乘数法估计四川乐山市中区吸毒人群基数研究

目的:使用乘数法估计乐山市中区籍现有吸毒人群基数。方法:获得当地强戒所和自愿咨询检测门诊2003年5月31-2004年5月31日收戒或咨询人数r,问卷调查获乘数1/p,N=r/p计算估计数,定性和定量研究结合以解释估计结果。结果:r=507/511人,271份问卷获自称戒毒比例23.99%/4.17、咨询比例32.47%/3.08,估计数2114/1574人。23.99%和核对比例23.25%比较,χ2=0.0952,P=0.7576;一致性检验,k=0.5705,95%可信区间[0.4547,0.6862];灵敏度68.25%和特异度89.42%。与2002年自称戒毒比例(25.54%)比较,χ2=0.1623,P>0.05。公安部门登记、乘数法计算的总吸毒率为0.20%、0.39%和0.29%,三者多重比较,χ2为185.46、320.27、83.85和12.41,均P<0.01。结论:强戒所和VCT门诊为依托机构进行乘数法估计是可行的;自称戒毒比例稳定为24%,VCT比例33%,可满足估计,但需关注戒毒假阴性问题;至2004年7月26日目标人群估计数1574-2114人,是公安部门同期现有吸毒登记数的1.5-2倍。     

捕获—再捕获资料的对数线性模型及其在估计婴儿死亡人数 …

介绍了捕获 -再捕获方法的对数线性模型 ,并应用于估计广州番禺市 1999年的婴儿死亡人数     

捕获-再捕获资料的对数线性模型及其在估计婴儿死亡人数中的应用

介绍了捕获 -再捕获方法的对数线性模型 ,并应用于估计广州番禺市 1999年的婴儿死亡人数     

改良Delphi法在吸毒人群基数估计中的应用

目的:探索Delphi法在吸毒人群及相关指标估计中的应用情况,为乐山市艾滋病疫情预测及各类相关工作提供吸毒人群基础数据。方法:用改良Delphi法于2004年尝试对乐山市市中区吸毒人群基数及相关指标进行估计。结果:在2004年7月26日,得到乐山市市中区吸毒人群主要指标估计数:乐山市市中区籍现有吸毒人群估计数2480人,约是同期登记在册人数(1101人)的2.5倍;其中男女性别比为4∶1;注射吸毒者所占比例80%,其中男女性别比4∶1;共用针具比例30%;强戒所收戒覆盖率70%;HIV检测覆盖率70.5%;美沙酮覆盖率20%;年流出比例5%;年死亡比例2.5%;年吸毒者增加比例10%,等。结论:经过良好的设计、组织和实施,改良Delphi法可满足吸毒人群基数估计及相关指标估计的需要,但不推荐作为独立方法使用,宜与其他平行估计方法的结果相互补充验证。     

改良捕获再捕获技术在评估全国合成毒品滥用人群基数中的应用

目的:估算全国合成毒品滥用人群基数.方法:根据公安机关吸毒人员动态管控库数据,应用改良的捕获再捕获方法,将三年内查获的合成毒品滥用人员作为标记个体,第二次捕获期设置为6个月,并将观察点前处于强制隔离戒毒的人员不纳入计算范围内进行统计分析.结果:全国合成毒品滥用人群实际数量是登记在册人群数量的3.87±0.03倍,其中男...     

西昌市静脉吸毒人群前瞻性队列研究2年随访死亡分析

目的:了解四川省凉山彝族自治州西昌市静脉吸毒人群死亡率及死因。方法:于2002年11月招募静脉吸毒人群前瞻性研究队列376人,调查其社会人口学、吸毒行为和性行为特征。计算静脉吸毒人群随访2年的死亡率和死因构成,对其影响因素采用单因素和多因素Cox回归模型分析。结果:在队列2年随访中,死亡39人,死亡率为55.30/1000人年(95%CI:37.95-72.66),标准化死亡比为34.53(95%CI:21.60-54.54)。吸毒过量占全部死因的66.7%(26/39)。多因素Cox回归模型分析未见与全因死亡关系有统计学意义的变量;但见吸毒年限(≥9年)与吸毒过量死亡有统计学关联(P=0.0347),其危险比是2.31(95%CI:1.06-5.04)。结论:吸毒过量是西昌市静脉吸毒者的主要死因,需进一步探讨吸毒过量死亡的影响因素及其干预对策。     

新疆乌鲁木齐市吸毒人群首次吸毒的影响因素分析

目的:了解乌鲁木齐市吸毒人群首次吸毒的发生情况。方法:于2004年9―10月,应用结构式问卷调查乌鲁木齐市吸毒者性别、年龄、民族、文化程度,首次吸毒时间、方式及种类,首次吸毒前调查对象的吸烟、饮酒,家庭成员、朋友和亲戚吸毒情况。结果:提供知情同意书的509名吸毒者中,研究对象从出生到首次吸毒的发生率为4.90/100人年(95%CI为4.48-5.33),发生首次吸毒的中位时间为19.7(95%CI为19.1-20.4)岁。在多因素Cox比例风险回归模型分析中,维族(HR值为1.50;95%CI为1.25-1.80)、15岁以前开始吸烟(HR值为2.12,95%CI为1.77-2.55)及亲戚吸毒(HR值为1.36;95%CI为1.05-1.75)与发生首次吸毒的关系有统计学意义。结论:本调查提示青少年早期吸烟干预的健康教育对预防毒品滥用有必要,维族应该是当地干预的重点对象。     

气相色谱电子捕获法测定人体血浆中尼索地平的浓度

目的 :建立测定人血浆中尼索地平的毛细管气相色谱电子捕获检测法。方法 :色谱柱为 2 5m× 0 32 8mmDB- 1交联熔融毛细管柱 ,膜厚 0 5 2 μm ,检测器为63Ni电子捕获检测器。内标为尼莫地平 ,血浆样品在碱性条件下用乙醚 -环己烷 (1∶1)提取。结果 :在 0 1～ 30ng·mL-1浓度范围内峰面积比与浓度呈良好的线性关系 ,r =0 9997。人血浆中尼索地平的最低检出浓度为 5 0pg·mL-1。高、中、低 3种浓度的平均回收率为 91 92 %～ 97 89% ,日内和日间精密度的RSD分别小于 4 6 %和 6 9%。结论 :此方法为尼索地平的药代动力学研究提供一检测方法     

吸毒人群从首次吸毒到静脉注射吸毒的转变研究

目的:了解四川省某地区吸毒人群从首次吸毒到静脉注射吸毒的发生率及影响因素.方法:于2002年11月在社区招募吸毒人员382人,调查该人群的社会人口学特征,首次吸毒、首次静脉注射吸毒时间等.结果:从首次吸毒到静脉注射吸毒的发生率为32.56/100人年.在多因素分析中,首次吸毒时年龄(HR值为1.66;95%CI为1.35-2.05)、民族(HR值为1.38;95%CI为1.10-1.74)、文化(HR值为0.75;95%CI为0.60-0.93)和收入(HR值为0.64;95%CI为0.52-0.79)与首次吸毒转变为静脉吸毒的发生率有统计学意义.结论:应针对不同的民族、文化、收入及年龄特点,对吸毒人群开展健康教育和行为干预,控制艾滋病病毒的传播.     

静脉吸毒人群前瞻性队列研究2年随访HIV血清抗体保持率分析

目的:了解静脉吸毒人群前瞻性队列研究2年随访的HIV血清抗体阳转率和保持率情况。方法:于2002年11月,在四川省西昌市从社区招募了HIV血清抗体阴性的静脉吸毒人群前瞻性研究队列333人,队列每6个月随访1次和采集血样进行HIV抗体检测,以及分析队列本底的静脉吸毒人群社会人口学和HIV高危行为特征与队列保持率的关系。结果:静脉吸毒人群队列研究2年随访的HIV血清抗体阳转率为2.53/100人年(95%CI,1.10-3.97)和保持率为75.7%(252/333)。在多因素logistic回归模型分析中,与队列保持率的关系有统计学意义的变量为:彝族(OR,0.52;95%CI,0.29-0.91)、6个月回访(OR,4.72;95%CI,2.69-8.28)、和近3个月静脉吸毒频率高(OR,2.06;95%CI,1.12-3.80)。结论:本研究队列静脉吸毒人群HIV血清抗体阳转率较高和彝族静脉吸毒人群队列保持率低。     

Estimating prevalence of injecting drug use: a comparison of multiplier and capture-recapture methods in cities in England and Russia

We consider the question of what method should be recommended to estimate the prevalence of injecting drug use (IDU); and compare multiplier and capture-recapture (CRC) methods of estimating prevalence of injecting drug use (IDU). The prevalence of injecting drug use in four cities (Brighton, Liverpool, London and Togliatti) was estimated using similar methods: covariate capture-recapture (CRC) and multipliers. The multipliers, generated either from a community recruited survey or historical/literature-based, were applied to a range of 'benchmarks': specialist drug treatment, arrests, accident and emergency department (A&E), syringe exchange, HIV tests and opiate overdose deaths. The CRC estimates were assumed to be 'preferred/gold standard' [2,304 (95% confidence interval 1,514 - 3,737) in Brighton, 2,910 (2,546 - 4,977) in Liverpool, 16,782 (13,793 - 21,620) in 12 London boroughs and 15,039 (12,696 - 18,515) male IDU in Togliatti]. The ranges given by the multiplier estimates obtained through the community survey varied from 200 to 770 in Brighton, 530 to 1,300 in Liverpool, 2,900 to 10,600 in London and 12,400 to 91,000 in Togliatti. Several multipliers gave implausible results, lower than the observed data collected for another benchmark, and in the three English cities all these multiplier estimates were below the lower 95% confidence interval of the CRC estimate. In Togliatti, only one multiplier estimate was close to the preferred CRC estimates, with the rest implausibly high. The multiplier estimates based on historical/literature multipliers also ranged widely from 390 to 4,800 for Brighton, from 1,645 to 2,800 in Liverpool, from 4,650 to 12,600 in the 12 London boroughs and 12,800 to 32,000 in Togliatti. In the three UK cities the mortality multiplier estimates were closest to the capture-recapture estimates. The study was a practical demonstration comparing a range of multiplier estimates with a single CRC study. In almost all the individual comparisons the multiplier estimates performed poorly. CRC methods should be preferred as the means of estimating numbers of drug users with multiplier methods being used with caution and only where CRC is not possible.     

How to estimate the population that is covered by community pharmacies? An evaluation of two methods using drug utilisation information

PURPOSE: Pharmacy-dispensing data are valuable sources of drug information, but the population that is covered by the pharmacies is often difficult to determine. We evaluated two methods using drug utilisation information to estimate the population size: a drug-use-based extrapolation of a known part of the population and a capture-recapture estimation without any prior knowledge of the population. METHODS: Using pharmacy-dispensing data of three towns with known populations in the Netherlands, we estimated age-and-sex specific population sizes by extrapolating the proportion of drug-using inhabitants. In addition, we applied two-source and three-source capture-recapture models with all combinations of the following drug groups as different sources: anti-asthmatics, analgesics, antibiotics and anti-histamines. RESULTS: Drug-use-based extrapolation resulted in the best estimates with the least variability. All capture-recapture models provided underestimations of the true population. Three-source capture-recapture resulted in better average estimates than two-source capture-recapture, but also had more variability. CONCLUSIONS: If a part of the population is known, and if there is reason to assume that drug utilisation patterns do not vary within the region, it is best to use drug-use-based extrapolation. In all other situations capture-recapture may be considered, with as main limitation that we found all models to underestimate the population considerably.     

Methods for population size estimation of problem drug users using a single registration

BackgroundThe number of problem drug users is used as a key indicator to monitor the drug situation in the European Union. An alternative approach to estimate the number of problem drug users is given by ‘the one-source capture–recapture analysis’ that uses a single registration.MethodsTwo variants of the one-source capture–recapture analysis were applied to a single registration: the truncated Poisson regression model (TPR) and the Zelterman regression model. These models were applied to data about clinical drug-related hospital admissions derived from the Dutch Hospital Registration (LMR). The TPR accounts for heterogeneity in capture probabilities by allowing for covariates and the Zelterman regression model relies on the problem drug users that were seen only once or twice in the hospital; the latter model is known to be robust against unobserved heterogeneity.ResultsThe TPR model was found to have a bad fit due to unobserved heterogeneity. The Zelterman regression model estimated the population size at 10,415 problem drug users (95% CI is 8400–12,429). This figure is an estimate of the number of problem drug users who are at risk of a clinical hospital admission due to the medical consequences of their drug use. The model can also provide estimates of different subgroups of problematic drug users.ConclusionThe method presented here offers a promising alternative for estimating the number of problem drug users, including different subgroups of drug users. In addition, observed and unobserved heterogeneity can be accounted for in these estimates.     

The relationship between injection and noninjection drug use and HIV disease progression

Background

Injection drug use is associated with poor HIV outcomes even among persons receiving highly active antiretroviral therapy (HAART), but there are limited data on the relationship between noninjection drug use and HIV disease progression.

Methods

We conducted an observational study of HIV-infected persons entering care between January 1, 1999, and December 31, 2004, with follow-up through December 31, 2005.

Results

There were 1,712 persons in the study cohort: 262 with a history of injection drug use, 785 with a history of noninjection drug use, and 665 with no history of drug use; 56% were White, and 24% were females. Median follow-up was 2.1 years, 33% had HAART prior to first visit, 40% initiated first HAART during the study period, and 306 (17.9%) had an AIDS-defining event or died. Adjusting for gender, age, race, prior antiretroviral use, CD4 cell count, and HIV-1 RNA, patients with a history of injection drug use were more likely to advance to AIDS or death than nonusers (adjusted hazard ratio [HR] = 1.97, 95% confidence interval [CI] = 1.43-2.70, p < .01). There was no statistically significant difference of disease progression between noninjection drug users and nonusers (HR = 1.19, 95% CI = 0.92-1.56, p = .19). An analysis among the subgroup who initiated their first HAART during the study period (n = 687) showed a similar pattern (injection drug users: HR = 1.83, 95% CI = 1.09-3.06, p = .02; noninjection drug users: HR = 1.21, 95% CI = 0.81-1.80, p = .35). Seventy-four patients had active injection drug use during the study period, 768 active noninjection drug use, and 870 no substance use. Analyses based on active drug use during the study period did not substantially differ from those based on history of drug use.

Conclusions

This study shows no relationship between noninjection drug use and HIV disease progression. This study is limited by using history of drug use and combining different types of drugs. Further studies ascertaining specific type and extent of noninjection drug use prospectively, and with longer follow-up, are needed.     

Heavy drug abuse in Sweden 1979 — A national case-finding study

An investigation was carried out as a case-finding study to estimate the scale of heavy drug abuse in Sweden. Just over 8200 persons were reported as heavy drug abusers, 80% of these as injecting. For the majority of those reported more than one type of drug was indicated. There was concurrent abuse of alcohol by a majority of the heavy drug abusers. After correction for non-response with a modified capture-recapture technique and for erroneous classification, the scale of heavy drug abuse was estimated at 10 000–14 000 persons.     

Homeless drug users in Rotterdam,the Netherlands: profile,way of life,and the need for assistance

Decreasing the number of homeless drug users is one of the main characteristics of inner city drugs policy. The present study selected an urban-ethnographic perspective (the subculture theory) in order to explore why one drug user is homeless and another 7 not, and to attempt to describe and define the homeless and their immediate social environment. These issues were formulated into the following research questions: 1. What are the sociodemographic characteristics of homeless drug users in Rotterdam, and do they differ from domiciled drug users? 2. What are their living conditions? 3. What are the reasons for being homeless? 4. Does the period of homelessness play a role in the need to change one's lifestyle? Five research methods were employed for this study: a literature search, interviews with key persons, field notes from community fieldworkers, a survey among drug users (n = 204), and photographic reports from six homeless users. Data were collected in 1998/1999. The results document that in our study population there were more women, more illegal persons, and more foreigners than among domiciled drug users, and that the homeless group used heroin and cocaine on more days. A large proportion of the homeless users had no identity papers and no health insurance. This did not, however, lead to more self-reported sickness or a higher prevalence of infectious diseases compared with nonhomeless drug users. Easily accessible (low threshold) social care centers and assistance are very important. Few of the homeless had voluntarily chosen a homeless life-most describe an event that was a trigger for their homelessness. The average duration of being homeless was 17 months, and the longer someone had been homeless the less inclined they were to change their situation. This paper also discusses policymaking implications.