Health-associated quality of life impairment in people who inject drugs (PWID) after bloodstream infection

BACKGROUND: People who inject drugs (PWID) have high rates of bloodstream infections (BSI) with Staphylococcus aureus (SA) and group A streptococcus (GAS). Little is known about health-related quality of life outcomes after BSI. METHODS: We performed a prospective pilot cohort study of patients with BSI due to SA or GAS. Health-related quality of life, anxiety, depression and cognitive function were assessed using validated tools (EQ5-5D-5L), Hospital Anxiety and Depression Score (HADS) and Montreal Cognitive Assessment (MOCA) at baseline, 28 days post-discharge and 6 months post-infection. FINDINGS: 66 patients were recruited over a 12-month period, including 17 PWID. For the whole cohort, global health rank improved from baseline to day 28 (median 40 to 60, p=0.002), with no significant improvement from day 28 to day 168 (median 60 to 75, p=0.161). At baseline, PWID had lower overall health-related quality of life than non-PWID (median 25 vs 45, p=0.229), persisting at day 28 (non-PWID median 65, PWID median 43, p=0.036) and day 168 (non-PWID median 75, PWID median 40, p=0.035). This difference was driven by worse scores in the EQ-5D-5L mental health component and HADS, with HADS scores being significantly impaired in PWID at baseline (p=0.001) and day 28 (p=0.007). CONCLUSION: PWID have impaired health-related quality of life after SA and GAS BSI that persists for up to 6 months. Poor mental health is the major component of this, and further studies could clarify if this is a target for intervention.