Slowing the revolving door: stabilization programs reduce homeless persons' substance use after detoxification

Journal of Substance Abuse Treatment 24 (2003) 197 – 207

Regular article

Slowing the revolving door: stabilization programs reduce homeless persons’ substance use after detoxification Stefan G. Kertesz, M.D., M.Sc. a,*, Nicholas J. Horton, Sc.D. b, Peter D. Friedmann, M.D., M.P.H. c, Richard Saitz, M.D., M.P.H. d, Jeffrey H. Samet, M.D., M.A., M.P.H. e a

Divisions of Preventive Medicine and General Internal Medicine, Department of Medicine, University of Alabama at Birmingham, 1530 3rd Avenue South, MT608, Birmingham, AL 35294-4410, USA b Department of Mathematics, Smith College, 44 College Lane, Northampton, MA 01063, USA c Division of General Internal Medicine, Department of Medicine, Rhode Island Hospital and Brown Medical School, 593 Eddy Street, Multiphasic-138, Providence, RI 02903, USA d Section of General Internal Medicine (Clinical Addiction Research and Education Unit), Department of Medicine, Boston University School of Medicine and Department of Epidemiology, Boston University School of Public Health, and Boston Medical Center, 91 East Concord St, Suite 200, Boston, MA 02118, USA e Section of General Internal Medicine (Clinical Addiction Research and Education Unit), Department of Medicine, Boston University School of Medicine and Department of Social and Behavioral Sciences, Boston University School of Public Health, and Boston Medical Center, 91 East Concord St, Suite 200, Boston, MA 02118, USA Received 14 June 2002; received in revised form 25 November 2002; accepted 20 February 2003

Abstract This study examined whether homelessness predicted earlier resumption of substance use after detoxification, and sought evidence concerning the impact of post-detoxification stabilization programs among homeless and nonhomeless individuals. Kaplan-Meier plots and proportional hazards models were used to determine the association between homelessness, stabilization program use, and recurrent substance use in a prospective cohort of persons entering inpatient detoxification (n = 470). Among 254 persons available at 6 months, 76% reported recurrent substance use. Homeless persons not using stabilization programs experienced the highest hazard of return to substance use after detoxification, Hazard Ratio (HR) 1.26, 95% CI (0.88, 1.80). Homeless persons using these programs had the lowest rate of return to substance use: HR 0.61, 95% CI (0.40, 0.94). A similar impact of stabilization programs was not seen among nonhomeless subjects. Post-detoxification stabilization programs were associated with improved outcomes for homeless addicted persons. This treatment modality may slow the ‘‘revolving door’’ phenomenon of relapse after detoxification among homeless persons. D 2003 Elsevier Inc. All rights reserved. Keywords: Homeless persons; Addiction treatment utilization; Substance abuse; Stabilization programs; Relapse

1. Introduction Alcohol and drug dependence are common among the homeless (Burt et al., 1999; Fischer & Breakey, 1991) and have implications for health, mortality, and health service utilization (Burt et al., 1999; Gelberg, Andersen, & Leake, 2000; Gelberg, Stein, & Neumann, 1995; Hwang et al., 1998). Compared to nonaddicted peers, substance-abusing homeless persons are subject to higher risks of illness and death (Hibbs et al., 1994; Hwang et al., 1998; Wright & Weber, 1987). Addiction accounts for a major proportion of outpatient and hospital service utilization among the home* Corresponding author. 1530 3rd Ave South, MT608, Birmingham, AL 35294-4410, USA. Tel.: 205-934-2958; fax: 205-934-5979. E-mail address: [email protected] (S.G. Kertesz). 0740-5472/03/$ – see front matter D 2003 Elsevier Inc. All rights reserved. doi:10.1016/S0740-5472(03)00026-6

less (O’Toole, Gibbon, Hanusa, & Fine, 1999; Salit, Kuhn, Hartz, Vu, & Mosso, 1998), and predicts increased likelihood of seeking outpatient care (Padgett, Struening, & Andrews, 1990). Substance abuse also numbers among the vulnerabilities that may contribute to homelessness (Breakey, 1997; Jencks, 1994; McCarty, Argeriou, Huebner, & Lubran, 1991; Segal, 1991). Because of addiction’s major health and social implications in this particular population, policy responses to homelessness have placed special emphasis on substance abuse treatment. The McKinney Homelessness Assistance Act of 1987 (Public Law No. 100-77) directed funds to the National Institute on Alcohol Abuse and Alcoholism and the National Institute on Drug Abuse for evaluation of substance abuse treatment in the homeless (Orwin, GarrisonMogren, Jacobs, & Sonnefeld, 1999; Orwin et al., 1994;

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Stahler, Shipley, Bartelt, DuCette, & Shandler, 1995). Likewise, continuing federal programs on homelessness, exceeding $1 billion in 2001, emphasize a ‘‘continuum of care’’ linking housing support with services for other related needs such as substance abuse (United States Department of Housing and Urban Development, 2001). For addicted homeless persons in urban settings, inpatient detoxification programs represent an important point of entry to the addiction treatment system. Recurrent substance use following inpatient detoxification is common, however, and has been described as a ‘‘revolving door’’ phenomenon (Fagan & Mauss, 1978; Sadd & Young, 1987). Published reports convey both the severity of homeless persons’ addictions (Stahler & Cohen, 1995) and the impression that their treatment is likely to fail (Thomas, Kelly, & Cousineau, 1990). Based on popular expectation and published research, clinicians in detoxification settings may expect homeless clients to recur in their substance use earlier than other clients. Whether this expectation is truly justified, however, remains unclear. Our study posed the question, ‘‘Compared to nonhomeless substance abusers, do the homeless resume substance use sooner after detoxification?’’ To answer this question we examined a cohort recruited from a detoxification unit to assess the hypothesis on the basis of information that would ordinarily be known to clinicians working in the detoxification setting. In Massachusetts, placement in a post-detoxification stabilization program is one of the few treatment modalities that can be directly arranged by clinicians in the detoxification setting. A second goal, therefore, was to determine the impact of post-detoxification stabilization programs on the resumption of substance use among homeless and nonhomeless persons undergoing detoxification.

2. Materials and methods 2.1. Study design and population For this investigation we conducted a secondary analysis of baseline and 6-month followup data obtained prospectively from the cohort of patients enrolled in the Health Evaluation and Linkage to Primary care (HELP) trial. The results of the trial have been reported elsewhere (Samet et al., 2003). The HELP trial, conducted in a 35-bed inner-city short-term inpatient detoxification unit, was a randomized controlled trial of a multidisciplinary clinical session (the HELP intervention) designed to link substance abusing persons to outpatient primary medical care. Subjects randomized to the HELP intervention received a 90-min clinical session with a physician, nurse and social worker prior to leaving the detoxification unit, along with a customized appointment for primary medical care. Control subjects did not receive this intervention but were treated similarly in all other respects. Pre-enrollment and baseline

interviews took place between June 1997 and April 1999. The usual length of stay for a detoxification admission was 6 days for heroin dependence and 4 days for alcohol dependence. Eligibility criteria for the HELP trial included: (a) inpatient detoxification admission; (b) age greater than 17 years; and (c) report of alcohol, heroin or cocaine as the substances of first or second choice. Exclusion criteria were: (a) having a primary care provider and having seen that provider on at least one occasion in the preceding 2 years; (b) pregnancy; (c) Mini-Mental State examination (Folstein, Folstein, & McHugh, 1975) score less than 21; (d) lack of fluency in either English or Spanish; (e) less than three contacts available to facilitate followup; or (f ) specific plans to leave the Boston area within 24 months. Trained research associates identified 642 trial-eligible subjects 24 to 48 h after admission for detoxification, of whom 470 (73%) consented to be in the HELP trial. Research associates performed a 60 –90 min interview with all subjects prior to discharge. A followup interview was conducted with subjects 6 months after the baseline interview. Interviews were conducted in English or Spanish. The Spanish instruments were translated from the English, backtranslated by a different individual, reviewed for discrepancies and corrected. Subjects were modestly compensated for their time in the interview. The Institutional Review Board at Boston Medical Center approved this research. 2.2. Techniques to enhance followup We used exhaustive techniques to track subjects enrolled in the HELP trial over the followup period. These techniques included use of contacts designated by the subjects, appointment wallet cards, reminders by post and Federal Express, telephone calls, and van transportation to promote attendance at followup interviews. Subjects received supermarket certificates and a meal in compensation for their time. Homeless subjects were offered a hot shower, clean underwear, and socks. For subjects with children, we offered child care during the interviews. We made further efforts to locate subjects, including a regular computerized check of Boston Medical Center inpatient and appointment databases against our subject list. We reviewed detoxification unit daily census reports, contacted various state and local institutions, put up posters at residential treatment facilities and shelters, spoke with outreach teams and walked through public areas in Boston to look for our subjects. We also reviewed subjects’ files at the Boston Public Health Commission’s Substance Abuse Services Central Intake, a major triage site for substance abuse services, and put reminder cards in the files of study subjects. 2.3. Outcome variable For this secondary analysis of prospective trial data, the primary outcome variable was ‘‘time to first use of any substance,’’ (alcohol, heroin or cocaine) counted from the

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date of discharge from the detoxification unit. This variable was derived from each subject’s response to the following question, presented at the 6-month followup interview: ‘‘On what day did you first use (substance) after leaving the detox?’’ All subjects answered this question for alcohol, heroin and cocaine, and the shortest reported latency to substance use was taken to represent time to first use. 2.4. Explanatory variables The key explanatory variables of interest were homelessness and stabilization program use. Homelessness was defined as the subject’s self-report of having spent one or more nights either in a shelter or on the streets during the 6 months prior to detoxification. This definition corresponds to the concept of literal homelessness (Rossi, Wright, Fisher, & Willis, 1987). Subjects who spent no nights in these settings prior to baseline were defined as ‘‘nonhomeless.’’ While all comparative analyses include homelessness as a binary variable, we repeated Kaplan-Meier survival time curves after stratification of subjects by duration of homelessness (nonhomeless, 1– 6 nights, 7 – 21 nights, 22 –90 nights and 91 or more nights) to assess any effects specific to greater durations of homelessness. Exposure to a stabilization program, assessed at 6-month followup, was based on subject’s response to a questionnaire item presenting a list of known Boston area stabilization programs. Stabilization programs, which typically receive referrals directly from detoxification units, are voluntary, short-term, transitional facilities offering temporary treatment support and residence for 2 to 6 weeks while longerterm residential placement options are considered (Argeriou & McCarty, 1993). To varying degrees these support units offer case management, group meetings, discharge planning, and a requirement that clients remain sober while placement options are sorted out (Health & Addictions Research Inc., 2000). If subjects reported having spent one or more nights in a stabilization program since baseline detoxification, then they were considered exposed to a stabilization program. Race/ethnicity was categorized as African American, White, Hispanic and Other. Employment was based on the subject’s reported status during the 6 months prior to detoxification and was classified as Full-time vs. Part-time/School vs. None. Designation of each subject’s substance of choice was based on the subject’s report at the baseline interview. Additional control variables evaluated for inclusion in the multivariable analysis of recurrent use were drawn from existing relapse literature (Hore, 1971; Marlatt, 1996; McKay, 1999; Miller, Westerberg, Harris, & Tonigan, 1996; Pickens, Hatsukami, Spicer, & Svikis, 1985; Rubin, Stout, & Longabaugh, 1996; Vaillant, 1988), and discussion with experienced clinicians. These variables included depressive symptoms, as reflected by CES-D (Center for Epidemiological Studies-Depression) score (Radloff, 1977), and self-reported receipt of a psychiatric medication prescription in their lifetime. Addiction severity was defined on

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the basis of the drug and alcohol composite scores of the Addiction Severity Index (ASI/d and ASI/a; McLellan et al., 1992), while the ASI Medical composite score represented health status (ASI/m). Motivation for sobriety was determined using the ‘‘Taking Steps’’ scale of the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) questionnaire, and for multivariable analysis subjects were coded with respect to their decile of performance on this scale (Miller & Tonigan, 1996). A history of sexual or physical abuse was based on the subject’s response to questions seeking a lifetime history of exposure to either type of abuse (Liebschutz et al., 2002). Exposure to jail or prison was treated as a binary variable based on spending any nights in jail during the 6 months preceding detoxification. We identified subjects as ‘‘exposed to a sobriety-threatening social environment’’ if they reported that (a) a live-in partner abused drugs or alcohol, or (b) half or more of the persons in the subject’s immediate social environment drank alcohol or used drugs. We obtained these reports from the baseline interview. Lastly, because this study made use of data obtained in a randomized controlled trial of the HELP intervention, trial assignment group (linkage intervention vs. usual care) was included as a potential explanatory variable. 2.5. Analysis We first characterized the study sample, then fitted bivariate and multivariable models relating the two explanatory variables (homeless status, stabilization programs) to the outcome of time to first recurrent substance use. Because the principal outcome (time to first use of any substance) represented time-to-event data, our analyses used KaplanMeier survival estimates and Cox proportional hazards models (Collett, 1994). All analyses were run using SAS statistical software (SAS Institute Inc., 2001). 2.5.1. Sample characterization To characterize the sample, homeless and nonhomeless subjects were compared with regard to sociodemographic variables, substance of choice, and the baseline variables specified above (and specified in Table 1). We used Fisher’s exact test for comparison of categorical variables, and the Wilcoxon test for continuous variables. 2.5.2. Recurrent substance use Characterization of median time to recurrent use was based on the number of days by which 50% of the followup sample had resumed substance use. To test our primary hypothesis that pre-detoxification homelessness would predict earlier resumption of substance use, we calculated the Kaplan-Meier survival estimate for the outcome of time to first use of any substance in order to compare homeless and nonhomeless subjects. We used the Log Rank test to compare survival estimates for homeless and nonhomeless subjects. We also used Kaplan-Meier and Log Rank test calculations to determine whether time to first use of the

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Table 1 Characteristics of detoxification subjects recruited from 6/97 to 4/99, stratified by homelessa status Variable Age (yrs) Male % Race % African American White Hispanic Other Employed % Fulltime Part-time Jail, past 6 mos % Substance of choiceb Alcohol % Cocaine % Heroin % Depressive symptomsc Psych Medd % ASI/druge ASI/alcohole ASI/medicale SOCRATESf Past history of abuse %g Social sobriety threat %h Stabilization program use post-detoxification %

Homeless (n = 219)

Nonhomeless (n = 251)

36.5 81

35.1 73

40 43 10 6.4

52 31 12 5.6

34 18 38

48 18 24

50 28 22 34.1 32 0.24 0.55 0.38 35.4 73 81 43

30 38 31 31.8 20 0.26 0.41 0.33 36.2 71 69 32

p .05 .04 .03

.007

< .001 < .001

.02 .006 .30 < .001 .11 .05 .68 .002 .09

Adapted with permission from S.G. Kertesz, Influence of Homelessness and Stabilization Programs on Recurrent Substance Use After Detoxification, unpublished master’s thesis, Boston University, p. 11, n2002, Stefan G. Kertesz. a Homeless defined by 1 or more nights spent on the streets or in shelters during the 180 nights prior to study entry. b Substance of choice was defined on basis of subject’s self-report at time of initial screening (see Methods). One subject defined ‘‘marijuana’’ as the substance of choice and is not included. c Depressive symptoms, using the Center for Epidemiologic Studies Depression Scale (Radloff, 1977). d Drug, alcohol and medical composite scores of the Addiction Severity Index (McLellan et al., 1992). e Subjects responding ‘‘yes’’ to receipt of prescription for psychiatric medication during the course of their lifetime. f SOCRATES = Raw score on the ‘Taking Steps’ scale from the Stages of Change Readiness and Treatment Eagerness Scale instrument (Miller & Tonigan, 1996). g Past history of abuse was based on the subject’s response to questions seeking a lifetime history of exposure to physical or sexual abuse. h A social sobriety threat was based on subject’s characterization of alcohol or drug use by at least one person with whom they spent substantial amounts of time.

substance of choice differed depending on whether alcohol, cocaine or heroin was the substance of choice. We then developed a multivariable proportional hazards regression model for the outcome of time to first use of any substance. We pre-specified seven explanatory variables for inclusion in the multivariable model: homelessness, stabilization program use, as well as age, gender, race/ethnicity, substance of choice, and subjects’ trial arm assignment within the HELP trial. We used bivariate proportional

hazards (Cox) regression to test all other proposed explanatory variables for inclusion in the multivariable proportional hazards model. Two variables met a p-value criterion of < .10 (SOCRATES score, and Employment status), and were therefore included. Because we anticipated that exposure to stabilization programs might have distinctive implications for homeless persons, we constructed the multivariable model to include a term for the interaction of homelessness and stabilization program exposure. No other interaction terms were specified. 2.5.3. Analyses of availability vs. nonavailability At 6 months, 254 out of 470 subjects were available for followup evaluation. We performed comparisons to assess whether the 254 subjects available at 6 months could be considered representative of the original 470 persons in the HELP trial cohort. These comparisons drew on (a) information collected at baseline (available for all 470 subjects), (b) research interviews occurring at 12, 18, and 24 months (available for 344 of 470 subjects), and (c) administrative records of addiction treatment utilization (available for all 470 subjects). First, subjects who were available and unavailable at 6 months were compared with respect to approximately 100 baseline variables, including sociodemographic characteristics, homelessness, measures of substance use (McGovern & Morrison, 1992; Skinner & Horn, 1984), addiction severity (McLellan et al., 1992), substance use consequences (Tonigan & Miller, 2002), addiction treatment utilization, health status (Ware, Kosinski, & Keller, 1994), mental status (Folstein et al., 1975), depressive symptoms (Radloff, 1977), medical care, medical care utilization and other parameters (full list available from authors). To partially account for multiple comparisons, we applied a significance criterion of p < .01 to these tests. Additionally, 344 subjects were available for planned followup at 12, 18 or 24 months (73% of the total sample). Within this group, 135 had not been available for evaluation at the 6-month time point, and 209 had completed both a 6-month evaluation and one of the subsequent evaluations. To assess whether subjects unavailable at 6 months had experienced worse addiction outcomes, we compared subjects who had been available at 6 months (n = 209) to those unavailable at 6 months (n = 135) with respect to the first post-6 month Addiction Severity Index drug and alcohol composite scores. Finally, all research subjects (n = 470) were matched to administrative treatment records of the Massachusetts Bureau of Substance Abuse Services, which include all treatment episodes occurring in facilities that accept any public payment source. We compared available and unavailable subjects with respect to use of inpatient detoxification during the initial 6-month followup period in order to further assess whether outcomes were worse for subjects who had not been available at 6 months.

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2.5.4. Secondary analyses As part of additional, post-hoc exploratory analyses undertaken because of observed baseline differences between homeless and nonhomeless subjects, we compared time to first use for homeless and nonhomeless subjects after stratification by employment status, and after stratification by substance of choice.

3. Results 3.1. Sample characterization Of 470 subjects, 219 (47%) met the study definition for homelessness, and the rest were categorized as ‘‘nonhomeless.’’ The number of homeless nights defining the 25th, 50th and 75th percentiles were 5, 21, and 90 nights, respectively. Differences between homeless and nonhomeless subjects are reviewed in Table 1. Homeless subjects were slightly older, more likely to be male, white, and not employed fulltime, compared to nonhomeless subjects. In addition to employment status, the homeless attained more unfavorable scores on other parameters including depressive symptoms and alcohol addiction severity. The homeless subjects more often identified alcohol as their substance of choice (50% of homeless subjects) compared to the nonhomeless, for whom

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cocaine was the most commonly identified substance of choice (38% of nonhomeless subjects). Additionally, 62% of homeless subjects and 51% of nonhomeless subjects reported a second substance of choice, with the most common combination involving alcohol and cocaine, reported by approximately one third of both homeless and nonhomeless subjects. Within the followup cohort, homeless subjects were slightly more likely to have used a stabilization program after their detoxification (43% vs. 32%, p = .09). Six-month interviews were completed in 54% (254/470). Complete information concerning recurrent substance use was available for 252 subjects, who form the basis for most analyses below. Compared with those subjects unavailable at 6 months, available subjects did not differ with respect to homelessness reported upon entry into the trial. Of 100 other baseline variable comparisons between subjects available and unavailable at 6-month followup, none were significant. We used addiction outcomes and administrative records of treatment utilization to further evaluate the potential for selection bias within the cohort interviewed at 6 months. Three hundred forty-four individuals completed an interview at 12, 18, or 24 months (73% of the entire study sample, including 135 who had been unavailable at 6 months). Composite ASI drug scores were similar among subjects who had been available and unavailable for the

Fig. 1. Time to first use for homeless vs. nonhomeless subjects. Comparative survival curves for time to first recurrent use of any substance, for subjects identified as nonhomeless or homeless prior to baseline detoxification.

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6-month interview (0.13 vs. 0.14, respectively, p = .27). Composite ASI alcohol scores, however, were worse among subjects who had not been available at 6 months (0.32 vs. 0.24, p = .007), suggesting that 6-month nonavailability could have been associated with worse alcohol outcomes. Our review of statewide administrative records of addiction treatment utilization captured 100% of the index detoxification admissions for study subjects. We found no difference in the proportion of subjects readmitted to detoxification units (65% of available subjects, 67% of unavailable subjects, p = .62). 3.2. Recurrent substance use At 6 months, 76% of subjects reported recurrent substance use, at a median of 31 days after leaving detoxification. The initial comparison of nonhomeless and homeless subjects did not show a difference in time to recurrent use ( p = .74 by Log Rank test, Fig. 1). Recurrent substance use was reported by 77% and 75% of nonhomeless and homeless subjects, respectively. Additionally, time to recurrent use did not differ when subjects were stratified by length of time homeless ( p = .96). Time to recurrent use of the subjects’ substance of choice did vary by substance, with a median of 59, 92, and 14 days for recurrent use of alcohol, cocaine, and heroin respectively ( p = .02). Following the first resumption of use, the median duration of continuous daily use was 3 days for alcohol, 4 days for cocaine, and 14 days continuous use for heroin. In the multivariable regression model to analyze the principal outcome of time to first use of any substance, a term for the interaction between homelessness and stabilization program exposure proved significant (Hazard Ratio [HR] = 0.52, 95% CI 0.28, 0.99) (Table 2). Analysis of Kaplan-Meier curves defined jointly by homeless and stabilization program exposure status showed that the homeless subjects exposed to stabilization programs remained abstinent the longest. Homeless subjects not using these programs experienced the highest rate of return to use ( p = .004 for comparison across all 4 curves). These effects persisted across the 6-month followup period (Fig. 2). Relative to nonhomeless subjects who did not use stabilization programs, the calculated hazard ratio for recurrent use among homeless subjects using stabilization programs was 0.61 (95% CI 0.40, 0.94), and it was 1.26 (95% CI 0.88, 1.80) among homeless subjects not using stabilization programs. A hazard ratio of 0.92 (95% CI 0.60, 1.42) was seen among nonhomeless subjects who used stabilization programs. Because the outcome of recurrent use differed markedly between homeless persons using stabilization programs and homeless persons who had not used these programs, we compared these two groups with respect to all baseline variables shown in Table 1 (post-hoc). Because of stabilization programs’ putative role in connecting clients to longerterm residential treatment, we also compared these two

groups with regard to use of residential treatment during the 6 months after baseline detoxification (e.g. a list of Boston-area therapeutic communities and ‘‘half-way houses’’ presented on the 6-month interview instrument). Compared to homeless persons not using stabilization programs, homeless stabilization program users were more likely to report alcohol as their substance of choice (58% vs. 41% among homeless persons not using stabilization programs), and less likely to report heroin as their substance of choice (11% vs. 29%, p = .05 for comparison across the three substances of alcohol, cocaine, or heroin). Residential treatment use also differed markedly between the two groups. At 6 months, homeless persons using stabilization programs were more likely to have gone to a residential treatment program (79%) compared to homeless persons who had not made use of stabilization program (49%, p < .0001). 3.3. Secondary analyses Although our main planned regression model included substance of choice as an explanatory variable and demonstrated no effect of that variable on recurrent use, the difference in time to first use between groups defined by substance of choice led us to pursue an exploratory post-hoc

Table 2 Results from multivariable proportional hazards regression model for predictors of recurrent substance use after detoxificationa Variable

HR

95% CI

Homeless Stabilization program use post-detoxification Homeless & Stabilization program use Interaction Age Sex Male Female Race/Ethnicity African American White Hispanic Other Employment Fulltime Part-time/Student Substance of choice Alcohol Cocaine Heroin SOCRATESb Randomized to HELP linkage intervention

1.26 0.92 0.53 1.0

(0.88,1.80) (0.60,1.42) (0.28,0.99) (0.98,1.01)

1.0 0.75

(0.52,1.08)

1.0 0.80 0.74 1.05

(0.55,1.17) (0.43,1.27) (0.57,1.94)

0.73 0.82

(0.52,1.03) (0.55,1.22)

1.0 0.91 1.45 1.0 0.92

(0.62,1.35) (0.98,2.13) (0.99,1.00) (0.68,1.23)

Adapted with permission from S.G. Kertesz, Influence of Homelessness and Stabilization Programs on Recurrent Substance Use After Detoxification, unpublished master’s thesis, Boston University, p. 15, n2002, Stefan G. Kertesz. a All listed predictors were included in a multivariable proportional hazards regression using the outcome time to recurrent substance use. HR indicates hazard ratio; CI, confidence interval. b SOCRATES = Raw score on the ‘Taking Steps’ scale from the Stages of Change Readiness and Treatment Eagerness Scale instrument (Miller & Tonigan, 1996).

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Fig. 2. Time to first use by homeless status (homeless/nonhomeless) and post-detoxification stabilization program use (Yes/No). Comparative survival curves for time to first recurrent use of any substance, for subjects categorized by homeless status prior to baseline detoxification and by exposure to stabilization programs following detoxification.

analysis. In this analysis we repeated the regression model on the outcome of time to first use after stratification by substance of choice. With this approach we found that compared with the nonhomeless, homelessness was associated with earlier first use among subjects whose substance of choice was alcohol (HR = 1.92, 95% CI 1.10,3.35), later first use among subjects with heroin as their substance of choice (HR = 0.47, 95% CI 0.23,0.95), and no difference between homeless and nonhomeless subjects for whom cocaine was their substance of choice (HR = 1.58, 95% CI 0.84, 2.97). This result suggests that associations between homelessness and recurrent substance use may vary by substance of choice. We found no difference between homeless and nonhomeless subjects in analyses stratified by employment status (data not shown).

stabilization programs mitigated the risk for recurrent substance use. Homeless persons using these programs returned to use at a rate as low as, or lower than that of nonhomeless subjects. By contrast, a comparison of nonhomeless and homeless subjects that did not take post-detoxification stabilization programs into account identified no difference between homeless and nonhomeless subjects for the outcome of recurrent substance use (as displayed in Fig. 1). Although stabilization program admissions typically last from 2 to 6 weeks, the differences in outcomes remained evident at 6 months (Fig. 2). No similar difference was seen among nonhomeless subjects. In short, this observation suggests that where the homeless person goes after completing inpatient detoxification has important prognostic implications. 4.1. Stabilization programs and time in treatment

4. Discussion Our data demonstrate that homeless persons not using stabilization programs experienced the highest risk of returning to substance use after detoxification (Fig. 2). Such persons move most rapidly through the ‘‘revolving door’’ at detoxification centers (Fagan & Mauss, 1978; Sadd & Young, 1987). Among the homeless, however, the use of

Our finding of an apparent beneficial effect of stabilization programs on recurrent substance use agrees with a 1986 review that, while largely skeptical of inpatient alcoholism treatment, held out that ‘‘pragmatic and humanitarian reasons’’ may justify residential treatment for homeless alcoholics (Miller & Hester, 1986). It may also be consistent with a prior report that among homeless and near-homeless

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subjects who entered a stabilization program, recurrent detoxification admissions were delayed for those persons who completed the program (Argeriou & McCarty, 1993). Stabilization programs per se have received little attention in the literature, in part because they are not typically considered a form of treatment. They are more often viewed as sober environments to ‘‘hold’’ the addicted person while sorting out placement options after brief 3– 5 day stays in medically supervised detoxification programs. The logistical need for such intermediate facilities led the Massachusetts Bureau of Substance Abuse Services to formally invest in 212 transitional program beds in FY1999 (Brolin, 2000), with statewide investment in this program growing to 8.3 million dollars in the 2001 fiscal year (Personal communication, Teresa Anderson, PhD, Director of Research and Evaluation, Massachusetts Bureau of Substance Abuse Services). Effectiveness data, however, are sparse (Argeriou & McCarty, 1993). One way to interpret this study’s finding of an association between stabilization programs and delayed substance resumption among the homeless is to suggest that many homeless persons do require special interventions to help them stay connected to treatment in the days following detoxification. The competing priorities of daily life (shelter, food, transportation) have been shown to impede homeless persons’ engagement in medical care (Gelberg, Gallagher, Andersen, & Koegel, 1997). These same pressures may confer on the homeless a special vulnerability to disruptions of substance abuse treatment pursued on a nonresidential basis. Time in treatment is of unquestioned value to homeless and nonhomeless addicted persons alike (Liberty et al., 1998; Simpson, 1979; Stahler et al., 1995). By staving off the particularly intense demands of homelessness, the stabilization programs in this study may have protected treatment engagement at a crucial juncture for some homeless addicted persons. Our analysis supports this explanation. While this study did not attempt to comprehensively model all post-detoxification treatment usage, we did note greater use of formal residential treatment programs such as therapeutic communities and halfway houses among those homeless persons who had gone to a stabilization program compared to homeless persons who had not (79% vs. 49%, p < .0001). In short, our findings suggest that for addicted homeless persons, stabilization programs probably accomplish exactly what they are supposed to do, which is to facilitate placement into longer-term residential treatment programs. Our findings, however, do not explain why such benefit was not evident among nonhomeless subjects. 4.2. Homelessness and relapse Other studies have touched on the prognostic implications of homelessness for substance abuse treatment. For instance, O’Brien’s finding of 100% treatment dropout rates among homeless cocaine-addicted persons (O’Brien, Alterman,

Walter, Childress, & McLellan, 1989) led Milby et al. (1996) to propose, ‘‘There is something about homelessness which compromises a substance abusing person’s ability to favorably respond to treatment.’’ Likewise Vaillant (1988) identified ‘‘skid-row social adjustment’’ as portending worse prognosis in a 12-year alcoholic cohort. In contrast, one study found that pre-treatment housing status did not predict the endpoints of reduced alcohol or cocaine use 6 months after completing a program. That study, however, combined homeless subjects who underwent residential and nonresidential forms of treatment (Stahler et al., 1995). In this report, the interaction between homelessness and stabilization program use suggests that homelessness does portend a worse outcome for homeless individuals who do not continue on to stabilization programs after detoxification. 4.2.1. Lapse and relapse This study’s operational definitions of both the outcome and explanatory variables should qualify the interpretation of its findings. The outcome of time to recurrent use, which is a ‘‘lapse’’ in theoretical literature (Marlatt & Gordon, 1985), does differ from other relapse-related outcomes such as treatment program retention (O’Brien et al., 1989), long-term abstinence (Vaillant, 1988), and reduced substance use at 6 months (Stahler et al., 1995). The prognostic implications of homelessness could vary for these alternative endpoints. Nonetheless, as the necessary precursor to relapse, the initial lapse merits attention. Although reports describe an important minority of addicted persons who quickly return to abstinence following a lapse, the majority does not follow this pattern (Gossop, Green, Phillips, & Bradley, 1989; Pickens et al., 1985). In this study, most lapses resulted in at least several days of continued use. While we concur with Miller (Page S24; 1996), who has criticized the clinical application of a dichotomous relapse concept due to the ‘‘longitudinal complexity of addictive behaviors,’’ we regard the analysis of recurrent substance use as an informative mechanism for clarifying factors important to supporting sobriety among persons at risk. 4.2.2. Homelessness This study’s definition of homelessness should also frame its interpretation. Homeless status was based on one or more nights spent on the streets or in shelters during the 6 months preceding inpatient detoxification. A restriction to the use of streets or shelters corresponds to an established notion of ‘‘literal homelessness,’’ (Link et al., 1995; Rossi et al., 1987) but does not include subjects who would qualify as homeless due to doubling-up, and/or uncertainty as to how long they might prevail on family or friends for shelter. The derivation of homeless status based on as little as a single night is not unlike that deployed in some studies, but typically the ‘‘night’’ in these other studies was the night before the interview (Gelberg, Doblin, & Leake, 1996;

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Gelberg, Linn, Usatine, & Smith, 1990; Robertson, Zlotnick, & Westerfelt, 1997). Stratification by length of time homeless, however, did not alter our finding that time to first use remained similar between subjects regardless of the number of homeless nights. Additionally, we must stress that the present study operationalizes homelessness from data available at baseline detoxification (Shiffman, 1989). This approach avoids the problem of attempting to infer a causal relationship between post-detoxification homelessness and post-detoxification substance use. 4.3. Limitations and strengths A limitation to this study lies in the percentage of subjects available at 6 months (54%), which means that we cannot exclude the possibility that explanatory variables we studied could have operated differently among persons unavailable for 6-month interview. The challenge to longitudinal followup of substance abusers is well known. A detailed examination of the relationship between ease of followup and addiction outcomes in a 654-person cohort of addicted persons presenting for treatment found that addiction outcome models based on the 60% of the sample who were most easily located differed only minimally from models that included the 90 –100% of subjects ultimately found (Hansten, Downey, Rosengren, & Donovan, 2000). The authors suggest cautious appraisal, rather than dismissal, of substance abuse cohorts with significant numbers of nonavailable subjects. In the present study, extensive baseline data, administrative treatment use reports (available for 100% of subjects) and post-6 month interviews (73% of subjects) permitted us to assess the potential for followup bias. We conclude that the 6-month cohort is likely to be representative of the entire cohort studied, as 100 baseline characteristics, subsequent detoxification utilization, and post-6 month ASI drug (but not alcohol) use outcomes were similar regardless of availability at 6 months. Where a single difference was found (the post-6 month ASI alcohol score), scores were similarly worse among unavailable homeless and nonhomeless subjects. We acknowledge that a differential attrition of ‘worse’ alcoholics could have biased our estimates concerning the overall proportion of subjects who experienced recurrent use. This particular attrition effect, however, is unlikely to account for our findings concerning the relative likelihood of recurrent use among homeless and nonhomeless subjects using and not using stabilization programs. The pattern of differential loss to followup required to artifactually produce the interaction between homelessness and stabilization program use observed in this study may be less plausible. A separate limitation is that reliance on subject’s selfreport of substance use introduces the possibility of misclassification due to failure of subjects to volunteer accurate information, although the literature offers conflicting impressions on whether subjects systematically misstate this

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information (Appel et al., 2001; Harrell, 1985; Stephens, 1972). In this study, acknowledgments of recurrent substance use by over 70% of subjects makes a reluctance to report seem unlikely. Additionally, a pattern of differential recall bias sufficient to account for the observed interaction between homelessness and stabilization program use is improbable. A necessary qualification to this study is that it does not exclude the possibility of specific poor-prognosis or goodprognosis subgroups among nonhomeless or homeless persons seeking detoxification. While our main regression model did not find a main effect of substance of choice on the outcome of time to first use, exploratory analyses suggested the possibility of differences between homeless and nonhomeless subjects depending on the designated substance of choice. For example, 17 of 108 homeless alcoholics reported first use on the day they left the detoxification program, in contrast to 2 out of 62 nonhomeless alcoholics. The risks specific to this particular subgroup of homeless alcoholic early-lapsers remain unclear from the data at hand, and could reflect a range of factors unmeasured in the present study, ranging from coping skills and self-efficacy, to early or unsuccessful detoxification discharge (Gordon et al., 2001), or even specific factors related to substance access. Similarly the present methodology did not attempt to assess whether polysubstance abuse carried distinctive prognostic implications. Such qualifications underscore the importance of not presuming homogeneity among subjects identified as ‘‘homeless’’ at baseline, and reinforce the need for further study. This study’s strengths lie in the size of the cohort, the broad range of psychosocial information systematically collected at a similar point in the course of each subject’s substance abuse history, and the high representation of subjects with histories of homelessness. Our statistical controls for substance of choice, addiction severity, motivation, employment, and depressive symptoms, in addition to the customary sociodemographic variables, reduces the likelihood of confounding. 4.4. Conclusions The high prevalence of substance abuse among the homeless warrants particular attention, as this problem contributes to illness and death, and may perpetuate homelessness itself (Breakey et al., 1989; Burt et al., 1999; Fischer & Breakey, 1991; Hibbs et al., 1994; Hwang et al., 1998; Koegel & Burnam, 1988). Continued high numbers of homeless individuals (Burt, Aron, Lee, & Valente, 2001) lend special urgency to the search for effective interventions. This study found that among homeless subjects, exposure to post-detoxification stabilization programs was associated with a reduced risk of recurrent substance use. Homeless subjects not accessing these programs did poorly. A similar contrast was not seen among nonhomeless subjects. The present study supports the use of post-detoxification interventions for a vulnerable population, the homeless.

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Acknowledgments We gratefully acknowledge the assistance of Michael Winter in the preparation of analyses, and the insight of Denise Petrella concerning the role of stabilization programs. We thank the staff of the HELP study for their help in the conduct of this research. Primary grant support for the HELP study came from the National Institute on Drug Abuse (R01-10019) and the National Institute on Alcohol Abuse and Alcoholism (R0110870). Dr. Kertesz was funded by an Institutional National Research Service Award Grant. Drs. Friedmann and Saitz receive support as Generalist Physician Faculty Scholars of the Robert Wood Johnson Foundation. Dr. Friedmann was also supported by National Institute on Drug Abuse grants 5K08-00320 and R01-13615. This research was conducted in part in the General Clinical Research Center at Boston University School of Medicine, USPHS grant M01 RR00533. A limited portion of these findings was presented, in abstract form, at the annual meetings of the Society of General Internal Medicine (San Diego, 2001), the College on Problems of Drug Dependence (Scottsdale, 2001), and the National Research Service Award Trainees’ Meeting (Atlanta, 2001).

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