Abstract
Background: Injecting-related bacterial and fungal infections cause substantial illness and disability among people who use illicit drugs. Opioid agonist treatment (OAT) reduces injecting frequency and the transmission of blood borne viruses. We estimated the impact of OAT on hospitalisations for non-viral infections and examine trends in incidence over time.
Methods: We conducted a retrospective cohort study using linked administrative data. The cohort included 47 163 individuals starting OAT between August 2001 and December 2017 in New South Wales, Australia, with 454 951 person-years of follow-up. The primary outcome was hospitalisation for injecting-related infections. The primary exposure was OAT status (out of OAT, first four weeks of OAT, and OAT retention [i.e., more than four weeks in treatment]). Covariates included calendar demographic characteristics, year of hospitalisation, and recent clinical treatment.
Results: 9122 participants (19·3%) had at least one hospitalisation for any injecting-related disease. Compared to time out of treatment, retention on OAT was associated with a reduced rate of injecting-related diseases (adjusted rate ratio[ARR]=0·92; 95%CI 0·87-0·97; p=0·003). The first four weeks of treatment was associated with an increased rate (ARR 1·53, 95%CI 1·38-1·70; p<0.001), which we believe is explained by referral pathways between hospital and community OAT services. The age-adjusted incidence rates of hospitalisations for any injecting-related disease increased from 34·8 (95% CI =30·2-40·0) per 1000 person-years in 2001 to 54·9 (95%CI=51·3-58·8) in 2017.
Interpretation: Stable OAT is associated with reduced hospitalisations for injecting-related bacterial infections; however, OAT appears insufficient to prevent these harms as the rate of these infections is increasing in Australia.
Keywords: Injecting drug use, bacterial infections, endocarditis, skin diseases, opioid use disorder, injecting-related injuries and diseases
Methods: We conducted a retrospective cohort study using linked administrative data. The cohort included 47 163 individuals starting OAT between August 2001 and December 2017 in New South Wales, Australia, with 454 951 person-years of follow-up. The primary outcome was hospitalisation for injecting-related infections. The primary exposure was OAT status (out of OAT, first four weeks of OAT, and OAT retention [i.e., more than four weeks in treatment]). Covariates included calendar demographic characteristics, year of hospitalisation, and recent clinical treatment.
Results: 9122 participants (19·3%) had at least one hospitalisation for any injecting-related disease. Compared to time out of treatment, retention on OAT was associated with a reduced rate of injecting-related diseases (adjusted rate ratio[ARR]=0·92; 95%CI 0·87-0·97; p=0·003). The first four weeks of treatment was associated with an increased rate (ARR 1·53, 95%CI 1·38-1·70; p<0.001), which we believe is explained by referral pathways between hospital and community OAT services. The age-adjusted incidence rates of hospitalisations for any injecting-related disease increased from 34·8 (95% CI =30·2-40·0) per 1000 person-years in 2001 to 54·9 (95%CI=51·3-58·8) in 2017.
Interpretation: Stable OAT is associated with reduced hospitalisations for injecting-related bacterial infections; however, OAT appears insufficient to prevent these harms as the rate of these infections is increasing in Australia.
Keywords: Injecting drug use, bacterial infections, endocarditis, skin diseases, opioid use disorder, injecting-related injuries and diseases
| Original language | English |
|---|---|
| Article number | 109494 |
| Number of pages | 25 |
| Journal | Drug and Alcohol Dependence |
| Volume | 236 |
| Early online date | 13 May 2022 |
| DOIs | |
| Publication status | Published - 1 Jul 2022 |
Bibliographical note
Funding Information:This research article was reviewed by the OATS Aboriginal reference group, including Alan Bennett, Doug James, Kim Sullivan, and Craig Vaughan. We acknowledge the Australian Institute of Health and Welfare, NSW Ministry of Health, Centre for Health Record Linkage, and Bureau of Crime Statistics and Research for their support in data provision and linkage. Record linkage for the OATS study was conducted by the NSW Ministry of Health and the Centre for Health Record Linkage. Data from the reoffending database is provided by the NSW Bureau of Crime Statistics and Research. The National Drug and Alcohol Research Centre is supported by funding from the Australian Government Department of Health under the Drug and Alcohol Program. SC holds a Scientia PhD Scholarship from UNSW, Sydney and an Australian National Health and Medical Research Council (NHMRC) PhD Scholarship. SL holds a Fonds de recherche du Québec – Santé research scholar award. TDB is supported by a Dalhousie University Internal Medicine Research Foundation Fellowship, a Canadian Institutes of Health Research Fellowship (CIHR-FRN no. 171259), and the Research in Addiction Medicine Scholars (RAMS) Program (National Institute on Drug Abuse; no. R25DA033211). DL is funded by the National Institute for Health Research (NIHR; Doctoral Research Fellowship DRF-2018–11-ST2–016). AP is supported by an Australian NHMRC Investigator Fellowship (#1174630). LD is supported by an Australian NHMRC Senior Principal Research Fellowship (#1135991) and a US National Institutes of Health (NIH) National Institute on Drug Abuse grant (R01DA1104470). The OATS study is funded by the National Institutes of Health (R01 DA144740 PI:Degenhardt). MH acknowledges funding from National Institute of Health Research (NIHR) Health Protection Research Unit in Behavioural Sciences and Evaluation, NIHR Bristol Biomedical Research Centre at Bristol, NIHR School for Public Health Research, and NIHR EPIToPe. NJ acknowledges funding from the ASCEND program grant. This paper presents independent research. The views expressed are those of the authors and not necessarily those of the funding bodies described above.
Funding Information:
The National Drug and Alcohol Research Centre is supported by funding from the Australian Government Department of Health under the Drug and Alcohol Program. SC holds a Scientia PhD Scholarship from UNSW, Sydney and an Australian National Health and Medical Research Council (NHMRC) PhD Scholarship. SL holds a Fonds de recherche du Québec – Santé research scholar award. TDB is supported by a Dalhousie University Internal Medicine Research Foundation Fellowship, a Canadian Institutes of Health Research Fellowship (CIHR-FRN no. 171259), and the Research in Addiction Medicine Scholars (RAMS) Program (National Institute on Drug Abuse; no. R25DA033211). DL is funded by the National Institute for Health Research (NIHR; Doctoral Research Fellowship DRF-2018–11-ST2–016). AP is supported by an Australian NHMRC Investigator Fellowship (#1174630). LD is supported by an Australian NHMRC Senior Principal Research Fellowship (#1135991) and a US National Institutes of Health (NIH) National Institute on Drug Abuse grant (R01DA1104470). The OATS study is funded by the National Institutes of Health ( R01 DA144740 PI:Degenhardt). MH acknowledges funding from National Institute of Health Research (NIHR) Health Protection Research Unit in Behavioural Sciences and Evaluation, NIHR Bristol Biomedical Research Centre at Bristol, NIHR School for Public Health Research, and NIHR EPIToPe. NJ acknowledges funding from the ASCEND program grant. This paper presents independent research. The views expressed are those of the authors and not necessarily those of the funding bodies described above.
Publisher Copyright:
© 2022 Elsevier B.V.
Keywords
- Injecting drug use
- bacterial infections
- endocarditis
- skin diseases
- opioid use disorder
- injecting-related injuries and diseases