Using Population Based Hospitalization Data to Monitor Increases in Conditions Causing Morbidity Among Persons Who Inject Drugs

The burden of skin and soft tissue, bone and joint infections in an Australian cohort of people who inject drugs

INTRODUCTION

There are currently limited data regarding the clinical and economic significance of skin and soft tissue infections (SSTI) and bone and joint infections in Australian people who inject drugs (PWID).

METHODS

Retrospective cohort study in adult PWID admitted to Monash Health, a large heath care network with six hospitals in Victoria, Australia. Inpatients were identified using administrative datasets and International Classification of Disease (ICD-10) coding for specific infection-related conditions. Cost analysis was based on mean ward, intensive care and hospital-in-the-home (HITH) lengths of stay. Spinal infections and endocarditis were excluded as part of previous studies.

RESULTS

A total of 185 PWID (61 female, 124 male, median age 37) meeting the study criteria were admitted to Monash Health between January 2010 and January 2021. Admitting diagnoses included 78 skin abscesses, 80 cellulitis, 17 septic arthritis, 4 osteomyelitis, 3 thrombophlebitis and 1 each of necrotising fasciitis, vasculitis and myositis. Pain (87.5%) and swelling (75.1%) were the most common presenting complaints. Opioids (67.4%) and methamphetamine (37.5%) were the most common primary drugs injected. Almost half (46.5%) of patients had concurrent active hepatitis C (HCV) infection on admission. Hepatitis B (HBV) and Human Immunodeficiency Virus (HIV) were uncommon. The most significant causative organism was methicillin-susceptible Staphylococcus aureus (24.9%). In 40.0% (74/185) no organism was identified. Patients required a median acute hospital stay of 5 days (2-51 days). There were 15 patients admitted to the intensive care unit (ICU) with median duration 2 days. PICC line insertion for antibiotics was required in 16.8% of patients, while 51.4% required surgical intervention. Median duration of both oral and IV antibiotic therapy was 11 days. Almost half (48.6%) of patients were enrolled in an opioid maintenance program on discharge. Average estimated expenditure was AUD $16, 528 per admission.

CONCLUSION

Skin and soft tissue and joint infections are a major cause of morbidity for PWID. Admission to hospital provides opportunistic involvement of addiction specialty services.

HIV and HCV testing at clinical encounters among people who inject drugs, 2013-2018-Opportunities for increased testing and prevention

People who inject drugs (PWID) with unsafe injection practices have substantial risk for HIV and hepatitis C virus (HCV) infections. We describe frequency of, and factors associated with, HIV and HCV testing during clinical encounters with PWID. Inpatient and Emergency Department clinical encounters at an Atlanta hospital were abstracted from medical records spanning January 2013-December 2018. We estimated frequency of HIV and HCV testing during injection drug use (IDU)-related encounters among PWID without previous diagnoses. We assessed associations between patient factors and testing using generalized estimating equations models. HIV testing occurred in 39.3% and HCV testing occurred in 17.1% of eligible IDU-related encounters. Testing was more likely in IDU-related encounters during 2017-2018 than in encounters during 2013-2014; (HIV, AOR = 2.14, 95% CI, 1.32-3.49, p < .01). Testing was less likely among Black/African American patients compared to White patients (adjusted odds ratio [AOR]: HIV, AOR = 0.48, 95% confidence interval [CI], 0.33-0.72, p < .01); HCV, AOR = 0.41, 95% CI, 0.24-0.70, p < .01). This difference may be attributable to recent testing among Black patients in non-IDU related encounters. HIV and HCV testing improved over time; however, missed opportunities for testing still existed. Strategies should aim to improve equitable HIV and HCV testing among PWID.

Missed opportunities for prevention: prevalence and incidence of human immunodeficiency virus and hepatitis C virus diagnoses among a cohort of individuals discharged from an urban hospital with injection drug-related diagnoses, 2012-2019

PURPOSE

Risk for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections has increased due to the ongoing opioid epidemic and unsafe injection practices. We estimated the prevalence and incidence of HIV and HCV diagnoses among people who inject drugs from hospital-based clinical encounters.

METHODS

We linked clinical encounters at an Atlanta hospital during 2012-2018 with state HIV and HCV surveillance records to examine the prevalence of infections at discharge and incidence of infections post clinical encounter.

RESULTS

At discharge, 32.9% and 28.6% of patients with injection drug use-related clinical encounters had an HIV or HCV diagnosis, respectively. HIV and HCV diagnoses at the time of discharge were mostly among 40-64 years old patients, males, and Black/African Americans. Post clinical encounter, 3.8% of patients were later diagnosed with HIV, and 16.5% were later diagnosed with HCV, translating to incidence rates of 9.3 per 1000 person-years and 41.5 per 1000 person-years, respectively. The majority of HIV and HCV diagnoses post clinical encounter occurred among Black/African Americans and males. Of patients with HIV and HCV diagnoses post clinical encounter, 27.3% and 11.9% had been tested during their clinical encounter, respectively.

CONCLUSIONS

Targeted interventions for HIV/HCV prevention, screening, diagnosis, and linkage to treatment are needed to reduce the incidence of new infections among people who inject drugs.

Estimated Number of People Who Inject Drugs in the United States

BACKGROUND

Public health data signal increases in the number of people who inject drugs (PWID) in the United States during the past decade. An updated PWID population size estimate is critical for informing interventions and policies aiming to reduce injection-associated infections and overdose, as well as to provide a baseline for assessments of pandemic-related changes in injection drug use.

METHODS

We used a modified multiplier approach to estimate the number of adults who injected drugs in the United States in 2018. We deduced the estimated number of nonfatal overdose events among PWID from 2 of our previously published estimates: the number of injection-involved overdose deaths and the meta-analyzed ratio of nonfatal to fatal overdose. The number of nonfatal overdose events was divided by prevalence of nonfatal overdose among current PWID for a population size estimate.

RESULTS

There were an estimated 3 694 500 (95% confidence interval [CI], 1 872 700-7 273 300) PWID in the United States in 2018, representing 1.46% (95% CI, .74-2.87) of the adult population. The estimated prevalence of injection drug use was highest among males (2.1%; 95% CI, 1.1-4.2), non-Hispanic Whites (1.8%; 95% CI, .9-3.6), and adults aged 18-39 years (1.8%; 95% CI, .9-3.6).

CONCLUSIONS

Using transparent, replicable methods and largely publicly available data, we provide the first update to the number of people who inject drugs in the United States in nearly 10 years. Findings suggest the population size of PWID has substantially grown in the past decade and that prevention services for PWID should be proportionally increased.

Sensitivity, specificity and predictive values of ICD-10 substance use codes in a cohort of substance use-related endocarditis patients

Background: Healthcare databases have the potential to become efficient tools for epidemiological research in People Who Inject Drugs (PWID). The validity of ICD-10 codes for specific substances in this population has not been assessed.Objectives: Validate ICD-10 diagnosis codes relating to the use of specific substance classes in a cohort of endocarditis patients.Methods: Our study sample consisted of 379 first-episode infective endocarditis patients (Male: 208, Female: 171), aged 18-55, admitted to any of three hospitals in London, Ontario from 2007 to 2018. Of these, 287 used drugs. We validated ICD-10 substance use codes for opioids (F11), stimulants (F15), cocaine (F14) and multiple substances (F19). Sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were calculated for each code, using self-reported substance use documented on medical record review as a gold standard. We conducted a comparative analysis between code-negative users and code-positive users for each substance.Results: All substance use codes shared the same pattern: high specificity, high PPV and low sensitivity, with code F11 yielding the highest PPV (96.3%; 95% C.I.: 90.8-98.6) and sensitivity (42.6%; 95% C.I. 36.3-49.1). The code-positives and code-negatives for each substance did not differ significantly in any characteristics compared.Conclusion: Our results suggest that the individual ICD-10 codes analyzed should not be used for research without adjustment for low sensitivity. However, due to high PPV and specificity, these codes may still have potential for research use. Because code-negative patients did not differ from code-positive patients, their data may be extrapolated to the overall group of substance users.

Severe bacterial infections in people who inject drugs: the role of injection-related tissue damage

Background

In the context of the current U.S. injection drug use epidemic, targeted public health harm reduction strategies have traditionally focused on overdose prevention and reducing transmission of blood-borne viral infections. Severe bacterial infections (SBI) associated with intravenous drug use have been increasing in frequency in the U.S. over the last decade. This qualitative study aims to identify the risk factors associated with SBI in hospitalized individuals with recent injection drug use.

Methods

Qualitative analysis (n = 15) was performed using an in-depth, semi-structured interview of participants admitted to Bellevue Hospital, NYC, with SBI and recent history of injection drug use. Participants were identified through a referral from either the Infectious Diseases or Addition Medicine consultative services. Interviews were transcribed, descriptively coded, and analyzed for key themes.

Results

Participants reported a basic understanding of prevention of blood-borne viral transmission but limited understanding of SBI risk. Participants described engagement in high risk injection behaviors prior to hospitalization with SBI. These practices included polysubstance use, repetitive tissue damage, nonsterile drug diluting water and multipurpose use of water container, lack of hand and skin hygiene, re-use of injection equipment, network sharing, and structural factors leading to an unstable drug injection environment. Qualitative analysis led to the proposal of an Ecosocial understanding of SBI risk, detailing the multi-level interplay between individuals and their social and physical environments in producing risk for negative health outcomes.

Conclusions

Structural factors and injection drug use networks directly impact drug use, injection drug use practices, and harm reduction knowledge, ultimately resulting in tissue damage and inoculation of bacteria into the host and subsequent development of SBI. Effective healthcare and community prevention efforts targeted toward reducing risk of bacterial infections could prevent long-term hospitalizations, decrease health care expenditures, and reduce morbidity and mortality.

The Emergency Department Longitudinal Integrated Care (ED-LINC) intervention targeting opioid use disorder: A pilot randomized clinical trial

INTRODUCTION

Opioid use disorder (OUD) and related comorbid conditions are highly prevalent among patients presenting to emergency department (ED) settings. Research has developed few comprehensive disease management strategies for at-risk patients presenting to the ED that both decrease illicit opioid use and improve initiation and retention in medication treatment for OUD (MOUD).

METHODS

The research team conducted a pilot pragmatic clinical trial that randomized 40 patients presenting to a single ED to a collaborative care intervention (n = 20) versus usual care control (n = 20) conditions. Interviewers blinded to patient intervention and control group status followed-up with participants at 1, 3, and 6 months after presentation to the ED. The 3-month Emergency Department Longitudinal Integrated Care (ED-LINC) collaborative care intervention for patients at risk for OUD included: 1) a Brief Negotiated Interview at bedside, 2) overdose education and facilitation of MOUD, 3) longitudinal proactive care management, 4) utilization of the statewide health information exchange platform for 24/7 tracking of recurrent ED utilization, and 5) weekly caseload supervision that incorporated measurement-based care treatment assessment with stepped-up care for patients with recalcitrant symptoms.

RESULTS

Overall, the ED-LINC intervention was feasibly delivered and acceptable to patients. The pilot study achieved >80% follow-up rates at 1, 3, and 6 months. In adjusted longitudinal mixed model regression analyses, no statistically significant differences existed in days of opioid use over the past 30 days for ED-LINC intervention patients when compared to patients receiving usual care (incidence-rate ratio (IRR) 1.50, 95% CI 0.54-4.16). The unadjusted mean number of days of illicit opioid use decreased at the 1-month and 3-month follow-up time points for both groups. ED-LINC intervention patients had increased rates of MOUD initiation compared to control patients (50% versus 30%); intervention versus control comparisons did not achieve statistical significance, although power to detect significant differences in the pilot was limited.

CONCLUSIONS

The ED-LINC intervention for patients with OUD can be feasibly implemented and warrants testing in larger scale, adequately powered randomized pragmatic clinical trial investigations.

CLINICALTRIALS

gov NCT03699085.

Injection and Non-Injection Drug Use Among Adults with Diagnosed HIV in the United States, 2015-2018

Understanding behavioral characteristics and health outcomes of people with HIV (PWH) who inject drugs and PWH who use drugs, but do not inject, can help inform public health interventions and improve HIV clinical outcomes. However, recent, nationally representative estimates are lacking. We used 2015-2018 Medical Monitoring Project data to examine health outcome differences among adults with diagnosed HIV who injected drugs or who only used non-injection drugs in the past year. Data were obtained from participant interviews and medical record abstraction. We reported weighted percentages and prevalence ratios with predicted marginal means to assess differences between groups (P < 0.05). PWH who injected drugs were more likely to engage in high-risk sex; experience depression and anxiety symptoms, homelessness, and incarceration; and have lower levels of care retention, antiretroviral therapy adherence, and viral suppression. Tailored, comprehensive interventions are critical for improving outcomes among PWH who use drugs, particularly among those who inject drugs.

Demonstration of an Analytic Process using Home Health Care Electronic Health Records: A Case Example Exploring the Prevalence of Patients with a Substance Use History and a Venous Access Device

Electronic health records (EHR) are an important, but underutilized source for home health care research and practice improvement. Although the use of EHR is more efficient than prospective data collection, an analysis of EHR data can be complex and time-consuming. To demonstrate the overall process, we describe a secondary analysis of EHR data that explored the prevalence of home health care patients with a substance use history (SUH) and a venous access device (VAD). We detail our process of EHR data extraction, management, and analysis to assist researchers and clinicians interested in similar work. The example analysis showed that that 10.6% of adult home health care patients had a SUH, 8.8% had a long-term VAD, and 1.3% had both. EHRs can be a valuable data source for home health care research and quality improvement projects, but a systematic and thoughtful strategy is needed to fully leverage their potential.

Factors associated with injury and blood-borne infection risk when providing assisted injection among people who inject drugs

OBJECTIVE

Prior research has associated assisted injection with risk behaviors, but other risks such as injury, missed veins, and incidental exposures to blood-borne infections during an injection episode have not been assessed. In the following, we present the frequency of these other risks and determine factors associated with missing a vein and incidental blood exposure among people who inject drugs (PWID).

METHODS

We conducted a cross-sectional analysis of data from PWID who were recruited using targeted sampling in Los Angeles and San Francisco, California, during 2016 and 2017. The analytic sample consist of 336 participants who reported providing injection assistance in the last 6 months. Multivariate logistic regression models were developed for reporting the following risks: missing a vein; getting the recipient's blood on the injection provider; and getting blood on clothes or surfaces.

RESULTS

In the last 6 months, the most common negative consequences were getting blood on clothes or surfaces (40%), getting the recipient's blood on the injection provider (23%), and missing a vein (17%). In multivariate logistic regression analysis, missing the vein was significantly associated with higher odds of assisting a leg injection while getting the injection recipient's blood on the provider or getting blood on clothes or nearby surfaces was associated with higher odds of assisting a groin injection injecting in the groin.

CONCLUSION

Providing injection assistance can result in incidental blood exposures and injury, particularly when injecting in sensitive locations on the body. Harm reduction interventions to reduce risks associated with this practice are essential to improving the well-being of PWID.

Native Vertebral Osteomyelitis in Patients with Staphylococcus aureus Bacteremia

BACKGROUND

The purpose of the study was to assess the epidemiology, risk factors and outcomes of native vertebral osteomyelitis (NVO) in patients with Staphylococcus aureus bacteremia (SAB).

METHODS

A retrospective institutional review was conducted at Mayo Clinic, Minnesota. Patients aged ≥ 18 years with SAB who developed NVO from January 1, 2006 to December 31, 2020 were included and 3-month follow-up data were abstracted. Data pertaining to patient demographics, risk factors and outcomes were recorded using REDCap. A 1:2 nested case-control analysis was performed, and controls were matched according to age, sex and year of SAB diagnosis.

RESULTS

A total of 103 patients had NVO. A majority (60.2%) of patients was male, with a median age of 62.0 years. Thirty-one (30.1%) cases were caused by methicillin-resistant S. aureus (MRSA). The lumbar spine was most commonly (57.6%) and the most commonly reported comorbid conditions included diabetes mellitus (36.9%) and coronary artery disease (27.2%). Mortality at three-month follow-up was 18.6%. Nested case-control analysis revealed that injection drug use (IDU) and tobacco consumption were significant risk factors associated with NVO, while chronic hemodialysis and chronic liver disease (CLD) were associated with a decreased risk of NVO.

CONCLUSIONS

Atherosclerotic vascular disease was prominent in our contemporary cohort with NVO in the setting of SAB. Diabetes mellitus, tobacco consumption, older age and male sex likely contributed to this profile. Because IDU was associated with NVO, an increased number of cases should be anticipated among patients with IDU given the ongoing opioid epidemic in the United States.

Infective Endocarditis Among Persons Aged 18-64 Years Living with Human Immunodeficiency Virus, Hepatitis C Infection, or Opioid Use Disorder, United States, 2007-2017

BACKGROUND

Infective endocarditis (IE) is a life-threatening bacterial infection of the heart valves, most often diagnosed in older persons and persons with prior cardiac surgery. It is also associated with injection drug use, a behavior that has increased in recent years along with the US opioid crisis.

METHODS

We conducted a retrospective cohort analysis of commercial and Medicaid health insurance databases to estimate incident cases of IE in the United States in 2017, stratified by persons living with human immunodeficiency virus (HIV), hepatitis C virus (HCV), and opioid use disorder (OUD). We also estimated annual percentage changes (EAPCs) in IE from 2007-2017 among persons with commercial insurance.

RESULTS

The weighted incidence rate of IE was 13.8 cases per 100 000 persons among persons with commercial insurance, and 78.7 among those with Medicaid. The incidence rate of IE among commercially insured persons increased slightly from 2007-2017 (EAPC, 1.0%). It decreased among commercially insured persons living with HIV, from 148.0 in 2007 to 112.1 in 2017 (EAPC, -4.3%), and increased among those with HCV infection, from 172.4 in 2007 to 238.6 in 2017 (EAPC, 3.2%). Among persons aged 18-29 years with HCV infection, IE increased from 322.3 in 2007 to 1007.1 in 2017 (EAPC, 16.3%), and among those with OUD it increased from 156.4 in 2007 to 642.9 in 2017 (EAPC, 14.8%).

CONCLUSIONS

The incidence rate of IE increased markedly among young persons with HCV infections or OUD. This increase appears to parallel the ongoing national opioid crisis. Harm reduction with syringe services programs, medications for opioid use disorder, and safe injection practices can prevent the spread of HIV, HCV, and IE.

Association between discharges against medical advice and readmission in patients treated for drug injection-related skin and soft tissue infections

BACKGROUND

The prevalence of injection drug use (IDU)-related skin and soft tissue infections (SSTI) in Philadelphia has been steadily increasing since 2013. Patients seeking treatment for these infections are more likely to be discharged against medical advice (AMA), increasing the likelihood that they will end antibiotic treatment prematurely and require additional medical interventions.

METHODS

The research team performed a nested case-control study using the Pennsylvania Health Care Cost Containment Council database for Philadelphia residents hospitalized for SSTI and substance use-related diagnoses between 2013 and 2018. The primary outcome was readmission in the same or following quarter. The study examined the impact of discharge AMA on readmission along with clinical characteristics including diagnoses for anxiety, bipolar disorder, depression, schizophrenia, diabetes, and polydrug use.

RESULTS

There were 8265 hospitalizations for IDU-related SSTI and 316 (6%) were readmitted to the hospital at least once in the same or following quarter. In total, 23.4% of cases and 13% of controls left AMA. In the final multivariable regression model, AMA discharge (AOR 2.04, 95% CI 1.46-2.86), anxiety (AOR 1.44, 95% CI 1.01-2.05), diabetes (AOR 2.02, 95% CI 1.46-2.81), and polydrug use (AOR 2.11, 95% CI 1.52-2.92) were associated with higher odds of readmission.

CONCLUSIONS

Our study demonstrates that readmissions for IDU-related SSTI are associated with recent discharge AMA. As IDU-related SSTI and polydrug use continue to rise, premature antibiotic treatment completion will impact more people, leading to worse health outcomes and additional strain on the health care system.

Bacterial Infections Associated With Substance Use Disorders, Large Cohort of United States Hospitals, 2012-2017

BACKGROUND

Rises in the incidence of bacterial infections, such as infective endocarditis (IE), have been reported in conjunction with the opioid crisis. However, recent trends for IE and other serious infections among persons with substance use disorders (SUDs) are unknown.

METHODS

Using the Premier Healthcare Database, we identified hospitalizations from 2012 through 2017 among adults with primary discharge diagnoses of bacterial infections and secondary SUD diagnoses, using International Classification of Diseases, Clinical Modification Ninth and Tenth Revision codes. We calculated annual rates of infections with SUD diagnoses and evaluated temporal trends. Blood and cardiac tissue specimens were identified from IE hospitalizations to describe the microbiology distribution and temporal trends among hospitalizations with and without SUDs.

RESULTS

Among 72 481 weighted IE admissions recorded, SUD diagnoses increased from 19.9% in 2012 to 39.4% in 2017 (P < .0001). Hospitalizations with SUDs increased from 1.1 to 2.1 per 100 000 persons for IE, 1.4 to 2.4 per 100 000 persons for osteomyelitis, 0.5 to 0.9 per 100 000 persons for central nervous system abscesses, and 24.4 to 32.9 per 100 000 persons for skin and soft tissue infections. For adults aged 18-44 years, IE-SUD hospitalizations more than doubled, from 1.6 in 2012 to 3.6 in 2017 per 100 000 persons. Among all IE-SUD hospitalizations, 50.3% had a Staphylococcus aureus infection, compared with 19.4% of IE hospitalizations without SUDs.

CONCLUSIONS

Rates of hospitalization for serious infections among persons with SUDs are increasing, driven primarily by younger age groups. The differences in the microbiology of IE hospitalizations suggest that SUDs are changing the epidemiology of these infections.

A qualitative assessment of discharge against medical advice among patients hospitalized for injection-related bacterial infections in West Virginia

BACKGROUND

The incidence of infective endocarditis (IE) and other systemic bacterial infections is increasing, and people who inject drugs (PWID) have higher rates of discharge against medical advice (AMA) for these infections than patients whose infections are not injection-related. In this study, we characterize factors that contribute to AMA hospital discharge among PWID.

METHODS

We conducted qualitative interviews with twenty PWID hospitalized with serious injection-related bacterial infections in West Virginia. Participants completed a brief survey and in-depth qualitative interview. Interviews were recorded and transcribed verbatim and analyzed using a codebook developed based on deductive and inductive thematic analysis. We also conducted medical records abstraction and used descriptive statistics to summarize medical and survey data.

RESULTS

Average age was 34 years, 55% were female, 95% identified as white, and 75% had a primary diagnosis of IE. Drugs injected prior to hospitalization were methamphetamine (60%), prescription opioids (38%), and/or heroin/fentanyl (25%). Participants cited multiple contributors to AMA discharge including negative interactions with hospital staff that they perceived as stigmatizing, including being searched or monitored for illicit drug use; inadequate management of pain and withdrawal; boredom and confinement during lengthy hospitalizations; and isolation from family and other social supports.

CONCLUSION

We identified multiple factors contributing to AMA discharge that are amenable to intervention. Given the significant morbidity, mortality, and financial costs associated with hospitalizing PWID for serious injection-related bacterial infections, hospitals should be highly motivated to develop and test interventions designed to improve outcomes among these patients.

National Public Health Burden Estimates of Endocarditis and Skin and Soft-Tissue Infections Related to Injection Drug Use: A Review

BACKGROUND

Despite concerns about the burden of the bacterial and fungal infection syndromes related to injection drug use (IDU), robust estimates of the public health burden of these conditions are lacking. The current article reviews and compares data sources and national burden estimates for infective endocarditis (IE) and skin and soft-tissue infections related to IDU in the United States.

METHODS

A literature review was conducted for estimates of skin and soft-tissue infection and endocarditis disease burden with related IDU or substance use disorder terms since 2011. A range of the burden is presented, based on different methods of obtaining national projections from available data sources or published data.

RESULTS

Estimates using available data suggest the number of hospital admissions for IE related to IDU ranged from 2900 admissions in 2013 to more than 20 000 in 2017. The only source of data available to estimate the annual number of hospitalizations and emergency department visits for skin and soft-tissue infections related to IDU yielded a crude estimate of 98 000 such visits. Including people who are not hospitalized, a crude calculation suggests that 155 000-540 000 skin infections related to IDU occur annually.

DISCUSSION

These estimates carry significant limitations. However, regardless of the source or method, the burden of disease appears substantial, with estimates of thousands of episodes of IE among persons with IDU and at least 100 000 persons who inject drugs (PWID) with skin and soft-tissue infections annually in the United States. Given the importance of these types of infections, more robust and reliable estimates are needed to better quantitate the occurrence and understand the impact of interventions.

Use of Population-Based Surveys for Estimating the Population Size of Persons Who Inject Drugs in the United States

BACKGROUND

In the United States, injection is an increasingly common route of administration for opioids and other substances. Estimates of the number of persons who inject drugs (PWID) are needed for monitoring risk-specific infectious disease rates and health services coverage.

METHODS

We reviewed design and instruments for 4 national household surveys, 2012-2016, for their ability to produce unbiased injection drug use (IDU) prevalence estimates. We explored potential analytic adjustments for reducing biases through use of external data on (1) arrest, (2) narcotic overdose mortality, and (3) biomarker-based sensitivity of self-reported illicit drug use.

RESULTS

Estimated national past 12 months IDU prevalence ranged from 0.24% to 0.59% across surveys. All surveys excluded unstably housed and incarcerated persons, and estimates were based on <60 respondents reporting IDU behavior in 3 surveys. No surveys asked participants about nonmedical injection of prescription drugs. Analytic adjustments did not appreciably change IDU prevalence estimates due to suboptimal specificity of data points.

CONCLUSIONS

PWID population size estimates in the United States are based on small numbers and are likely biased by undercoverage of key populations and self-report. Novel methods as discussed in this article may improve our understanding of PWID population size and their health needs.

Infectious Complications of Addiction: A Call for a New Subspecialty Within Infectious Diseases

Infectious diseases (ID) physicians are increasingly responsible for the management of infectious consequences of substance use disorders (SUD). While we are often consulted for diagnosis and treatment of the infectious disease, it is clear that successful management of these infections requires a holistic approach, including acknowledgement and treatment of the underlying SUD. As we have learned through years of treating human immunodeficiency virus and hepatitis C virus infections, ID physicians have unique expertise in addressing both the infection and the complex biopsychosocial factors that underpin the infection. Many ID physicians have incorporated the management of addiction as part of their scope of practice, and here we seek to give a name and define the role of these ID/addiction dual specialists. We define the potential role of ID/addiction physicians in clinical care, health administration, and research, as well as provide recommendations to bolster the supply and reach of this burgeoning subspecialty.

Consider the Source: Associations between Syringe Sources and Risky Injection Behaviors in California's Central Valley

BACKGROUND

Sterile syringe access is critical to prevent serious viral and bacterial infections among people who inject drugs (PWID) but many areas across the United States lack sufficient access. Although California law allows nonprescription pharmacy syringe sales and syringe services programs (SSPs), access gaps remain in the largely rural Central Valley.

OBJECTIVE

The purpose of this study was to examine syringe access and related injection behaviors among PWID in Fresno, California.

METHODS

We used respondent driven sampling to recruit 494 individuals for a survey about syringe access and injection behaviors between April and September 2016. Participants were ≥18 years old and injected at least twice in the past 30 days. Descriptive statistics examined syringe access and logistic regression determined if discrete syringe source categories were significantly associated with syringe sharing and/or reuse.

RESULTS

A majority (67%) obtained syringes from an authorized source; SSPs were most common (59%), while few reported pharmacy purchase (14%). Unauthorized sources were even more common (79%), primarily friends (64%) or someone on the street (37%). Compared to PWID who used only authorized sources, those using only unauthorized sources had a higher odds of syringe sharing (AOR = 3.40, 95% CI: 1.66, 6.95) and syringe reuse (AOR = 6.22; 95% CI: 2.24, 17.29), as did those who reported mixed sources (AOR = 3.78; 95% CI: 1.90, 7.54 and AOR = 4.64; 95% CI: 2.08, 10.35).

CONCLUSIONS

Our findings demonstrate a need to expand syringe access in nonurban California to prevent the syringe sharing and reuse that contributes to serious viral and bacterial infections among PWID.

Impact of medications for opioid use disorder among persons hospitalized for drug use-associated skin and soft tissue infections

BACKGROUND

Skin and soft tissue infections (SSTI) are common complications of injection drug use. We aimed to determine if rehospitalization and recurrent SSTI differ among persons with opioid use disorder (OUD) hospitalized for SSTI who are initiated on MOUD within 30 days of discharge and those who are not.

METHODS

We performed a retrospective analysis of commercially insured adults aged 18 years and older in the U.S. with OUD and hospitalization for injection-related SSTI from 2010-2017. The primary exposure was initiation of MOUD in the 30 days following hospitalization for SSTI. The primary outcomes included 30-day and 1-year 1) all-cause rehospitalization and 2) recurrent SSTI. We calculated the incidence rates for the two groups: MOUD group and no MOUD group for the primary outcomes. We developed Cox models to determine if rehospitalization and recurrent SSTI differ between the two groups.

RESULTS

Only 5.5 % (357/6538) of people received MOUD in the month following their index SSTI hospitalization. 30-day rehospitalization incidence was higher in the MOUD group compared to no MOUD (35.9 vs 27.5 per 100 person-30 days) and one-year SSTI recurrence was lower (10.3 vs 18.7 per 100 person-years). In multivariable modeling, the MOUD group remained at significantly higher risk of 30-day rehospitalization compared to the no MOUD group and at lower risk for one-year SSTI recurrence.

CONCLUSIONS

MOUD receipt following SSTI hospitalization decreases risk of recurrent SSTI among persons with OUD. Further expansion of these in-hospital services could provide an effective tool in the U.S. response to the opioid epidemic.

Use of ICD-10 Codes for Identification of Injection Drug Use-Associated Infective Endocarditis Is Nonspecific and Obscures Critical Findings on Impact of Medications for Opioid Use Disorder

Background

No International Classification of Diseases, 10th revision (ICD-10), diagnosis code exists for injection drug use–associated infective endocarditis (IDU-IE). Instead, public health researchers regularly use combinations of nonspecific ICD-10 codes to identify IDU-IE; however, the accuracy of these codes has not been evaluated.

Methods

We compared commonly used ICD-10 diagnosis codes for IDU-IE with a prospectively collected patient cohort diagnosed with IDU-IE at Barnes-Jewish Hospital to determine the accuracy of ICD-10 diagnosis codes used in IDU-IE research.

Results

ICD-10 diagnosis codes historically used to identify IDU-IE were inaccurate, missing 36.0% and misclassifying 56.4% of patients prospectively identified in this cohort. Use of these nonspecific ICD-10 diagnosis codes resulted in substantial biases against the benefit of medications for opioid use disorder (MOUD) with relation to both AMA discharge and all-cause mortality. Specifically, when data from all patients with ICD-10 code combinations suggestive of IDU-IE were used, MOUD was associated with an increased risk of AMA discharge (relative risk [RR], 1.12; 95% CI, 0.48–2.64). In contrast, when only patients confirmed by chart review as having IDU-IE were analyzed, MOUD was protective (RR, 0.49; 95% CI, 0.19–1.22). Use of MOUD was associated with a protective effect in time to all-cause mortality in Kaplan-Meier analysis only when confirmed IDU-IE cases were analyzed (P = .007).

Conclusions

Studies using nonspecific ICD-10 diagnosis codes for IDU-IE should be interpreted with caution. In the setting of an ongoing overdose crisis and a syndemic of infectious complications, a specific ICD-10 diagnosis code for IDU-IE is urgently needed.

Prevalence and severity of abscesses and cellulitis, and their associations with other health outcomes, in a community-based study of people who inject drugs in London, UK

BACKGROUND

Skin and soft tissue infections (SSTI) are a common but preventable cause of morbidity and mortality among people who inject drugs (PWID). They can be severe, and hospitalisations of PWID with SSTI are rising. The most common SSTI presentations are abscesses and cellulitis.

METHODS

We used data from Care & Prevent, a cross-sectional community survey of PWID in London. We reported the lifetime prevalence of SSTI, severity of infections, key risk factors, and associated sequelae. Pictorial questions were used to assess SSTI severity.

RESULTS

We recruited 455 PWID. SSTI lifetime prevalence was high: 64% reported an abscess and/or cellulitis. Over one-third (37%) reported a severe infection, 137 (47%) reported hospitalisation. SSTIrisk factors were: aged 35+ years, injecting once or more times a day, subcutaneous or intra-muscular injections, and making four or more attempts to achieve an injection. Those who reported having other health conditions were at higher odds of having an abscess or cellulitis, with risk tending to increase with number of reported conditions. Half (46%) employed self-care for their worst SSTI, and 43% waited for ten or more days before seeking medical care or not seeking medical care at all.

CONCLUSIONS

Abscess and cellulitis are very common among PWID in London. We corroborate findings indicating SSTIs are associated with risks, e.g. venous access problems, as well as other co-morbid conditions: septicaemia, endocarditis, DVT, and kidney disease. These co-morbidities may impact SSTIs severity and outcomes. Delayed healthcare seeking potentially exacerbates infection severity, which in turn increases poorer health outcomes and complications.

Association of Self-Reported Abscess With High-Risk Injection-Related Behaviors Among Young Persons Who Inject Drugs

Abscess is a common source of morbidity for people who inject drugs. We used data from the Study to Assess Hepatitis C Risk to measure prevalence of abscess and identify factors associated with the history of abscess. Of 541 participants, 388 (72%) were male and 149 (28%) were female. Almost half (n = 258, 48%) reported ever having an abscess. Persons who inject drugs with an abscess history were significantly more likely to have more injection partners (p = .01), inject heroin daily (p < .05), and share cookers (p = .001) and less likely to report using new syringes with each injection (p = .02). Most reported self-treating their last abscess and increasing drug use when having an abscess. High-risk injection-related activity was associated not only with infections such as HIV and hepatitis C virus but also with abscess. Nurses should screen patients presenting with abscess for high-risk practices and provide prevention education.

When is an abscess more than an abscess? Syringe services programs and the harm reduction safety-net: a case report

Background

Syringe services programs (SSPs) are able to offer wrap-around services for people who inject drugs (PWID) and improve health outcomes.

Case presentation

A 47-year-old man screened positive for a skin and soft tissue infection (SSTI) at an SSP and was referred to a weekly on-site student-run wound care clinic. He was evaluated by first- and third-year medical students, and volunteer attending physicians determined that the infection was too severe to be managed on site. Students escorted the patient to the emergency department, where he was diagnosed with a methicillin-resistant Staphylococcus aureus arm abscess as well as acute HIV infection.

Conclusion

Student-run wound care clinics at SSPs, in conjunction with ongoing harm reduction measures, screenings, and treatment services, provide a safety-net of care for PWID and help mitigate the harms of injection drug use.

A 9-Point Risk Assessment for Patients Who Inject Drugs and Require Intravenous Antibiotics: Focusing Inpatient Resources on Patients at Greatest Risk of Ongoing Drug Use

A 9-point risk assessment identified persons with a history of injection drug use who were safe for discharge. "Low-risk" patients were discharged with outpatient antibiotics; others continued inpatient treatment. Use of the assessment reduced the mean length of stay by 20 days and total direct cost by 33%, creating capacity for an additional 333 patients.

Reasons for assisting with injection initiation: Results from a large survey of people who inject drugs in Los Angeles and San Francisco, California

Injection drug initiation usually requires assistance by someone who already injects drugs. To develop interventions that prevent people from starting to inject drugs, it is imperative to understand why people who inject drugs (PWID) assist with injection initiation.

METHODS

Injection initiation history and motives for initiating others were collected from 978 PWID in Los Angeles and San Francisco, CA, from 2016-17. This article documents motivations for providing injection initiation assistance and examines demographic, economic, and health-related factors associated with these motivations using multivariable logistic regression modeling.

RESULTS

Among the 405 PWID who ever facilitated injection initiation, motivations for initiating were: injury prevention (66%), skilled at injecting others (65%), to avoid being pestered (41%), in exchange for drugs/money (45%), and for food/shelter/transportation (15%). High frequency initiation (>5 lifetime injection initiations) was associated with all motivations except for being pestered. Initiation to prevent injury was associated with being female. Initiation due to pestering was associated with recycling income and sex work. Being skilled was associated with age and HIV status, while initiation for money or drugs was associated with age, race, education, social security income, and substance use treatment. Lastly, initiation for food, shelter, or transportation was associated with age, sexual orientation and education level.

CONCLUSION

Diverse factors were associated with reported motivations for assisting someone to initiate injection for the first time. Our analysis underscores the need for prevention strategies focused on improving economic and housing conditions along with implementing drug consumption rooms to disrupt the social processes of injection initiation.

Outcomes Associated With Medications for Opioid Use Disorder Among Persons Hospitalized for Infective Endocarditis

BACKGROUND

Endocarditis, once predominately found in older adults, is increasingly common among younger persons who inject drugs. Untreated opioid use disorder (OUD) complicates endocarditis management. We aimed to determine if rates of overdose and rehospitalization differ between persons with OUD with endocarditis who are initiated on medications for OUD (MOUDs) within 30 days of hospital discharge and those who are not.

METHODS

We performed a retrospective cohort study using a large commercial health insurance claims database of persons ≥18 years between July 1, 2010, and June 30, 2016. Primary outcomes included opioid-related overdoses and 1-year all-cause rehospitalization. We calculated incidence rates for the primary outcomes and developed Cox hazards models to predict time from discharge to each primary outcome as a function of receipt of MOUDs.

RESULTS

The cohort included 768 individuals (mean age 39 years, 51% male). Only 5.7% of people received MOUDs in the 30 days following hospitalization. The opioid-related overdose rate among those who did receive MOUDs in the 30 days following hospitalization was lower than among those who did not (5.8 per 100 person-years [95% confidence interval [CI], 5.1-6.4] vs 7.3 per 100-person years [95% CI, 7.1-7.5], respectively). The rate of 1-year rehospitalization among those who received MOUDs was also lower than those who did not (162.0 per 100 person-years [95% CI, 157.4-166.6] vs 255.4 per 100 person-years [95% CI, 254.0-256.8], respectively). In the Cox hazards models, the receipt of MOUDs was not associated with either of the outcomes.

CONCLUSIONS

MOUD receipt following endocarditis may improve important health-related outcomes in commercially insured persons with OUD.

Dalbavancin Use in Vulnerable Patients Receiving Outpatient Parenteral Antibiotic Therapy for Invasive Gram-Positive Infections

Introduction

Dalbavancin is approved for acute bacterial skin and skin structure infections (ABSSSIs) but offers a potential treatment option for complicated invasive gram-positive infections. Importantly, dalbavancin’s real benefits may be in treating complicated infections in vulnerable patient populations, such as persons who inject drugs (PWID).

Methods

A multicenter retrospective analysis was performed from March 2014 to April 2017 to assess 30- and 90-day clinical cure and adverse drug events (ADEs) in adult patients who received ≥ 1 dose of dalbavancin for a non-ABSSSI indication.

Results

During the study period, 45 patients received dalbavancin, 28 for a non-ABSSSI indication. The predominant infections treated included osteomyelitis (46%), endovascular infection (25%) and uncomplicated bacteremia (14%). Half of the patients had positive Staphylococcus aureus in cultures, 29% methicillin resistant and 21% methicillin susceptible. Most patients were prescribed dalbavancin as sequential treatment with a median of 13.5 days of prior antibiotic therapy. The most common reason for choosing dalbavancin over standard therapy use was PWID (54%). Seven patients were lost to follow-up at day 30. Of the remaining evaluable patients, 30-day clinical cure was achieved in 15/21 (71%) patients. The most common reason for failure was lack of source control (4/6, 67%). At day 90, relapse occurred in two patients. Three patients had a potential dalbavancin-associated ADE: two patients with renal dysfunction and one patient with pruritus.

Conclusions

This study demonstrates a possible role for dalbavancin in the treatment of non-ABSSSI invasive gram-positive infections in select vulnerable OPAT patients.

Estimated Prevalence of Opioid Use Disorder in Massachusetts, 2011-2015: A Capture-Recapture Analysis

OBJECTIVES

To estimate the annual prevalence of opioid use disorder (OUD) in Massachusetts from 2011 to 2015.

METHODS

We performed a multisample stratified capture-recapture analysis to estimate OUD prevalence in Massachusetts. Individuals identified from 6 administrative databases for 2011 to 2012 and 7 databases for 2013 to 2015 were linked at the individual level and included in the analysis. Individuals were stratified by age group, sex, and county of residence.

RESULTS

The OUD prevalence in Massachusetts among people aged 11 years or older was 2.72% in 2011 and 2.87% in 2012. Between 2013 and 2015, the prevalence increased from 3.87% to 4.60%. The greatest increase in prevalence was observed among those in the youngest age group (11-25 years), a 76% increase from 2011 to 2012 and a 42% increase from 2013 to 2015.

CONCLUSIONS

In Massachusetts, the OUD prevalence was 4.6% among people 11 years or older in 2015. The number of individuals with OUD is likely increasing, particularly among young people.

Burkholderia cepacia complex Cervical Osteomyelitis in an Intravenous Drug User

Gram-negative vertebral osteomyelitis infections are increasing due to rising intravenous drug use but overall remain uncommon. Here, we present a case of Burkholderia cepacia complex cervical osteomyelitis in an intravenous drug user. Burkholderia cepaciacomplex vertebral osteomyelitis has been infrequently described in the literature thus far with varied antibiotic treatment regimens. A 68-year-old male presented to the emergency department with neck pain after minor trauma. He endorsed active intravenous heroin and methamphetamine use. CT and MRI imaging of the cervical spine revealed destructive changes of C5-C6 vertebral bodies consistent with osteomyelitis. Neurological exam was stable and vital signs were within normal limits; so, antibiotics were held, and he was admitted for diagnostic evaluation. Five sets of blood cultures were drawn on admission and were ultimately negative. He subsequently underwent C5-C6 corpectomy, C4-C7 anterior fusion, and C3-T1 posterior fusion with allograft placement. Deep operative tissue cultures grew Burkholderia cepacia complex. He was treated with 6 weeks of intravenous ceftazidime followed by indefinite oral minocycline due to hardware placement. Burkholderia cepacia complex should be considered among pathogenic etiologies of pyogenic vertebral osteomyelitis, particularly among patients with intravenous drug use. Ceftazidime monotherapy was an effective treatment in this particular case.

Outcomes of Outpatient Parenteral Antimicrobial Therapy in Patients With Injection Drug Use

BACKGROUND

Historically, there has been a restrictive approach toward outpatient parenteral antimicrobial therapy (OPAT) in patients with injection drug use (IDU) due to the fear that they might utilize the intravenous catheter to inject illicit substances.

OBJECTIVE

We tested the hypothesis that patients with current IDU on OPAT would have less favorable treatment outcomes compared to those without current IDU.

METHODS

In this retrospective cohort chart review study of Cleveland Clinic OPAT registry, we identified patients with current IDU by both electronic and manual review. For each patient with current IDU, we identified 3 matched controls among those on OPAT and without current IDU, by propensity score matching on age, sex, OPAT year, and OPAT diagnosis. We compared treatment failure, infection relapse, line infection, hospital readmission, number of emergency room visits, and 90-day mortality, for patients with current IDU and their matched controls.

RESULTS

We identified 39 patients with current IDU and 117 matched controls. Most patients with current IDU (82%) were discharged to skilled nursing facilities, whereas the majority of the control group (74%) was treated at home (p < 0.01). There was no significant difference in the examined treatment outcomes between the 2 groups.

CONCLUSIONS

Patients with current IDU on OPAT did not have less favorable treatment outcomes compared to those without current IDU. Although the reason for this finding could potentially be related to difference in disposition, more studies need to be done to assess safety of home disposition among these patients.