Contribution of problem drug users' deaths to excess mortality in Scotland: secondary analysis of cohort study

Abstract

Objectives To examine the "Scottish effect"-namely, the growing divergence between mortality in Scotland and England that is not explained by national differences in levels of deprivation-and, more specifically, to examine the extent to which the Scottish effect is explained by cross national differences in the prevalence of problem drug use. Design Secondary analysis of cohort study (the DORIS study). Participants 1033 Scottish drug users recruited to the cohort study in 33 drug treatment facilities across Scotland in 2001-2 and followed up 33 months later in 2004-5. Results 38 deaths occurred in the cohort, giving a standardised mortality ratio for the cohort of 1244 (95% credible interval 876 to 1678). Only 22 of the 38 deaths in drug users were classified as drug related deaths. From estimates of the size of the problem drug using populations in both England and Scotland, the contribution of deaths in drug users to national death rates can be estimated: the attributable risk fraction for Scotland is 17.3% (12.3% to 22.8%) and that for England is 11.1% (7.8% to 14.8%). Excluding estimated numbers of deaths in drug users would bring down age standardised mortality at ages 15-54 years from 196 to 162 per 100 000 in Scotland and from 138 to 122 per 100 000 in England; 32.0% (22.3% to 43.0%) of the excess mortality in Scotland is due to drug use. Conclusion Although problem drug use is a low prevalence risk behaviour, it carries a high mortality; the standardised mortality ratio for Scottish drug users is 12 times as high as for the general population. The higher prevalence of problem drug use in Scotland than in England accounts for a third of Scotland's excess mortality over England. Successful public health efforts to reduce the prevalence of problem drug use in Scotland or deaths in Scottish drug users would have a dramatic impact on overall mortality in Scotland. INTRODUCTIONDeath rates are known to be higher in Scotland than in England and Wales. In recent years, although Scottish death rates have been falling, the relative difference

Why does Scotland have a higher suicide rate than England? An area-level investigation of health and social factors

“…Liver cirrhosis deaths in Scottish men doubled between 1987–91 and 1997–2001 compared with a rise of 67% in England and Wales 35. Similarly, it has been estimated that the prevalence of problem drug use was 1.8% for Scotland and 1.1% for England, accounting for a third of Scotland's excess mortality over England 36. In our study, drug misuse accounted for 17% of the overall between-country difference in suicide risk.…”

Mortality and cause of death in a cohort of people who had ever injected drugs in Glasgow: 1982–2012

“…Although we reported on HIV status at study entry, we could not measure the incidence of HIV and/or Hepatitis C infection or reinfection. We were also unable to ascertain the proportion of participants who have moved out of Scotland and died elsewhere, which could lead to an underestimation of mortality rates (Bloor et al, 2008). There is some uncertainty in the quality of the cause of death diagnosis in death registers, as has been noted in other studies (Kielland et al, 2013).…”

Over 1200 drugs-related deaths and 190,000 opiate-user-years of follow-up: Relative risks by sex and age group

“…Mortality studies in cohorts of problem drug users or injectors are arguably a better approach still (see Wahren et al, 1997;Versino et al, 2000;Langendam et al, 2001;Bargagli et al, 2001;Risser et al, 2001;Gossop et al, 2002;Hickman et al, 2003;Galai et al, 2003;Copeland et al, 2004;Bargagli et al, 2005;Bloor et al, 2008) because: a) they document not only drugsrelated but also HIV-related and other-cause mortality (see Ross, 2002 andBloor et al, 2008), b) the covariate influences of sex and current age on the risk of drugs-related death can be estimated for individuals whose drugs history, including treatment referral (Buster et al, 2002 andFugelstad et al, 2007), route of administration of primary drug and initiation age, was documented in a standardized manner at enrolment to the cohort (Hickman et al, 2003 andCopeland et al, 2004), and c) with shared protocol for enrolment, comparably-estimated risks can be compared across cohorts. , for example, applied evidence-synthesis techniques to published data from Scotland to deduce that the relative risk of drugs-related death per 100 injectors could be 1.8 times as high for males (95% CI: 1.3 to 2.3) and two to six times higher for older injectors.…”