Cost-effectiveness of induction of labour versus serial antenatal monitoring in the Canadian Multicentre Postterm Pregnancy Trial.

OBJECTIVE: To determine the cost-effectiveness of induction of labour versus serial fetal monitoring while awaiting spontaneous labour in postterm pregnancies. DESIGN: Cost-effectiveness and cost-minimization analyses conducted as part of a Canadian multicentre randomized clinical trial. SETTING: Twenty-two Canadian hospitals, of which 19 were teaching hospitals and 3 were community hospitals. PATIENTS: Women with uncomplicated pregnancies of 41 or more weeks' gestation were randomly assigned to induction of labour or serial antenatal monitoring. Of the 3418 women enrolled, no data were received on 11. Therefore, results were based on data from 1701 women in the induction arm of the study and 1706 women in the monitoring arm. MAIN OUTCOME MEASURES: Perinatal mortality and neonatal morbidity, rates of cesarean section and health care costs. Hospital costing models were developed specifically for the study. Data on use of major resources (e.g., length of hospital stay, surgical procedures, major diagnostic tests and procedures, and medications) for all trial participants were collected and combined with data on minor tests and procedures (e.g., laboratory tests) abstracted from a detailed review of medical records of a sample of patients. RESULTS: Because the results of the clinical trial showed a nonsignificant difference in perinatal mortality and neonatal morbidity between the induction and monitoring arms, the authors conducted a cost-minimization rather than a cost-effectiveness analysis. The mean cost per patient with a postterm pregnancy managed through monitoring was $3132 (95% confidence interval [CI] $3090 to $3174) and per patient who underwent induction of labour was $2939 (95% CI $2898 to $2981), for a difference of $193. The significantly higher (p < 0.0001) mean cost per patient in the monitoring arm was due mainly to the costs of additional monitoring and the significantly higher rates of cesarean section among these patients. Estimated conservatively, the savings resulting from a universal policy of managing postterm pregnancies by induction of labour in Canada may be as high as $8 million a year. CONCLUSIONS: A policy of managing postterm pregnancy through induction of labour not only results in more favourable outcomes than a monitoring strategy but does so at a lower cost.     

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.     

Impact of first-line vs second-line antibiotics for the treatment of acute uncomplicated sinusitis

CONTEXT: Studies suggest little benefit in relief of acute sinusitis symptoms from the use of newer and more expensive (second-line) antibiotics instead of older and less expensive (first-line) antibiotics. However, researchers have failed to include development of complications and cost of care in their analyses. OBJECTIVE: To compare the effectiveness and cost of first-line with second-line antibiotics for the treatment of acute uncomplicated sinusitis in adults. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study using a pharmaceutical database containing demographic, clinical (International Classification of Diseases, Ninth Revision), treatment, and charge information for 29 102 adults with a diagnosis of acute sinusitis receiving initial antibiotic treatment between July 1, 1996, and June 30, 1997. MAIN OUTCOME MEASURES: Absence of additional claim for an antibiotic in the 28 days after the initial antibiotic, presence of a claim for a second antibiotic, serious complications of sinusitis, and direct charges and use for the acute sinusitis treatment. RESULTS: There were 17 different antibiotics prescribed in this study. The majority (59.5%) of patients received 1 of the first-line antibiotics. The overall success rate was 90.4% (95% confidence interval [CI], 90.0%-90.8%). The success rate for the 17 329 patients who received a first-line antibiotic was 90.1% and for the 11 773 patients who received a second-line antibiotic was 90.8%, a difference of 0.7% (95% CI, 0.01%-1.40%; P<.05). There were 2 cases of periorbital cellulitis, one in each treatment group. The average total direct charge for patients receiving a first-line antibiotic was $68.98 and a second-line antibiotic was $135.17, a difference of $66.19 (95% CI, $64.95-$67.43; P<.001). This difference was due entirely to the difference in charge of antibiotics and not other charges, such as professional fees, laboratory tests, or emergency department visits. CONCLUSIONS: Patients treated with a first-line antibiotic for acute uncomplicated sinusitis did not have clinically significant differences in outcomes vs those treated with a second-line antibiotic. However, cost of care was significantly higher for patients treated with a second-line antibiotic.     

Left ventricular reconstruction with no-patch technique: early and late clinical outcomes

Background Few studies have evaluated late clinical outcome of no-patch technique in patients with large left ventricular aneurysms. The objectives of this study were to evaluate a no-patch surgical technique to reconstruct the left ventricle in patients with left ventricular aneurysm and to assess early and late clinical outcomes.Methods In 1995, we began using a no-patch technique in patients with dyskinetic left ventricular aneurysms. A total of 145 patients underwent left ventricular reconstruction with this technique and were followed up for （59±29） months （range,1-127 months）. Risk factors for early mortality were analyzed by bivariate analyses. Cox＇s proportional hazards model was used to calculate risk factors for all-cause mortality and hospital readmission. Kaplan-Meier methodology was used to analyze late survival.Results One week after operation, left ventricular end-diastolic diameter had decreased from （61±8） mm to （55±8）mm, and geometry of the left ventricle was restored to a more normal conical shape. Early mortality was 3% and late mortality 11%. Over a 5-year follow-up period, hospital readmission was 28%. One-, 5-, and 10-year survival estimates were 95% （95% confidence interval （CI） 91%-99%）, 86% （95% CI 78%-94%）, and 74% （95% CI 60%-88%）.Readmission-free survival at 1 and 5 years after operation was 87% （95% CI81%-93%） and 60% （95% CI50%-70%）,respectively.Conclusion The no-patch technique for left ventricular reconstruction is an effective and simple procedure that can achieve satisfactory early and late clinical outcomes in patients with left ventricular aneurysms.     

Effects of random breath testing on hospital admissions of traffic-accident casualties in the Hunter Health Region

During the period of six years from 1977 to 1982, the number of admissions of victims of traffic accidents to public hospitals in the Hunter Health Region of New South Wales fell from 2099 to 1734, a decline of 21%. About three-quarters of these patients were male; one-quarter were in the 15-20 year age group. Since the introduction of random breath testing (RBT) in 1982, there has been a further decline in admissions of traffic accident victims to hospitals of nearly 20%, attributable to the introduction of RBT. The initial decline of 30% appears to have stabilized at 20% after 12 months. The decline in admissions occurred in the urban hospitals (31%), and not in the rural hospitals; it was greater among male (31%) than among female (8%) accident victims. In the Hunter region, it is estimated that RBT has resulted in a saving of more than 3000 hospital bed-days in its first year.     

The relationship of house staff experience to the cost and quality of inpatient care

The inexperience of house staff has been offered as one explanation for the increased cost of care at teaching hospitals, but conclusive evidence for this has been lacking. We studied the relationship of house staff experience to the cost and quality of inpatient care in a large series of internal medicine patients at one teaching hospital. We defined house staff experience by the month of academic year during which the patient received care. Our measures of cost were length of hospital stay and total hospital charges, while our measures of quality were hospital deaths, hospital readmissions, and nursing home placement. Multiple linear regression analysis on 21,679 hospital discharges revealed increasing house staff experience to be associated with a significant decline in length of stay (95% confidence interval for b, -0.006 to -0.066 days per discharge per month of house staff experience) and total hospital charges (95% confidence interval for b, -0.002 to -0.017 log dollars per discharge per month of house staff experience). These findings constitute an estimated average decline of 0.43 days per discharge and +370 per discharge over the academic year. Logistic regression analysis found no relationship of house staff experience to hospital deaths, readmissions, or nursing home placement. These findings suggest that the process of training inexperienced physicians may represent an important source of inefficiency for teaching hospitals struggling in a competitive environment.     

Hypertension and the risk of ischaemic heart disease

The magnitude of the effect of hypertension as a risk factor for acute myocardial infarction (AMI) was estimated in 250 patients who presented with a first AMI who were aged 35-64 years (199 survivals and 51 deaths within 24 h), whose names were obtained from a community-based register of myocardial infarctions in the Hunter Region of New South Wales. The cases were matched by sex, age and residential area, and control subjects were obtained from a random population sample from the same region. A history of hypertension (odds ratio, 5.5; 95% confidence limits, 3.4 and 8.9) and treatment for hypertension (odds ratio, 4.2; 95% confidence limits, 2.5 and 7.2) were each significantly (P less than 0.0001) associated with an increased risk of AMI--persons with treated or untreated hypertension were four to five times more likely to develop AMI than were persons without hypertension. Adjustment for smoking did not affect the association between hypertension and the incidence of AMI. Cigarette smoking appears to have had less influence on the incidence of AMI (odds ratio, 1.7; 95% confidence limits, 1.1 and 2.4; P less than 0.01) than did a history of hypertension. Twenty-four per cent of the first AMIs that occurred in the study population were attributable to hypertension (after adjustment for smoking) and twenty-seven per cent were attributable to smoking (after adjustment for hypertension).     

Universal precautions to prevent HIV transmission to health care workers: an economic analysis.

The universal precautions recommended by the US Centers for Disease Control (CDC), Atlanta, for the prevention of HIV (human immunodeficiency virus) transmission to health care workers are widely accepted, despite little documentation of their effectiveness and efficiency. We reviewed the evidence on the risk of HIV transmission to hospital workers and the effectiveness of the universal precautions. We also evaluated the costs of implementing the recommendations in a 450-bed acute care teaching hospital in Hamilton, Ont. On the basis of aggregated results from six prospective studies the risk of HIV seroconversion among hospital workers after a needlestick injury involving a patient known to have AIDS (acquired immune deficiency syndrome) is 0.36% (upper 95% confidence limit 0.67%); the risk after skin and mucous membrane exposure to blood or other body fluids of AIDS patients is 0% (upper 95% confidence limit 0.38%). We estimated that 0.038 cases of HIV seroconversion would be prevented annually in the study hospital if the CDC recommendations were followed. The incremental cost of implementing the universal precautions was estimated to be about $315,000 per year, or over $8 million per case of HIV seroconversion prevented. If all HIV-infected workers were assumed to have AIDS within 10 years of infection the of the program would be about $565,000 per life-year saved. When less conservative, more probable assumptions were applied the best estimate of the implementation cost was $128,862,000 per case of HIV seroconversion prevented. The universal precautions implemented in the study hospital were not found to be efficacious or cost-effective. To minimize the already small risk of HIV transmission in hospitals the sources of risk of percutaneous injury should be better defined and the design of percutaneous lines, needles and surgical equipment as well as techniques improved. Preventive measures recommended on the basis of demonstrated efficacy and aimed at routes of exposure that represent true risk are needed.     

Trends in ischaemic heart disease in the Hunter Region of New South Wales 1985-1989

OBJECTIVE: To find out whether trends in rates of non-fatal myocardial infarction (MI) parallel trends in rates of coronary death. DESIGN: A population-based observational study involving continuous surveillance of all suspected heart attacks or coronary deaths from 1985 to 1989. STUDY POPULATION: Residents of the Hunter Region of New South Wales aged under 70 years. MAIN OUTCOME MEASURES: Rates of non-fatal definite or possible MI or fatal MI or coronary death, as defined by the diagnostic criteria of the WHO MONICA Project. RESULTS: For men, mortality rates declined by an average of 16.2 per 100,000 per year (95% confidence interval [CI]: -23.8, -8.7); rates of non-fatal definite MI declined by 16.2 per 100,000 (95% CI: -27.8, -4.6); rates of non-fatal possible MI increased initially and then stabilised. For women smaller changes occurred in the same directions. CONCLUSION: In this population trends in rates for non-fatal definite MI paralleled the declines in mortality rates. Rates for less severe non-fatal possible MI did not follow this pattern, perhaps reflecting increased medical attention to chest pain.     

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.     

Intravenous tubing with burettes can be safely changed at 48-hour intervals

No studies of safety in changing intravenous systems containing in-line burettes at 48 hours in an intensive care setting have been performed. Patients entering a surgical intensive care unit were alternatively assigned to have any line with an in-line burette changed at either 24-hour (64 patients) or 48-hour (59 patients) intervals. Daily quantitative cultures with a 2-mL aliquot of burette fluid were obtained. Contaminated burette fluid was detected in nine of 452 (2.0%; 95% confidence interval, 0.7% to 3.3%) samples from 24-hour interval burettes and in nine of 224 (4.0%; 95% confidence interval, 1.4% to 6.6%) samples from 48-hour interval burettes. Bacterial contamination of burette fluid with ten or more colonies per milliliter occurred in only five (1.1%) cultures from patients in the 24-hour interval group compared with only two cultures (0.9%) in the 48-hour group. None of the contaminated burette fluids was associated with primary bacteremia. Change of in-line burettes in intensive care at 48-hour intervals is safe and should result in substantial cost savings.     

How cost sharing affects the use of ambulatory mental health services

The less generous insurance coverage for mental health care has generated some controversy. The major unresolved question is how the demand for outpatient mental health care responds to cost sharing. We used data from a randomized trial of fee-for-service health insurance for the nonelderly to address this question. The study enrolled 5809 persons. The results are based on 19 819 person-years of data. One hundred thirty-three percent more is spent on outpatient psychotherapy when care is free to patients than when they pay 95% of the fee, subject to an annual catastrophic limit. But, the absolute level of expenditure is low on all plans; $32 per person per year with free care. The response to psychotherapy services to cost sharing is insignificantly larger than that for outpatient general medical services. We found no evidence that more generous coverage for outpatient psychotherapy decreases total health expenditures.     

Computed tomography evaluation of patients with chronic headache.

OBJECTIVE: To determine whether the rate of detecting a tumour, arteriovenous malformation (AVM) or aneurysm with the use of enhanced or unenhanced computed tomography (CT) is significant in patients with chronic headache and to calculate the cost. DESIGN: Case series. SETTING: Chronic headache clinic at a tertiary care referral centre. PATIENTS: All 373 consecutive patients with chronic headache (284 women, 89 men) referred for CT scanning from May 1987 to October 1992 who met one or more of the following criteria: increased severity of symptoms or resistance to appropriate drug therapy (287 patients [76.9%]), change in characteristics or pattern of headache (78 [20.9%]) or family history of intracranial structural lesion (8 [2.1%]). INTERVENTIONS: CT scans of the head were enhanced with nonionic contrast medium (292 scans), were unenhanced (70) or involved both methods (40). OUTCOME MEASURES: Number and nature of minor and major findings, and total price per scan. RESULTS: Of the 402 CT scans 14 (95% confidence interval [CI] 7 to 21) revealed minor findings that did not alter patient management: infarct (9 scans), cerebral atrophy (2), cavum vergae (1), hyperostosis frontalis interna (1) and communicating hydrocephalus (1). Four scans (95% CI 0 to 8) showed significant lesions: osteoma (2), low-grade glioma (1) and aneurysm (1); only the aneurysm was treated. There were no cases of AVM. An unenhanced scan cost $82.63 and an enhanced scan $204.05. The cost per significant finding was over $18,000. In all, it cost $74,243 to find one treatable vascular lesion. CONCLUSIONS: The detection rate of CT scanning in patients with chronic headache is similar to that expected in the general population, provided the neurologic findings are normal. The cost of detecting intracranial lesions in this patient population is high [corrected].     

Hospital costs of older people in New South Wales in the last year of life

OBJECTIVE: To estimate hospital inpatient costs by age, time to death and cause of death among older people in the last year of life. DESIGN AND SETTING: Cross-sectional analytical study of deaths and hospitalisations in New South Wales from linked population databases. PARTICIPANTS: 70,384 people aged 65 years and over who died in 2002 and 2003. MAIN OUTCOME MEASURES: Hospital costs in the year before death. RESULTS: Care of people aged 65 years and over in their last year of life accounted for 8.9% of all hospital inpatient costs. Hospital costs fell with age, with people aged 95 years or over incurring less than half the average costs per person of those who died aged 65-74 years ($7028 versus $17,927). Average inpatient costs increased greatly in the 6 months before death, from $646 per person in the sixth month to $5545 in the last month before death. Cardiovascular diseases (43.1% of deaths) were associated with an average of $11,069 in inpatient costs, while cancer (25.0% of deaths) accounted for $16,853. The highest average costs in the last year of life were for people who died of genitourinary system diseases ($18,948), and the highest average costs in the last month of life were for people who died of injuries ($8913). CONCLUSION: Population ageing is likely to result in a shift of the economic burden of end-of-life care from the hospital sector to the long-term care sector, with consequences for the supply, organisation and funding of both sectors.     

Access to recombinant erythropoietin by Medicare-entitled dialysis patients in the first year after FDA approval.

OBJECTIVE--Examine access to recombinant human erythropoietin (rHuEPO) by dialysis-dependent end-stage renal disease (ESRD) patients during the first year after FDA approval for use in clinical practice and Medicare coverage. DESIGN--Longitudinal and cross-sectional claims data analyses. SETTING--All US providers of outpatient dialysis treatment. PATIENTS--126,201 Medicare-entitled dialysis patients (approximately 93% of all US dialysis patients). OUTCOME MEASURES--Percentage of patients who received rHuEPO, odds of receiving rHuEPO according to patient characteristics, and cost of rHuEPO to Medicare. RESULTS--One year after FDA approval, 52% of all dialysis and 60% of in-center hemodialysis patients who regularly had Medicare-paid dialysis services received rHuEPO at a monthly cost to Medicare of $19 million (18% of Medicare ESRD outpatient expenditures and 6% of all ESRD program expenditures). Blacks were less likely than whites to receive rHuEPO (odds ratio, 0.88; 95% confidence interval, 0.86 to 0.91). Home peritoneal and hemodialysis patients were less likely than in-center hemodialysis patients to receive rHuEPO (odds ratios, 0.17 and 0.22, respectively; 95% confidence intervals, 0.16 to 0.17 and 0.20 to 0.24, respectively). Use of rHuEPO varied across geographic regions. The odds of receiving rHuEPO were lower for patients of male vs female sex, of ages 35 through 64 years vs less than 35 years and greater than 65 years, with a longer history of ESRD, with polycystic kidney disease vs other causes of ESRD, and receiving care in nonprofit vs for-profit facilities. First-month hematocrits were slightly higher (1.2 percentage points) for patients starting rHuEPO in the 12th month than in the first month after FDA approval. CONCLUSIONS--With prompt insurance coverage, the majority of Medicare-entitled dialysis patients received rHuEPO following widespread availability. Factors that may not be related to clinical need (race, setting of care, and geography) possibly influenced early patient access. More attention should be paid to monitoring the appropriate use of high-cost biotechnologic therapy.     

The epidemiology of disease expenses. The costs of caring for children with cancer

We determined medical costs and family out-of-pocket expenses over time for 569 children with malignant neoplasms. All medical charges (inpatient and outpatient), family out-of-pocket expenses, and wages lost were collected and annualized. The mean cost of cancer care and treatment per patient-year was $29,708, with variation by diagnosis, prognosis, and year since diagnosis. The mean annual hospital inpatient cost was $15,455; mean ambulatory care cost, $3,806; and family out-of-pocket disease-related expenses, $9,787. Family out-of-pocket expenses added about 50% to the total cost of disease-related care and consumed 38% of gross annual family income; wages lost accounted for nearly half. About 95% of all medical costs was paid by private, public, or charitable payers. Out-of-pocket medical expenses for which the family was responsible were about $1,000 each year. However, all nonmedical, disease-related expenses were borne by the family.     

Prognostic importance of social and economic resources among medically treated patients with angiographically documented coronary artery disease.

OBJECTIVE--To evaluate the hypothesis that diminished social and economic resources impact adversely on cardiovascular mortality in patients with coronary artery disease. DESIGN--Inception cohort study of patients undergoing cardiac catheterization from 1974 through 1980 and followed up through 1989. SETTING--Tertiary care university medical center. PATIENTS--Consecutive sample of 1965 medically treated patients with stenosis 75% or greater of at least one major coronary artery. Five hundred patients were not enrolled due to logistic problems; 33 refused; 64 had missing data on key medical variables. The final study population included 1368 patients, 82% male, with a median age of 52 years. MAIN OUTCOME MEASURE--Survival time until cardiovascular death. RESULTS--Independent of all known baseline invasive and noninvasive medical prognostic factors, patients with annual household incomes of $40,000 or more had an unadjusted 5-year survival of 0.91, compared with 0.76 in patients with incomes of $10,000 or less (Cox model adjusted hazard ratio, 1.9; 95% confidence interval, 1.57 to 2.32; P = .002). Similarly, unmarried patients without a confidant had an unadjusted 5-year survival rate of 0.50, compared with 0.82 in patients who were married, had a confidant, or both (adjusted hazard ratio, 3.34; 95% confidence interval, 1.84 to 6.20; P less than .0001). CONCLUSIONS--Low levels of social and economic resources identify an important high-risk group among medically treated patients with coronary artery disease, independent of important medical prognostic factors. Additional study will be required to see if interventions to increase these resources improve prognosis.     

Cost-effectiveness of enoxaparin versus warfarin prophylaxis against deep-vein thrombosis after total hip replacement.

OBJECTIVE: To compare the efficacy and cost-effectiveness of enoxaparin, a low-molecular-weight heparin derivative, with that of low-dose warfarin in the prevention of deep-vein thrombosis (DVT) after total hip replacement. DATA SOURCES: English-language articles on enoxaparin and warfarin prophylaxis is patients undergoing total hip replacement published from January 1982 to December 1992. STUDY SELECTION: Four trials of enoxaparin (involving 567 patients) and six trials of warfarin (involving 630) met the following criteria: randomized controlled trial, prophylaxis started no later than 24 hours after surgery and continued for at least 7 days, warfarin dose monitored and adjusted appropriately, enoxaparin dosage 30 mg twice daily, and DVT confirmed by bilateral venography. DATA EXTRACTION: Rates of DVT, cost of prophylaxis, diagnosis and treatment per patient, rate of pulmonary embolism (PE), number of deaths and incremental cost-effectiveness (cost per life-year gained). DATA SYNTHESIS: The pooled rate of DVT was 13.6% with enoxaparin (95% confidence interval [CI] 10.9% to 16.3%) and 20.6% with warfarin (95% CI 17.4% to 23.8%). At a cost of $19.55 per day for enoxaparin the total cost per patient, including prophylaxis and management of DVT, exceeded that per patient receiving warfarin by about $121. For every 10,000 patients treated the use of enoxaparin will prevent 47 cases of DVT, 3 cases of PE and 4 deaths. Thus, the estimated incremental cost-effectiveness of enoxaparin is $29 120 per life-year gained. CONCLUSION: On the basis of current Canadian cost-effectiveness guidelines the results of this study would be considered moderate to strong evidence to adopt enoxaparin prophylaxis against DVT after total hip replacement. However, because of the limited data the estimates are uncertain. Future trials should compare enoxaparin and warfarin and incorporate a prospective economic appraisal.     

罗哌卡因、左旋布比卡因复合芬太尼用于剖宫产术后镇痛半数有效浓度的研究

目的探讨罗哌卡因、左旋布比卡因复合芬太尼用于剖宫产术后镇痛半数有效浓度。方法选择要求剖宫产术后镇痛的初产妇80例,ASAⅠ～Ⅱ,随机分为罗哌卡因(R)组和左旋布比卡因(L)组。每组第1例产妇分别使用0.125%罗哌卡因、左旋布比卡因复合芬太尼(2μg/mL)100mL混合液镇痛,应用序贯法以0.025%的浓度梯度升降调整局麻药浓度,记录硬膜外自控镇痛(PCEA)开启时(0h)、开启后4、24、48h的血压(BP)、脉搏氧饱和度(SpO2)、心率(HR)、VAS评分、下肢运动阻滞程度、不良反应发生率及总体满意度,计算罗哌卡因、左旋布比卡因术后镇痛的半数有效浓度(EC50)及其95%可信区间。结果两组产妇镇痛效果、感觉阻滞平面、Bromage评分、不良反应发生率及总体满意度比较差异无统计学意义(P>0.05);4hR组的EC50及95%CI为0.151%(0.109%～0.183%),L组的EC50及95%CI为0.126%(0.098%～0.154%),相对效价比R∶L为0.83。结论 R、L与芬太尼混合用于剖宫产术后硬膜外镇痛的EC50及95%CI分别为0.151%(0.109%～0.183%)、0.126%(0.098%～0.154%),R的效能小于左旋布比卡因。