title: Assessing gender disparities in excess mortality of heroin or cocaine users compared to the general population.
abstract: Previous analyses of excess mortality in drug users compared with the general population have almost always been based on mortality ratios, reporting much higher figures in women than men. This study tests the hypothesis that being a heroin or cocaine user adds more death risk in women than men in Spain.
  
  
  
  A retrospective cohort of 15,305 heroin users (HUs) and 11,905 cocaine users (CUs) aged 15-49 starting drug treatment in 1997-2007 was recruited in Spain and followed until December 2008 to determine vital status and cause of death. Excess mortality in men and women compared to the general population was assessed with directly age-standardized rate ratios (SRRs) and differences (SRDs).
  
  
  
  SRR was significantly higher in women than men for all causes (14.7 vs. 9.4), natural causes (8.7 vs. 6.2), overdose (331.6 vs. 163.9) and other external causes (46.9 vs. 11.8) among HUs; and for overdose (170.8 vs. 40.5) and other external causes (21.0 vs. 4.7) among CUs. However, the opposite happened with SRD for all causes (1294 vs. 1845 deaths/100,000 person-years), natural causes (675 vs. 1016 deaths/100,000 person-years) and overdose (331 vs. 619 deaths/100,000 person-years) among HUs, while no significant SRD gender disparities were observed among CUs.
  
  
  
  Compared with the general population, being a heroin user adds greater absolute risk in men than women, but this does not happen with cocaine users. Similar results would likely have been found in most published cohort studies if this indicator had been used; the exclusive use of relative indices of disparity as in previous meta-analysis can be extremely misleading.
authors.affiliation: Public Health Agency, Barcelona, Spain; Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Brugal
authors.affiliation: National Epidemiology Center, Carlos III Health Institute, Madrid, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Molist
authors.affiliation: National Epidemiology Center, Carlos III Health Institute, Madrid, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Sarasa-Renedo
authors.affiliation: National Epidemiology Center, Carlos III Health Institute, Madrid, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Spain. Electronic address: lfuente@isciii.es.
authors.forename: Luis
authors.initials: L
authors.lastname: de la Fuente
authors.affiliation: Public Health Agency, Barcelona, Spain; Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), Spain; Departament de Psicobiologia i Metodologia de les Ciències de la Salut, Universitat Autónoma de Barcelona, Bellaterra, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Espelt
authors.affiliation: Addiction Institute, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Mesías
authors.affiliation: Addiction Institute, Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Puerta
authors.affiliation: Public Health Agency, Barcelona, Spain; Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Guitart
authors.affiliation: National School of Public Health, Carlos III Health Institute, Madrid, Spain.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Barrio
mesh_terms: D000293:Adolescent; D000328:Adult; D019970:Cocaine-Related Disorders / Q000401:mortality* / Q000534:rehabilitation; D015331:Cohort Studies; D005260:Female; D006556:Heroin Dependence / Q000401:mortality* / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology; D016320:Substance Abuse Treatment Centers; D055815:Young Adult
keywords: Cocaine; Cohort; Drug treatment; Excess mortality; Gender; Heroin