Prevalence and incidence of emergency department presentations and hospital separations with injecting-related infections in a longitudinal cohort of people who inject drugs

People who inject drugs are at risk of acute bacterial and fungal injecting-related infections. There is evidence that incidence of hospitalizations for injecting-related infections are increasing in several countries, but little is known at an individual level. We aimed to examine injecting-related infections in a linked longitudinal cohort of people who inject drugs in Melbourne, Australia. A retrospective descriptive analysis was conducted to estimate the prevalence and incidence of injecting-related infections using administrative emergency department and hospital separation datasets linked to the SuperMIX cohort, from 2008 to 2018. Over the study period, 33% (95%CI: 31-36%) of participants presented to emergency department with any injecting-related infections and 27% (95%CI: 25-30%) were admitted to hospital. Of 1,044 emergency department presentations and 740 hospital separations, skin and soft tissue infections were most common, 88% and 76%, respectively. From 2008 to 2018, there was a substantial increase in emergency department presentations and hospital separations with any injecting-related infections, 48 to 135 per 1,000 person-years, and 18 to 102 per 1,000 person-years, respectively. The results emphasize that injecting-related infections are increasing, and that new models of care are needed to help prevent and facilitate early detection of superficial infection to avoid potentially life-threatening severe infections.

A prospective cohort study of hospital separations among people who inject drugs in Australia: 2008-2013

OBJECTIVES

Injecting drug use is a persistent behaviour that increases the risk of morbidities and mortality. We assessed the burden of hospital separations among people who inject drugs (PWID), the excess compared to the general population and characteristics of separations associated with frequent use.

DESIGN

Prospective cohort study.

SETTING

All public and private hospitals in Victoria.

PARTICIPANTS

757 community-based PWID with hospital separations between January 2008 and June 2013 identified through record linkage, who contributed over 3729 person-years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Counts, proportions and rates of hospital separations, descriptive administrative data including all diagnoses, comparison of separation rates to the general population, trend in separations and factors associated with frequent separations.

RESULTS

There were 2106 separations in the cohort. The most common principal diagnoses were related to mental and behavioural disorders (31%), but social circumstances influencing health was the most common group of diagnoses (61%) when all contributing diagnoses for each patient were considered. Separation rates were up to three times higher than in the age-matched population, and there was a 12% increase in separations every 6 months. Over a quarter (29%) of the cohort had frequent separations (defined as two or more separations in a calendar year), which were associated with mental health-related diagnoses, being discharged to locations other than a patient's residence, having a medical as opposed to surgical intervention, seasonal patterns, relationship status and gender.

CONCLUSIONS

Mental health conditions and other characteristics associated with separations and frequent separations in particular, emphasise the importance of providing referrals to harm reduction, social services and mental health services at discharge in order to reduce excess hospital separations among PWID.