Detected heroin use in an Australian methadone maintenance program

Journal of Substance Abuse

Treatment,

Vol. 10, pp. 553-559,

0740-5472/93$6.00 + .oO Copyright 0 1993Pergamon Press Ltd.

1993

Printed in the USA. All rights reserved.

INTERNATIONAL

PERSPECTIVE

Detected Heroin Use in an Australian Methadone Maintenance Program JOHN R.M.

MB, BS, MPH,* DAVID K. REILLY, MPSY,? AND ALEX WODAK, MB, BS, FRACP$

CAPLEHORN,

*Department of Public Health, Building A27 Fisher Road, University of Sydney, NSW, Australia; tNorth Coast Regional Office, N.S.W. Department of Health, Lismore, NSW, Australia; $Alcohol and Drug Services, St. Vincent’s Hospital, Darlinghurst, NSW, Australia

Abstract-A reanalysis was undertaken of survey and retrospective urinalysis data on patients remaining in an abstinence-oriented, public methadone maintenance program in Sydney, Australia. A comparison of urinalysis results with those of previous reports of Australian methadone programs suggests that the clinic’s disciplinary program failed to reduce detected heroin use; morphine was detected in 27% of urine specimens. Women, those with a partner in methadone maintenance, and exprisoners were significantly more likely to submit morphine positive urines. When account was taken of subjects’ General Health Questionnaire scores in a second logistic regression model, the more psychologically disturbed patients were one fifth as likely to submit a morphine positive specimen as the less disturbed. This and other findings are interpreted as indicating that psychologically disturbed patients who continued to use heroin were more likely to be expelled from or otherwise leave treatment than the less psychologically disturbed who continued to use heroin. Keywords-methadone

maintenance; urinalysis; clinical review; cross-sectional study.

all opioids was not regarded as a relevant criterion of outcome (Gearing, 1974; Gearing & Schweitzer, 1974). However, when methadone programs were established in other cities in the United States (Jaffe, 1970) and other countries (Lewis, 1973) they generally functioned as abstinence-oriented, out-patient clinics (Dole & Nyswander, 1976; Caplehorn, 1990). The first Australian methadone maintenance program, established in 1969 in Sydney, New South Wales (N.S.W.), was modeled on Dole and Nyswander’s New York program but initially sought to promote total abstinence from opioids after three years treatment (Dalton & Duncan, 1979; Connexions, 1989). However, by 1976 clinical experience and contact with Dr. Nyswander had caused a reorientation towards longer term maintenance (Dalton, 1980; Connexions, 1989; Caplehorn & Batey, 1992). The next public methadone program established in Sydney sought to achieve total abstinence from opioids after short periods of maintenance (Reynolds & Magro, 1975). However a followup study published in 1975 revealed that this clinic had failed to achieve its principal objective-total abstinence from opioids (Reynolds & Magro, 1975).

INTRODUCTION

THE ORIGINAL METHADONE MAINTENANCE PROGRAM designed by Dr. Marie Nyswander (Hentoff, 1965a, 1965b) was the historical descendant of the narcotic maintenance clinics established in the United States in the early twentieth century (Terry, 1914; Council on Mental Health, 1957). The Nyswander program included an initial in-patient phase and was oriented towards “improved health and social rehabilitation” (Dole & Nyswander, 1976, p. 2117). Abstinence from Professor David Kleinbaum, University of North Carolina, suggested the strategy used in data analysis and reviewed the subjects and methods and results sections of the report. Val Gebski, Statistical Laboratory, Macquarie University, kindly provided an advanced version of the SPIDA package and advice on its use. The contributions of the staff and patients of the methadone program and the staff of the Oliver Latham Laboratory have been acknowledged in a previous publication. Funding for data collection was provided by the N.S.W. Drug and Alcohol Authority. Dr. Caplehorn received an Australian Postgraduate Award scholarship. Requests for reprints should be addressed to John Caplehorn, MB, BS, Department of Public Health, Building A27 Fisher Road, University of Sydney, NSW, 2006, Australia.

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The failure to promote abstinence in the short-term did not cause a reorientation of policy towards longer term maintenance but, rather, led to a scaling-down and restructuring of services and to the eventual establishment of a new clinic (O’Neill, 1987) which is the subject of this report. This clinic was established as a model for future development and was comparatively well resourced. The staff included a full-time medical officer and, by current standards, a high proportion of psychologists and social workers (O’Neill, 1987). The clinic had been functioning for about fifteen months prior to the study period although some staff and patients had been continuously involved in methadone maintenance treatment for five or more years. Clinic staff attempted to identify factors causing an individual’s heroin dependence during the assessment process and to draw up a detailed treatment plan (O’Neill, 1987; Caplehorn, 1985). As the demand for methadone maintenance far exceeded the number of treatment places, many of those assessed for maintenance were offered other in- and out-patient treatments (O’Neill, 1987). While most of the recommended, individualised interventions were behavioural (e.g., relaxation, assertiveness and skills training), all patients attending the maintenance clinic received individual counselling and repeated attempts were made to establish group therapies. Low dose maintenance was preferred as it was believed that higher doses would interfere with the process of problem resolution (Caplehorn, 1985). The clinic also used a disciplinary program to promote in-treatment abstinence from illicit and other drugs. Many patients were informed at assessment that the penalty for three morphine positive urine samples was involuntary withdrawal from methadone and dismissal from treatment. Patients who returned urine samples in which extraneous drugs were detected were routinely given the same warning. While some patients were required to sign written treatment contracts, the disciplinary program lacked the structure needed for successful contingency management: the program was never formally documented; there was no system of written contracts; no system of review of contracts; no system of peer review or other process of clinical supervision; and, no single individual was responsible for checking and compiling all urinalysis results (Calsyn & Saxon, 1987). However, such a disciplinary program is typical of those currently enforced in Australian (Caplehorn & Batey, 1992) and overseas methadone maintenance programs. This report presents the results of a reanalysis of data collected in the course of a cross-sectional study of the methadone maintenance program and the accompanying retrospective review of urinalysis results (Reilly, O’Connor, Wodak, & Clarke, 1987). The reanalysis was performed in order to more adequately summarise the urinalysis data, identify patient vari-

J.R.M.

Caplehorn et al.

ables which predict in-treatment drug use and to test the hypothesis that disciplinary sanctions were unevenly applied. MATERIALS AND METHODS The clinic records of the 253 patients who received methadone maintenance in the 15 months prior to the review were inspected in December 1985. Of the 122 individuals who had been continuously in treatment for at least six months at the time of the review (Reilly et al., 1987), demographic and other personal data and at least ten urinalysis results were available for 85 subjects. Twenty-two of the 122 either failed to attend or refused to participate in a structured interview and have previously been reported to be similar to those who participated (Reilly et al., 1987). Ten other potential subjects were dispensed their methadone at a retail pharmacy and were not required to provide urine samples while data on five others were incomplete or missing. Patient descriptors were obtained during structured interview and, where possible, data were validated by an inspection of clinic records (Reilly et al., 1987). Subjects’ urinalysis and treatment data were obtained from a review of clinic files. Urine samples were collected once a week, on a weekday selected at random at the start of the week, (i.e., on a fixed interval schedule, Harford & Kleber, 1978) and were analysed at the government reference laboratory. Specimens were screened by thin-layer chromatography (TLC) and positive results confirmed by two dimensional TLC and gas-liquid chromatography (Lewis, Bowron, & Learoyd, 1985). As is standard practice, morphine was used as the biological marker for heroin use. A 28-question version of the General Health Questionnaire (GHQ) was self-administered during assessment by 64 of the 85 subjects in order to provide a measure of nonpsychotic psychological impairment (Tennant, 1977). GHQ scores were obtained from clinic files (the maximum possible score was 28). Data were analysed using logistic regression with the outcome variable the proportion of urine samples in which morphine was detected. The predictor variables of interest were the subjects’ sex, the reported time (in years) between first opiate dependence and entering the current treatment episode and whether or not: their partner was receiving methadone treatment, they reported living with at least one of their children, they reported being in part- or full-time employment, and they reported ever having been imprisoned for a criminal offence. The period from first dependence to treatment was included as a continuous variable while the other six were binary categorical variables. The starting and current daily methadone doses (in milligrams) were added to give “total dose”, which was included as a continuous variable together with the

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Detected Heroin Use in Methadone Maintenance

duration of the present treatment episode (in months). the subject’s GHQ score on entry to the program was identified both as a potential confounder (Rounsaville, Weissman, Crits-Christoph, Wilber, & Kleber, 1982) and as a potential modifier of the effect of the other predictor variables on the outcome variable (Metzger & Platt, 1987). As GHQ score was only available for 64 of the 85 subjects, two principal analyses were conducted. One analysis included GHQ score both as a confounder and modifier of the effect of all the other predictor variables and used 64 observations while the other analysis did not include GHQ score and used data from all 85 subjects. Statistical models were developed in accordance with the recommendations of Kleinbaum, Kupper, and Muller (1988) with the additional consideration that they remained consistent with the hierarchy principle (Bishop, Fienberg, & Holland, 1975, p. 67). The models were tested for collinearity and influential observations and interaction terms were eliminated on the basis of the significance of their estimated regression coefficients. All analyses were performed on an Amstrad 2386 PC using the Statistical Package for Interactive Data Analysis (SPIDA; Statistical Laboratory, Macquarie University, Sydney, Australia).

There was a median 52 urinalysis results available for each subject (lower quartile 42, upper quartile 59). The eleven subjects who had no morphine detected in their urine gave a median 42 urine specimens (mean 42, range 10 to 70). The median number of morphine positive urinalysis results for all 85 subjects was 11 (lower quartile 3, upper quartile 19, maximum 71) and the median percentage of urine specimens in which morphine was detected was 21 (mean 27%, SD 24070, lower quartile 6.7070, upper quartile 40070,maximum 97%). The detailed results of the analysis which excluded consideration of GHQ score and initially included all 85 observations are displayed in Table la. One subject submitted 90 urine samples, 71 of which tested morphine positive and was excluded from the final model as an influential observation (Cook, 1977). Women, those with a partner in methadone maintenance, and exprisoners were significantly (p < 0.0001)

TABLE 1 Results of Logistic Regression Analyses: Proportion of Urine Samples in Which Morphine was Detected Variable

RESULTS

Of the 253 maintenance patients who had received methadone at the clinic in the 15 months prior to the clinical review, 51 (20%) were expelled from treatment for a variety of reasons including continuing use of heroin and “other drugs” and failure to attend for dispensing on three consecutive days. Another 45 (18%) obtained treatment at another, usually private, maintenance program. As some of the latter group were known to be undergoing withdrawal from methadone or were in conflict with the clinic’s disciplinary program at the time of their departure, the implementation of the disciplinary program was associated with a loss of up to 96 of 253 (38%) of the patient group. Of the 85 subjects in the present study, 50 (59%) were male, 36 (42%) had a partner in methadone maintenance, 47 (55%) had custody of a child, 48 (56%) were in full- or part-time work and 38 (45%) had been imprisoned for a criminal offence. The 85 subjects had been dependent on heroin a median 7 years (lower quartile 4 years, upper quartile 10 years) before admission to the current program and had been continuously in treatment a median 14 months (lower quartile 12 months, upper quartile 16 months). The median starting dose of methadone was 40 mg (lower quartile 40 mg, upper quartile 50 mg) and the median current dose was 50 mg (lower quartile 40 mg, upper quartile 60 mg, maximum 85 mg). The median GHQ score for the 64 subjects for whom data are available was 11.5 (lower quartile 5.5, upper quartile 17).

p value

odds

95% c.1.*

a Constant Sex’ Part_meth* Children3 Employment4 Years-add5 Time_prog’ Gael’ Total_dosee

0.000 0.000 0.000

0.363 0.060 0.113 0.000 0.000 0.000

1.586 1.410 0.929 1.174 1 .017 1.035 1.482 1.007

1,344-l 1.208-l 0,793-l 0,993-l 0.996-l 1,024-l 1,259-l 1.003-l

,872 ,645 .088 .389 .038 .046 .746 ,010

1.535 0.556 0.997 0.937 0.980 0.799 1.014 0.870 1.082 1.031 1.084

1,251-l ,885 0.363-0.851 0,657-l ,514 0.758-l. 157 0,955-l ,004 0,556-l ,148 1 .Ol o-1 ,019 0.848-0.893 1.051-1.113 1.001-l .061 1.056-l. 113

b Constant Sex’ Part_meth* Children3 Employment4 Years-add5 Gael’ Total_dose’ GHQ score GHQ* Part_methg GHQ* Children9 GHQ* Gaolg

0.000 0.000 0.007 0.990 0.544 0.102 0.226 0.000 0.000 0.000 0.040 0.000

95% confidence interval (of odds estimate). ‘Sex (1 = male, 2 = female). *Whether or not partner on methadone at time of interview (0 = no, 1 = yes). 3Whether or not caring for a child at time of interview (0 = no, 1 = yes). 4Whether or not in part or full time employment at time of interview (0 = no, 1 = yes). 5Time in years from first addiction to entry into current treatment. ‘Time in treatment in months. ‘Whether or not imprisoned for a criminal offence (0 = no, 1 = yes). sTotal dose (starting + current dose, mg). ‘Interaction term of GHQ scores with other predictor variables.

l

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J.R.M. Caplehorn et al.

more likely to submit morphine positive urines. The model accounted for only 10% of the total deviance (Gebski, Leung, McNeil, & Lunn, 1992, p. 7-4). The detailed results for the analysis which included GHQ score as both a confounder and potential effect modifier, and in which only 64 observations were considered are presented in Table lb. Two subjects (with 71 of 90 and 33 of 66 urine samples morphine positive) were excluded from the final model as influential observations, and the value of the GHQ score for one observation was changed from 22 to 12 (the median). The potential confounder, time in treatment, was excluded on the grounds of collinearity. Women were again more likely to use heroin than men (OR 1.54, 95% C.I. 1.25 to 1.89). The model accounted for 28% of the total deviance. In order to demonstrate the clinical significance of the estimated regression coefficients for continuous variables, odds ratios were computed using the values of the lower and upper quartiles for the continuous variables. Allowing for the other variables in the model, the odds of subjects with the upper quartile GHQ score of 17 on entry submitting a morphine positive urine specimen were one-fifth those of subjects with the lower quartile GHQ score of 5.5 (odds ratio 0.20, 95% C.I. 0.15 to 0.27). The odds of subjects with a partner in methadone maintenance and who had a GHQ score of 17 on entry to the program submitting a morphine positive urine specimen were 2.48 times those of subjects with a partner in methadone maintenance and with a GHQ score of 5.5 on entry (95% C.I. 1.77 to 3.48). Allowing for the other variables in the model, the odds of those taking care of a child with a GHQ score of 17 presenting a urine specimen in which morphine was detected were 1.41 times those of similar subjects with a GHQ score of 5.5 on entry (95% C.I. 1.01 to 1.98). The odds of exprisoners with a GHQ score of 17 submitting a morphine positive specimen were 2.66 those of exprisoners with a GHQ score of 5.5 (95% C.I. 1.89 to 3.40). A “total dose” of methadone of 100 mg was associated with a 32% increase in the odds of respondents submitting morphine positive urines compared with a “total dose” of 80 mg (95% C.I. 22% to 43%). DISCUSSION

There have been no previous Australian studies of the association of patient factors with urinalysis results and no international study has attempted to use urinalysis data to assess the impact of a clinic’s disciplinary policies outside of an experimental setting. The results suggest that the clinic’s attempts to induce abstinence were quite unsuccessful and that disciplinary sanctions were applied in such a way as to disadvantage the more psychologically disturbed patients. How-

ever, while this conclusion is of considerable interest, its overall impact is weakened by the fact that data were only collected on patients remaining in treatment, rather than on all those who entered treatment. The fixed interval urinalysis schedules used in this and most other N.S.W. maintenance programs allow individuals who have more control over their drug use to avoid detection. One study has found that fixed interval urinalysis detected approximately half the number of morphine positive urine specimens revealed by random urinalysis (Harford & Kleber, 1978). Given that morphine is detected for a day after an injection of heroin (Lewis dz Chesher, 1990), Goldstein and Brown (1970) have demonstrated that, even with random testing, a run of 20 negative urinalysis results only indicates that there is a 95% probability that the subject is not using heroin weekly. Moreover, the laboratory which analysed the urine specimens used procedures that ensured a high specificity but have a low sensitivity, less than half that of other procedures (Goldstein, Horns, & Hansteen, 1977; Kaul& Davidow, 1981; Magura & Lipton, 1988). As low concentrations of drugs or their metabolites would often not be detected, subjects who used small amounts of heroin would have been able to evade detection by drinking large quantities of water and presenting to the clinic as late as possible the day after drug use (Montalvo, Scrignar, Alderette, Harper, & Eyer, 1972). The urinalysis data, therefore, do not provide a valid measure of in-treatment abstinence. It is likely that some or even most of the 11 subjects who did not have morphine detected in their urine could have continued to use heroin intermittently but were either sufficiently fortunate or sufficiently controlled in their drug use to avoid detection. Indeed, one of the 11 presented 46 morphine-free specimens yet later admitted to an interviewer that she had used heroin on at least 12 occasions whilst in treatment. However, these limitations merely serve to reinforce the point that the program did not achieve its principal objective, abstinence from heroin use. As urine collection schedules and laboratory procedures had remained relatively constant for a decade, the urinalysis results can usefully be compared with those previously reported for N.S.W. methadone programs. Prior to the restructuring of the N.S.W. methadone program, morphine was reportedly detected in 23% (Waters, Gaha, & Reynolds, 1975) and 25% (Reynolds, Di Giusto, & McCulloch, 1976) of all urine specimens analysed in the central laboratory. Morphine was detected in 24% of urine specimens submitted after six months’ treatment by another group of methadone patients in 1986, that is around the time of the present study (Lewis & Chesher, 1990). A recent review of the urinalysis results of a cohort of patients admitted to a much more liberal N.S.W. methadone

Detected Heroin Use in Methadone Maintenance

program found that morphine was detected in 29% of specimens submitted within two years of the start of treatment (Caplehorn, Bell, Kleinbaum, & Gebski, 1993). As morphine was detected in 27% of the urine specimens collected from those who remained in maintenance at the study clinic for over six months, the disciplinary program seems to have failed to reduce intreatment heroin use. Such a conclusion is in keeping with the available international evidence (Nightingale, Michaux, & Platt, 1972; Bigelow et al., 1980) and the results of a recent, local comparison of the urinalysis results of an abstinence-oriented with those of an indefinite maintenance clinic (Caplehorn, 1993). Moreover, the probability of a subject submitting a morphine positive specimen did not decrease with time in treatment, again suggesting that the disciplinary program failed to promote abstinence. The disciplinary program, which was often colloquially summarised as “three dirty urines and you’re off”, caused up to 38% of patients to either be expelled from or leave maintenance treatment. However, over half of those retained at least six months in treatment submitted over 10 urine specimens in which morphine was detected and 12 individuals submitted over 30 such specimens. While there are no data on the number of morphine positive specimens submitted by those expelled, these results suggest that the punitive sanction, involuntary discharge from treatment, may not have been uniformly enforced. From this suggestion, and observations made by the principal author when he worked in the clinic, came the hypothesis that certain patients were allowed to remain in methadone treatment while submitting significantly more morphine positive urine specimens than other patients. The finding that women and the unemployed were more likely to submit a morphine positive urine specimen is consistent with the results of a recent, local cohort study and does not of itself suggest bias in the implementation of clinic policy (Caplehorn et al., 1993; Caplehorn, 1993). However, the question remains as to why women, the unemployed and exprisoners were permitted to remain in treatment despite continuing heroin use. The suggestion that the contingency management program may have been unevenly enforced is principally supported by the findings of the model which included subjects’ initial General Health Questionnaire (GHQ) results (Table lb). This model was also the statistically more powerful, accounting for nearly three times the proportion of the deviance explained by the model which included only demographic data. The lower the GHQ score, that is, the less disturbed a patient was on entry to treatment, the more likely he or she was to be known to be using heroin. Using the interquartile range of GHQ scores as the basis of the estimate, the odds of less disturbed patients hav-

557

ing morphine detected in their urine specimens were five times those of more disturbed patients (95% C.I. 3.7 to 6.7). If all things were equal, the less disturbed patients would be expected to be less likely to have morphine detected in their urine (Rounsaville et al., 1982). However, it must be noted that to be included in the study subjects must have remained in maintenance for at least six months. This result is interpreted as suggesting that psychologically disturbed patients were more likely to be expelled for continuing heroin use than less disturbed patients who continued to use heroin. While the GHQ has not been validated with a drug using population, and some somatic expressions of psychopathology may be indistinguishable from withdrawal symptomatology, this is unlikely to have affected the result, that is, to have introduced differential measurement error. Subjects completed the GHQ before entering treatment, and increased severity of withdrawals would be expected to increase the likelihood of heroin use. Moreover, the effect of GHQ score is in the expected direction when the GHQ is used as an effect modifier with demographic variables. The higher an exprisoner’s GHQ score at assessment the greater the likelihood that morphine would be detected in any urine specimen he or she submitted (odds ratio across the interquartile range 2.66). Similarly, the higher the GHQ score for subjects with a partner in methadone treatment or for those who were taking care of a child the greater the proportion of morphine positive specimens. The results suggest that disturbed patients’ continuing drug use was more likely to be tolerated if they had a partner in methadone treatment, were taking care of a child or were an exprisoner. When allowance is made for GHQ score and the interaction term of GHQ score and partner’s methadone status (Table lb), those with a partner in methadone maintenance are significantly less likely to submit a morphine positive urine specimen than those without a partner in methadone treatment (p < 0.01, odds ratio 0.56). Whereas, when no account is taken of GHQ score and the interaction term, (Table la) those with a partner in methadone treatment submitted a significantly higher proportion of morphine positive urine samples, (p < 0.000, odds ratio 1.41). These contrasting results suggest that patients with a partner on methadone were, in fact, at decreased risk of submitting a morphine positive urine sample and that the observed increase in the proportion of morphine positive specimens resulted from the unit’s staff allowing the more disturbed members of the group to continue to use heroin and remain in maintenance treatment. It is argued that more psychologically disturbed patients were likely to be at a disadvantage when entering into negotiation with clinic staff over their urinalysis results and hence were more likely to be expelled from or otherwise leave treatment unless they were in a fa-

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vored group. This suggestion is indirectly supported by the literature. Firstly, there is evidence that, in the absence of close clinical supervision, methadone maintenance unit staff do not consistently enforce the punitive sanctions dictated by contingency contracts (Nolimal & Crowley, 1990). Metzger & Platt (1987) have suggested that those patients who were better able to negotiate with authority figures obtained higher doses of methadone while Blumberg et al. (1974) found that addicts who communicated well with the clinic doctor were more likely to obtain opioid maintenance treatment. Research into the efficacy of counselling given in the context of methadone maintenance has indicated that the quality of the counselor-patient relationship is a powerful predictor of outcome (Luborsky, McLellan, Woody, O’Brien, & Auerbach, 1985). It is likely that the more psychologically disturbed patients would have been less able to overcome the problems posed by their continuing heroin use and would have been more likely to develop and continue an unsatisfactory relationship with their counselor. They would, thereby, have been at increased risk of leaving treatment. The results of the present study suggest that the more psychologically disturbed patients were more likely to be punished for their continuing heroin use and, thereby, are less likely to be retained in maintenance treatment. This finding is of particular concern given the failure of the disciplinary regime to decrease in-treatment heroin use and given the evidence from several countries that retention in methadone maintenance reduces the likelihood of infection with the HIV (Ball, Lange, Myers, &Friedman, 1988; Blix & Gronbladh, 1988). It would seem that, in order to avoid the possibility that heroin dependent individuals are needlessly exposed to an increased risk of infection with the HIV, patients should not be routinely expelled from maintenance treatment for continuing to use heroin or other drugs (Nolimal & Crowley, 1990). Positive reinforcers should be used to encourage abstinence within a structured contingency management program that is fully documented and open to peer review (Stitzer, Bigelow & McCaul, 1983; Calsyn & Saxon, 1987; Nolimal& Crowley, 1990). Furthermore, the objectives of such a contingency management program should be individualised and set during a process of negotiation and not imposed on patients.

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