Drug use, mortality and outcomes among drug users in the general population and in methadone maintenance treatment

The two general aims of this thesis were to longitudinally analyse the association between drug use experience among young men and mortality and socio-economic situation up to late middle age and secondly the impact of methadone maintenance treatment on opiate dependents’ life course. Study I and II were based on a cohort of 48 024 of 50 465 men, born in 1949-51 and compulsory conscripted in 1969/70. Information about use of illicit drugs and not prescribed medical drugs classified as narcotics, alcohol, smoking, family, behavioural and social factors and assessed levels of intellectual ability and emotional control were extracted from the conscription survey. The conscription data were linked to the cause of death, conviction, inpatient care and LISA registers. Study I analysed the association between main drug use at conscription and mortality. Study II analysed the probability among conscripts alive December 31, 2006 with various main drug use and risk and protective factors for favourable socio-economic outcome in education (≥ 12 years), work (be at work) and income (> median) in 1990 and 2006. Study III and IV were based on two cohorts of opiate dependent subjects admitted to Stockholm methadone maintenance treatment (MMT). Study I found that a significantly increased hazard ratio for mortality among stimulant, cannabis and unspecified drug users after adjusting for risk factors only remained for stimulant use (HR 1.82, 95 % CI 1.002-3.31) after including drug injecting and hospitalizations with drug diagnosis and convictions during follow-up. HR to die was 4.19 (95 % CI 3.355.24) among those drug users who were hospitalized with drug diagnosis, while other drug users had no increased HR compared to non drug users. Several factors were independently associated with mortality. Study II showed that the cannabis and hallucinogen groups had significantly higher OR to have an education twelve years or more but not a higher OR to be at work or to have an income over the median in 1990 and 2006 after adjustment for other factors. Drug users hospitalised with drug diagnosis had less probability for a favourable socio-economic outcome in 2006 than in 1990. Some (protective) factors, e.g. high intellectual ability, god contact with parents and having a father from social class I increased the probability for a favourable socioeconomic situation, not least among those with few risk factors. In study III illicit drug use during MMT was analysed among 204 subjects first time admitted 1995-June 2000 in relation to retention, kind of psychosocial intervention, methadone dose and sex and up to December 31, 2000 using urine analyses data and medical records. Almost all patients relapsed to illicit drug use once. Those who were discharged had more relapse periods, more side misuse and lower methadone dose. A structured psychosocial intervention was associated with fewer relapse periods. In study IV, the role of MMT for mortality, criminality, social assistance, inpatient care, coercive treatment was analysed among 157 subjects admitted 1989-91 and followed for 18-years. Data was linked between seven registers and medical journals. Criminality, inpatient care, coercive treatment, convictions and prison sentences were lower during MMT although it differed between those who remained in first MMT, was in the second MMT, discharged from first MMT or from second MMT. The results showed that it is important to adapt protective interventions and treatment to the heterogeneity of young drug users and to opiate dependent users. List of Publications The present thesis is based on the following papers, which will be referred to in the text by their Roman numerals: I. Davstad I, Leifman A, Stenbacka M, Romelsjo A. A 35-year follow-up of illicit drug use and mortality among 48, 024 Swedish conscripts. Manuscript. II. Davstad I, Leifman A, Allebeck P, Romelsjo A. Predictors for a favourable socio-economic situation in middle age among Swedish conscripts with selfreported illicit drug use. Manuscript. III. Davstad I, Stenbacka M, Leifman A, Beck O, Korkmaz S, Romelsjo A. (2007) Patterns of illicit drug use and retention in a methadone program. A longitudinal study. J Opioid Manag 3: 27–34. IV. Davstad I, Stenbacka M, Leifman A, Romelsjo. (2009) An 18-year follow-up of patients first time admitted to methadone treatment. J Addict Dis 28: 39–56.