SUPPLEMENT ARTICLE METHODS

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1 SUPPLEMENT ARTICLE Effects of Long-Term, Medically Supervised, Drug-Free Treatment and Methadone Maintenance Treatment on Drug Users Emergency Department Use and Hospitalization Barbara J. Turner, 1 Christine Laine, 2 Chuya P. Yang, 1 and Walter W. Hauck 3 1 Division of General Internal Medicine, Department of Medicine, University of Pennsylvania School of Medicine, and 2 Division of Internal Medicine, Center for Research in Medical Education and Health Care, and 3 Division of Clinical Pharmacology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania We examined the effect of drug treatment in 1996 on repeated ( 2) emergency department visits and hospitalization in 1997 in a cohort of New York State Medicaid enrolled human immunodeficiency virus (HIV) positive and HIV-negative drug users. In HIV-positive drug users, the adjusted odds of repeated emergency department visits were increased for those receiving no long-term treatment (odds ratio [OR], 1.65; 95% confidence interval [CI], ), whereas the adjusted odds for those receiving methadone treatment and those receiving drug-free treatment for 6 months did not differ. The adjusted odds of hospitalization in the HIV-positive group were higher for those receiving long-term methadone treatment (OR, 1.69; 95% CI, ) and for those receiving no long-term treatment (OR, 1.91; 95% CI, ), compared with those receiving drug-free treatment. In the HIV-negative group, these associations were similar but weaker. For both HIV-positive and HIV-negative drug users, long-term drug-free treatment was at least as effective as longterm methadone treatment in reducing use of services indicative of poorer access to care and/or poorer health. Drug abuse is increasingly understood to be a chronic health condition necessitating long-term treatment [1]. Long-term treatment for injection drug users has been shown to reduce the risk of HIV seroconversion [2] and death [3]. A National Institutes of Health Expert Consensus Report reaffirmed the value of long-term methadone treatment as an effective intervention for opiate dependence [4]. Yet, it is less clear whether medically supervised treatment without methadone or other pharmacological agents (i.e., drug-free programs) has Financial support: National Institutes of Health (grant DA-11606). The opinions of the authors do not necessarily reflect those of the New York State Department of Health. Reprints or correspondence: Dr. Barbara J. Turner, University of Pennsylvania, 1123 Blockley Hall/6021, 423 Guardian Dr., Philadelphia, PA (bturner@ mail.med.upenn.edu). Clinical Infectious Diseases 2003; 37(Suppl 5):S by the Infectious Diseases Society of America. All rights reserved /2003/3712S5-0023$15.00 similar favorable effects on patients outcomes. Because many patients in drug-free treatment abuse nonopiate drugs, such as cocaine, an assessment of the benefits of this care has relevance to regions of the world where cocaine abuse is prevalent. Both HIV-positive and HIVnegative drug users have drug-related medical and other conditions that prompt heavy use of emergency departments (EDs) and hospitals [5, 6]. This study probes the benefits of these 2 dominant forms of nonresidential drug treatment with regard to 2 types of services indicative of clinical instability: repeated ED utilization and hospitalization. METHODS We conducted a retrospective cohort study of drug users enrolled in the New York State Medicaid program from federal fiscal year 1996 through Data were from longitudinally linked claims for all ambulatory Drug Treatment and Hospital Use among IDUs CID 2003:37 (Suppl 5) S457

2 Table 1. Characteristics of a cohort of HIV-positive and HIV-negative drug users in New York State in Variable Demographic (n p 4569) No. (%) of study subjects, by long-term treatment received and HIV status Methadone Drug-free None (n p 11,370) (n p 126) (n p 1154) (n p 6861) (n p 34,163) Female Age in years! Area of residence New York City New York City suburbs Upstate urban Small city Rural Clinical Chronic diseases other than HIV infection Mental health disorder Health care Regular source of medical care HIV specialty care 68.9 NA 61.1 NA 57.4 NA NOTE. NA, not applicable. medical services from physicians and clinics as well as substance abuse services covered by the Medicaid program. These files contain information on inpatient, pharmacy, home health care, case management, and laboratory diagnostic services. We identified Medicaid claims associated with illicit drug use, HIV infection, and AIDS by means of previously reported and evaluated algorithms [7 9]. The operating characteristics of the algorithms for finding drug users and HIV cases are very good to excellent [6]. We identified drug users who were aged years in 1996 and enrolled in Medicaid for at least 10 months in 1996 ( n p 78,943). Of these drug users, 77,618 had 1 out- patient visit(s) in 1996 (required for analysis of patterns of care), 59,104 were enrolled in Medicaid for 10 months in 1997, but demographic data were available for 59,092. After excluding women who were pregnant in 1997, we studied a total of 58,243 persons. Study-dependent variables were 1 hospitalization in federal fiscal year 1997 and 2 ED visits during that year. Hospitalizations were determined from Medicaid claims for inpatient stays of 1 day. We considered repeated ED visits, as evidenced by claims on separate days, as our outcome, because 1 visit does not indicate excessive reliance on the ED for care [10]. ED claims made before a hospitalization were not included. By use of Medicaid claims in 1996, we classified drug users as having either long-term ambulatory drug treatment from a single methadone program or a medically supervised drug-free treatment program (as defined in New York State regulations, title 12 NYCRR, part 822, mental hygiene law, chemical dependence outpatient services) for at least 6 contiguous calendar months in 1996 or neither form of long-term drug treatment. We did not consider detoxification, residential, and non medically supervised ambulatory programs in this analysis so as to focus on the effects of medically supervised outpatient care. We applied a 6-month minimum criterion for the duration of drug treatment on the basis of evidence from studies of methadone and cocaine abuse treatment [11, 12]. Our final drug treatment categories included the following: long-term methadone maintenance treatment, long-term medically supervised drug treatment, and no long-term drug treatment. Some persons who received residential drug treatment may be included in the S458 CID 2003:37 (Suppl 5) Turner et al.

3 Table 2. Unadjusted association of health care delivery variables repeated emergency department (ED) use and hospitalization in 1997 for a cohort of HIV-positive and HIV-negative drug users in New York State. Percentage of study subjects, by repeated ED use, hospitalization, and HIV status Repeated ED use Hospitalization Health care delivery variable (n p 11,556) (n p 46,687) (n p 11,556) (n p 46,687) Overall proportion Long-term treatment a Drug-free 16.7 b 16.2 b 34.1 b 23.9 b Methadone None Regular source of medical care a No b b Yes HIV specialty care a No 25.5 NA 58.8 b NA Yes 24.7 NA 53.7 NA NOTE. NA, not applicable. a Proportions of each group receiving each type of treatment or care are shown in table 1. b P!.001; x 2 test. no long-term treatment group. Alternatively, some persons in the long-term treatment groups might have had previous residential care. A regular source of medical care was defined as a provider that was visited at least twice by a study patient during 1996 and that conducted 135% of all outpatient medical encounters with that patient in that same year [13]. These providers could be clinics, group practices, or individual physicians but excluded such health-care providers as radiologists and ED physicians. When 11 provider could be considered the regular source, we selected the regular medical provider according to a previously developed hierarchy of specialists [9]. For HIV-positive persons only, we identified any visits in 1996 to clinics or private physicians with an agreement with New York State to offer HIVrelated services and expertise in exchange for higher Medicaid payment rates or from a provider of infectious diseases care [14, 15]. Patient demographic data were obtained from claims and Medicaid eligibility files and included age, sex, and New York State area of residence (determined from zip codes). New York State Medicaid files do not contain reliable data on ethnicity. Data on the following comorbid conditions were also defined, on the basis of International Classification of Diseases, version 9, Clinical Modification codes, for inpatient and outpatient claims files in 1996: mental health disorders (e.g., depression, non drug-related psychoses, and anxiety), chronic diseases other than HIV infection (e.g., diabetes), and clinical AIDS (in the HIV-positive cohort). We calculated the total hospital days in 1996 as a proxy for unmeasured health status. Because of skewed distribution, we log-transformed these data and used quartiles of the log-transformed hospital days data as a categorical variable in our analysis. After examining bivariate associations between all covariates and 2 main end points repeated ED use and hospitalization we estimated multivariable logistic regression for each outcome in the HIV-positive and the HIV-negative groups. We wanted to use similar specifications of variables for the 2 groups but had to compromise between goodness-of-fit, as assessed by the Hosmer-Lemeshow statistic, and comparability of models. The Hosmer-Lemeshow statistics for the reported models for repeated ED use and hospitalization in the HIV-positive group were in the acceptable range (0.28 and 0.14, respectively), whereas in the HIV-negative group, the fit was not as good (0.07 and 0.01, respectively). Differing specification of some of the variables in the models did improve the fit. However, the effects of the key independent variable (i.e., drug treatment category) were consistent across all models in the HIV-positive and HIV-negative groups regardless of the specification of the other variables in the models. Therefore, we report models with similar specifications of the variables in both HIV status groups. Analyses were done with SAS software, version 8.0 (SAS Institute). RESULTS Among the 11,556 HIV-positive drug users, 39.5% were in longterm methadone treatment, 1.1% were receiving long-term, Drug Treatment and Hospital Use among IDUs CID 2003:37 (Suppl 5) S459

4 Table 3. Adjusted associations of health-care delivery, demographic, and clinical characteristics with repeated emergency department use in 1997 for a cohort of HIV-positive and HIVnegative drug users in New York State. Characteristic Adjusted OR (95% CI) Health care delivery Long-term treatment Drug-free Methadone 1.25 ( ) 0.95 ( ) None 1.65 ( ) 1.37 ( ) Regular source of medical care Yes 0.88 ( ) 1.22 ( ) HIV specialty care No 1.00 Yes 0.99 ( ) NA Demographic Sex Male Female 1.17 ( ) 1.02 ( ) Age in years! ( ) 1.00 ( ) ( ) 0.87 ( ) ( ) 0.76 ( ) Area of residence New York City New York City suburbs 1.21 ( ) 1.11 ( ) Upstate urban 1.42 ( ) 1.34 ( ) Small city 2.20 ( ) 1.98 ( ) Rural 1.80 ( ) 1.67 ( ) Clinical Chronic diseases other than HIV infection None ( ) 1.77 ( ) ( ) 2.08 ( ) ( ) 2.81 ( ) Mental health disorder Yes 1.07 ( ) 1.37 ( ) NOTE. Data also adjusted for log inpatient hospital days in NA, not applicable. medically supervised drug-free treatment, and 59.4% were receiving no longitudinal drug treatment, whereas among the 46,687 HIV-negative drug users, these proportions were 24.3%, 2.5%, and 73.2%, respectively. Even though the proportions of persons receiving long-term drug-free treatment are relatively small, roughly 125 HIV-positive and 1150 HIV-negative persons received this type of care. Comparison of the HIV-positive and HIV-negative groups is shown in table 1. In both groups, the most common drug of abuse diagnosed by health-care providers for persons in drug-free treatment was cocaine (30.2% and 23.5%, respectively) versus only 17.7% and 9.1%, respectively, for patients receiving methadone. However, usually the type of drug abuse or dependence was unspecified. Overall, 25% of the HIV-positive group used the ED repeatedly, compared with 22.1% of the HIV-negative group, and 55% of the HIV-positive group were hospitalized, compared with 37.5% of the HIV-negative group (table 2). In both groups, the drug treatment category was significantly associated with repeated use of the ED and hospitalization. Overall, persons not receiving long-term drug treatment were most likely to use these services. In the HIV-positive group, those receiving longterm methadone and drug-free treatment had similar rates of repeated ED use, whereas those receiving methadone were more likely to be hospitalized than persons in the drug-free treatment group. In the HIV-negative group, more-minor differences appeared. Other types of care generally showed less strong differences for both outcomes in both groups. Compared with persons receiving long-term, medically supervised drug-free treatment, the adjusted odds of using the ED repeatedly were significantly increased for persons without this care but similar for those receiving long-term methadone treatment (table 3). These findings held true for both HIVpositive and HIV-negative groups, but the benefit of treatment was weaker in the latter group. The presence of a usual source of medical care had opposite effects for HIV-positive and HIVnegative drug users, with lower adjusted odds for the former group and higher odds for the latter group. HIV specialty care showed no effect on repeated ED use. HIV-positive women were more likely to use the ED, but there was no effect with respect to sex in the HIV-negative group. Increasing age was negatively associated with ED use in both groups. In both groups, persons who lived outside of New York City were more likely to use the ED repeatedly. The adjusted odds of repeated ED visits rose with the number of non HIV-specific chronic conditions. Mental health disorders were associated with ED use only in the HIV-negative group. Persons receiving methadone treatment and those not receiving long-term drug treatment had significantly increased adjusted odds of hospitalization, compared with drug users receiving long-term, medically supervised drug-free treatment (table 4). This effect was strongest in the HIV-positive group. The adjusted odds of hospitalization for persons with a usual source of care was significantly lower for the HIV-positive group only, and HIV specialty care showed an independent protective S460 CID 2003:37 (Suppl 5) Turner et al.

5 Table 4. Adjusted associations of health-care delivery, demographic, and clinical characteristics with hospitalization in 1997 for a cohort of HIV-positive and HIV-negative drug users in New York State. Characteristic Adjusted OR (95% CI) Health care delivery Long-term treatment Drug-free Methadone 1.69 ( ) 1.16 ( ) None 1.91 ( ) 1.58 ( ) Regular source of medical care Yes 0.84 ( ) 0.99 ( ) HIV specialty care No 1.00 Yes 0.82 ( ) NA Demographic Sex Male Female 1.08 ( ) 0.84 ( ) Age in years! ( ) 1.18 ( ) ( ) 1.24 ( ) ( ) 1.22 ( ) Area of residence New York City New York City suburbs 1.00 ( ) 1.01 ( ) Upstate urban 0.91 ( ) 1.06 ( ) Small city 0.72 ( ) 0.94 ( ) Rural 1.15 ( ) 0.96 ( ) Clinical Chronic diseases other than HIV infection None ( ) 1.31 ( ) ( ) 1.50 ( ) ( ) 2.13 ( ) Mental health disorder Yes 1.07 ( ) 1.33 ( ) NOTE. Data also adjusted for the log of inpatient days in NA, not applicable. association of the same magnitude. The other effects observed in the model predicting hospitalization are of similar magnitude to those observed in the ED model. DISCUSSION Repeated ED use and hospitalization indicate poor clinical health status and, potentially, poor access to care. Many drug users receive medical care only when crises arise that require ED or inpatient care [16 20]. In our population-based cohort, we found significant reductions in the adjusted odds of both repeated ED use and inpatient care for both HIV-positive and HIV-negative persons receiving long-term drug treatment. These results expand our prior analyses that found a favorable association between reduced hospitalization and outpatient drug treatment and a usual source of medical care [6]. We found that drug users not receiving long-term drug treatment had consistently higher adjusted odds of ED and hospital care than did drug users receiving medically supervised drug-free treatment. Drug users receiving long-term methadone treatment had similar ED use but significantly higher adjusted odds of hospitalization than did persons in drug-free treatment. Cocaine was the most common type of drug abuse specified for persons receiving drug-free treatment. Use of cocaine use, particularly crack cocaine, is common in New York City [21] and accounts for a large number of ED visits in the United States [22]. Cocaine abuse is increasingly common in Canada [23]; in South America, it is most the common drug of abuse, and its use continues to rise [24, 25]. Injection of cocaine is a risk factor for HIV infection in South America [26], and cocaine abuse increases risky sexual practices [27]. Given the detrimental effects of cocaine on personal health and associated crime in the Americas [28 30], the identification of successful treatment strategies is a critical public health issue. In a US study of 1605 cocaine-dependent patients in residential and outpatient medically supervised drug-free treatment programs, relapse to weekly or more frequent use of cocaine was lowest for patients treated for 90 days [31]. Others report that day treatment is a clinically and economically effective alternative to residential treatment for many cocaine abusers [32, 33]. For cocaine-dependent patients in both long-term residential and outpatient drug-free treatment programs, it has been demonstrated that there are reductions in crime-related costs, compared with costs before entry into a treatment program [34]. In addition to cost savings, excessive demand for ED services by drug users may be addressed by accessible drug treatment [35]. We found that persons not receiving long-term drug treatment were 130% 60% more likely, depending on HIV status, to use the ED repeatedly. Our study focused only on ambulatory treatment for drug users. This form of care may be useful only for patients with less severe dependence. Although we studied drug treatment that lasted for 6 months, other investigators have reported improved outcomes after only 3 months of treatment [31]. The optimal duration of medically supervised drug-free therapy is Drug Treatment and Hospital Use among IDUs CID 2003:37 (Suppl 5) S461

6 not known, but current thinking on drug abuse treatment is leaning toward longer-term therapy [1]. HIV-positive drug users showed the most marked benefits of long-term drug treatment on our 2 outcomes. HIV-positive drug users rely heavily on inpatient care because of drug abuse related complications, HIV-related complications, and other non HIV-specific diseases. Others have argued that treatment programs are an integral part of any strategy to decrease hospital use among HIV-positive injection drug users [36]. In the HIV-positive group, having an HIV specialty provider was associated with a reduced rate of hospitalization. Perhaps this effect may reflect an improved clinical status of HIV-positive patients who receive care from persons with more HIV expertise, as has been reported by our group previously [37]. Limitations of our study include the fact that we did not have primary data on the types of drugs used by study patients. Second, long-term, medically supervised drug-free treatment was a relatively uncommon form of drug treatment in this cohort. Third, we did not study reasons for emergency department and hospital episodes. Hospitalization for detoxification may represent a positive health outcome. Finally, our data allow us only to speculate on the mechanisms by which long-term drug treatment decreases ED and hospital care. Given the paucity of data about addiction programs other than methadone maintenance programs, these data provide important evidence that medically supervised drug-free treatment is an effective option for the treatment of addiction to nonopiate drugs. Future studies should examine the mechanisms by which drug-free treatment achieves its benefits, the types of drug users who are better candidates for drug-free programs, the optimal duration of therapy, and the benefits of drug-free treatment on a wider range of health care outcomes. References 1. 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