REVIEW Drug and Alcohol Review (July 2010), 29, 420–425 DOI: 10.1111/j.1465-3362.2009.00168.x Lifetime multiple substance use pattern among heroin users before entering methadone maintenance treatment clinic in Yunnan, Chinadar_168 420..425 LEI LI1, RASSAMEE SANGTHONG2, VIRASAKDI CHONGSUVIVATWONG2, EDWARD MCNEIL2 & JIANHUA LI1 1Yunnan Institute of Drug Abuse, Kunming,Yunnan, China; and 2Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, HatYai,Songkhla,Thailand Abstract Introduction and Aims. Multiple substance use leads to greater levels of psycho-behavioural problems, unsafe sex, and therefore a high risk of contracting sexually transmitted diseases, and is also more difficult to treat.This study aims to determine pattern of lifetime multiple substance use among Chinese heroin users before entering methadone maintenance treatment clinic. Design and Methods. A survey to obtain retrospective longitudinal data on lifetime multiple substance use was conducted among 203 heroin users in two of the biggest methadone maintenance clinics in Kunming City,Yunnan province. Results. All participants used more than one substance in their lifetime. Most of them used four or more substance groups (range two to seven groups).The most common substance patterns in lifetime use were alcohol, tobacco, opiates and depressants.Approximately 80% of them had a history of simultaneous substance use (co-use).The most common combination of co-use pattern was heroin with depressant. Common reasons for co-use were to get high, to experiment, to sleep and to increase the potency of other drugs. Determinants of co-use were education, marital status and family relationship. Discussion and Conclusions. Multiple substance use is highly prevalent among Chinese heroin users. Depressants are the most common substances used in combination with heroin. [Li L, Sangthong R, Chongsuvivatwong V, McNeil E, Li J. Lifetime multiple substance use pattern among heroin users before entering methadone maintenance treatment clinic in Yunnan, China. Drug Alcohol Rev 2010;29;420–425] Key words: lifetime, multiple substance use, heroin abuse, MMT clinic. China is among the countries with the highest preva- Introduction lence of opiate users, with a reported 2 348 800 users in Multiple substance use, either at different times or at 2006 and multiple substance use is expected to be a the same time—simultaneous multiple substance use or common problem [12,13]. Methadone maintenance co-use, has increased and is of great health concern treatment (MMT) program has been recently imple- among drug users [1,2]. Multiple substance use is sig- mented in China since 2004. Knowledge on multiple nificantly related to greater levels of psycho-behavioural substance use pattern is important for treatment con- problems, such as memory loss, major depression, sideration and may lead to a better treatment outcome panic disorder and generalised anxiety disorder [3–5]. [13,14]. Most previous studies on multiple substance Multiple substance users have a tendency to engage in use, however, were conducted in high-income countries unsafe sex, increasing their risk of contracting HIV and in which multiple substance use pattern is suspected to other blood-borne diseases [6,7]. Risk of overdose tox- be different from low- and middle-income countries, icity and fatality is increased among simultaneous mul- including China [2,15–19]. In addition, previous tiple substance users [8,9]. Moreover, multiple studies on pattern of multiple substance use usually substance use is also more difficult to treat successfully limited to a specific type of a few substances use and in than single substance use [10,11]. a defined duration [2,13,16–19]. This study primarily Lei Li MD, MSc, Researcher, Rassamee Sangthong MD, PhD, Senior Lecturer, Virasakdi Chongsuvivatwong MD, PhD, Professor, Edward McNeil MSc, Senior Lecturer, Jianhua Li MD, Associate Professor. Correspondence to Dr Lei Li,Yunnan Institute of Drug Abuse, 300 #, Wu Jia Dui, Xi Hua Yuan, Kunming City, Yunnan Province, 650228, China. Tel: +86 871 4632023; Fax: +86 871 4626055; E-mail: lilei_86414@ hotmail.com Received 26 September 2009; accepted for publication 27 November 2009. © 2010 Australasian Professional Society on Alcohol and other Drugs Lifetime multiple substance use pattern 421 examined patterns of lifetime substance use both at stance use, addictive substances, except alcohol and different time and at the same time among Chinese tobacco, were grouped into cannabinoids, opiates/ heroin users before entering MMT clinics. narcotic analgesics, depressants (benzodiazepine, bar- biturate, and others, e.g. some antipsychotic and sedating antihistamine), dissociative anaesthetics and Methods stimulants [20]. Data on co-use between heroin and A survey was conducted in two biggest MMT clinics in other substances and other co-use were aggregated urban areas of Kunming City.The study was conducted into groups to examine its pattern. Determinants of during May 2008 and June 2009. The criteria for simultaneous multiple substance use were examined patient enrolment into MMT programs in China are: by multivariate analysis [21]. All analyses were done (i) aged 20 years or above; (ii) local resident with fixed using R software version 2.8.1 [22]. abode; (iii) currently active opiate user with history of multiple unsuccessful treatments; (iv) received compul- sory detoxification treatment at least once in a rehabili- Results tation unit; and (v) willing to sign an agreement to take responsibility for his/her own treatment and behaviour. Out of approximately 330 eligible clients during the All patients who had been attending the MMT clinic study period, a total of 203 MMT clients were inter- for at least 1 month were eligible to participate in the viewed. Fifty-eight per cent of them were male and the study. However, only patients who were willing to par- median age was 37 years old. Most of them were Han ticipate in the study and could obtain written informed ethnic, had below high school education, had never consent were recruited to the study. At least 150 clients married, were unemployed, lived with family and had were needed to estimate 90% of multiple substance use fair to very good family relationship. Eighty-four per among MMT clients with precision of 0.05 from the cent had a history of injection drugs and nearly one- estimate. third reported that they had shared needles and/or After building a rapport with a patient, a face-to- syringes at one time in their lives. All experienced at face interview was carried out in a private room of the least one form of substance abuse treatment. (Table 1) clinic by a well-trained independent researcher using a Differences in baseline characteristics of eligible clients structured questionnaire. Baseline sociodemographic who did and did not participate in the study were not data were obtained. History of any substances use and statistically significant. route of administration were asked and then con- Table 2 presents prevalence, initial age of use, life- firmed by a prompted list of commonly abused sub- time exposure and duration from last use of each sub- stance used that was modified from the National stance until entering MMT clinic. Heroin (100%), Institute of Drug Abuse [20]. Participants were also tobacco (99%) and alcohol (94.1%) were the most asked to give details of simultaneous substance use, if commonly used substances.When compared with other any, as well as the reasons for the co-use. Any sub- substances, alcohol, tobacco and heroin were the earli- stance use with an approval by the doctor was est few substances used and had the longest lifetime excluded. To obtain information on age and duration exposures. Only tobacco and heroin were still being of substance use from initial use until entering MMT used (duration from last use = 0 year) before entering program, the Life Experience Timeline (LET) for col- MMT clinic. lecting time-anchored history was adapted to a year- All participants used more than one substance in by-year timeline approach that linked substance use to their lifetime. Table 3 shows combination patterns of important life events (Hillhouse M et al. 2004, unpub- lifetime multiple substance use by gender. Number of lished data). substance group used in lifetime ranged from 2 to 7 All information was kept strictly confidential and was and most of them used four or more substance used for research purpose only. This study was groups. The most common substances used were approved by the Human Studies Committee ofYunnan alcohol, tobacco, and other substances in opioid and Institute of Drug Abuse (YIDA), China, and the Ethics morphine derivatives, and depressant groups. No Committee of the Faculty of Medicine, Prince of significant differences in patterns of lifetime Songkla University, Thailand. substance use were found between men and women (P = 0.208). Prevalence of simultaneous multiple substance use Statistical analysis was 80.3%. Table 4 shows different combination pat- Descriptive statistics were used to determine preva- terns of simultaneous multiple substance use. Heroin as lence, age at first use, lifetime exposure and duration a primary substance with at least one depressant was from last use. To see pattern of lifetime multiple sub- the most common combination. More specifically, © 2010 Australasian Professional Society on Alcohol and other Drugs 422 L. Li et al. Table 1. Baseline characteristics of the participants before sive substances (39.9%). The reason was not mutually entering MMT (n = 203) exclusive therefore the total was added to more than 100%. Characteristics n (%) Independent risk factors of simultaneous multiple substance use were secondary school education, fair Age (years) median [range] 37 [23–61] family relationship. Protective factors were married and Gender divorced/widowed. Male 118 (58.1) Female 85 (41.9) Age of entering MMT (years) median 36 [23–60] Discussion [range] Ethnicity Before entering MMT clinic, all heroin users in this Han 187 (92.1) study used four or more substance groups in their life- Others 16 (7.9) Education level time and 80% of them experienced simultaneous mul- Primary school 15 (7.4) tiple substance use.