Journal ofSubstance Abuse Treatment, Vol.9, pp. 383-387, 1992 Printed in the USA. All rights reserved.
INTERNATIONAL
Copyright
0
0740-5472/92$5.00 + .CXJ 1992 Pergamon PressLtd.
PERSPECTIVE
Controlled Use of Heroin in Patients on Methadone Maintenance Treatment ENRICA BIANCHI, Computer Sci D,* ICRO MAREMMANI, MD,? DOMENICO MELONI, MD, * AND ALESSANDRO TAGLIAMONTE, MD* *Institute
of Pharmacology,
University
of Siena,
Italy; tInstitute
of Psychiatry,
University
of Pisa, Italy
Abstract - The efficacy of methadone maintenance
treatment was evaluated on 93 patients after IO years of therapy. On the basis of therapeutic compliance, patients were divided into three groups: (a) 40 Total-Agreement subjects on weekly take-home methadone; (b) 28 Partial-Agreement subjects, who regularly attended the clinic daily but presented episodic positive urinalysis; (c) 25 NoAgreement patients, who were absent from the clinic more than twice a month and had a high rate of urinalysis positive for morphine. Statistical analysis, based on social adjustment improvement and criminality rate decrease, divided the 93 patients into 2 distinct categories. The first category, characterized by high social adjustment and low criminality score, incIuded the Total- and Partialagreement groups. The second, characterized by significantly lower social adjustment and higher criminality score, included all No-Agreement patients. This suggests that methadone treatment was able to dissociate heroin use from low social functioning. It was concluded that, in a condition of adequate compliance the episodic use of heroin is of no harm to patients on methadone maintenance therapy, that is, methadone maintenance treatment permits a controlled use of heroin.
Keywords- heroin addiction; methadone maintenance.
treated at a daily dose ranging from 80 to 100 mg stop using heroin (Dole, 1989). This means that an individual variability of response to methadone exists, so that the psychiatrist must tailor the correct dose for each patient. Such a dose, to be attained gradually, by definition should not produce sedation, nodding, euphoria, or any other acute, central opioid effect (Kreek, 1983). Usually, the validity of a methadone maintenance program is evaluated in terms of percentage versus time of retention in therapy, coincident use of heroin, employment rate, job keeping, family care, number of arrests (Dole, Nyswander, Des Jarlais, &Joseph, 1982). Social parameters are usually altered as a consequence of heroin use, and thus constitute an unspecific, indirect, and yel valid estimate of the disease. As a consequence, many questions related to the efficacy of chronic methadone remain unanswered. The staff members of a methadone clinic know, for instance, that many patients do very well although they keep using heroin episodically; that is, methadone protects the patient from the dysphoric effects produced by heroin.
INTRODUCTION isthemostpragmaticand effective approach available for heroin addiction. It is pragmatic since its main aim is the reduction, up to complete cessation, of heroin use (Goldstein & Judson, 1983), but it does not eradicate opiate dependency leading to a drug-free condition (Newman, 1987). It is effective because, given orally once a day, it prevents or abolishes all withdrawal symptoms, eliminates craving, equilibrates mood (Dole & Joseph, 1978) and has few and well-accepted side effects (Kreek, 1983). Methadone is a full opiate agonist, with a selective affinity to the p-receptor similar to that of morphine (Jaffe & Martin, 1990). Given chronically, it produces tolerance to most of its effects. The use of illicit opioids is inversely related to the methadone dose used: more than 90% of the patients METHADONEMAINTENANCE
Requests for reprints should be addressed to Prof. Alessandro Tagliamonte, Institute of Pharmacology, University of Siena, Via delle Scotte, n6, 53100 - Siena, Italy.
383
384
E. Bianchi et al.
However, the presence of morphine in urine is considered a symptom of heroin use as serious as that of low social functioning, thus its occurrence in methadonemaintained patients is mentioned in the official literature only as a negative outcome (Dole et al., 1982). The reason for this is that a positive conclusion could favor an excess of permissivism. Therefore, the main issue to be solved is whether heroin use by addicted individuals in methadone maintenance therapy is to be equated with the negative effects of opiates. The aim of the present report is to verify the actual relationship between the persistence of heroin use and the degree of social adjustment and rate of criminality, which are the most powerful criteria of positive outcome in methadone maintained patients. The data obtained suggest that a correct compliance to methadone maintenance therapy seems compatible with a controlled, that is, harmless use of heroin. MATERIALS
AND METHODS
Patients
The data reported in the following tables are from a public service for drug abuse assistance active in Cagliari, Sardinia, since October 1980. The service has, since then, assisted more than 3,000 heroin addicted individuals. The approach proposed to such a large population of patients is that of a substitutive therapy with methadone. Patients are initially allowed to choose between a short-term detoxification or a maintenance program. At the end of 1990, about 1,200 patients were under treatment, and 1,000 of them were on methadone maintenance therapy. The therapeutic protocol proposed to these patients is based on their gradual acquisition of privileges as a function of their adherence to the prescribed program. Patients are required to attend the clinic daily, ingest methadone in front of a nurse, and report any possible problem relevant to the situation to a staff member. Urine samples are taken weekly and analyzed randomly for the presence of morphine. The methadone dosage is empirically decided by the first physician to visit a patient and is modified if necessary on the basis of the therapeutic outcome. The patient is constantly informed of any changes and the motivations for such changes. After a month of complete compliance and urinalysis negative for morphine, patients are allowed to take methadone home on Sunday. After 6 months of complete protocol adherence, patients who do not present peculiar traits (e.g., diagnosis of psychosis) may go to the clinic once a week for due controls and staff interviews and take methadone home for the remaining 6 days. To a large number of patients, take-home methadone becomes a positive reinforcement that controls their behavior and contributes to reduction and cessation of heroin use. Naturally, the privilege of tak-
ing methadone home remains bound to the absence of morphine from urine. Thus, the total patient population divides into different groups on the basis of therapeutic compliance, with those subjects who must attend the clinic daily on the one side and those who have earned a relative self-sufficiency on the other. About 20% of the patients presently in therapy, a total of 186 subjects, started treatment 10 years ago. Only 93 of them had a personal file with sufficient data to be included in the present study. In each patient the following parameters were considered: sex, age, age of onset of heroin abuse, number of years addicted, abuse of other drugs (alcohol, marijuana, central nervous system stimulants, benzodiazepines, hallucinogens), mean methadone dosage, protocol compliance, presence of morphine in urine, social adjustment, and criminality rate at the time of the first interview and during the last treatment year. The only selection criterion applied initially to the present population was the diagnosis of heroin addiction. Social adjustment was evaluated according to the guide line of the Global Assessment of Functioning (GAF) Scale of the DSM-III-R (American Psychiatric Association [APA], 1987), which provides a total score from 1 to 90. The most serious score (l-lo), is related to the persistent danger of severely hurting self or others (e.g., recurrent violence) OR persistent inability to maintain minimalpersonal hygiene OR serious suicidal act with clear expectation of death; the other extreme score (81-90) is related to absent or minimal symptoms (e.g., mild anxiety before an exam), goodfunctioning in all areas, interested and involved in a wide range of activities, socially effective, generally satisfied with life, no more than everyday problems or concerns. Since we had to re-evaluate the data collected 10 years before the final interview, the scale was simplified to 3 scores: 1, included the GAF scores from 1 to 30; 2, from 31 to 60, and 3, from 61 to 90. Criminality rate was evaluated by attributing a score for each conviction, and then normalized as follows: 0 for no crimes, 1 for conviction without prison, and 2 for serving a prison sentence. The 93 patients were divided on the basis of their compliance with the therapeutic program, as described above: 40 of them had earned the weekly take-home protocol, and the remaining 53 had to attend the clinic daily to ingest methadone. The 53 daily patients were further subdivided into two subgroups: the first one (28 subjects) who regularly attended the clinic every day, took the prescribed dose of methadone, had from 30% to 70% of urinalysis positive for morphine, maintained a correct relationship with the staff, and a second group of 25 subjects who were absent from the clinic more than twice a month, tried repeatedly to modify the dosage of methadone, had a high rate of urinalysis positive for morphine, and had a difficult relationship with the staff.
Heroin
Use in Methadone
Patients
385
TABLE 1 Characteristics of the sample (a) Group
Age Age of onset Addiction years Polydrug use
1 No-Agreement
2
3
Part-Agreement
Total-Agreement
(n = 25)
(n = 28)
(n = 40)
Mean
SD
Mean
SD
Mean
SD
F
P
34.0 19.0 15.0 0.9
3.5 3.0 2.9 1 .o
33.1 19.3 13.8 1.2
3.4 3.1 1.8 1.1
33.0 18.1 14.9 1.1
4.3 4.3 3.2 0.9
0.67 1.10 1.81 1.32
.51 .33 .16 .27
Fstatistical test was used to evaluate the differences between the three considered groups with respect to age, age of onset, addiction years, and polydrug use. Patients could be classified into 9 classes according to the group they belonged to and the three different mean methadone daily dosages (60 mg): the obtained contingency ( 3 x 3) table was submitted to chi-square test. Two-factor repeated measure analysis of variance was used to evaluate the score evolution of both social adjustment and criminality rate. Finally, multidimensional data analysis was applied in order to study whether the 93 subjects could be partitioned into homogeneous categories according to the best explicative or discriminant variables. Principal component analysis and stepwise discriminant analysis were used.
RESULTS As described in Methods, the 93 patients were divided, on the basis of therapeutic compliance, into the following three homogeneous groups: 1, No-Agreement with the program (25 patients); 2, Partial-Agreement (28 patients); 3, Total-Agreement (40 patients). Such a classification appeared to be independent of the patient’s age, age of onset of the disease, number of years of addiction, and use of other psychotropic drugs, as shown in Table 1 by the probability values associated to the Ftest. Sex was not considered since only 4 subjects were female. Chi-square analysis reported in Table 2, shows that the mean methadone dosages were significantly different between the groups at a probability level of .Ol. In fact, 75% of the patients in group 1 used a dose from 30 to 60 mg a day, 30% of those in group 2 used a dose higher than 60 mg, and 40% of group 3 used a dose below 30 mg a day. On the whole, Total-Agreement subjects used the lowest mean dosage. Analysis of variance (ANOVA) for two-factor repeated measures was calculated in order to analyze the
social adjustment score of the three groups. Results are reported in Table 3. The result of ANOVA with respect to the considered factors, that is, group division and score change from basal (bas) to observation (obs) time, showed significant differences. In fact, as shown by the value of Scheffe Ftest, basal social adjustment scored significantly higher in the Total-Agreement group as compared to group 1. All groups showed a significant improvement during the elapsed 10 year time as demonstrated by the paired t value. Finally, the Total- and Partial-Agreement groups presented a similar improvement in social adjustment, which was higher than that of the No-Agreement group. Two-factor repeated measures ANOVA was applied to the three groups in order to evaluate the criminality score at the time of the first visit (bas) as compared to that of the last year of treatment (obs). Results are reported in Table 4. No initial differences were detected between the three groups, whereas the evolution of criminality score paralleled that of social adjustment. In fact, the improvement was significant within each group, as shown by the values of the paired t test, and appeared more marked in groups 2 and 3 as compared to group 1. Multidimensional data analysis was applied in order to study whether the 93 subjects could be partitioned into homogeneous categories. The following variables were simultaneously considered for each sub-
TABLE 2 Percentage of Mean Methadone Dosages With Respect to the Three Groups (a) Group
60
Totals
No-Agreement Part-Agreement Total-Agreement
12.50 14.81 40.00
75.00 55.56 50.00
12.50 29.63 10.00
100 100 100
Totals
25.27
58.24
16.48
100
Chi-square= 11.89, p =
.Ol
386
E. Bianchi
TABLE 3 ANOVA of Social Adjustment Score in the Three Groups of Patients (a) Group 1 No-Agreement (n = 25)
2 Part-Agreement (n = 28)
3 Total-Agreement (n = 40)
bas
obs
bas
obs
bas
obs
1.04
2.12
1.25
2.84
1.45
2.83
Two-factor repeated measures ANOVA: Groups F = 12.6, p < .OOl Score Change F = 202.7, p < ,001. Baseline: 1 vs 3: Scheffe F = 3.87, p < .05. Observation: 1 vs 2: Scheffb F test = 4.18, Scheffe F test = 8.86 p < .05.
p < .05. 1 vs 3:
of the axis. Therefore Partial- and Total-Agreement groups were embedded into one group (Partial-TotalAgreement). Stepwise discriminant analysis (Morrison, 1967) was applied to the above data. The stepwise procedure consists of selecting the best explicative or discriminant variable; then the best couple of discriminant variables, and so on. This procedure is stopped when no more information to differentiate the groups is obtained by introducing a new variable. The two groups (No- and Partial-Total-Agreement) were considered the a priori class. The result of Bayesian discriminant analysis are reported in Table 5. The variables that discriminate the two groups are, in decreasing order, the following: final social adjustment, final criminality score, and starting social adjustment.
Pairedttest:1:t=-5.66,p
INTERNATIONAL
Copyright
0
0740-5472/92$5.00 + .CXJ 1992 Pergamon PressLtd.
PERSPECTIVE
Controlled Use of Heroin in Patients on Methadone Maintenance Treatment ENRICA BIANCHI, Computer Sci D,* ICRO MAREMMANI, MD,? DOMENICO MELONI, MD, * AND ALESSANDRO TAGLIAMONTE, MD* *Institute
of Pharmacology,
University
of Siena,
Italy; tInstitute
of Psychiatry,
University
of Pisa, Italy
Abstract - The efficacy of methadone maintenance
treatment was evaluated on 93 patients after IO years of therapy. On the basis of therapeutic compliance, patients were divided into three groups: (a) 40 Total-Agreement subjects on weekly take-home methadone; (b) 28 Partial-Agreement subjects, who regularly attended the clinic daily but presented episodic positive urinalysis; (c) 25 NoAgreement patients, who were absent from the clinic more than twice a month and had a high rate of urinalysis positive for morphine. Statistical analysis, based on social adjustment improvement and criminality rate decrease, divided the 93 patients into 2 distinct categories. The first category, characterized by high social adjustment and low criminality score, incIuded the Total- and Partialagreement groups. The second, characterized by significantly lower social adjustment and higher criminality score, included all No-Agreement patients. This suggests that methadone treatment was able to dissociate heroin use from low social functioning. It was concluded that, in a condition of adequate compliance the episodic use of heroin is of no harm to patients on methadone maintenance therapy, that is, methadone maintenance treatment permits a controlled use of heroin.
Keywords- heroin addiction; methadone maintenance.
treated at a daily dose ranging from 80 to 100 mg stop using heroin (Dole, 1989). This means that an individual variability of response to methadone exists, so that the psychiatrist must tailor the correct dose for each patient. Such a dose, to be attained gradually, by definition should not produce sedation, nodding, euphoria, or any other acute, central opioid effect (Kreek, 1983). Usually, the validity of a methadone maintenance program is evaluated in terms of percentage versus time of retention in therapy, coincident use of heroin, employment rate, job keeping, family care, number of arrests (Dole, Nyswander, Des Jarlais, &Joseph, 1982). Social parameters are usually altered as a consequence of heroin use, and thus constitute an unspecific, indirect, and yel valid estimate of the disease. As a consequence, many questions related to the efficacy of chronic methadone remain unanswered. The staff members of a methadone clinic know, for instance, that many patients do very well although they keep using heroin episodically; that is, methadone protects the patient from the dysphoric effects produced by heroin.
INTRODUCTION isthemostpragmaticand effective approach available for heroin addiction. It is pragmatic since its main aim is the reduction, up to complete cessation, of heroin use (Goldstein & Judson, 1983), but it does not eradicate opiate dependency leading to a drug-free condition (Newman, 1987). It is effective because, given orally once a day, it prevents or abolishes all withdrawal symptoms, eliminates craving, equilibrates mood (Dole & Joseph, 1978) and has few and well-accepted side effects (Kreek, 1983). Methadone is a full opiate agonist, with a selective affinity to the p-receptor similar to that of morphine (Jaffe & Martin, 1990). Given chronically, it produces tolerance to most of its effects. The use of illicit opioids is inversely related to the methadone dose used: more than 90% of the patients METHADONEMAINTENANCE
Requests for reprints should be addressed to Prof. Alessandro Tagliamonte, Institute of Pharmacology, University of Siena, Via delle Scotte, n6, 53100 - Siena, Italy.
383
384
E. Bianchi et al.
However, the presence of morphine in urine is considered a symptom of heroin use as serious as that of low social functioning, thus its occurrence in methadonemaintained patients is mentioned in the official literature only as a negative outcome (Dole et al., 1982). The reason for this is that a positive conclusion could favor an excess of permissivism. Therefore, the main issue to be solved is whether heroin use by addicted individuals in methadone maintenance therapy is to be equated with the negative effects of opiates. The aim of the present report is to verify the actual relationship between the persistence of heroin use and the degree of social adjustment and rate of criminality, which are the most powerful criteria of positive outcome in methadone maintained patients. The data obtained suggest that a correct compliance to methadone maintenance therapy seems compatible with a controlled, that is, harmless use of heroin. MATERIALS
AND METHODS
Patients
The data reported in the following tables are from a public service for drug abuse assistance active in Cagliari, Sardinia, since October 1980. The service has, since then, assisted more than 3,000 heroin addicted individuals. The approach proposed to such a large population of patients is that of a substitutive therapy with methadone. Patients are initially allowed to choose between a short-term detoxification or a maintenance program. At the end of 1990, about 1,200 patients were under treatment, and 1,000 of them were on methadone maintenance therapy. The therapeutic protocol proposed to these patients is based on their gradual acquisition of privileges as a function of their adherence to the prescribed program. Patients are required to attend the clinic daily, ingest methadone in front of a nurse, and report any possible problem relevant to the situation to a staff member. Urine samples are taken weekly and analyzed randomly for the presence of morphine. The methadone dosage is empirically decided by the first physician to visit a patient and is modified if necessary on the basis of the therapeutic outcome. The patient is constantly informed of any changes and the motivations for such changes. After a month of complete compliance and urinalysis negative for morphine, patients are allowed to take methadone home on Sunday. After 6 months of complete protocol adherence, patients who do not present peculiar traits (e.g., diagnosis of psychosis) may go to the clinic once a week for due controls and staff interviews and take methadone home for the remaining 6 days. To a large number of patients, take-home methadone becomes a positive reinforcement that controls their behavior and contributes to reduction and cessation of heroin use. Naturally, the privilege of tak-
ing methadone home remains bound to the absence of morphine from urine. Thus, the total patient population divides into different groups on the basis of therapeutic compliance, with those subjects who must attend the clinic daily on the one side and those who have earned a relative self-sufficiency on the other. About 20% of the patients presently in therapy, a total of 186 subjects, started treatment 10 years ago. Only 93 of them had a personal file with sufficient data to be included in the present study. In each patient the following parameters were considered: sex, age, age of onset of heroin abuse, number of years addicted, abuse of other drugs (alcohol, marijuana, central nervous system stimulants, benzodiazepines, hallucinogens), mean methadone dosage, protocol compliance, presence of morphine in urine, social adjustment, and criminality rate at the time of the first interview and during the last treatment year. The only selection criterion applied initially to the present population was the diagnosis of heroin addiction. Social adjustment was evaluated according to the guide line of the Global Assessment of Functioning (GAF) Scale of the DSM-III-R (American Psychiatric Association [APA], 1987), which provides a total score from 1 to 90. The most serious score (l-lo), is related to the persistent danger of severely hurting self or others (e.g., recurrent violence) OR persistent inability to maintain minimalpersonal hygiene OR serious suicidal act with clear expectation of death; the other extreme score (81-90) is related to absent or minimal symptoms (e.g., mild anxiety before an exam), goodfunctioning in all areas, interested and involved in a wide range of activities, socially effective, generally satisfied with life, no more than everyday problems or concerns. Since we had to re-evaluate the data collected 10 years before the final interview, the scale was simplified to 3 scores: 1, included the GAF scores from 1 to 30; 2, from 31 to 60, and 3, from 61 to 90. Criminality rate was evaluated by attributing a score for each conviction, and then normalized as follows: 0 for no crimes, 1 for conviction without prison, and 2 for serving a prison sentence. The 93 patients were divided on the basis of their compliance with the therapeutic program, as described above: 40 of them had earned the weekly take-home protocol, and the remaining 53 had to attend the clinic daily to ingest methadone. The 53 daily patients were further subdivided into two subgroups: the first one (28 subjects) who regularly attended the clinic every day, took the prescribed dose of methadone, had from 30% to 70% of urinalysis positive for morphine, maintained a correct relationship with the staff, and a second group of 25 subjects who were absent from the clinic more than twice a month, tried repeatedly to modify the dosage of methadone, had a high rate of urinalysis positive for morphine, and had a difficult relationship with the staff.
Heroin
Use in Methadone
Patients
385
TABLE 1 Characteristics of the sample (a) Group
Age Age of onset Addiction years Polydrug use
1 No-Agreement
2
3
Part-Agreement
Total-Agreement
(n = 25)
(n = 28)
(n = 40)
Mean
SD
Mean
SD
Mean
SD
F
P
34.0 19.0 15.0 0.9
3.5 3.0 2.9 1 .o
33.1 19.3 13.8 1.2
3.4 3.1 1.8 1.1
33.0 18.1 14.9 1.1
4.3 4.3 3.2 0.9
0.67 1.10 1.81 1.32
.51 .33 .16 .27
Fstatistical test was used to evaluate the differences between the three considered groups with respect to age, age of onset, addiction years, and polydrug use. Patients could be classified into 9 classes according to the group they belonged to and the three different mean methadone daily dosages (60 mg): the obtained contingency ( 3 x 3) table was submitted to chi-square test. Two-factor repeated measure analysis of variance was used to evaluate the score evolution of both social adjustment and criminality rate. Finally, multidimensional data analysis was applied in order to study whether the 93 subjects could be partitioned into homogeneous categories according to the best explicative or discriminant variables. Principal component analysis and stepwise discriminant analysis were used.
RESULTS As described in Methods, the 93 patients were divided, on the basis of therapeutic compliance, into the following three homogeneous groups: 1, No-Agreement with the program (25 patients); 2, Partial-Agreement (28 patients); 3, Total-Agreement (40 patients). Such a classification appeared to be independent of the patient’s age, age of onset of the disease, number of years of addiction, and use of other psychotropic drugs, as shown in Table 1 by the probability values associated to the Ftest. Sex was not considered since only 4 subjects were female. Chi-square analysis reported in Table 2, shows that the mean methadone dosages were significantly different between the groups at a probability level of .Ol. In fact, 75% of the patients in group 1 used a dose from 30 to 60 mg a day, 30% of those in group 2 used a dose higher than 60 mg, and 40% of group 3 used a dose below 30 mg a day. On the whole, Total-Agreement subjects used the lowest mean dosage. Analysis of variance (ANOVA) for two-factor repeated measures was calculated in order to analyze the
social adjustment score of the three groups. Results are reported in Table 3. The result of ANOVA with respect to the considered factors, that is, group division and score change from basal (bas) to observation (obs) time, showed significant differences. In fact, as shown by the value of Scheffe Ftest, basal social adjustment scored significantly higher in the Total-Agreement group as compared to group 1. All groups showed a significant improvement during the elapsed 10 year time as demonstrated by the paired t value. Finally, the Total- and Partial-Agreement groups presented a similar improvement in social adjustment, which was higher than that of the No-Agreement group. Two-factor repeated measures ANOVA was applied to the three groups in order to evaluate the criminality score at the time of the first visit (bas) as compared to that of the last year of treatment (obs). Results are reported in Table 4. No initial differences were detected between the three groups, whereas the evolution of criminality score paralleled that of social adjustment. In fact, the improvement was significant within each group, as shown by the values of the paired t test, and appeared more marked in groups 2 and 3 as compared to group 1. Multidimensional data analysis was applied in order to study whether the 93 subjects could be partitioned into homogeneous categories. The following variables were simultaneously considered for each sub-
TABLE 2 Percentage of Mean Methadone Dosages With Respect to the Three Groups (a) Group
60
Totals
No-Agreement Part-Agreement Total-Agreement
12.50 14.81 40.00
75.00 55.56 50.00
12.50 29.63 10.00
100 100 100
Totals
25.27
58.24
16.48
100
Chi-square= 11.89, p =
.Ol
386
E. Bianchi
TABLE 3 ANOVA of Social Adjustment Score in the Three Groups of Patients (a) Group 1 No-Agreement (n = 25)
2 Part-Agreement (n = 28)
3 Total-Agreement (n = 40)
bas
obs
bas
obs
bas
obs
1.04
2.12
1.25
2.84
1.45
2.83
Two-factor repeated measures ANOVA: Groups F = 12.6, p < .OOl Score Change F = 202.7, p < ,001. Baseline: 1 vs 3: Scheffe F = 3.87, p < .05. Observation: 1 vs 2: Scheffb F test = 4.18, Scheffe F test = 8.86 p < .05.
p < .05. 1 vs 3:
of the axis. Therefore Partial- and Total-Agreement groups were embedded into one group (Partial-TotalAgreement). Stepwise discriminant analysis (Morrison, 1967) was applied to the above data. The stepwise procedure consists of selecting the best explicative or discriminant variable; then the best couple of discriminant variables, and so on. This procedure is stopped when no more information to differentiate the groups is obtained by introducing a new variable. The two groups (No- and Partial-Total-Agreement) were considered the a priori class. The result of Bayesian discriminant analysis are reported in Table 5. The variables that discriminate the two groups are, in decreasing order, the following: final social adjustment, final criminality score, and starting social adjustment.
Pairedttest:1:t=-5.66,p
