1. Hospitalizations Due to Infectious Disease Complications of Drug Use in Oregon, 2008–2015
Jeffrey Capizzi, Judith Leahy, Haven Wheelock, Ann Thomas, Jonathan Garcia, Sean Schafer,
P. Todd Korthuis
αOregon Health Authority, βOutside In, γOregon State University, δOregon Health and Science University
42nd Annual AMERSA Conference, San Francisco, CA
November 10, 2018

2. Disclosures Dr. Korthuis has no financial conflicts.
He serves as principal investigator for NIH- funded trials that accept manufacturer- donated buprenorphine/naloxone (from Indivior) and extended-release naltrexone (from Alkermes).
Funder: NIH National Institute on Drug Abuse (UG3DA044831, UG1DA015815)

3. Background
People who inject drugs are often hospitalized for serious bacterial infections (SBI)
Prior studies document local increases in drug-related hospitalizations,1,2 but few population-based estimates exist
The purpose of this study was to assess statewide trends in injection drug use (IDU)- related hospitalizations for SBI, diagnoses, and costs in Oregon over time.
1 Tookes H, PLOS One 2015
2 Fanucchi LC, J Addict Med 2018

4. Methods Study Design: Retrospective cohort study
Data Source: Oregon Hospital Discharge Data
State database of all hospitalizations in Oregon, excluding VA & psychiatric hospitalizations,
IDU-Related SBI Hospitalizations:
Hospitalization involving ≥ 1 ICD-9/10 codes for:
Opioids, amphetamines, cocaine, sedatives, or other drug use
and
Serious bacterial infections (SBI): ≥ 1 ICD-9/10 codes for:
bacteremia\sepsis
Endocarditis
Osteomyelitis
Skin/soft tissue infection
We used Oregon Hospital Discharge Data, which captures administrative claims data for most hospitalizations in Oregon, to identify IDU-related hospitalizations from January 2008 through September IDU-associated hospitalizations were those with at least one diagnostic code associated with use of opioids, amphetamines, cocaine, sedatives, or other drugs and at least one diagnosis code for bacteremia\sepsis, endocarditis, osteomyelitis, or skin/soft tissue infection. Cost was determined by adjusting the charged amount with Cost-to-Charge ratios by hospital.

5. Methods Cost Measurement
Patient hospitalization charges adjusted using AHRQ hospital Cost-to-Charge ratios, and converted to 2015 U.S. dollars
Analysis: Descriptive statistics reporting trends over time
We used Oregon Hospital Discharge Data, which captures administrative claims data for most hospitalizations in Oregon, to identify IDU-related hospitalizations from January 2008 through September IDU-associated hospitalizations were those with at least one diagnostic code associated with use of opioids, amphetamines, cocaine, sedatives, or other drugs and at least one diagnosis code for bacteremia\sepsis, endocarditis, osteomyelitis, or skin/soft tissue infection. Cost was determined by adjusting the charged amount with Cost-to-Charge ratios by hospital.

6. Patient Characteristics at First Hospitalization, 2008-2015
IDU-Related
(n = 65,783)
Non-IDU-Related
(n = 725,156)
Mean Age (SD)
46 yrs (16.1)
63 yrs (20.7)
Female
51.2%
50.5%
Race/Ethnicity
White (nonHisp.)
Black
Hispanic
Native American
Other/Unknown
65.6%
2.6%
2.1%
4.9%
23.5%
72.4%
1.4%
3.0%
18.7%
Portland Metro residence
50.7%
36.6%
Insurance
Private
Medicaid
Medicare
Uninsured
17.1%
27.2%
29.1%
23.3%
10.2%
56.4%
5.4%
HIV-infected
2.2%
0.5%
Chronic HCV
26.1%
3.8%
At their first hospitalizations, Patients with IDU-related SBI hospitalizations were younger and more likely to have Medicaid or no Insurance, HIV, and Chronic HCV.

7. Results
IDU-Related SBI Hospitalizations Account for Increasing Proportion of All Hospitalizations Over Time
increased from 975 to 5,256 (0.26% to 1.44% of all hospitalizations) from 2008 to 2015, a 5.5-fold increase

8. IDU-Related SBI Hospitalizations, by Substance, 2008-2015
Opioids, n= 9,417 (62%)
Amphetamines, n= 3,626 (24%)
Cocaine, n=324 (2%)
n=92 (1%)
n=1,350 (9%)
n=269 (2%)
n=121 (1%)

9. Results
Number of IDU-Related SBI Hospitalizations Over Time, by Drug Use

10. Results
Number of IDU-Related SBI Hospitalizations Over Time, by Infection Category

11. IDU-Related SBI Hospitalizations, by County
Oregon Population Density, by County
High rates of IDU-related SBI hospitalizations in rural, low population density Counties.

12. Total Costs of IDU-Related SBI Hospitalizations in Oregon, Over Time*
$218,987,964
$69,385,527
3.1-fold increase in costs due to IDU-Related SBI hospitalizations from
*Adjusted for charge-to-cost and inflation (2015 USD)

13. Limitations
Administrative claims data may misclassify hospitalizations, drug use, and infections
Likely resulting in a conservative estimate
Experience in single state may not be generalizable to other states

14. Conclusions
IDU-related SBI hospitalizations comprise an increasing proportion of all hospitalizations in Oregon
Rural counties have high rates of IDU-related SBI hospitalization
IDU-related SBI hospitalization costs increased 3.1-fold,
Policies that promote drug use disorder treatment and harm reduction services may decrease hospitalization costs

15. Discussion

16. Supplemental Slides

17. Results
Proportion of IDU-Related SBI Hospitalizations of All Hospitalizations Over Time, by Drug Use

18. Results
Proportion of IDU-Related SBI Hospitalizations Among All Hospitalizations Over Time, by Infectious Category

19. Longer Mean Length of Stay for IDU-Related Hospitalizations
Year of Discharge
Non-IDU Hospitalizations
(days)
IDU-Related Hospitalizations
2008
4.00
6.70
2009
3.98
6.09
2010
3.94
5.63
2011
3.89
5.07
2012
3.87
5.01
2013
3.93
5.16
2014
3.99
5.65
2015
4.05
7.04

20. Increasing Proportion of Total Drives Increased Costs
Proportion of SBI Total hospital days and Cost attributable to IDU hospitalizations (2015 dollars)