Epidemiology, Microbiology, and Clinical Outcomes Among Patients With Intravenous Drug Use-Associated Infective Endocarditis in New Brunswick

Economic evaluation of the effect of needle and syringe programs on skin, soft tissue, and vascular infections in people who inject drugs: a microsimulation modelling approach

BACKGROUND

Needle and syringe programs (NSP) are effective harm-reduction strategies against HIV and hepatitis C. Although skin, soft tissue, and vascular infections (SSTVI) are the most common morbidities in people who inject drugs (PWID), the extent to which NSP are clinically and cost-effective in relation to SSTVI in PWID remains unclear. The objective of this study was to model the clinical- and cost-effectiveness of NSP with respect to treatment of SSTVI in PWID.

METHODS

We performed a model-based, economic evaluation comparing a scenario with NSP to a scenario without NSP. We developed a microsimulation model to generate two cohorts of 100,000 individuals corresponding to each NSP scenario and estimated quality-adjusted life-years (QALY) and cost (in 2022 Canadian dollars) over a 5-year time horizon (1.5% per annum for costs and outcomes). To assess the clinical effectiveness of NSP, we conducted survival analysis that accounted for the recurrent use of health care services for treating SSTVI and SSTVI mortality in the presence of competing risks.

RESULTS

The incremental cost-effectiveness ratio associated with NSP was $70,278 per QALY, with incremental cost and QALY gains corresponding to $1207 and 0.017 QALY, respectively. Under the scenario with NSP, there were 788 fewer SSTVI deaths per 100,000 PWID, corresponding to 24% lower relative hazard of mortality from SSTVI (hazard ratio [HR] = 0.76; 95% confidence interval [CI] = 0.72-0.80). Health service utilization over the 5-year period remained lower under the scenario with NSP (outpatient: 66,511 vs. 86,879; emergency department: 9920 vs. 12,922; inpatient: 4282 vs. 5596). Relatedly, having NSP was associated with a modest reduction in the relative hazard of recurrent outpatient visits (HR = 0.96; 95% CI = 0.95-0.97) for purulent SSTVI as well as outpatient (HR = 0.88; 95% CI = 0.87-0.88) and emergency department visits (HR = 0.98; 95% CI = 0.97-0.99) for non-purulent SSTVI.

CONCLUSIONS

Both the individuals and the healthcare system benefit from NSP through lower risk of SSTVI mortality and prevention of recurrent outpatient and emergency department visits to treat SSTVI. The microsimulation framework provides insights into clinical and economic implications of NSP, which can serve as valuable evidence that can aid decision-making in expansion of NSP services.

Partial oral versus full intravenous antibiotic treatment of endocarditis in people who inject drugs: A systematic review

Background

Prolonged intravenous (IV) antibiotic therapy may not be optimal for people who inject drugs (PWID) with infective endocarditis (IE) due to unique social and medical needs. The role of partial IV antibiotic therapy with continued oral (PO) antibiotic therapy is unclear.

Methods

A systematic review was performed using EMBASE and MEDLINE databases. Included studies compared PO to IV antibiotic treatment for IE in PWID.

Results

Four studies met eligibility. Observational studies included full IV treatment groups and partial IV, partial PO treatment groups for severe injection-related infections. PWID with IE comprised 41.0%-64.7% of the study populations but outcomes specific to IE were not separately reported. All-cause 90-day readmission rates were comparable between the IV treatment group (27.9%-31.5%) and partial IV, partial PO treatment group (24.8%-32.5%). Ninety-day mortality was non-significantly different between IV treatment (4.9%-10.7%) and partial IV, partial PO treatment groups (2.4%-13.0%). One small randomized clinical trial compared IV oxacillin or vancomycin with gentamicin to PO ciprofloxacin plus rifampin. The cure rates were 91% and 90%, respectively.

Conclusion

There is limited evidence comparing IV treatment to partial IV, partial PO antibiotic treatment in PWID with IE. Observational studies suggest that PO antibiotic therapy after initial IV treatment may be equivalent to full IV treatment alone within specific parameters, but randomized trials are needed to inform recommendations. Substantial clinical and social benefits for PWID and advantages for the health care system will result if PO treatment strategies with equal efficacy can be implemented.

Opioid agonist treatment and risk of death or rehospitalization following injection drug use-associated bacterial and fungal infections: A cohort study in New South Wales, Australia

BACKGROUND

Injecting-related bacterial and fungal infections are associated with significant morbidity and mortality among people who inject drugs (PWID), and they are increasing in incidence. Following hospitalization with an injecting-related infection, use of opioid agonist treatment (OAT; methadone or buprenorphine) may be associated with reduced risk of death or rehospitalization with an injecting-related infection.

METHODS AND FINDINGS

Data came from the Opioid Agonist Treatment Safety (OATS) study, an administrative linkage cohort including all people in New South Wales, Australia, who accessed OAT between July 1, 2001 and June 28, 2018. Included participants survived a hospitalization with injecting-related infections (i.e., skin and soft-tissue infection, sepsis/bacteremia, endocarditis, osteomyelitis, septic arthritis, or epidural/brain abscess). Outcomes were all-cause death and rehospitalization for injecting-related infections. OAT exposure was classified as time varying by days on or off treatment, following hospital discharge. We used separate Cox proportional hazards models to assess associations between each outcome and OAT exposure. The study included 8,943 participants (mean age 39 years, standard deviation [SD] 11 years; 34% women). The most common infections during participants' index hospitalizations were skin and soft tissue (7,021; 79%), sepsis/bacteremia (1,207; 14%), and endocarditis (431; 5%). During median 6.56 years follow-up, 1,481 (17%) participants died; use of OAT was associated with lower hazard of death (adjusted hazard ratio [aHR] 0.63, 95% confidence interval [CI] 0.57 to 0.70). During median 3.41 years follow-up, 3,653 (41%) were rehospitalized for injecting-related infections; use of OAT was associated with lower hazard of these rehospitalizations (aHR 0.89, 95% CI 0.84 to 0.96). Study limitations include the use of routinely collected administrative data, which lacks information on other risk factors for injecting-related infections including injecting practices, injection stimulant use, housing status, and access to harm reduction services (e.g., needle exchange and supervised injecting sites); we also lacked information on OAT medication dosages.

CONCLUSIONS

Following hospitalizations with injection drug use-associated bacterial and fungal infections, use of OAT is associated with lower risks of death and recurrent injecting-related infections among people with opioid use disorder.

Dealing with the epidemic of endocarditis in people who inject drugs

North America is facing an opioid epidemic and growing illicit drug supply, contributing to growing numbers of injection drug use-related infective endocarditis (IDU-IE). Patients with IDU-IE have high early and late mortality. Patients with IDU-IE more commonly present with right-sided IE compared to those with non-IDU-IE and a majority are a result of S. aureus. While most patients can be successfully managed with intravenous antibiotic treatment, surgery is often required in part related to high relapse rates, potential treatment biases, and more aggressive pathophysiology in some. Multidisciplinary management as endocarditis teams, including not only cardiologists and cardiac surgeons but also infectious disease specialists, drug addiction experts, social workers, neurologists and/or neurosurgeons, is essential to best manage substance use disorder and facilitate safe discharge to home and society. Structural and population-level interventions, such as harm reduction programs, are necessary to reduce IDU-IE relapse rates in the community and other IDU-related health concerns such as overdoses. In this review, we describe the pathophysiological, clinical, surgical, social, and ethical characteristics of IDU-IE and the management thereof. We present the most recent clinical guidelines for this condition and discuss existing gaps in knowledge to guide future research, practice changes, and policy interventions.

"I have such a hard time hitting myself, I thought it'd be easier": perspectives of hospitalized patients on injecting drugs into vascular access devices

Background

Hospital patients who use drugs may require prolonged parenteral antimicrobial therapy administered through a vascular access device (VAD). Clinicians’ concerns that patients may inject drugs into these devices are well documented. However, the perspectives of patients on VAD injecting are not well described, hindering the development of informed clinical guidance. This study was conducted to elicit inpatient perspectives on the practice of injecting drugs into VADs and to propose strategies to reduce associated harms.

Methods

Researchers conducted a focused ethnography and completed semi-structured interviews with 25 inpatients at a large tertiary hospital in Western Canada that experiences a high rate of drug-related presentations annually.

Results

A few participants reported injecting into their VAD at least once, and nearly all had heard of the practice. The primary reason for injecting into a VAD was easier venous access since many participants had experienced significant vein damage from injection drug use. Several participants recognized the risks associated with injecting into VADs, and either refrained from the practice or took steps to maintain their devices while using them to inject drugs. Others were uncertain how the devices functioned and were unaware of potential harms.

Conclusions

VADs are important for facilitating completion of parenteral antimicrobial therapy and for other medically necessary care. Prematurely discharging patients who inject into their VAD from hospital, or discontinuing or modifying therapy, results in inequitable access to health care for a structurally vulnerable patient population. Our findings demonstrate a need for healthcare provider education and non-stigmatizing clinical interventions to reduce potential harms associated with VAD injecting. Those interventions could include providing access to specialized pain and withdrawal management, opioid agonist treatment, and harm reduction services, including safer drug use education to reduce or prevent complications from injecting drugs into VADs.

Uptake of slow-release oral morphine as opioid agonist treatment among hospitalised patients with opioid use disorder

INTRODUCTION

Buprenorphine and methadone are highly effective first-line medications for opioid agonist treatment (OAT) but are not acceptable to all patients. We aimed to assess the uptake of slow-release oral morphine (SROM) as second-line OAT among medically ill, hospitalised patients with opioid use disorder who declined buprenorphine and methadone.

METHODS

This study included consecutive hospitalised patients with untreated moderate-to-severe opioid use disorder referred to an inpatient addiction medicine consultation service, between June 2018 and September 2019, in Nova Scotia, Canada. We assessed the proportion of patients initiating first-line OAT (buprenorphine or methadone) in-hospital, and the proportion initiating SROM after declining first-line OAT. We compared rates of outpatient OAT continuation (i.e., filling outpatient OAT prescription or attending first outpatient OAT clinic visit) by medication type, and compared OAT selection between patients with and without chronic pain, using χ² tests.

RESULTS

Thirty-four patients were offered OAT initiation in-hospital; six patients (18%) also had chronic pain. Twenty-one patients (62%) initiated first-line OAT with buprenorphine or methadone. Of the 13 patients who declined first-line OAT, seven (54%) initiated second-line OAT with SROM in-hospital. Rates of outpatient OAT continuation after hospital discharge were high (>80%) and did not differ between medications (P = 0.4). Patients with co-existing chronic pain were more likely to choose SROM over buprenorphine or methadone (P = 0.005).

DISCUSSION AND CONCLUSIONS

The ability to offer SROM (in addition to buprenorphine or methadone) increased rates of OAT initiation among hospitalised patients. Increasing access to SROM would help narrow the opioid use disorder treatment gap of unmet need.

Epidemiology of infective endocarditis: novel aspects in the twenty-first century

INTRODUCTION

The epidemiology of infective endocarditis (IE) in this millennium has changed with emergence of new risk factors and reemergence of others. This, coupled with modifications in national guidelines in the setting of a pandemic, prompted an address of the topic.

AREAS COVERED

Our goal is to provide a contemporary review of IE epidemiology considering changing incidence of rheumatic heart disease (RHD), cardiac device implantation, and injection drug use (IDU), with SARS-CoV-2 pandemic as the backdrop.

METHODS

PubMed and Google Scholar were used to identify studies of interest.

EXPERT OPINION

Our experience over the past two decades verifies the notion that there is not one 'textbook' profile of IE. Multiple factors have dramatically impacted IE epidemiology, and these factors differ, based, in part on geography. RHD has declined in many areas of the world, whereas implanted cardiovascular devices-related IE has grown exponentially. Perhaps the most influential, at least in areas of the United States, is injection drug use complicating the opioid epidemic. Healthy younger individuals contracting a potentially life-threatening infection has been tragic. In the past year, epidemiological changes due to the COVID-19 pandemic have also occurred. No doubt, changes will characterize IE in the future and serial review of the topic is warranted.

Unequal access to opioid agonist treatment and sterile injecting equipment among hospitalized patients with injection drug use-associated infective endocarditis

BACKGROUND

Addiction treatment and harm reduction services reduce risks of death and re-infection among patients with injection drug use-associated infective endocarditis (IDU-IE), but these are not offered at many hospitals. Among hospitalized patients with IDU-IE at the two tertiary-care hospitals in the Canadian Maritimes, we aimed to identify (1) the availability of opioid agonist treatment (OAT) and sterile drug injecting equipment, and (2) indicators of potential unmet addiction care needs.

METHODS

Retrospective review of IDU-IE hospitalizations at Queen Elizabeth II Health Sciences Centre (Halifax, Nova Scotia) and the Saint John Regional Hospital (Saint John, New Brunswick), October 2015 -March 2017. In Halifax, there are no addiction medicine providers on staff; in Saint John, infectious diseases physicians also practice addiction medicine. Inclusion criteria were: (1) probable or definite IE as defined by the modified Duke criteria; and (2) injection drug use within the prior 3 months.

RESULTS

We identified 38 hospitalizations (21 in Halifax and 17 in Saint John), for 30 unique patients. Among patients with IDU-IE and untreated opioid use disorder, OAT was offered to 36% (5/14) of patients in Halifax and 100% (6/6) of patients in Saint John. Once it was offered, most patients at both sites initiated OAT and planned to continue it after discharge. In Halifax, no patients were offered sterile injecting equipment, and during five hospitalizations staff confiscated patients' own equipment. In Saint John, four patients were offered (and one was provided) injecting equipment in hospital, and during two hospitalizations staff confiscated patients' own equipment. Concerns regarding undertreated pain or opioid withdrawal were documented during 66% (25/38) of hospitalizations, and in-hospital illicit or non-medical drug use during 32% (12/38). Two patients at each site (11%; 4/38) had self-directed discharges against medical advice.

CONCLUSIONS

Patients with IDU-IE in the Canadian Maritimes have unequal access to evidence-based addiction care depending on where they are hospitalized, which differs from the community-based standard of care. Indicators of potential unmet addiction care needs in hospital were common.

Social and structural determinants of injecting-related bacterial and fungal infections among people who inject drugs: protocol for a mixed studies systematic review

INTRODUCTION

Injecting-related bacterial and fungal infections are a common complication among people who inject drugs (PWID), associated with significant morbidity and mortality. Invasive infections, including infective endocarditis, appear to be increasing in incidence. To date, preventive efforts have focused on modifying individual-level risk behaviours (eg, hand-washing and skin-cleaning) without much success in reducing the population-level impact of these infections. Learning from successes in HIV prevention, there may be great value in looking beyond individual-level risk behaviours to the social determinants of health. Specifically, the risk environment conceptual framework identifies how social, physical, economic and political environmental factors facilitate and constrain individual behaviour, and therefore influence health outcomes. Understanding the social and structural determinants of injecting-related bacterial and fungal infections could help to identify new targets for prevention efforts in the face of increasing incidence of severe disease.

METHODS AND ANALYSIS

This is a protocol for a systematic review. We will review studies of PWID and investigate associations between risk factors (both individual-level and social/structural-level) and the incidence of hospitalisation or death due to injecting-related bacterial infections (skin and soft-tissue infections, bacteraemia, infective endocarditis, osteomyelitis, septic arthritis, epidural abscess and others). We will include quantitative, qualitative and mixed methods studies. Using directed content analysis, we will code risk factors for these infection-related outcomes according to their contributions to the risk environment in type (social, physical, economic or political) and level (microenvironmental or macroenvironmental). We will also code and present risk factors at each stage in the process of drug acquisition, preparation, injection, superficial infection care, severe infection care or hospitalisation, and outcomes after infection or hospital discharge.

ETHICS AND DISSEMINATION

As an analysis of the published literature, no ethics approval is required. The findings will inform a research agenda to develop and implement social/structural interventions aimed at reducing the burden of disease.

PROSPERO REGISTRATION NUMBER

CRD42021231411.

Hospital admissions and mortality due to complications of injection drug use in two hospitals in Regina, Canada: retrospective chart review

BACKGROUND

Infectious complications of injection drug use (IDU) often require lengthy inpatient treatment. Our objective was to identify the number of admissions related to IDU in Regina, Canada, as well as describe patient demographics and comorbidities, yearly mortality, readmission rate, and cumulative cost of these hospitalizations between January 1 and December 31, 2018. Additionally, we sought to identify factors that increased risk of death or readmission.

METHODS

This study is a retrospective chart review conducted at the two hospitals in Regina. Eligible study cases were identified by querying the discharge database for predetermined International Classification of Diseases code combinations. Electronic medical records were reviewed to assess whether each admission met inclusion criteria, and hospitalization and patient data were subsequently extracted for all included admissions. Mortality data were gleaned from hospital and Ministry of Health databases. Data were analyzed using Excel and IBM SPSS Statistics to identify common comorbidities, admission diagnoses, and costs, as well as to compare patients with a single admission during the study period to those with multiple admissions. Logistic regression analysis was used to identify the relationship between individual variables and in- and out-of-hospital annual mortality.

RESULTS

One hundred and forty-nine admissions were included, with 102 unique patients identified. Common comorbidities included hepatitis C (47%), human immunodeficiency virus (HIV) (25%), and comorbid psychiatric disorders (19%). In 23% of all admissions, patients left hospital prior to treatment completion, and 27% of patients experienced multiple admissions. Female patients and those with chronic pain were more likely to be readmitted (p = 0.024 and p = 0.029, respectively). Patients admitted with infective endocarditis were more likely to die during hospitalization (p = 0.0001). The overall mortality was 15% in our cohort. The estimated cumulative cost of inpatient treatment of complications of IDU in Regina was $3.7 million CAD in 2018.

CONCLUSION

Patients with history of IDU and hospital admission experience high mortality rates in Regina, a city with paucity of inpatient supports for persons who use injection drugs. Needle syringe programs, opioid agonist therapy, and safe consumption sites have been shown to improve outcomes as well as reduce healthcare costs for this patient population. We will use our findings to advocate for increased access to these harm reduction strategies in Regina, particularly for inpatients.

Implementation and evaluation of a novel, unofficial, trainee-organized hospital addiction medicine consultation service

BACKGROUND

To evaluate a novel, unofficial, trainee-organized, hospital addiction medicine consultation service (AMCS), we aimed to assess whether it was (1) acceptable to hospital providers and patients, (2) feasible to organize and deliver, and (3) impacted patient care. Methods: We performed a retrospective descriptive study of all AMCS consultations over the first 16 months. We determined acceptability via the number of referrals received from admitting services, and the proportion of referred patients who consented to consultation. We evaluated feasibility via continuation/growth of the service over time, and the proportion of referrals successfully completed before hospital discharge. As most referrals related to opioid use disorder, we determined impact through the proportion of eligible patients offered and initiated on opioid agonist therapy (OAT) in hospital, and the proportion of patients who filled their outpatient prescription or attended their first visit with their outpatient OAT prescriber. Results: The unofficial AMCS grew to involve six hospital-based residents and five supervising community-based addiction physicians. The service received 59 referrals, primarily related to injection opioid use, for 50 unique patients from 12 different admitting services. 90% of patients were seen before discharge, and 98% agreed to addiction medicine consultation. Among 34 patients with active moderate-severe opioid use disorder who were not already on OAT, 82% initiated OAT in hospital and 89% of these patients continued after discharge. Conclusions: Established in response to identified gaps in patient care and learning opportunities, a novel, unofficial, trainee-organized AMCS was acceptable, feasible, and positively impacted patient care over the first 16 months. This trainee-organized, unofficial AMCS could be used as a model for other hospitals that do not yet have an official AMCS.