticoagulant) against VTE. All underwent ultrasonography of both legs before discharge, with a small, symptomatic group also undergoing a ventilation/perfusion lung scan (V/Q scan) and computed tomographic pulmonary angiography. MAIN OUTCOME MEASURES: Prevalence of deep-vein thrombosis (DVT) and symptomatic pulmonary embolism (PE) before discharge. RESULTS: Among a total of 5999 patients, the pre-discharge prevalence of DVT after THR, TKR or bilateral TKR was 8.9%, 25.6% and 36.9%, respectively. The prevalence of symptomatic non-fatal in-hospital PE was 1.9%, while the prevalence of fatal in-hospital PE was 0.05%. CONCLUSIONS: Despite short-term chemical and physical thromboprophylaxis, the prevalence of DVT after lower-limb joint replacement, measured by pre-discharge ultrasonography, was high. The rate of symptomatic non-fatal in-hospital PE was moderate, but fatal in-hospital PE was rare.     

达比加群220mg与依诺肝素对膝、髋关节置换术后静脉血栓预防的疗效及安全性比较评价

目的系统评价达比加群220 mg相比于依诺肝素对膝、髋关节置换术后静脉血栓预防的疗效及安全性。方法计算机检索中国知网(CNKI)、维普数据库(VlP)、万方数据库(Wanfang Data)、Cochrane Library、Embase、Pubmed and Medline Databases,同时追溯纳入文献的参考文献,时间为1990—2012年。2位研究员根据GRADE系统推荐分级方法,对纳入研究的文献质量进行严格评价和资料提取,对符合质量标准的RCT采用Rview Manager 5.1进行Meta分析。结果共纳入4篇文献,包括10 265例患者。结果显示达比加群220 mg相比于依诺肝素不增加膝、髋关节置换术后静脉血栓形成和出血的风险,其结果分别为总静脉血栓和全因病死率[OR=1.01,95%CI(0.81～1.26)]、近端静脉血栓[OR=0.76,95%CI(0.55～1.07)]、主要静脉血栓和静脉血栓相关死亡[OR=0.79,95%CI(0.59～1.06)]、主要出血[OR=1.11,95%CI(0.75～1.65)]、临床相关出血[OR=1.18,95%CI(0.92～1.51)]。结论达比加群220 mg预防膝、髋关节置换术后静脉血栓的疗效及安全性不亚于依诺肝素,且其出血风险不存在明显的差别。     

Rational thromboprophylaxis in medical inpatients: not quite there yet

Routine thromboprophylaxis in hospitalised medical patients is based on trials that predominantly use asymptomatic deep vein thrombosis (DVT) as the endpoint. As asymptomatic DVT is 10-30-fold more common than symptomatic DVT, this exaggerates estimates of benefit and cost-effectiveness. Based on symptomatic disease, the number needed to treat per venous thromboembolism (VTE) prevented is high (150-1600), and the true cost-effectiveness of thromboprophylaxis for symptomatic event reduction is uncertain. The incidence of major bleeding among patients receiving prophylaxis is at least equal to the reduction in clinical VTE. Routine thromboprophylaxis in hospitalised medical patients is not warranted, and better patient selection is needed.     

Low-molecular-weight heparin (LMWH) in the treatment of thrombosis

Thromboembolic complications are a common and costly medical problem, associated with significant morbidity and mortality, especially in postoperative patients. There have been reports of death due to thromboembolic complications even after short procedures, e.g. arthroscopy. Low-molecular-weight heparins (LMWHs) (e.g., certoparin, dalteparin, enoxaparin, nadroparin, reviparin, tinzaparin) have been tested for treatment of deep vein thrombosis in comparison to unfractionated heparin (UFH) in many patients being effective and safe alternative for treatment of deep vein thrombosis (DVT) and venous thromboembolism (VTE). Fixed-dose subcutaneous LMWH once daily is in most cases of equivalent efficacy and safety compared to conventional UFH therapy. There may be less risk for bleeding, less platelet activation together with a control of markers of haemostatic system activation, and either no progression or regression of thrombus size in patients treated with LMWH. The handling of LMWH is more comfortable for patients and less time consuming for nurses and laboratories compared to UFH. The cost-effectiveness analysis showed that LMWH are more cost effective than UFH. It has been calculated that outpatient treatment with LMWH may save 1641 dollars per patient in comparison to hospital treatment. This economic benefit of outpatient treatment of DVT seems to be realized in different health systems. Women with antiphospholipid antibodies and a history of either prior thrombotic events or pregnancy loss are at high risk during pregnancy for either another fetal death or thrombosis and may benefit from treatment with LMWH. In patients with malignant tumors secondary prophylaxis or long-term treatment with LMWH is successful. Patients with a contraindication for oral anticoagulants may benefit from treatment with LMWH as do patients on chronic anticoagulation treatment scheduled for an operative intervention. In most instances LMWH (dalteparin, enoxaparin, nadroparin) treatment for DVT may be given once daily at a fixed dose without any harm, based on a prolonged antithrombin activity. Effectiveness and safety of LMWH (dalteparin, enoxaparin, nadroparin, tinzaparin) in comparison to UFH treatment on outpatient basis has been demonstrated in several studies. In summary, LMWHs have an established role in the treatment of DVT and pulmonary embolism (PE), on an in- and outpatient basis and could realize substantial savings. Most studies were performed with dalteparin, enoxaparin and nadroparin. There is evidence that LMWHs may help to prolong survival in cancer patients and to avoid complications of the acute coronary syndrome.     

Nonionic contrast media: economic analysis and health policy development.

The replacement of old radiologic contrast media with supposedly safer but more expensive media has created a dilemma for radiologists and hospital administrators. To quantitate the nature of this trade-off we performed a cost-utility analysis using optimistic assumptions that favoured the new media. A complete conversion to the new media would result in an incremental cost of at least $65,000 to gain 1 quality-adjusted life-year (QALY). For a selective strategy in which only high-risk patients would receive the new media the cost would be about $23,000 per QALY gained. However, the incremental cost for low-risk patients is over $220,000 per QALY gained. Conversion to the new contrast media, although not necessarily the most efficient use of scarce resources, has already occurred in Ontario, primarily because of press publicity, pressure from insurers and a political unwillingness of policymakers to decide the fate of identifiable victims. We found that funding of a new intervention associated with a high cost-utility ratio rather than interventions with lower ratios might save some identifiable victims at the expense of a larger number of unidentifiable ones.     

Comparison of warfarin and external pneumatic compression in prevention of venous thrombosis after total hip replacement.

OBJECTIVE--To compare the effectiveness and safety of warfarin and external pneumatic compression (EPC) in prevention of venous thrombosis after total hip replacement. DESIGN--Prospective, randomized trial in consecutive patients, with blinded assessment of the primary end point. SETTING--University medical center and large community hospital. PATIENTS--Patients over age 18 years scheduled for elective primary total hip replacement were eligible. Of 254 patients interviewed, 232 were randomized, 220 patients had surgery and received prophylaxis, and 201 had venography. INTERVENTIONS--Patients were randomly assigned to prophylaxis with a device providing bilateral sequential EPC to both the calf and thigh or to receive warfarin in a low-intensity regimen beginning 10 to 14 days preoperatively. Prophylaxis was continued until venography. MAIN OUTCOME MEASURES--Venous thrombosis was diagnosed by venography between postoperative days 6 and 8. Bleeding was assessed by surgical blood loss, transfusion requirements, changes in hematocrit, and clinically identified bleeding complications. RESULTS--The total incidence of venous thrombosis was virtually the same in the warfarin and EPC groups (31% vs 27%), but the distribution of thrombi was different. Proximal thrombosis occurred in 12% of patients in the EPC group compared with only 3% in the warfarin group (P = .012, 95% confidence interval for difference, 2% to 18%). In contrast, calf vein thrombosis was more frequent in the warfarin group (21%) than in the EPC group (12%) (P = .021, 95% confidence interval for difference, 0% to 18%). Most proximal thrombi in EPC-treated patients were located within 15 cm of the femoral head and were not continuous with thrombi in deep calf veins. The high incidence of proximal thrombosis in the EPC group resulted in termination of the study by the safety monitoring committee. Blood loss and bleeding complications were similar in the two groups. CONCLUSION--Warfarin therapy is significantly more effective than EPC in preventing serious proximal vein thrombosis after total hip replacement. The greater effectiveness of warfarin therapy in preventing proximal vein thrombi and of EPC in preventing thrombosis in the calf suggests that there are differences in the pathogenesis of thrombosis in these two locations.     

Deep vein thrombosis after total hip and knee arthroplasty in Indian patients

Background: Deep vein thrombosis (DVT) is one of the most common complications of total hip (THA) and total knee arthroplasty (TKA). Though the reported incidence of DVT is very high, that of proximal DVT is low and that of fatal thromboembolism is very low. Hence the issue of prophylaxis for DVT remains controversial. The incidence of DVT is based on various studies in European and American populations. The Asian population is genetically and socially quite different from American and European populations, and the incidence of DVT can be quite different. Therefore a prospective study was initiated at our centre to determine incidence of DVT after THA and TKA in Indian patients. Methods: A prospective study was conducted on 60 hips in 45 patients and 46 knees in 26 patients who underwent THA and TKA respectively, without any known risk factors for thromboembolic disease. DVT was studied by preoperative and postoperative serial colour Doppler ultrasonography. No prophylaxis was given to any of the patients. Results: DVT was found in two patients who had undergone THA. No case of DVT was detected in any patient who had undergone TKA. Conclusion: These results suggest that the incidence of DVT in Indian patients is very low and is not comparable with American and European populations. It is therefore not cost effective to advise prophylaxis in Indian patients undergoing THA/TKA who have no known risk factors for DVT.     

The Cost-effectiveness of Preventing AIDS-Related Opportunistic Infections

Context.— Multiple options are now available for prophylaxis of opportunistic infections related to the acquired immunodeficiency syndrome (AIDS). However, because of differences in incidence rates as well as drug efficacy, toxicity, and costs, the role of different types of prophylaxis remains uncertain. Objective.— To determine the clinical impact, cost, and cost-effectiveness of strategies for preventing opportunistic infections in patients with advanced human immunodeficiency virus (HIV) disease. Design.— We developed a Markov simulation model to compare different strategies for prophylaxis of Pneumocystis carinii pneumonia (PCP), toxoplasmosis, Mycobacterium avium complex (MAC) infection, fungal infections, and cytomegalovirus (CMV) disease in HIV-infected patients. Data for the model were derived from the Multicenter AIDS Cohort Study, randomized controlled trials, and the national AIDS Cost and Services Utilization Survey. Main Outcome Measures.— Projected life expectancy, quality-adjusted life expectancy, total lifetime direct medical costs, and cost-effectiveness in dollars per quality-adjusted life-year (QALY) saved. Results.— For patients with CD4 cell counts of 0.200 to 0.300x10⁹/L (200-300/µL) who receive no prophylaxis, we projected a quality-adjusted life expectancy of 39.08 months and average total lifetime costs of $40288. Prophylaxis for PCP and toxoplasmosis with trimethoprim-sulfamethoxazole for patients with CD4 cell counts of 0.200x10⁹/L (200/µL) or less increased quality-adjusted life expectancy to 42.56 months, implying an incremental cost of $16000 per QALY saved. Prophylaxis for MAC for patients with CD4 cell counts of 0.050x10⁹/L (50/µL) or less produced smaller gains in quality-adjusted life expectancy; incremental cost-effectiveness ratios were $35000 per QALY saved for azithromycin and $74000 per QALY saved for rifabutin. Oral ganciclovir for the prevention of CMV infection was the least cost-effective prophylaxis ($314000 per QALY saved). Results were most sensitive to the risk of developing an opportunistic infection, the impact of opportunistic infection history on long-term survival, and the cost of prophylaxis. Conclusions.— The cost-effectiveness of prophylaxis against HIV-related opportunistic infections varies widely, but prophylaxis against PCP or toxoplasmosis and against MAC delivers the greatest comparative value. In an era of limited resources, these results can be used to set priorities and explore new alternatives for improving HIV patient care.      

Cutting into cholesterol. Cost-effective alternatives for treating hypercholesterolemia

We performed an analysis of the cost-effectiveness of treating individuals with significantly elevated levels of total serum cholesterol (greater than 6.85 mmol/L [greater than 265 mg/dL], comparing treatment with three alternative agents: cholestyramine resin, colestipol, and oat bran (a soluble fiber). We simulated a program for lowering cholesterol levels that was similar to that of the Coronary Primary Prevention Trial, and then used the outcomes of the trial to calculate the incremental cost per year of life saved (YOLS) from the perspective of society. Our findings suggest that the cost per YOLS ranges from $117,400 (cholestyramine resin packets) to $70,900 (colestipol packets) and $17,800 (oat bran). Using bulk drug reduces the cost per YOLS to $65,100 (cholestyramine resin) and $63,900 (colestipol). Targeting bulk colestipol treatment only to smokers has a cost per YOLS of $47,010; the incremental cost of treating nonsmokers would be $89,600 per additional YOLS. Although pharmacologic therapy has substantial costs, it may be more cost-effective when low-cost forms are applied to particular high-risk groups, such as smokers. However, a broad public health approach to lowered cholesterol levels by additional dietary modification, such as with soluble fiber, may be preferred to a medically oriented campaign that focuses on drug therapy.     

Incidence and risk factors for development of venous thromboembolism in Indian patients undergoing major orthopaedic surgery: results of a prospective study

Introduction

The incidence of venous thromboembolism (VTE) in Western populations undergoing major orthopaedic surgery without any thromboprophylaxis has been reported to range from 32% to 88%. There is however limited information on incidence of VTE in Indian patients and most of the Indian patients undergoing these surgeries do not receive any form of prophylaxis regardless of their risk profile.

Methods

A prospective study was performed on 147 patients undergoing major orthopaedic surgery for total knee replacement (TKR), total hip replacement (THR), and proximal femur fracture fixation (PFF) without any prophylaxis. These patients were profiled for presence of the known risk factors responsible for development of VTE. A duplex ultrasound on both lower limbs was done 6 to 10 days after surgery. Twenty three patients underwent THR, 22 patients underwent TKR, and 102 underwent surgery for PFF. The patients were assessed clinically for any signs of deep venous thrombosis (DVT) and pulmonary embolism (PE). A helical CT scan was done in case of suspicion of PE and a duplex ultrasound was done in case of clinical suspicion of DVT irrespective of the stage of study.

Results

The overall incidence of VTE was 6.12% and that of PE was 0.6%. The risk factors that were found to be significantly responsible for development of VTE (p < 0.05) were: immobility greater than 72 hours, malignancy, obesity, surgery lasting more than two hours.

Conclusion

The study reconfirms the belief that DVT has a lower incidence in Indian patients as compared with other ethnic groups.     

A cost-effectiveness analysis of hormone replacement therapy in the menopause.

OBJECTIVE: To evaluate the cost-effectiveness of hormone replacement therapy in the menopause with particular reference to osteoporotic fracture and myocardial infarction. DESIGN: The multiple-decrement form of the life table was the mathematical model used to follow women of age 50 through their lifetime under the "no hormone replacement" and "hormone replacement" assumptions. Standard demographic and health economic techniques were used to calculate the corresponding lifetime differences in direct health care costs (net costs in dollars) and health effects ("net effectiveness" in terms of life expectancy and quality, in "quality-adjusted life-years"). This was then expressed as a cost-effectiveness ratio or the cost ($) per quality-adjusted life-year (QALY) for each of the chosen hormone replacement regimens. SETTING AND PATIENTS: All women of age 50 in New South Wales, Australia (n = 27,021). RESULTS: The analysis showed that the lifetime net increments in direct medical care costs were largely contributed by hormone drug and consultation costs. Hormone replacement was associated with increased quality-adjusted life expectancy, a large percentage of which was attributed to a relief of menopausal symptoms. Cost-effectiveness ratios ranged from under 10,000 to over a million dollars per QALY. Factors associated with improved cost-effectiveness were prolonged treatment duration, the presence of menopausal symptoms, minimum progestogen side effects (in the case of oestrogen with progestogen regimens), oestrogen use after hysterectomy and the inclusion of cardiac benefits in addition to fracture prevention. CONCLUSIONS: Hormone replacement therapy for symptomatic women is cost-effective when factors that enhance its efficiency are considered. Short-term treatment of asymptomatic women for prevention of osteoporotic fractures and myocardial infarction is an inefficient use of health resources. Cost-effectiveness of hormone replacement in asymptomatic women is dependent on the magnitude of cardiac benefits associated with hormone use and the treatment duration.     

Cost-effectiveness of automated external defibrillators on airlines

CONTEXT: Installation of automated external defibrillators (AEDs) on passenger aircraft has been shown to improve survival of cardiac arrest in that setting, but the cost-effectiveness of such measures has not been proven. OBJECTIVE: To examine the costs and effectiveness of several different options for AED deployment in the US commercial air transportation system. DESIGN, SETTING, AND SUBJECTS: Decision and cost-effectiveness analysis of a strategy of full deployment on all aircraft as well as several strategies of partial deployment only on larger aircraft, compared with a baseline strategy of no AEDs on aircraft (but training flight attendants in basic life support) for a hypothetical cohort of persons experiencing cardiac arrest aboard US commercial aircraft. Estimates for costs and outcomes were obtained from the medical literature, the Federal Aviation Administration, the Air Transport Association of America, a population-based cohort of Medicare patients, AED manufacturers, and the Bureau of Labor Statistics. MAIN OUTCOME MEASURES: Quality-adjusted survival after cardiac arrest; costs of AED deployment on aircraft and of medical care for cardiac arrest survivors. RESULTS: Adding AEDs on passenger aircraft with more than 200 passengers would cost $35 300 per quality-adjusted life-year (QALY) gained. Additional AEDs on aircraft with capacities between 100 and 200 persons would cost an additional $40 800 per added QALY compared with deployment on large-capacity aircraft only, and full deployment on all passenger aircraft would cost an additional $94 700 per QALY gained compared with limited deployment on aircraft with capacity greater than 100. Sensitivity analyses indicated that the quality of life, annual mortality rate, and the effectiveness of AEDs in improving survival were the most influential factors in the model. In 85% of Monte Carlo simulations, AED placement on large-capacity aircraft produced cost-effectiveness ratios of less than $50 000 per QALY. CONCLUSION: The cost-effectiveness of placing AEDs on commercial aircraft compares favorably with the cost-effectiveness of widely accepted medical interventions and health policy regulations, but is critically dependent on the passenger capacity of the aircraft. Placing AEDs on most US commercial aircraft would meet conventional standards of cost-effectiveness.     

比较磺达肝癸钠与依诺肝素预防骨科大手术后静脉血栓栓塞症疗效与安全性的Meta分析

目的系统评价磺达肝癸钠与依诺肝素在预防骨科大手术后静脉血栓栓塞症（VTE）方面的疗效与安全性。方法计算机
检索MEDLINE、EMbase、Cochrance图书馆、中国期刊全文数据库、中国生物医学文献数据库、维普数据库及万方资源数据系
统,并手工检索相关杂志、会议论文等。检索无语种限制,时间均从建库至2012年10月。按特定的纳入排除标准,筛选出符合
标准的关于磺达肝癸钠与依诺肝素预防骨科大手术后VTE发生的随机对照试验。评价指标为总VTE、深静脉血栓（DVT）、症
状性VTE、肺栓塞、大出血事件和各种不良事件等的发生率。进行质量评价和数据提取后,采用RevMan 5.1.7软件进行Meta分
析。结果共纳入随机对照研究文献5篇,均为英文文献,研究对象有1篇为膝关节大手术患者,1篇髋部骨折手术患者,其余3
篇为全髋关节置换术患者,病例数为7611例。Meta分析结果显示：磺达肝癸钠组的总VTE发生率低于依诺肝素组[RR=0.52,
95% CI（0.40,0.67）,P<0.00001];磺达肝癸钠组DVT发生率低于依诺肝素组[RR=0.49,95%CI（0.42,0.58）,P<0.00001];磺达肝
癸钠组症状性VTE发生率与依诺肝素组无统计学差异[RR=1.52,95%CI（0.80,2.88）,P=0.20];磺达肝癸钠组大出血发生率高于
依诺肝素组[RR=1.55,95% CI（1.14,2.12)）,P=0.006];磺达肝癸钠组总死亡率与依诺肝素组无统计学差异[RR=0.93,95% CI
(0.63,1.37）,P=0.72]。结论磺达肝癸钠预防骨科大手术后VTE的疗效优于依诺肝素,虽然大出血风险较依诺肝素高,但并不
增加总死亡率。
     

全髋关节置换术后深静脉血栓形成的危险因素分析

目的 提高对全髋关节置换术后下肢深静脉血栓(DVT)形成临床特点的认识,并探讨其易发生的危险因素.方法 2000年1月至2012年6月间对在苏州吴中人民医院骨科行人工全髋关节置换治疗并有完整资料的145例患者行DVT形成相关风险因素分析,其中男性51例,女性94例,年龄23～83岁,平均(59.8±13.0)岁.所有患者均在术前、术后第7天分别行双下肢彩色多普勒超声检查,明确是否有下肢深静脉血栓形成.详细调查和记录患者的年龄、性别、体重指数(BMI)、血型、是否吸烟、是否饮酒、麻醉类型、术中出血量、输血量、是否使用骨水泥、手术人路、单侧或双侧置换、术后镇痛方式、术前诊断以及有无合并糖尿病、高血压病等,同时记录发生DVT的部位、类型以及有无深静脉血栓形成的临床症状.按BMI分为正常组(BMI≤25kg/m2)和肥胖组(BMI＞ 25 kg/m2).将DVT发生与否作为因变量,把以上可疑因素作为自变量,先进行单因素分析,得出有显著差异性的因素,再进行多因素非条件logistic分析,筛选出DVT发生的主要影响因素.结果 (1)本组病例共发生DVT 45例,发生率31％.单纯近端DVT为7例(15.6％),远端DVT 33例(73.3％),全静脉DVT 5例(11.1％),均未发生肺栓塞(PTF).无DVT临床症状的25例(55.5％),有DVT临床症状的20例(44.5％); (2)临床因素与术后DVT形成的关系:单因素x 2检验显示:高龄、女性、双侧关节同时置换、全身麻醉、使用骨水泥等与DVT形成显著相关(P＜0.05);将临床各因素进行Logistic多变量回归分析,最终进入Logistic回归模型的相关因素有4个,其中危险因素3个,分别是性别,肥胖及骨水泥的使用,其术后发生DVT的风险倍数分别增加到10.012,3.086,8.834;保护因素1个,为术前患者血型是O型,术后发生DVT的可能性减少到0.191倍.结论 全髋关节置换患者术后发生DVT常存在危险因素,最常见的危险因素有高龄、女性、双侧关节同时置换、全身麻醉、使用骨水泥等.认识DVT的各种危险因素及临床征象,及早给予相应的辅助检查及术前预防性的治疗,是防止PTE的发生和降低DVT的发生率的关键.     

A systematic review and economic analysis of drug-eluting coronary stents available in Australia

OBJECTIVES: To compare the safety, effectiveness and cost-effectiveness of drug-eluting coronary stents used in Australia with bare-metal stents and determine whether the benefits are greater for high-risk subgroups. DATA SOURCES: MEDLINE, Pre-Medline, EMBASE, Current Contents, CINAHL and the Cochrane Library database were searched to identify eligible randomised controlled trials and systematic reviews published in English between January 1966 and June 2004. STUDY SELECTION: Seven randomised controlled trials that assessed polymer-based paclitaxel- or sirolimus-eluting stents versus bare-metal stents in patients with coronary atherosclerosis and reported on stent thrombosis, mortality, myocardial infarction, coronary artery bypass grafting or target lesion revascularisation. DATA EXTRACTION: Two independent reviewers appraised eligible studies and extracted data. Relative risks (RRs) were calculated for each outcome and pooled using the Mantel-Haenszel method. DATA SYNTHESIS: Rates of stent thrombosis, mortality, myocardial infarction and bypass grafts did not differ by stent type. Drug-eluting stents (DESs) resulted in a 71%-80% lower risk of revascularisation at 12 months (RR 0.29 [95% CI, 0.20-0.43] for paclitaxel-eluting stents [n = 1593 patients]; RR 0.20 [95% CI, 0.13-0.29] for sirolimus-eluting stents [n = 1296 patients]). Similar benefits were seen in several high-risk subgroups of patients: those with diabetes, lesion length > 20 mm and target-vessel diameter < or = 2.5 mm. The benefits of DESs in these high-risk groups over lower-risk groups were inconclusive because of low numbers. The cost per revascularisation avoided by using DESs was 3,750-6,100 Australian dollars, with an estimated cost per quality-adjusted-life-year (QALY) gained of 46,829-76,467 Australian dollars. In sensitivity analyses, estimates varied from DESs being cost-saving to costing an additional 314,385 Australian dollars per QALY gained. CONCLUSIONS: DESs are effective in reducing revascularisation. Estimates of cost-effectiveness are very sensitive to changes in estimates of their true effects in clinical practice, market price and the number of stents used per patient. Decisions to limit DESs to only patients at the highest risk of restenosis may improve their cost-effectiveness but will need to be reassessed when evidence is available to compare absolute benefits between patient groups.     

Cost-effectiveness of primary tetanus vaccination among elderly Canadians.

Although tetanus is now rare, vaccination is currently recommended for the entire population. Most elderly North Americans have never received tetanus vaccination. We evaluated the expected cost-effectiveness of using mailed reminders from family physicians to increase primary tetanus vaccination coverage among elderly Canadians. We estimated that over 10 years the program would prevent five cases of tetanus and one death from tetanus, resulting in a gain of 13 life-years. There would be 16,700 adverse reactions to tetanus toxoid, 17% in people already immune to tetanus. The net cost of the program (in 1984 Canadian dollars) would be $1.9 million per case of tetanus prevented, $7.1 million per death prevented and $810,000 per life-year gained. These high cost-effectiveness ratios are largely attributable to the very low risk of tetanus, even among nonimmune elderly people. Tetanus toxoid and physicians' services for vaccination would account for 86% of the program costs. Because the mailed reminders would be responsible for only 13% of the program costs, other possible programs to increase primary tetanus vaccination coverage could not be expected to have substantially lower cost-effectiveness ratios. We conclude that efforts to increase primary tetanus vaccination coverage among elderly Canadians would be a questionable use of health care resources.     

Cost-effectiveness of low-molecular-weight heparin and unfractionated heparin in treatment of deep vein thrombosis

BACKGROUND: Acute deep vein thrombosis has traditionally been treated with unfractionated heparin (UFH), administered intravenously, but low-molecular-weight heparins (LMWH), administered subcutaneously, have recently become available. The authors sought to determine which therapy was more cost-effective for inpatient and outpatient treatment of deep vein thrombosis. METHODS: An incremental cost-effectiveness analysis based on a decision tree was performed for 4 treatment strategies for deep vein thrombosis. Rate of major hemorrhage while receiving heparin, rate of recurrence of venous thromboembolism 3 months after treatment and mortality rate 3 months after treatment were determined by meta-analysis. Costs for the UFH therapy were prospectively collected by a case-costing accounting system for 105 patients with deep vein thrombosis treated in fiscal year 1995/96. The costs for LMWH therapy were modelled, and cost-effectiveness was determined by decision analysis. RESULTS: Meta-analysis revealed a mean difference in risk of hemorrhage of -1.1% (95% confidence interval [CI] -2.4% to 0.3%), a mean difference in risk of recurrence of venous thromboembolism of -2.6% (95% CI -4.5% to -0.7%) and a mean difference in risk of death of -1.9% (95% CI -3.6% to -0.4%), all in favour of subcutaneous unmonitored administration of LMWH. The cost to treat one inpatient was $2993 for LMWH and $3048 for UFH. Even more would be saved if LMWH was delivered on an outpatient basis (cost of $1641 per patient). The cost-effectiveness analysis showed that LMWH in any treatment setting is more cost effective than UFH. A sensitivity analysis demonstrated the robustness of this conclusion. INTERPRETATION: Treatment of deep vein thrombosis with LMWH is more cost effective than treatment with UFH in both inpatient and outpatient settings.