The cost-effectiveness and budget impact of Vietnam's methadone maintenance treatment programme in HIV prevention and treatment among injection drug users

Abstract

We analysed the cost-effectiveness and budget impact of the methadone maintenance treatment (MMT) programme in HIV prevention and treatment among injection drug users (DUs) in Vietnam. The costs and health outcomes of providing MMT for opioid-dependent DUs versus non-MMT were estimated using a decision analytical model. Probabilistic sensitivity analysis using Monte Carlo simulation was conducted to justify uncertainties of model parameters simultaneously. The incremental cost-effectiveness ratio (ICER) of MMT in HIV prevention was US$3324 per one averted HIV case. The decision model showed that the cost-effectiveness ratio of MMT and non-MMT strategies was US$480 and US$204 per 1 quality-adjusted life year (QALY), equivalent to 0.43 and 0.18 times the gross domestic product per capita (GDPpc). The ICER for MMT versus non-MMT strategy was US$1964, approximately 1.76 times the GDPpc/QALY, classifying MMT as a cost-effective intervention. At the willingness to pay threshold of three times the GDPpc, the probability of MMT and non-MMT strategies being cost-effective was 80.3 and 19.7%, respectively. The budget impact of scaling up MMT from 2011 to 2015 will be US$97 million for 65% coverage or US$49 million for treating 80,000 DUs. The results indicated that MMT was cost-effective in HIV prevention and treatment among DUs who were opioid dependent.     

社区美沙酮维持治疗期间受治者HIV、梅毒阳转分析

目的探讨在社区美沙酮维持治疗期间相关因素对受治者人类免疫缺陷病毒(HIV)及梅毒阳转的影响。方法对广东省13个社区美沙酮维持治疗门诊4 909名受治者进行3年随访,于入组时及随后每年进行HIV、梅毒检测,每6个月进行1次问卷调查随访,入组时及入组后每个月记录尿检情况。结果4 909名受治者中,HIV、梅毒阳转率分别为0.41/100人年、1.30/100人年;已婚(RR=2.211)、过去1个月注射吸毒次数较多(RR=1.023)、过去3个月发生过性行为(RR=3.614)、基线时梅毒感染(RR=6.357)、阳性尿检次数比例较大(RR=3.235)是HIV阳转的危险因素,服用较高剂量美沙酮(RR=0.966)是HIV阳转的保护因素(P<0.05);女性(RR=4.148)、年龄较大(RR=1.098)、无工作(RR=1.866)、过去1个月注射吸毒(RR=4.515)以及过去3个月因吸毒发生性行为者(RR=17.910)梅毒阳转率较高(P<0.05)。结论注射吸毒及高危性行为是HIV及梅毒感染的高危因素,服用较高剂量美沙酮是HIV阳转的保护因素。     

美沙酮维持静脉注射吸毒者HIV感染危险因素分析

目的了解参与美沙酮维持的静脉吸毒人群特征及HIV感染危险因素,为实施有针对性干预措施提供依据。方法选取某医院美沙酮门诊82例静脉吸毒者,调查分析其HIV感染危险因素。结果参与美沙酮维持静脉吸毒者HIV经血液、性、母婴传播途径知晓率均在87.8%以上,蚊虫叮咬、共用游泳池或浴缸HIV非传播途径知晓率分别为54.9%、65.9%;认为没有感染HIV风险、不愿意与HIV/AIDS一起生活或交往、对HIV/AIDS继续工作学习持否定态度、如果不幸感染HIV将放弃治疗等负性态度分别占调查对象的78.0%、23.3%、29.2%、28.0%;调查对象中共用注射器、有2个或2个以上性伴侣、非固定性伴不使用安全套、美沙酮维持期间偷吸毒品等危险行为分别占37.8%、64.6%、23.2%、29.3%。结论美沙酮维持者AIDS防治非传播途径等知识知晓率偏低,其HIV感染危险行为主要有共用针具、不安全性行为、美沙酮维持期间偷吸毒品等。     

参加美沙酮维持治疗海洛因成瘾者传播艾滋病高危行为及应对

美沙酮维持治疗(methadone maintenance treatment,MMT)可以减少海洛因成瘾者感染或传播艾滋病病毒(human immunodeficiency virus,HIV)的相关危险行为,但部分参加者在治疗期间仍然会有吸毒等危险行为发生。治疗期间发生危险行为的原因受治疗前和治疗本身等多种因素影响。采用较高治疗剂量、提高保持率、加强综合干预措施等可以减少海洛因成瘾者治疗期间危险行为的发生,提高MMT预防HIV传播的效果。     

美沙酮维持治疗对海洛因成瘾者与HIV传播有关的危险行为的影响

目的 评估美沙酮维持治疗对海洛因成瘾者与HIV传播有关的危险行为的影响.方法 在贵州省8个美沙酮门诊内招募治疗时间不足2.5个月的海洛因成瘾者,通过面对面调查收集研究对象的基线信息和随访信息,基线信息包括人口学特征和与HIV传播有关的危险行为,随访调查只包括与HIV传播有关的危险行为.基线调查在2006年6月开始进行,随访调查在2007年6月结束.基线调查中共招募到1003例符合标准的研究对象,其中666例(66.4%)海洛因成瘾者在随访调查结束时仍在美沙酮门诊进行治疗.666例仍在接受治疗的海洛因成瘾者中,469例(70.4%)回答了随访调查问卷.使用Wilcoxon两样本非参数检验和McNemar检验对研究对象与HIV传播有关的危险行为的变化情况进行分析.结果 469例海洛因成瘾者平均每月使用海洛因的天数从26.4 d/月下降到0.9 d/月(Z=27.21,P＜0.05),饮酒天数基线为3.3 d/月,随访调查为3.7 d/月(Z=0.45,P=0.96).在过去30 d内共用针具行为的比例从基线的1.3%(6/469)下降到随访调查时的0.2%(1/469)(x2=5.00,P=0.02).基线调查时5.5%(26/469)的海洛因成瘾者报告在过去30 d内与多个性伴发生性行为,随访调查时这一比例达3.4%(16/469)(x2=3.18,P=0.08).基线调查显示6.4%(30/469)的海洛因成瘾者报告在过去30 d内和非固定性伴有过性关系,随访调查时达5.1%(24/469)(x2=0.95,P=0.33).基线调查时56.7%(17/30)的调查对象在与非固定性伴发生性关系时使用了安全套,随访时58.3%(14/24)使用了安全套(x2=1.96,P=0.16).结论 美沙酮维持治疗能够降低海洛因成瘾者通过共用针具传播HIV的危险,但未见传播HIV的危险性行为的统计学意义上的改变.     

美沙酮维持治疗中存在的问题及对策思考

美沙酮维持治疗在禁毒防艾中的重要性日益凸显,然而这种疗法的实践效果却因为种种原因而显得不太理想.文章以对云南省临沧市美沙酮维持治疗进行实地考察的成果为依据,试图通过分析当地美沙酮维持治疗推广过程中存在的一些问题来为目前的状况提供相应的对策.     

Willingness to pay for methadone maintenance treatment in Vietnamese epicentres of injection-drug-driven HIV infection

Objective

Willingness to pay for methadone maintenance treatment (MMT) in three Vietnamese epicentres of injection-drug-driven human immunodeficiency virus (HIV) infection was assessed.

Methods

A convenience sample of 1016 patients receiving HIV treatment in seven clinics was enrolled during 2012. Contingent valuation was used to assess willingness to pay. Interviewers reviewed adverse consequences of injection drug use and the benefits of MMT. Interviewers then described the government’s plan to scale up MMT and the financial barriers to scale-up. Willingness to pay was assessed using double-bounded binary questions and a follow-up open-ended question. Point and interval data models were used to estimate maximum willingness to pay.

Findings

A total of 548 non-drug-users and 468 injection drug users were enrolled; 988 were willing to pay for MMT. Monthly mean willingness to pay among non-drug-users, 347 drug users not receiving MMT and 121 drug users receiving MMT was 10.7 United States dollars [US$] (35.7% of treatment costs), US$ 21.1 (70.3%) and US$ 26.2 (87.3%), respectively (mean: US$ 15.9; 95% confidence interval, CI: 13.6–18.1). Fifty per cent of drug users were willing to pay 50% of MMT costs. Residence in households with low monthly per capita income and poor health status predicted willingness to pay less among drug users; educational level, employment status, health status and current antiretroviral therapy receipt predicted willingness to pay less among non-drug-users.

Conclusion

Willingness to pay for MMT was very high, supporting implementation of a co-payment programme.     

海洛因成瘾者社区美沙酮维持治疗工作门诊运营效率分析

目的:分析社区美沙酮维持治疗工作门诊(简称"门诊")的运营效率及影响因素。方法:通过问卷调查和定性访谈,运用边际成本方法进行分析。结果:日均门诊量287人是美沙酮门诊运营的最佳工作效率点,目前多数门诊未达到此状态;日均治疗例数、每工作人员和每平米面积分摊的治疗人数,以及例均成本和构成比较分析显示,美沙酮门诊运营的投资效率和成本控制均存在一定问题。建议:加强门诊服务的社会基础建设、激励机制建设和后续干预,提高治疗效果和门诊运行效率;中央转移支付应改变目前的支付方式和一刀切的支付标准,逐步建立一套考核指标及相应的效率补偿机制,以提高资金的运作效率和工作效率。     

Incremental cost-effectiveness of two zidovudine regimens to prevent perinatal HIV transmission in the United States

BACKGROUND: Recently concluded clinical trials in Thailand have demonstrated that a short course of zidovudine therapy administered to human immunodeficiency virus-infected women during late pregnancy and labor can substantially reduce the likelihood of perinatal transmission of HIV. This regimen is both less expensive and less effective than the full course of therapy recommended for use in the United States by the U.S. Public Health Service (PHS). The objective of the current study is to estimate the incremental cost-effectiveness of the full-course zidovudine regimen in comparison to the short-course regimen that was tested in Thailand and to determine conditions under which the PHS-recommended regimen produces a net savings in societal resource utilization, relative to the shorter regimen. METHODS: We used standard methods of incremental cost-effectiveness analysis and derived cost and effectiveness estimates from published studies. The main outcome measure is the incremental cost-effectiveness ratio, which is the additional cost per additional case of perinatal HIV infection averted by the full course of therapy. RESULTS: Full-course zidovudine therapy costs an additional $21,337 per additional case of HIV infection averted, relative to the shorter regimen; this is much less than the cost of treating a case of pediatric HIV infection. CONCLUSIONS: Economic and clinical findings both favor full-course zidovudine therapy over short-course therapy to prevent perinatal transmission of HIV in the United States.     

Retention and HIV seroconversion among drug users on methadone maintenance treatment in Yunnan,China

Setting: Thirteen methadone maintenance treatment (MMT) clinics across Yunnan, the province with the highest human immunodeficiency virus (HIV) burden in China.Objectives: To determine, among HIV-negative participants on MMT, the proportion lost to follow-up (defined as those who missed the 6-monthly follow-up examination), factors associated with loss to follow-up (LFU), HIV seroconversion rate and factors associated with seroconversion.Design: Prospective cohort study from October 2008 to April 2011. All participants were administered a pre-tested structured questionnaire to capture associated factors and offered HIV testing every 6 months. χ² test and log-binomial regression were used for data analysis.Results: Of 1146 participants, 541 (47%) were lost to follow-up in 2.5 years. Factors associated with higher LFU proportion include <6 months of previous MMT, inconvenient location of the MMT clinic and average methadone dose ⩽60 mg/day, with adjusted relative risks (RRs) of respectively 1.4 (95%CI 1.2–1.5), 1.2 (95%CI 1.0–1.4) and 1.1 (95%CI 1.0–1.3). The overall HIV seroconversion rate was 6.6 (95%CI 3.7–11.0) per 1000 person-years. Not living with a partner contributed to higher HIV rates, with an adjusted RR of 3.6 (95%CI 1.0–12.8).Conclusion: The retention rate of MMT participants in Yunnan was not satisfactory. Decentralising service delivery in the community and making directly observed treatment more convenient has the potential to improve retention.     

Policy implementation of methadone maintenance treatment and HIV infection: evidence from Hubei province,China

To view methadone maintenance treatment (MMT) globally, it is necessary to accumulate data on MMT policy implementation under different health service systems. The aim of the current study is to provide empirical evidence about policy implementation of MMT and HIV infection control, as well as recommendations for improvement of MMT in the future. Based on China’s national policy framework of MMT, policy implementation of MMT in Hubei province has two objectives: 1) to create linkages between health and public security, and 2) to provide integrated services for management of drug abusers. From 2007 to 2011, following the establishment of MMT clinics that provide methadone as well as HIV prevention services, the proportion of HIV infection among drug abusers decreased relatively quickly (12.12%?→?5.77%?→?5.19%?→?2.39%?→?2.04%). However, high drop-out rate and poor information management have been identified as particular problems which now need to be addressed. Furthermore, client drop-out from MMT programs may reflect social issues the clients encounter, and consequently, sustainable MMT development requires incorporation of social measures that help MMT clients return to society without discrimination, especially through family cooperation and employment opportunities.     

云南省开远市美沙酮门诊在治者HIV、HCV感染现状分析

目的 了解开远市美沙酮维持治疗(MMT)在治者HIV/HCV感染率及其危险因素。方法 以2014年6月MMT在治者为研究对象, 获得HIV/HCV感染率, 采用logistic回归模型分析相关危险因素。结果 2014年6月, 开远市MMT在治人数为275人, 美沙酮平均治疗时间为(4.0±2.4)年, 入组时HIV阳性者142人, 感染率为51.6%, 美沙酮治疗期间未发现HIV新发感染。入组时HCV阳性者222人, 感染率为80.7%, 美沙酮治疗期间共发现17例HCV新发感染, 新发感染率为32.1%(17/56);HIV/HCV混合感染135人, 混合感染率为49.1%。多因素logistic回归分析发现: 未婚/离异/丧偶(调整OR=2.39, 95%CI: 1.29~4.43)、有注射毒品史(调整OR=5.52, 95%CI: 2.69~11.35)、有共用注射器史(调整OR=2.32, 95%CI: 1.04~5.18)及吸毒时间长的MMT者感染HIV的风险更高;对于HCV感染, 注射吸毒史为其独立危险因素(调整OR=11.54, 95%CI: 4.79~27.80)。结论 开远市MMT在治者的HIV、HCV、HIV/HCV混合感染率均高于云南省其他地区。应加强注射吸毒人群中清洁针具交换及HIV/HCV干预工作。     

美沙酮维持治疗门诊受治者艾滋病病毒与丙型肝炎病毒共感染相关因素及交互作用分析

目的 了解美沙酮维持治疗（MMT）门诊受治者HIV/HCV共感染情况,探讨HIV/HCV共感染的相关因素及交互作用。方法 2014年9－11月从广西壮族自治区2所MMT门诊招募MMT受治者750人,进行面对面问卷调查及查阅病例资料,收集一般人口学特征、HIV和HCV感染情况、既往吸毒史、吗啡尿检、高危性行为、共用针具、脱失等信息。采用EpiData 3.1软件和SAS 9.2软件进行数据录入和统计学分析,采用χ²检验单因素分析、logistic回归多因素分析和交互作用,分析HIV/HCV共感染的相关因素。结果 共调查MMT受治者691人,HIV/HCV共感染率为18.31%（127/691）,共用针具者和MMT有脱失者的HIV/HCV共感染率分别为35.84%（81/226）和19.88%（64/322）,均高于非共用针具者（9.89%,46/465）和MMT无脱失者（17.07%,63/369）。控制混杂因素后,共用针具者HIV/HCV共感染的风险是非共用针具者的4.50倍（95% CI：2.72～7.43）,治疗期间有脱失者HIV/HCV共感染的风险较大（OR=1.71,95% CI：1.04～2.80）。共用针具和脱失存在相加交互作用（RERI=4.21,AP=0.44,SI=1.95）,未发现相乘交互作用。结论 MMT受治者存在共用针具和脱失行为,均与HIV/HCV共感染具有明显的相关性,应加强健康教育、心理辅导等措施,减少共用针具和脱失行为。     

Evaluating the cost-effectiveness of combination antiretroviral therapy for the prevention of mother-to-child transmission of HIV in Uganda

Objective

To model the cost-effectiveness in Uganda of combination antiretroviral therapy (ART) to prevent mother-to-child transmission of human immunodeficiency virus (HIV).

Methods

The cost-effectiveness of ART was evaluated on the assumption that ART reduces the risk of an HIV-positive pregnant woman transmitting HIV to her baby from 40% (when the woman is left untreated) to 25.8%, 17.4% and 3.8%, respectively, when the woman is given: (i) single-dose nevirapine (at an estimated total drug cost of 0.06 United States dollars [US$]); (ii) dual therapy with zidovudine and lamivudine for 7 weeks (at a total drug cost of US$ 15.63); or (iii) ART for 18 months (at a total annual cost of US$ 469.77). Lifetime ART (US$ 6883), recommended for pregnant women with < 350 CD4+ T lymphocytes per mm³, was assumed to give the same reduction in transmission risk in each subsequent pregnancy.

Findings

Compared with single-dose nevirapine, dual therapy and no therapy, 18 months of ART averted 5.21, 3.22 and 8.58 disability-adjusted life years (DALYs), respectively, at a cost of US$ 46, US$ 99 and US$ 34 per DALY averted. The corresponding figures for lifetime ART are, respectively, 19.20, 11.87 and 31.60 DALYs averted, at a cost of US$ 205, US$ 354 and US$ 172 per DALY averted.

Conclusion

In Uganda, ART appears highly cost-effective for the prevention of mother-to-child HIV transmission, even if continued over the patients’ lifetimes. Given the additional public health benefits of ART, efforts to ensure that all HIV-positive pregnant women have access to lifelong ART should be intensified.     

伊犁哈萨克自治州接受美沙酮维持治疗的HIV感染者死亡情况

目的 了解伊犁哈萨克自治州美沙酮维持治疗门诊中HIV感染者的死亡率及其影响因素.方法 采用回顾性队列研究方法,从AIDS综合防治信息系统中的美沙酮维持治疗系统和HIV/AIDS报告系统中收集新疆维吾尔自治区伊犁哈萨克自治州5个美沙酮门诊就诊者中所有HIV阳性就诊者(860例)的基线、治疗、随访和死亡信息.收集的信息包括人口学特征、美沙酮每日服药情况、CD4检测情况、抗病毒治疗情况以及死亡情况等.基线信息从2005年8月建立第一个美沙酮门诊起开始收集,随访信息收集到2011年5月.对缺失数据采用回归插补法进行处理,采用Cox比例风险回归对影响死亡的因素进行研究,使用Schoenfeld检验对比例风险假设进行检验.采用R软件对数据进行整理和统计学分析.结果 共分析860例HIV阳性海洛因成瘾者,平均年龄为(32.9±6.4)岁,67.3％( 579/860)的为已婚.美沙酮服药剂量为(38.2±20.7)mg/d,27.8％(239/860)参加了抗病毒治疗,38.7％(333/860)的从未检测过CD4.观察期间出现151例死亡病例,研究队列共观察了 2192.9人年,平均每人观察2.6年,全死因死亡率为68.9‰.Cox比例风险模型分析显示,参加抗病毒治疗(HR =0.53,95％CI:0.32～0.88)、基线CD4计数在200～350个/μl(HR=0.35,95％ CI:0.20 ～0.60)、基线CD4计数大于350个/μl(HR=0.16,95％CI:0.09～0.29)、已婚(HR =0.55,95％CI:0.37 ～0.82)是保护因素;年龄大于45岁(HR=5.20,95％ CI:2.60～10.20)、曾经共用过注射器(HR=1.40,95％CI:1.02 ～2.00)与参照组比较是死亡的危险因素.结论 伊犁哈萨克自治州美沙酮门诊中HIV感染者的死亡率较高,坚持抗病毒治疗有利于降低感染者的死亡率.     

The cost-effectiveness of preventing mother-to-child transmission of HIV in low- and middle-income countries: systematic review

Background

Although highly effective prevention interventions exist, the epidemic of paediatric HIV continues to challenge control efforts in resource-limited settings. We reviewed the cost-effectiveness of interventions to prevent mother-to-child transmission (MTCT) of HIV in low- and middle-income countries (LMICs). This article presents syntheses of evidence on the costs, effects and cost-effectiveness of HIV MTCT strategies for LMICs from the published literature and evaluates their implications for policy and future research.

Methods

Candidate studies were identified through a comprehensive database search including PubMed, Embase, Cochrane Library, and EconLit restricted by language (English or French), date (January 1st, 1994 to January 17^th, 2011) and article type (original research). Articles reporting full economic evaluations of interventions to prevent or reduce HIV MTCT were eligible for inclusion. We searched article bibliographies to identify additional studies. Two authors independently assessed eligibility and extracted data from studies retained for review. Study quality was appraised using a modified BMJ checklist for economic evaluations. Data were synthesised in narrative form.

Results

We identified 19 articles published in 9 journals from 1996 to 2010, 16 concerning sub-Saharan Africa. Collectively, the articles suggest that interventions to prevent paediatric infections are cost-effective in a variety of LMIC settings as measured against accepted international benchmarks. In concentrated epidemics where HIV prevalence in the general population is very low, MTCT strategies based on universal testing of pregnant women may not compare well against cost-effectiveness benchmarks, or may satisfy formal criteria for cost-effectiveness but offer a low relative value as compared to competing interventions to improve population health.

Conclusions and Recommendations

Interventions to prevent HIV MTCT are compelling on economic grounds in many resource-limited settings and should remain at the forefront of global HIV prevention efforts. Future cost-effectiveness analyses can help to ensure that pMTCT interventions for LMICs reach their full potential by focussing on unanswered questions in four areas: local assessment of rapidly evolving HIV MTCT options; strategies to improve coverage and reach underserved populations; evaluation of a more comprehensive set of MTCT approaches including primary HIV prevention and reproductive counselling; integration of HIV MTCT and other sexual and reproductive health services.     

15-month followup of women methadone patients taught skills to reduce heterosexual HIV transmission.

Heterosexual contact with intravenous drug users accounts for a growing proportion of cases of acquired immunodeficiency syndrome (AIDS) among women. In an earlier study designed to reduce sexual risk behavior, the authors randomly assigned 91 methadone maintained women to information-only or skills-building conditions. Modest outcomes favored participants in the skills-building group. In this 15-month followup of 62 remaining study participants, skills-training group members were more likely than controls to use condoms. In comparison with controls, members in the skills-building group felt more comfortable talking about safe sex, perceived themselves as more able to reduce their exposure to AIDS, but were more likely to attribute AIDS risk to luck. No associations were found between group condition and number of sexual partners or frequency of buying and carrying condoms. Some gains associated with a group intervention tended to be maintained over time, indicating that preventive interventions composed of multiple sessions and conducted in treatment settings may have promise as useful strategies to prevent human immunodeficiency virus (HIV) infection. Nevertheless, decay was evident in other domains, suggesting that prevention specialists should consider booster sessions or other means of maintaining changes in risk behavior.     

社区美沙酮维持治疗者HIV/AIDS高危行为及影响因素

目的了解广东省参与社区美沙酮维持治疗者人类免疫缺陷病毒（HIV）/获得性免疫缺陷综合征（AIDS）高危行为的影响因素。方法抽取广东省14家社区美沙酮门诊的7 288 例受治者在治疗入组时的调查数据,采用logistic回归分析高危行为的影响因素。结果过去1个月注射吸毒者占80.24%,最近1次性行为使用安全套者占42.53%,HIV感染率为7.46%,丙型肝炎病毒（HCV）感染率为78.96%;多因素分析结果显示,HIV感染（OR=3.54）、HCV感染（OR=3.94）、吸毒年限长（OR=1.78）是受治者注射吸毒的危险因素,有工作（OR=0.85）及教育程度高（OR=0.83）是注射吸毒行为的保护因素;与家人关系良好（OR=1.41）、HIV感染（OR=1.44）、年龄高者（OR=2.63）在发生性行为时会倾向于使用安全套;而已婚有配偶（OR=0.76）倾向于进行无保护性行为。结论HIV感染、HCV感染和较长的吸毒年限是高危行为主要危险因素,与家人关系良好、高教育程度和有工作是其保护因素。     

Heroin use during methadone maintenance treatment: the importance of methadone dose and cocaine use.

OBJECTIVES. The purpose of this study was to examine factors associated with heroin use during methadone maintenance treatment. METHODS. Logistic regression statistical models were used to examine data obtained in a cross-sectional sample of 652 methadone patients. RESULTS. Heroin use during the 3 months prior to interview was shown to be greatest among (1) patients maintained on methadone dosages of less than 70 mg/day (adjusted odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.3, 3.4) and (2) patients who used cocaine during treatment (adjusted OR = 5.9, 95% CI = 3.8, 9.1). These results were independent of treatment duration, treatment compliance, alcohol use, and socioeconomic factors. Cocaine users were more likely than nonusers of cocaine to use heroin at all methadone dosage levels. CONCLUSIONS. This study confirms and extends past research showing high-dose methadone maintenance to be important to heroin abstinence. Further investigation of the independent association between heroin use and cocaine use is needed.     

美沙酮维持治疗效果的Meta分析

目的分析评价美沙酮维持治疗在减少药物滥用、减少共用针具等方面所产生的效果。方法收集近10年国内外有关美沙酮维持治疗效果的相关文献,采用Meta分析方法对其进行分析。结果美沙酮维持治疗对药物滥用的影响：7个研究合并后的OR值为0．09,95％CI为0．05—0．18,OR值显著性检验Z值=7．06,P〈0．05。美沙酮维持治疗对共用针具的影响：用随机效应模型进行数据合并,3个研究合并后的OR值为0．34,95％CI为0．14～0．83,OR值显著性检验Z值=2．38,P〈0．05。结论美沙酮维持治疗对减少药物滥用、减少共用针具吸毒有一定效果。