Initiating abstinence in cocaine abusing dually diagnosed homeless persons

DEPENDENCE ELSEVIER

Drug

and Alcohol

Dependence

60 (2000) 55-67 www.elsevier.com/locate/drugalcdep

Initiating

abstinence in cocaine abusing dually diagnosed homeless persons

Jesse B. Milby * Division

of Preventive

,

Medicine,

Joseph E. Schumacher, Cecelia McNamara, Dennis Stuart Usdan, Troy McGill, Max Michael 2 401 Medical

Towers,

The University Accepted

of Alabama

26 October

at Birmingham,

Birmingham,

Wallace l,

AL 352944410,

USA

1999

Abstract This study measured effectiveness of behavioral day treatment plus abstinence contingent housing and work therapy (DT + ) versus behavioral day treatment alone (DT). A randomized controlled trial assessed participants at baseline, 2 and 6 months. Participants (N = 110) met criteria for cocaine abuse or dependence, non-psychotic mental disorders, and homelessness. DT + achieved greater abstinence at 2 and 6 months and more days housed at 6 months than DT. Effectiveness of DT + was demonstrated, with greatest impacts on abstinence outcomes. Results replicated earlier work demonstrating effectiveness of behavioral day treatment and contingency management as an effective combination for cocaine abusing homeless persons. 0 2000

Elsevier Science Ireland Ltd. All rights reserved. Keywords:

Substance

abuse;

Cocaine;

Treatment;

Homeless;

Dual diagnosis

1. Introduction American surveys estimated 3 000 000 persons were homeless during 1993, with 600 000 homeless any particular night (Cable News Network, 1994), and 13 500 000 homeless during their lifetime, with 3.1% (5.7 million) of the US population homeless between 1985 and 1990 (Link et al., 1994). High prevalence of alcoholism and other substance abuse among homeless persons is well established (Corrigan and Anderson, 1984; Koegel et al., 1988; Rosenheck et al., 1989; Rahav and Link, 1995; Rahav et al., 1995). An analysis of variables predicting homelessness among veterans found substance abuse accounted for the greatest variance (Rosenheck, 1994). Another study of homelessness using a random sample comparison of housed poor, found currently homeless were almost twice as likely to have a lifetime diagnosis of substance abuse as those never homeless (Toro et al., 1997). Those previously * Corresponding author. Tel.: + l-205-934-8960; fax: + 1-205-9756153. E-mail address: [email protected] (J.B. Milby) ’Present address: Kansas University Medical School. ’ Also at Birmingham Health Care for the Homeless Coalition. 0376-8716/00/$ - see front PII: SO376-8716(99)00139-S

matter

0 2000 Elsevier

Science Ireland

homeless had a higher rate of substance abuse than those never homeless. Toro and Wall (1991) also found first homelessness episodes usually followed first serious symptoms of substance abuse. Drug abuse declined in the US among young adults, and first time use of cocaine declined from 1991 to 1997, but after dropping from a peak of 3.9% in 1987 to 1.5% in 1991, crack cocaine use among high school seniors has risen again to 2.4% in 1997 (National Institute on Drug Abuse [NIDA], 1991, 1998). While cocaine use dropped among high school seniors, crack emerged as a major abused drug among young homeless persons (Raczynski et al., 1993). With the exception of National Institute of Alcoholism and Alcohol Abuse research demonstrations, typical treatment for substance abusing homeless persons has emphasized intervention for substance abuse or homelessness, rarely addressing both with equal attention and intensity (Stahler, 1995). Typical approaches targeting homelessness rely on inter-agency consultation and coordination for a network of services provided at multiple sites (McCarty et al., 1991). Two effective outpatient interventions for cocaine abuse have emerged from clinical research: a day treat-

Ltd. All rights

reserved.

56

J.B. Milby et al. /Drug and Alcohol Dependence 60 (2000) 55-67

ment model (O’Brien et al., 1989; Washton and Stone-Washton 1990; Wallace, 1991; Milby et al., 1996a) and a contingency management behavioral therapy program (Higgins et al., 1991, 1994; Carol1 et al., 1994; Silverman et al., 1996). But controlled outcome studies on cocaine dependence treatment are scarce. Investigators could find only four published, controlled clinical trials which have shown effective treatment for cocaine dependence (Higgins et al., 1991, 1994; Carol1 et al., 1994; Milby et al., 1996a; Silverman et al., 1996). However, only Milby et al. (1996a) reported success with cocaine abusing homeless. It is likely that O’Brien et al.‘s (1989) homeless patients discontinued day treatment found effective for non homeless cocaine abusers because they did not receive homelessness interventions found sufficient for retention and treatment response by Milby et al. (1996a). In a two group, randomized, controlled trial, Milby et al. (1996a), compared usual care of once weekly individual and group counseling to substance abuse day treatment which included unique interventions for homelessness in addition to substance abuse. Interventions included transportation to and from shelters, lunch, and abstinence contingent housing and work therapy. On three of four major outcomes, alcohol, drug use, and homelessness, day treatment produced significantly better results than usual care. This research led investigators to refine day treatment structure, including a modest whereby program voucher system adapted from Higgins et al. (1991), provided exposure to a rich density of non-drug related reinforcers. This modified day treatment was utilized as a new usual care control (DT), where patients were treated at the same time and place, and in the same groups by the same counselors as the experimental group in order to control for common threats to internal validity (Campbell and Stanley, 1963). In the experimental group (DT + ), abstinence contingent housing was utilized as a reinforcer during day treatment in addition to abstinence contingent work and housing access following day treatment, used previously. This study addressed the ultimate question: What are the necessary and sufficient conditions to initiate abstinence and to most effectively treat dually diagnosed, homeless, cocaine abusing persons? Its main objective was to determine if, in addition to day treatment, innovative interventions for homelessness, i.e. abstinent contingent housing and work therapy, adapted from earlier research (Milby et al., 1996a), would produce greater improvement. The main hypothesis was that abstinent contingent housing and work, with day treatment, would yield better treatment outcomes than day treatment alone.

2. Method

2.1. Purticipan ts Participants were recruited from the largest health care agency for homeless persons in Alabama, Birmingham Health Care for the Homeless Coalition (BHCHC). They came from health clinics, substance abuse programs, homeless shelters, where our tracker left fliers describing the program and admission criteria and/or personally made contact with potential clients. They also came from established outreach activities, and were self or BHCHC staff referred. Inclusion and exclusion criteria were: (1) homelessness as defined by McKinney Act criteria (McKinney and Stewart, 1987). These criteria define a homeless person as someone who lacks a fixed, regular and adequate nighttime residence, including: those whose primary nighttime residences are shelters or other temporary accommodations; public or private places not designed for or ordinarily used as, a regular sleeping accommodation for human beings; or someone at imminent risk of becoming homeless; (2) DSM-III-R diagnoses of cocaine or polysubstance abuse or dependence that included cocaine use, with cocaine use reported within the last 2 weeks; (3) coexisting non-psychotic mental disorder as measured by a T-score of 70 or above on the Hopkins Symptom Checklist, revised (SCL-90-R); (4) report by the subject that he/she intended to stay within the Birmingham area with no plans to leave within 12 months; (5) ability to provide informed consent; (6) no severe medical or psychiatric problem requiring immediate inpatient treatment; and (7) willingness to participate in interventions and assessments as indicated by a signed informed consent. Of 132 persons screened, 110 were found eligible, were admitted and randomly assigned April 19955 May 1996. One refused participation after baseline assessment but before random assignment, 16 failed to show for baseline, and five were found ineligible after screening and consent.

2.2. Design This study used a two-group, randomized controlled design comparing behavioral day treatment alone (DT) to behavioral day treatment plus abstinent contingent housing and work therapy (DT +). The independent variable was the presence (DT + ) or absence (DT) of the contingency management intervention. The dependent or outcome variables were alcohol and drug use, homelessness, and employment.

J.B. Milby et al. /Drug

and Alcohol Dependence 60 (2000) 55-67

2.3. Intervention components The manual-guided, behavioral day treatment was similar to that described previously (Milby et al., 1996a). Phase I (months O-2) consisted of 8 weeks of behavioral day treatment for both groups and additional abstinence contingent housing for participants assigned to DT + . Day treatment met week days from 07:30-14:00 h and included lunch and transportation to and from shelters. The following groups were conducted: participant governed morning meeting, process group, AIDS education, relapse prevention training, goal development, goal review, assertiveness training, role play, weekend planning, reinforcement exposure and planning, recreation outing group, 12 Steps, relaxation, recreation goal development and recreation goal review. It also included individual counseling, psychological evaluation and twice weekly urine monitoring. Excluding time for lunch and breaks, the length of behavioral day treatment was approximately 4 h and 50 min per day. Behavioral day treatment utilized objectively defined, long and short-term participant goals which addressed five common domains of dysfunction: substance abuse, homelessness, unemployment, lack of non-drug related social and recreational activities, and emotional-psychiatric problems. Participants collaborated in goal development by deciding goal content. Staff helped define goals objectively. Goal attainment was rated in a weekly goal review group. Ratings were based on goal completion evidenced by eye witness account and/or documentation of goal behavior by the patient and group members. Goal attainment was socially reinforced. Additionally, for accomplishment of non-drug related social and recreational goals only, participants received 1 (75% goal attainment)-2 (100% goal attainment) vouchers weekly worth $7.50 each to purchase non-drug related social and recreational items/activities from the recreational therapist. The DT + group formulated employment and housing goals with the vocational and housing specialists as part of the contingency management independent variable. Both specialists conducted other groups and functions for members of DT + and DT. Thus, other than differences in the independent variable, behavioral day treatment was the same for both groups. During Phase I, when DT + members achieved 2 consecutive weeks of abstinence, evidenced by four consecutive negative urine toxicologies, they were moved immediately to a program-provided, rent-free, furnished apartment or unit in a group house. There were four group houses and one 12 room apartment complex available and owned by BHCHC for this project. Some of these apartments and houses were purchased for below market values and renovated by

57

the work therapy program from a previous grant project and some were purchased and renovated from the present grant. These residences were comfortably furnished by the project housing manager complete with furnished living rooms, bedrooms, bathrooms, and kitchens with basic appliances. The houses roomed up to four and each apartment roomed two persons. The houses and apartment complex were located in low income but safe and clean neighborhoods. For DT + , detected (urine toxicology result) drug or alcohol use caused immediate eviction (the same day) and transportation to a shelter until subjects reestablished abstinence with two consecutive negative urine drug toxicologies. Following this reestablished abstinence, within approximately 6 h, subjects were moved back to the same apartment if available, or a similar one if not. Continued program provided, abstinent contingent, housing was made available during months 3-6 (Phase II) for a modest rent of $161.28 per month. Contingencies for Phase II housing were the same as Phase I. Rent was earned through work therapy stipends or other employment. No one was evicted for not paying rent and public assistance was not used for rent support. During Phase II about half the clients living in program provided housing remained in the original apartment house unit provided in Phase I but rent was collected for it, or if they participated in work therapy, rent was deducted from their wages. In other cases, clients moved into program managed individual houses for which rent was collected or deducted from work therapy wages. During months 336 (Phase II), the DT + group clients could participate in abstinence contingent work therapy based on the same contingencies that housing required. Based on a work skills and interest assessment conducted by the vocational rehabilitation therapist, clients were referred to bad boy builders (BBB) for work hardening experiences or placed in the few food service positions within the BHCHC agency. BBB was an independent construction company contracted by the project that consisted of three work trainers experienced in construction. Under the supervision of BBB, clients worked 5.5 h per day, 5 days per week, for minimum wage of $5.25 per hour paid weekly, and were involved in basic housing and apartment renovation jobs like painting, dry wall work, basic plumbing and electrical work, and landscaping. Participants were suspended from work as a result of drug or alcohol use, but were able to return after two consecutive negative urine toxicologies. From months 3-6 (Phase II) both groups participated in aftercare, consisting of once weekly 1.5 h group therapy utilizing goals and psycho-education content from Phase I, at least once weekly random urine surveillance with immediate feedback from results, and individual counseling once per week or less.

58

J.B. Milby et al. /Drug

DT + clients could continue aged by the agency.

in low rent housing

and Alcohol Dependence

man-

2.4. Outcome measurement: methods, variables, and instruments Participants were assessed by research interviewers who were ‘blind’ to group assignment at baseline, 2and 6-months. Participants were paid $25 for each completed assessment. Assessments took 2.5-3.0 h. Assessment and diagnoses of mental disorders, including psychoactive substance use disorders, was conducted during the 1st week of treatment and at 6 months using the DSM III-R Checklist (Hudziak et al., 1993). Measurement methodology included the use of a full time tracker who attempted to locate all subjects for followup regardless of current treatment status. To insure efforts were made to locate subjects that dropped from treatment, a $25 incentive was paid to the tracker for all subjects who completed a scheduled follow-up. Evidence that intention to treat procedures were effective in locating for follow-up these difficult to follow subjects, is found in the follow-up rates for high and low rate attenders at the 2- and 6-month assessments. Drug use was randomly measured weekly and at scheduled baseline and follow-up points (2-, 6- and 12-months) using urine drug toxicology testing. Weekly testing included cocaine, marijuana, and alcohol for all clients. Other substances were added for participants who tested positive or admitted to their use at baseline. At follow-up points, amphetamine, morphine and benzodiazepines were added. During Phase I, urine specimens were observed by trained staff and taken randomly, 2 days each week (excluding weekends), but never on 2 consecutive days. During Phase II, urine specimens were observed and taken on Monday (during the scheduled aftercare meeting) and then once more that week randomly, but never on 2 consecutive days. Toxicology drug test results were used for imposing housing and work therapy contingencies as well as for outcome measurement. Also, urines were collected at follow-up points for outcome data. Urine was analyzed using the Ontrak Radioimmunoassay system for abused drug testing manufactured by Roche Diagnostic Systems. This system permitted on site testing and instant feedback on whether a drug was detected. Positive tests disputed by participants were subjected to confirmation testing via gas chromatography/mass spectrometry, by Roche Laboratories (Nashville, TN). With disputed drug tests, participants remained in housing or work therapy until test confirmation. 2.5. Homelessness and employment Homelessness

and

employment

were

measured

by

60 (2000) 55-67

sections of the retrospective interview for housing, employment, and treatment history (RHETRO) derived from the personal history form (PHF). The PHF was the standard instrument used to assess housing, employment and treatment engagement outcomes in two multi-center research demonstrations supported by NIAAA (Barrow et al., 1985). It has well documented psychometric properties (Drake et al., 1995) and accounted for total days housed, employed, or in treatment. The RHETRO was designed to account for housing, employment, and treatment utilization across a 6 month time period rather than just the last 60 days. From the RHETRO employment section, employment data were extracted to yield information on full and part time employment. Fully employed was defined as employed at greater than 35 h per week over the last 60 days, or consistently employed at the same site less than 35 h per week over the last 60 days. Homelessness was measured as number of days homeless over the last 60 days.

2.6. Data analysis This study’s repeated measures design allowed assessment of treatment, effects at different time points. However, statistical analyses were complicated by incomplete data from participants who dropped from treatment or missed follow-up. Outcome measures and associated statistical methods were selected to analyze effects both between groups and longitudinally within groups while accounting for complications in data structure. The analyses were conducted in two stages. The primary analyses in the first stage focused on straightforward tests of hypotheses on the effect of treatment on the primary outcomes of abstinence, housing, and employment separately at the end of Phases I and II (months 2 and 6, respectively). The primary analyses were conducted using an intention to treat approach. The secondary analyses in Phase II addressed two primary issues. First additional analyses of the abstinence variable used modified definitions of prevalent abstinence and sustained abstinence to provide a comprehensive assessment of the relationship between treatment and abstinence. Second, because the DT + group showed greater retention in treatment than the DT group, secondary analyses examined whether the treatment had effects beyond those associated with retention. The primary analyses examined effect of treatment on three outcomes - percentage of days abstinent in the last 60 days as determined from the percentage of random urine samples over the 60 day period prior to the 2- and 6-month assessment points that were drug free, percentage of days housed in the last 60 as determined by the RHETRO, and percentage of days em-

J.B. Milby

et al. /Drug

and Alcohol Dependence

ployed in the last 60 as determined by the RHETRO. For these analyses, investigators followed the primary precept of an intention to treat analysis (Lewis and Machin, 1992) by including all patients in the analysis in the groups to which they were randomized, even if they did not adhere to the treatment protocol for that group. Second, investigators made every attempt to collect data on all subjects, even those not adhering to treatment. However, even with intense efforts at followup, a substantial number of subjects were not retained in treatment over the &month period. Consistent with classic intention to treat analyses, subjects with missing assessment data were included in the analyses using the following imputation rules. For the abstinence outcome, subjects who missed scheduled urine samples were classified as positive for that sample. For the housing and employment outcomes, missed assessments were imputed using the last observation carried forward principle. For each of the three primary outcome measures, histograms were developed for each treatment group at the two time points to assess treatment effects and characterize distributional properties. Generally, these descriptive measures indicated bimodal behavior for most outcomes at each time point. Consequently, the non-parametric Wilcoxon-Mann-Whitney rank sum test (which provides a more appropriate test of effects than does the t-test under extreme non-normal behavior) was used to test for treatment effects at each time. For all analyses a significance level of 0.05 was used with no adjustment for multiple comparisons. All analyses were conducted with SAS software. Because of the limited number of females recruited (n = 26), gender effects were not considered in the analyses. For secondary analyses, drug and alcohol abstinence was characterized with two outcomes - prevalence of abstinence in each treatment on a weekly basis which was used to evaluate the overall level of population abstinence achieved by each treatment over time, and consecutive weeks abstinence in individual subjects. The latter outcome was used to evaluate sustainable abstinence in the two treatment groups. For these analyses, the definition of abstinence at a particular assessment was modified from the definition used in the primary intention to treat analyses. A participant was classified as abstinent if all scheduled urines during that week were negative, as not abstinent if at least one urine during the week tested was positive or was missing without a valid reason, and as randomly missing if the participant failed to show, but had valid reason confirmed by study staff. For example, one valid reason for randomly missing was the participant was unable to provide a urine because of being in the hospital during urine collection hours. Percent participants abstinent for a week was then computed as the ratio (multiplied by 100) of the number of abstinent participants to the

60 (2000) 55-67

59

sum of abstinent and non-abstinent participants for that week, on a week by week basis. Randomly missing data were not used in the analyses or figures. The number of consecutive weeks abstinent was based on the same operational definitions of abstinent, not abstinent, and randomly missing for a week as those defined above. Consecutive weeks abstinent was computed for each subject by counting the maximal number of consecutive weeks abstinent for each subject. If a subject was classified as randomly missing for a week, that week was not counted as an abstinent week in computing consecutive weeks abstinent. However, that week also did not break a string of consecutive weeks abstinent. This modified definition is consistent with the intention to treat principle in that all subjects are included in the analyses in the group to which they were randomly assigned. Furthermore, for each of the abstinence assessments, project personnel classified subjects as missing at random only if the reasons for missed exams were unlikely to be related to abstinence outcomes. If subjects could not be classified as missing at random, they were assumed to have the most adverse outcome (non-abstinence) in the general spirit of an intention to treat approach. By ignoring missing observations only if they were missing at random, the analytical approach provides unbiased estimates of treatment effects. For the abstinence prevalence measure, each subject was characterized as abstinent or not abstinent for each week, and the proportion of subjects abstinent in each treatment group was computed for each week. Graphical displays were used to characterize trends over time and marginal model extensions to the generalized linear models, as described by Liang and Zeger (1986) and McCullagh and Nelder (1989), were used to characterize these patterns analytically. In the model-based analysis, prevalence over time was characterized as a function of treatment and study phase using a binomial model with an identity link. For the consecutive weeks abstinent measure, the Wilcoxon-Mann-Whitney rank sum test was used to test for differences in treatment during Phases I and II. Also, the linear mixed model was used to assess temporal effects of treatment and treatment by time interactions for consecutive weeks abstinent. The linear mixed model, which is comparable to repeated measures ANOVA, was used for these analyses because it is more flexible in handling missing observations and heterogeneity of variance across treatment groups. As a part of the secondary analyses, investigators calculated effect sizes for three of the main outcome variables: consecutive weeks abstinent, days homeless in the last 60, and days employed in the last 60. For the consecutive weeks outcome variable, the distribution

60

J.B. Milby et al. /Drug

and Alcohol Dependence 60 (2000) 55-67

was not extremely non-normal. Consequently, we used Cohen’s formula (Cohen, 1988) whereby the mean difference between groups is divided by the pooled, between participants standard deviation, i.e.: (Xl - X2) S.D.

pooled

’

This provides the reader a standard gauge by which to interpret strength of treatment relative to other treatment effects, i.e. medication, surgery, etc. Because the homelessness and employment measures were quite bimodal, mean differences appear to be less reasonable measures of effect. Using results described by Grisson (1994) for measuring the strength of clinical effect for studies in which a Wilcoxon-Mann-Whitney rank sum test is an appropriate statistical measure, we measured the effect size for homelessness and employment using the equation: ES=Ij

DT+

>DT-$DT>DT+

that in a random pair where $i,j is the probability drawn from two groups, the outcome for the subject from group i will be greater than the outcome from group j. As noted by Grisson (1994) this probability is exactly the population characteristic tested by the Mann-Whitney U-test. Grisson suggests that the strength of the effect can be interpreted in much the same way measures of association such as correlation coefficients are interpreted. As reported in the results section, retention in treatment differed in the two treatment groups. Investigators recognize that differences in treatment effect may simply result from differential retention and attendant exposure to treatment. Secondary analyses were conducted to examine the relationship between subject attendance and follow-up as well as attendance and outcomes for Phases I and II. For Phase I, subjects were classified as high rate attenders if they attended activities on 20 or more of the possible 40 days during the 8 week period. Subjects who attended less than 20 days were classified as low rate attenders. For Phase II, subjects who attended sessions during 8 or more weeks of the 16 week period (i.e. subjects who attended at least one session during a week for 8 or more weeks) were classified as a high rate attender while those who attended sessions on less than 8 weeks were classified as low rate attenders. Contingency table analyses were used to assess the association between follow-up and attendance during each phase in stratified analysis controlling for treatment using Mantel Haenszel procedures. Next, summary statistics were developed for the three primary outcomes (percentages of days employed, days housed and days abstinent) as defined in the primary analyses as well as continuous weeks abstinent as defined in the secondary analyses separately for Phases I and II for only those subjects who were high

rate attenders. The Wilcoxon-Mann-Whitney rank sum test was used to test for differences in outcome as a function of treatment.

3. Results 3.1. Participant characteristics Participants (N= 110) were 84 males (76.3%), 91 (82.7%) African Americans and 19 (17.2%) European Americans. The average age was 38.2 years (S.D. = 7.4, range = 20-65 years). Of the 110 participants, 97 were administered the DSM III-R Checklist at baseline. Of those 97, 91 (93.8%) met DSM III-R criteria for psychoactive substance use disorder, cocaine dependence or dependence in partial remission, and the following met dependence criteria for other drugs: 51 (52.6%) alcohol, 15 (15.5%) marijuana, 7 (7.2%) amphetamine, eight (8.2%) sedatives and sedative hypnotics, five opioids (5.2%), two (2.1%) hallucinogens. Of these 97, 79.4% met criteria for one or more DSM-III-R Axis I diagnoses other than substance or alcohol use disorders, including 54 with mood disorders (56%), 38 with anxiety disorders (39%) six with adjustment disorders (6%), four with psychotic or other organic mental disorders (4%), four with other disorders (4%) and 20 (20.6%) with no additional Axis I disorder. It should be noted that all participants met admission criteria for recent crack cocaine use and a non-psychotic mental disorder defined as a T-score of 70 or above on any subscale of the SCL-90-R. Additional demographic characteristics with treatment group comparisons are described in Table 1. Chi-square tests for categorical variables and two sample t-tests for continuous variables showed no evidence of a difference between the two groups suggesting randomization worked well. 3.2. Follow-up rates Number and percent who completed scheduled follow-up assessments (which included substance use, employment and housing outcomes) at 2 months, were 84 (76.3%) participants, with 49 (87.5%) of DT + participants and 35 (64.8%) of DT participants followed. At 6 months, data was collected for 82 (74.5%) participants, with 47 (83.9%) DT + participants and 35 (64.8%) DT participants followed. Chi-square tests for 2 x 2 contingency tables at each time point showed significantly higher percentages of DT + participants followed at each phase (2 months x2 = 7.84, d.f. = 1, P = 0.005 and 6 months x2 = 5.29, d.f. = 1, P = 0.021). Compliance with weekly urine testing reflected in the variable, percent participants abstinent, was sampled for weeks 1, 8, and 24. Compliance for DT + was 54 (96.4%) 51 (91.1%), and 42 (75.0%) and for DT it was 44 (81.5%)

J.B. Milby et al. /Drug Table 1 Demographic

characteristics

and treatment

Characteristic Gender Male (“Yo) Female (%) Age Race African American (‘XI) European American (%) Veteran (%) Education (years) Homeless (months) Longest full time job (months) Primary drug of abuse None (“!) Alcohol (%I) Cannabis (‘X) Cocaine (%)

group

and Alcohol Dependence 60 (2000) 55-67

comparisons All

DT

DT+

P-value

84 (76) 26 (24) 38.1 (7.4)

45 (83) 9 (17) 39.1 (7.5)

39 (70) 17 (30) 37.3 (7.2)

0.09

89 (81) 21 (19) 26 (24) 13.0 (2.2) 29.1 (47.6) 60.3 (52.3)

41 (76)

48 (86)

13 (24) 15 (29) 13.0 (2.3) 28.9 (47.7) 60.6 (53.5)

8 (14) 11 (20) 12.9 (2.0) 29.3 (48.0) 60.0 (51.5)

0 (0) 21 (19)

0 13 0 40

0 8 0 47

0 (0) 87 (79)

46 (85.2%) and 47 (87.0%), respectively. Compliance with weekly urine testing was also calculated by week for each treatment group and is presented in Table 2. Disparity between groups in loss to follow-up suggested differential attrition from treatment. Follow-up rates of high and low rate attenders at 2and 6-month follow-up for both treatment groups were calculated and compared to determine if a substantial number of low rate attenders were followed at both follow-up points from both treatment groups, consistent with the intention to treat analysis procedure. These results revealed that during Phase I, 20 of 54 DT subjects (37%) were high rate attenders (i.e. completed at least 50% of the intervention) while 43 of 56 DT + subjects (77%) were high rate attenders. Among the DT subjects 2-month assessments were obtained for 16 of 34 low rate attenders (47%) and 19 of 20 high rate attenders (95%). Among the DT + subjects 2-month assessments were obtained for six of 13 low rate attenders (46%) and 43 of 43 high rate attenders (100%). The breslow day test for homogeneity of association between the DT and DT + groups showed no evidence of a difference in the relationship between follow-up and attendance in the DT and DT + groups at 2 months the (x2 = 1.55 with d.f. = 1 and P = 0.21), although Mantel Haenszel test provided evidence of a substantial difference in follow-up in the two attendance groups (x2 = 32 with d.f. = 1 and P < 0.0001). During Phase II, nine of 54 DT subjects (17%) were high rate attenders while 17 of 56 DT + subjects (30%) were high rate attenders. Among the DT subjects, 6-month assessments were obtained for 27 of 45 low rate attenders (60%) and eight of nine high rate attenders (89%). Among the DT + subjects, 6-month assessments were obtained for 32 of 39 low rate attenders (82%) and 16 of 17 high rate attenders (94%). The breslow day test

(0) (24) (0) (74)

0.19

0.24 0.90 0.96 0.95 0.42

(0) (14) (0) (86)

for homogeneity of association between the DT and DT + groups showed no evidence of a difference in the relationship between follow-up and attendance in the DT and DT + groups at 6 months (x2 = 0.07 with the Mantel Haenszel d.f. = 1 and P = 0.79), although test again provided evidence of substantial difference in follow-up in the two attendance groups (x2 = 4.0 with Table 2 Percentage of random group by week Week

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

urine

samples

Treatment

collected

for each

treatment

group

DT (%)

DTf

69 59 64 47 44 36 41 31 25 26 25 20 18 26 21 23 18 16 17 14 15 19 15 19

89 84 79 76 73 76 73 71 69 65 62 68 61 57 55 54 54 48 46 50 47 44 39 39

(‘l/o)

62

J.B. Milby et al. /Drug

Table 3 Sample characteristics

as a function

Variable

Measure

Male gender Age (years) African American Veteran Education (years) Homeless (months) Longest full time Job (months) Primary drug of abuse None Alcohol Cannabis Cocaine Opiates

No. (“XI) Mean (S.D.) No. (%) No. (“X,) Mean (SD.) Mean (S.D.) Mean (SD.)

of treatment

group

und Alcohol Dependence

and treatment

exposure

during

DT

60 (2000) 55-67

day treatment

(Phase

I)

DT+

TX. exposed (N = 39)

Drop-out (N= 15)

P-value

TX. Exposed (N = 50)

Drop-out (N=6)

P-value

34 (87.2) 39.8 (8.3) 28 (71.8) 10 (27.8) 12.5 (2.3) 30.7 (49.6) 70.7 (56.9)

11 (73.3) 37.3 (4.8) 13 (86.7) 5 (33.3) 14.3 (2.3) 24.0 (43.6) 34.5 (32.4)

0.22 0.27 0.25 0.69 0.014 0.64 0.025

37 (74.0) 38 (7.2) 44 (88.0) 10 (20.0) 12.9 (1.9) 30.5 (50.1) 61.0 (53.7)

2 (33.3) 31.2 (3.3) 4 (66.7) 1 (16.7) 13.7 (2.4) 19.7 (25.6) 51.7 (28.3)

0.041 0.032 0.16 0.85 0.34 0.60 0.67

0.059 No. No. No. No. No.

(‘Yn) (%) (‘h/o) (5’0) (oh)

0 (0) 12 (30.8)

0 (0) 1 (6.7)

0 (0) 27 (69.2)

0 (0) 13 (86.7) 1 (6.7)

0 (0)

d.f. = 1 and P = 0.045). The data indicates that attendance and follow-up were greater in the DT + than in the DT group. However, data also indicated that association between attendance and follow-up was equivalent in the two groups with follow-up substantially greater in the high rate attenders in both groups. 3.3. Exposure to the independent variable Of Phases I and II treatment activities scheduled, subjects actually attended 51.8% of Phase I and 25.5% of Phase II. DT + attended 63.9% and DT attended 39.2% of Phase I activities and 34.1 and 16.7%, respectively, of Phase II activities. Of 110 participants, 56 were randomly assigned to DT + . Of those, 45 were eligible for free, abstinent contingent housing during Phase I. Of those eligible 45, 42 (93.3%) used the housing, the others found housing on their own or with family or friends. The mean days of earned free housing was 36.95 days (SD. = 12.97, range = 5552 days), with 100% earning 5 or more days. Of 56 participants assigned to DT + , 42 earned access to abstinence contingent rental housing in Phase II and 37 (88.1%) obtained and rented this housing. For this Phase II, DT + group, mean days earned housing was 67.14 (S.D. =38.51, range= 1-122). A total of 42 (75%) of the DT + participants also earned participation in work therapy via the same abstinence contingency requirements used for housing in Phase II, and 38 (90.5%) of them participated in some work therapy. 3.3.1. Treatment attrition In order to assess whether the differential follow-up participation reflected differential treatment attrition, number of treatment ‘drop-outs’ were compared to

0.53

0 (0) 8 (16) 0 (0) 41 (82) 1 (2)

0 (0) 0 (0) 0 (0) 6 (100) 0 (0)

‘treatment exposed’ (i.e. minimally sufficient dose of treatment). In Phase I, treatment exposed was defined as a participant who attended at least four morning treatment sessions. Anyone who attended less than four morning sessions, was considered a drop out. In Phase II a drop-out was defined as a participant who failed to attend at least two aftercare sessions and a treatment exposed participant was defined as attending two or more aftercare sessions. Of the N= 110, 80.9% were identified as Phase I treatment exposed (DT + = 89.3% and DT = 72.2%) and 40% of all participants were identified as Phase II treatment exposed (DT + = 53.6% and DT = 25.9%). Numbers of treatment exposed in each group at 2 and 6 months were examined in a 2 x 2 contingency table analysis and found to be significantly different favoring DT + , thus reflecting differential retention (2 months x2 = 5.18, d.f. = 1, P = 0.023 and 6 months x2 = 8.75, d.f. = 1, P = 0.003). Participants who remained in Phase I treatment may not have been representative of all participants recruited and randomly assigned. Therefore, participants in both groups who were exposed to some treatment during Phase I, were compared to drop outs, on eight demographic variables at baseline. These data are summarized in Table 3. In DT + , there were more treatment exposed men, more women drop-outs, and drop-outs were younger. In DT, treatment exposed held full time jobs for longer periods than drop-outs, but had fewer years of education. More treatment exposed endorsed alcohol as their primary drug of abuse on the AS1 at admission, (30.8% of DT and 16% of DT + ) compared to drop-outs (6.7% of DT, and 0% of DT + ). Differences between treatment exposed and drop-outs in overall primary drugs of abuse, however, did not significantly differ in DT or DT + groups. With the

J.B. Milby et al. /Drug

and Alcohol Dependence 60 (2000) 55-67

exception of these few differences, they were comparable on all other variables examined.

3.4. Outcomes: drug use Fig. 1 shows the primary intention to treat analysis of percent days abstinent, housed, and employed over the proceeding 60 days at baseline, 2 and 6 months follow-up, by treatment group. Table 4 presents means, medians and P levels for these analyses. The percent abstinent graph shows no data points for baseline because random urine toxicologies were not obtained prior to treatment entry. Percent days abstinent at 2 and 6 months, based on random urine toxicologies (l-2 per week) over the proceeding 60 days, show significant differences. Percentages at 2 months were for DT 41% versus DT + 71%, (Wilcoxon P > 0.0001). Percentages at 6 months were for DT 15% versus DT + 41% (Wilcoxon P = 0.0009). Abstinent

01

I

I

Baseline

2 MO.

I

6 MO.

HOUSCkl

0DT

Baseline

+DT+

2 MO.

6 MO.

Fig. 1. Intention to treat analysis of mean percentage days abstinent, housed, and employed at baseline, 2 and 6 months follow-up. Data are from 110 randomly assigned participants to day treatment (DT) only and day treatment plus abstinence contingency management for housing and work (DT + ).

63

Fig. 2 shows the secondary analysis of percent participants in each group that were abstinent from any drug or alcohol by week up to 6 months. Chi-square tests revealed that percent abstinent between treatment groups were not significantly different at week 0 (baseline), i.e. 50% abstinent for DT + and 48% abstinent for DT. It should be noted that measured urine toxicology at week 0 may have under estimated recent cocaine use prior to baseline. All participants admitted crack cocaine use within the last 2 weeks at study screening. Participants who did not, were excluded from the study. At baseline, participants reported on the addiction severity index an average of 16.9 (SD. = 10.12) days crack cocaine use within 30 days prior to admission. It seems many participants made an attempt to abstain from cocaine use as they sought treatment and were screened several days before treatment entry. Throughout 2 months of Phase I and 4 months of Phase II, DT + participants were always more abstinent than DT participants at any week. The results of the generalized linear model analyses suggest that abstinence varied as a function of treatment and phase with no evidence of a treatment by phase interaction. Based on model results, the best estimates of population prevalence of abstinence during Phase I were 0.42 for DT and 0.69 for DT + . For Phase II, the estimates were 0.18 for DT and 0.54 for DT + . The results suggest an average treatment difference for the two phases of about 0.35 favoring DT + (Wald x2 = 35, d.f. = 1, P < 0.0001) and an average decrease in abstinence from Phases I-II of about 0.2 (Wald xZ = 32, d.f. = 1, P < 0.0001). Fig. 3 displays the additional secondary analysis of frequency of the longest period of consecutive weeks abstinent for each subject from O-24 consecutive weeks among participants in DT and DT + across 3 week intervals. Both groups had substantial numbers of participants at three or fewer consecutive weeks abstinent. DT + had 10 participants and DT had 36. Across consecutive weeks abstinent intervals 16-18, 19-21 and 22-24, DT + had nine participants, DT had one. The modal frequency of DT + participants was 668 and 12- 14 week intervals, both intervals with 11 each. The modal frequency of DT participants was l-3 weeks with 22. This figure also reveals a treatment resistant population of 14 DT participants and five DT + participants who did not attain more than one consecutive week of abstinence during the 24 weeks of treatment. At 2 months, immediately following Phase I, DT + averaged 4.87 (S.D. = 2.77) consecutive weeks abstinent (median of 5) out of a maximum possible of 8 consecutive weeks, or 60.9% of the time abstinent. The DT group averaged 2.84 (S.D. = 2.71) consecutive weeks abstinent (median of 2) or 35.5% of the time consistently abstinent. A Wilcoxon test for location indicated a significant difference (P = 0.0004) between groups. At

J.B. Milhy et al. /Drug

64 Table 4 Intent to treat analysis groups (DT vs. DT+) Parameter

for primary at baseline

and Alcohol Dependence 60 (2000) 55-67

outcomes: mean and median percentage and 2 and 6 month follow-up

DT (n = 54) Mean (SD.)

days in the last 60 abstinent,

DT+

housed,

(n=56)

and employed

in two treatment

Wilcoxon

Median

Mean (SD.)

Median

0 0

0.11 (0.27) 0.23 (0.37)

0 0

Phase I (2-month follows-up) Abstinence 0.41 (0.35) Housing 0.12 (0.28) 0.20 (0.35) Employment

0.33 0 0

0.71 (0.35) 0.05 (0.19) 0.05 (0.15)

0.86 0 0

<0.0001 0.089 0.063

Phase II (6-month follow-up) Abstinence 0.15 (0.30) Housing 0.41 (0.45) Employment 0.43 (0.45)

0 0.04 0.27

0.41 (0.42) 0.59 (0.45) 0.61 (0.46)

0.28 0.87 0.95


Baseline Abstinence” Housingb Employmentb

_

P-value

_

0.16 (0.31) 0.19 (0.33)

0.24 0.39

a Abstinence was measured as percentage of negative random urine toxicologies in the past 60 days for all substances tested. A total of 60 days pre-treatment random urine toxicologies for the abstinence measure were not available, thus no data are reported for baseline. ’ Housing and employment were measured as percentage of days housed in a stable living situation and full time employed in the past 60 days.

the 6 month follow- up, immediately following Phase II, DT + averaged 9.51 (SD. = 6.67) consecutive weeks abstinent (median of 9) out of a possible 24 consecutive weeks or 39.6% of the time consistently abstinent. DT averaged 3.88 (S.D. = 3.99) consecutive weeks (median of 3) abstinent or 16.2% consistently abstinent. The Wilcoxon test again indicated a significant difference (P = 0.0001). Assessment for possible significant differences between groups in mean consecutive weeks abstinent from 2 to 6 months follow-up revealed greater change in DT + than in DT (F= 21.4, d.f. = 1, 100, P = 0.0001). The calculated effect sizes for differences between DT + and DT consecutive weeks abstinent at follow-up were 0.74 at 2 months and 1.06 at 6 months. 3.5. Robustness

of abstinence

outcomes

Significant differential attrition from treatment and follow-up favoring DT + occurred. Thus, DT + could have had a greater dose of day treatment than DT with increased day treatment being mainly responsible for observed differences between groups. Provided abstinence contingent housing during Phase I could have merely increased participation in behavioral day treatment. To determine the viability of this explanation, investigators completed an analysis of consecutive weeks abstinent for high rate attenders for both treatment groups after completion of Phase I and II at 2and 6-month assessment points. This analysis showed that after Phase I, DT (n = 20) high rate attenders had an average of 4.6 (S.D. = 2.6) consecutive weeks abstinence, and DT + (n = 43) high rate attenders had an average of 5.9 (S.D. = 2.0) consecutive weeks. After Phase II, DT (n = 9) high rate attenders had an average

of 7.7 (S.D. = 2.3) consecutive weeks abstinence, and DT + (n = 17) high rate attenders had an average of 14.9 (S.D. = 6.9) consecutive weeks. The Wilcoxon test for difference in location was significant for both follow-up points (P = 0.047 and P = 0.006), respectively. Thus, although the treatment effect was attenuated and there were more high rate attenders in the DT + group as compared to DT, a significant treatment effect remained beyond what could be accounted for by attrition.

3.6. Outcomes:

homelessness

Fig. 1 shows the primary intention to treat analysis of mean percentage days housed at baseline, 2 and 6 months follow-up. The percent housed graph shows that the only significant difference in percentage days housed between DT and DT + was at 6 months 100

60 E : 5 ‘: ii $+ {

70 60 50 40

g

30

2

20 10

Fig. 2. Percent participants abstinent per week in DT + and DT. Data are from 110 randomly assigned study participants. Urine toxicologies were collected randomly l-2 per week.

J.B. Milby et al. /Drug

65

and Alcohol Dependence 60 (2000) 55-67

25

IDT 20

___________....---

15

IO

rmn, 5

0

3

0

6

9

12

15

18

21

24

Consecutive Fig. 3. Number of participants 110 randomly assigned study

with longest periods of consecutive participants, with urine toxicologies

3

6

9

employment

Fig. 1 shows the primary intention to treat analysis of mean percentage days employed at baseline, 2 and 6 months follow-up. The percent employed graph shows there were no significant differences in percent employed between DT and DT + at baseline, 2 or 6 months. The mean percentage days employed for DT at baseline, 2 and 6 months respectively was 19, 20 and 43% versus DT + = 23, 5 and 61%.

4. Discussion This study revealed better outcomes for program provided, abstinence contingent, housing and work therapy, when combined with behavioral day treatment (DT + ), compared to day treatment alone (DT). Thus, the hypothesis that DT + would yield better treatment outcomes than day treatment alone was supported, especially for abstinence outcomes. Since DT was not compared to a no treatment control, it cannot be concluded that the efficacy of DT alone was demonstrated. However, because the earlier study employed a usual care treatment control and the current study employed the previous day treatment as a control, the current study systematically replicates effects of sub-

12

15

18

21

24

weeks abstinent

weeks abstinent from O-24 consecutive obtained randomly I-2 per week.

(Wilcoxon P = 0.016). The mean percentage days housed for DT at baseline, 2 and 6 months, respectively, was 16, 12 and 4% versus DT + = 11, 5 and 59%. 3.7. Outcomes:

0

weeks in DT + and DT. Data are from

stance abuse day treatment designed for homeless persons, found effective in this setting with similar participants (Milby et al., 1996b). Prior to this earlier study, the one study in the literature showing pre to post day treatment gains for cocaine dependence which included homeless persons, was not effective in retaining and treating cocaine abusing homeless persons (O’Brien et al., 1989). The major therapeutic impact of DT + seemed to be on drug abuse outcomes. At 2 and 6 months follow-up, homelessness and employment outcomes did not show as strong differences between DT + and DT as abstinence outcomes. At 6 months follow-up, there were differences between groups in percentage days housed, in spite of availability of HUD-provided housing for both groups in the community for homeless persons who completed substance abuse treatment. At 6 months follow-up, both groups made substantial gains in employment. Thus, although the abstinence contingency may have had an impact on both reduced homelessness and unemployment, the greatest impact targeted sustained abstinence. Two alternative explanations for differential treatment effects of DT + on abstinence outcomes should be considered; an enabling access to available services effect; and a differential attrition effect. Treatment effectiveness could be accounted for by enabling dysfunctional homeless persons to obtain available community services. Engaging in treatment may have allowed access to local and federally provided food stamps, low income housing, vocational assistance, etc. Such enabling did indeed occur. Participants in both groups

66

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and Alcohol Dependence 60 (2000) 55-67

became eligible for HUD-provided housing vouchers as they completed Phase II. Counselors assisted participants in attaining food stamps. Some participants obtained benefits from state vocational rehabilitation services. However, the few significant differences between groups in all but abstinence outcomes suggests that both DT and DT + were equally enabled by day treatment to take advantage of community resources and services, especially as reflected in measured outcomes of homelessness and employment. Thus, although the enabling effect may account for some rehabilitation outcomes common to both groups, it cannot account for the robust and differential effect of DT + on abstinence outcomes. The analysis of consecutive weeks abstinence outcomes from high rate day treatment attenders in both groups showed an attenuated but significant effect favoring DT + in spite of the treatment effect subsuming effects of differential attrition. Thus, increased attendance of DT + in day treatment is insufficient alone to explain between group differences, implying that provided abstinence contingent housing and work contributes significantly to the observed treatment effect. Indeed, the key to robust abstinence treatment effects of DT + may be its relative attractiveness to homeless substance abusers. The empirical question suggested by these results is, what are the relative roles of behavioral substance abuse day treatment versus the abstinence contingencies for housing and work. It is possible that abstinence contingent housing alone, or provided in conjunction with vocational counseling and work/training stipends, could be as effective or almost as effective, and thus more cost effective, than the same intervention which included behavioral day treatment. Though the slow decay of abstinence in the two groups after behavioral day treatment seems to occur at a constant rate for both groups in Fig. 2, there may be an underlying difference that increases from 2 to 6 months. Differences between groups in consecutive weeks abstinent, established during day treatment, seem to be increasing from immediately after day treatment to 6 months follow-up. During this time both groups attended the same aftercare group. The difference in treatment was access to a continued 4 month abstinence contingency for DT + . Both work therapy for pay and available housing for a modest rent were abstinence contingent. If behavioral day treatment could have been extended for participants who initiated abstinence late in treatment, more participants may have avoided relapse. If counselors could have deviated from research protocol limiting day treatment to 2 months, participants, who did not initiate abstinence until the 2nd month of day treatment, would have been treated for an additional month before discharge into Phase II aftercare. Ideally, aftercare plans should not be based on time

alone, but based on behavioral or other measurable criteria, as critics of current mental disorder treatment efficacy research advocate (Howard et al., 1996; Newman and Tejeda, 1996). Results, from previous research in this setting (Milby et al., 1996a) and the current study, suggest effective interventions for homelessness in combination with effective interventions for substance abuse may be sufficient, if not necessary and sufficient, to achieve maximal treatment effects for this dysfunctional population. The unique intervention for homelessness, abstinence contingent housing and work therapy during day treatment, seems sufficient for increased effectiveness. However, abstinence contingent housing was inseparable from program provided housing. It may be that program provided housing, without the abstinence contingency, is necessary and sufficient alone to produce maximum treatment effectiveness and would be less complex and costly for community agencies to manage. Thus, these results raise an important empirical question regarding the need to provide an abstinence contingency for any program provided housing. Several other empirical questions stem from these results: (1) would abstinence contingencies alone, especially for provided housing, be sufficient intervention for homeless substance abusers? The authors hypothesize that abstinence contingent housing and work therapy or vocational counseling alone, may be sufficient intervention for homeless persons with substance use disorders. (2) Would additional interventions for prevalent psychopathology, like depression and anxiety disorders, improve initial and long term treatment outcome? (3) Could extension of day treatment and/or increased aftercare intensity and frequency better sustain initiated abstinence? But the question, when answered, that could have greatest impact on treatment of this dysfunctional population, and most immediate effects on public policy for wide application of our knowledge, is; How necessary is an abstinence contingency, for provided housing, to maximize effectiveness from initial behavioral day treatment? Further research addressing these questions is needed.

Acknowledgements

This work was supported by grant ROl DA08475 from the National Institute of Drug Abuse. The authors express their appreciation to Karen Carney, Executive Director and Jonathan Dunning, Substance Abuse Program Director of BHCHC at the time of the study, and acknowledge their administrative support within their busy agency. They also express appreciation to Dr Stephen Higgins who provided valuable consultation on the adaptation of his voucher system and overall procedures for the study and Dr Samuel

J.B. h4ilby et al. /Drug

and Alcohol Dependence

Popkin who provided valuable clinical consultation and coordination of services with the VA Homeless Veterans Program.

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