Abstract
Drug related-soft tissue infections (DR-STIs) are a significant source of hospital utilization in inner-city urban areas where injection drug use is common but the magnitude of hospital utilization for DR-STIs outside of inner-city urban areas is not known. We described the magnitude and characteristics of hospital utilization for DR-STIs in urban versus rural counties in California. All discharges from all nonfederal hospitals in California in 2000 with ICD-9 codes for a soft tissue infection and for drug dependence/abuse were abstracted from the California Office of Statewide Health Planning and Development discharge database. There were 4,152 DR-STI discharges in 2000 from hospitals in 49 of California's 58 counties. Residents of 12 large metropolitan counties accounted for 3,598 discharges (87% of total). The majority of DR-STI discharges were from urban safety net hospitals with county indigent programs and Medicaid as the expected payment source and opiate related discharge diagnoses. Hospital utilization for DR-STIs in California is highest in large urban metropolitan counties, although DR-STI discharges are widespread. Increased access to harm reduction services and drug treatment may reduce government health care expenditures by preventing unnecessary hospital utilization for DR-STIs.
Keywords: Hospital utilization, Injection drug use, Medicaid, Soft tissue infection, Urban, Rural
Introduction
Soft tissue infections are a common complication of injection drug use1–5 and have been reported to be a significant source of hospital utilization in inner-city urban areas where injection drug use is common. For example, drug related soft tissue infections (DR-STI) were the leading cause of admissions to San Francisco General Hospital in 1999, resulting in charges of nearly $10 million.6 Recent reports suggest that injection drug use is increasing in suburban and rural areas,7,8 yet the magnitude of hospital utilization for DR-STIs outside of inner-city urban areas is not known. Therefore, we described the magnitude and characteristics of hospital utilization for DR-STIs in urban versus rural counties in California.
Materials and Methods
The study used the California Office of Statewide Health Planning and Development (OSHPD) hospital discharge dataset, which includes all discharges from nonfederal hospitals in California. DR-STI discharges were defined as any discharge in 2000 from an acute care hospital for a patient aged 15 to 74 years with a primary diagnosis of abscess and/or cellulitis of the trunk, buttocks, or extremities (International Classification of Diseases, Ninth Revision [ICD-9]) codes 682.2–682.7 and 682.9) and a primary or secondary diagnosis of opiate, cocaine, or amphetamine dependence/abuse (ICD-9 codes 304.0, 305.5, 304.2, 305.6, 304.4, 305.7). Demographics and expected payment source for DR-STI discharges were abstracted.
Counties were categorized using 2000 US Census data according to Office of Management and Budget definitions9 as metropolitan (at least one urbanized area of 50,000 or more population), micropolitan (at least one urban cluster of 10,000 to 49,999 persons), or rural (neither metropolitan nor micropolitan). The number of DR-STI discharges and incidence adjusted for age, gender, and race using the direct method10 with the 2000 US Census population of California as the standard population11 were calculated by county, race/ethnicity, and expected payment source. The number of DR-STI discharges identified in the OSHPD dataset was compared to the number identified via chart review of a random sample of 150 discharges for soft tissue infections at a single California hospital.
The study was approved by the Institutional Review Board at the West Los Angeles VA Medical Center and the University of Southern California School of Medicine.
Results
There were a total of 4,152 DR-STI discharges from non-federal hospitals in 49 of California's 58 counties in 2000 (Table 1). Residents of large metropolitan counties accounted for the majority of DR-STI discharges, with 12 metropolitan counties accounting for 3,598 discharges (87% of total). The largest absolute number of DR-STI discharges was in Los Angeles while the highest adjusted incidence of DR-STI discharges was in San Francisco. While the absolute number of DR-STI discharges in micropolitan and rural counties was small, the adjusted incidence of DR-STI discharges in Humboldt and Calaveras Counties was similar to that in metropolitan counties.
Table 1.
Hospital Utilization for Drug Related-soft Tissue Infections in Metropolitan, Micropolitan, and Rural Counties in California in 2000
County | DR-STIs, number | DR-STIs, incidence* | Total population |
---|---|---|---|
Metropolitan counties | |||
Los Angeles | 923 | 14.1 | 9,519,338 |
San Francisco | 855 | 147.9 | 776,733 |
Alameda | 320 | 23.1 | 1,443,741 |
San Diego | 274 | 13.4 | 2,813,833 |
Sacramento | 233 | 26.6 | 1,223,499 |
Santa Clara | 174 | 21.1 | 1,682,585 |
Orange | 168 | 8.5 | 2,846,289 |
Contra Costa | 167 | 16.3 | 948,816 |
San Bernardino | 145 | 11.4 | 1,709,434 |
Riverside | 119 | 11.4 | 1,545,387 |
San Joaquin | 118 | 30.0 | 563,598 |
Fresno | 102 | 21.6 | 799,407 |
Stanislaus | 72 | 19.8 | 446,997 |
Kern | 59 | 12.7 | 661,645 |
Sonoma | 43 | 10.8 | 458,614 |
San Mateo | 38 | 7.9 | 707,161 |
Ventura | 34 | 6.9 | 753,197 |
Monterey | 31 | 11.5 | 401,762 |
Imperial | 27 | 33.0 | 142,361 |
Tulare | 26 | 10.8 | 368,021 |
Solano | 18 | 32.2 | 394,542 |
Yuba | 18 | 5.2 | 60,219 |
Santa Cruz | 16 | 6.0 | 255,602 |
Santa Barbara | 15 | 19.2 | 399,347 |
Madera | 15 | 7.4 | 123,109 |
San Luis Obispo | 14 | 14.3 | 246,681 |
Yolo | 14 | 5.6 | 168,660 |
Placer | 13 | 5.9 | 248,399 |
Sutter | 11 | 20.9 | 78,930 |
Marin | 9 | 2.9 | 247,289 |
Butte | 6 | 9.7 | 203,171 |
Merced | 5 | 3.9 | 210,554 |
Shasta | 5 | 1.8 | 163,256 |
Kings | 4 | 4.7 | 129,461 |
El Dorado | 2 | 7.7 | 156,299 |
San Benito | 1 | 2.5 | 53,234 |
Napa | 0 | .0 | 124,279 |
Micropolitan counties | |||
Humboldt | 31 | 19.1 | 126,518 |
Lake | 3 | 5.7 | 58,309 |
Mendocino | 3 | 3.7 | 86,265 |
Nevada | 3 | 2.5 | 92,033 |
Tehama | 2 | 3.2 | 56,039 |
Inyo | 1 | 7.0 | 17,945 |
Tuolumne | 1 | 1.3 | 54,501 |
Del Norte | 0 | .0 | 27,507 |
Rural counties | |||
Amador | 6 | 9.4 | 35,100 |
Calaveras | 3 | 44.7 | 40,554 |
Plumas | 2 | 3.5 | 20,824 |
Colusa | 1 | 10.2 | 18,804 |
Mariposa | 1 | 4.8 | 17,130 |
Siskiyou | 1 | 2.3 | 44,301 |
Alpine | 0 | .0 | 1,208 |
Glenn | 0 | .0 | 26,453 |
Lassen | 0 | .0 | 33,828 |
Modoc | 0 | .0 | 9,449 |
Mono | 0 | .0 | 12,853 |
Sierra | 0 | .0 | 3,555 |
Trinity | 0 | .0 | 13,022 |
*Per 100,000 California population adjusted for age, gender, and race/ethnicity
The greatest absolute number of DR-STI discharges was among Non-Hispanic Whites while the highest age-adjusted incidences of DR-STI discharges were for ethnic minorities (Table 2). Opiate dependence/abuse was the most frequent drug-related discharge diagnosis, followed by cocaine and amphetamines. The most common expected payment sources for DR-STI discharges were county indigent programs, Medicaid, and self-pay. Fourteen (14) of California's 585 non-federal hospitals accounted for 2,938 DR-STI discharges (71% of total), of which 12 were urban city/county or safety net facilities (data not shown).
Table 2.
Hospital Utilization for Drug Related-soft Tissue Infections by Race/Ethnicity, Drug-related Discharge Diagnoses, and Expected Payment Source in California in 2000
Race/ethnicity | Number | Percent (%)* |
---|---|---|
White | ||
Male | 1,341 | 21.7 |
Female | 908 | 15.6 |
African American | ||
Male | 508 | 67.9 |
Female | 261 | 32.2 |
Hispanic | ||
Male | 541 | 18.0 |
Female | 223 | 6.9 |
Asian/Pacific Islander | ||
Male | 26 | 1.9 |
Female | 5 | .3 |
Native American | ||
Male | 16 | 23.6 |
Female | 18 | 25.9 |
Other race | ||
Male | 185 | 64.2 |
Female | 100 | 34.4 |
Missing | ||
Male | 10 | N/A |
Female | 10 | N/A |
Drug-related discharge diagnoses | Number | Percent (%) |
Opiates | 3,206 | 77 |
Cocaine | 558 | 13 |
Amphetamines | 344 | 8 |
Combination | 54 | 2 |
Expected payment source | Number | Percent (90) |
County indigent | 1,454 | 35 |
Medicaid | 1,090 | 27 |
Self-pay | 584 | 14 |
Medicare | 392 | 9.5 |
Private insurance | 345 | 8 |
Other govt./indigent | 286 | 7 |
Payor data missing | 1 | 0 |
*Per 100,000 California population adjusted for age
Review of hospital charts at a single California hospital yielded an estimate of 271 DR-STI discharges at that facility per year, compared to 336 DR-STI discharges identified in the OSHPD database for that hospital in 2000.
Discussion
We found that hospital utilization for DR-STIs at California non-federal hospitals is highest in large urban metropolitan counties, particularly San Francisco. These results confirm previous reports from San Francisco6 and may reflect a higher prevalence of injection drug use in San Francisco,12 more frequent injection practices associated with DR-STIs, including subcutaneous or intramuscular injecting,3 or use of black tar heroin,13,14 especially given the predominance of opiate use among DR-STI discharges.
While utilization for DR-STIs was highest in large urban centers, at least moderate levels of utilization were present throughout California, suggesting that injection drug use and the associated health complications are not limited to large urban centers. Despite the widespread occurrence of discharges for DR-STIs, services for treating and preventing DR-STIs are not widely available. For example, syringe exchange programs can prevent DR-STIs by providing injection drug users with sterile syringes, instruction in proper vein care, and early access to wound care.15 Yet four of the 12 California counties with the largest number of DR-STI discharges (Orange, San Bernardino, Riverside, and San Joaquin) have no syringe exchange programs,16 suggesting that wider implementation of harm reduction services, including syringe exchange programs, vein care education, and low threshold wound care clinics17 is needed.
We also found that utilization for DR-STIs in California disproportionately impacts vulnerable populations and the publicly funded programs and facilities that provide their care, including Medicaid, county indigent care programs, and safety net hospitals. The concentration of utilization and the resulting expenditures among public programs and safety net hospitals suggests that increased public funding for harm reduction services and drug treatment programs to prevent DR-STIs is likely to be cost effective due to subsequent reductions in government expenditures for expensive hospital care.
The study has several limitations. Discharges from federal hospitals are not included in the OSHPD database. Given the high prevalence of injection drug use at Veterans Administration hospitals,18 our study likely underestimates hospital utilization for DR-STIs in California. Also, our study identified DR-STIs using discharge diagnoses for drug dependence/abuse, which may underestimate DR-STI discharges if drug-related discharge diagnoses were not recorded. Our estimate of DR-STIs is similar to that obtained via our chart review at a single hospital, suggesting that our estimate is reliable.
In conclusion, hospital utilization for DR-STIs is greatest in large metropolitan urban areas, although utilization for DR-STIs is widespread. Wider implementation of harm reduction services and drug treatment programs to prevent hospitalization for DR-STIs is warranted.
Acknowledgements
This study was performed with support from the UCLA RWJ Clinical Scholars Program and the VA Health Services Research Fellowship Program.
Footnotes
Heinzerling is with the Department of Family Medicine, David Geffen, School of Medicine at UCLA Los Angeles, California, USA; Heinzerling and Asch are with the VA Greater Los Angeles Health Care System, USA; Etzioni is with the Department of Surgery, David Geffen, School of Medicine at UCLA, USA; Hurley and Holtom are with the Keck School of Medicine, University of Southern California, USA; Bluthenthal and Asch are with the Health Program and Drug Policy Research Center, RAND, USA.
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