Compliance therapy in psychotic patients: randomised controlled trial

INTERVENTION

Patients were randomly assigned by means of a table of random numbers to compliance therapy or control treatment. The intervention consisted of 4-6 sessions (mean 5.1) of compliance therapy, as described above, lasting 20-60 minutes roughly twice a week. The control treatment consisted of a similar number of sessions (mean 4.9) of supportive counselling in which the same therapists listened to the patients' concerns but declined to discuss treatment. Most of the therapy was carried out on the ward by a research psychiatrist (RK), with additional help from a clinical psychologist (PH).

In the first two sessions of compliance therapy patients were invited to review their history of illness and conceptualise the problem. In the next two sessions discussion became more specific, focusing on symptoms and the side effects of treatment. The benefits and drawbacks of drug treatment were considered, the patient's ambivalence was explored, and the therapist highlighted discrepancy between the patient's actions and beliefs, focusing on adaptive behaviours. In the last two sessions the stigma of drug treatment was tackled by considering that drugs are a freely chosen strategy to enhance the quality of life. Self efficacy was encouraged and the value of staying well and thus the need for prophylactic or maintenance treatment was emphasised. The therapist encouraged the use of metaphors such as “protective layer” and “insurance policy.”

After discharge from hospital, all subjects received routine aftercare as determined by the clinical teams responsible for their care.

ASSESSMENTS

Before the intervention all patients completed a battery of assessments, which included the brief psychiatric rating scale for the main psychiatric symptoms (range 24-168)22; the global assessment of functioning scale (range 0-100, with 10 defined anchor points relating to social competence)23; the national adult reading test, an estimate of IQ before the development of illness24; the drug attitudes inventory, a self reported scale predictive of compliance.25 Semistructured interviews included the expanded schedule for assessment of insight (with scores expressed as a percentage of maximum insight)10 26 and our own attitudes to medication questionnaire (available from us).20 Adverse effects of drug treatment were measured on the Simpson-Angus scale for extrapyramidal side effects27 and on the Barnes akathisia scale.28

OUTCOME MEASURES

Initial compliance was rated blind to intervention by the patients' primary nurses on a seven point rating scale. Complete refusal was scored as 1. Partial refusal—for example, refusing depot drugs or accepting only the minimum dose—was scored as 2. Reluctant acceptance—accepting only because treatment is compulsory or questioning the need for treatment often (every two days)—was scored as 3. Occasional reluctance about treatment—questioning the need for treatment once a week—was scored as 4. Passive acceptance was scored as 5. Moderate participation—some knowledge of and interest in treatment and no prompting needed to take the drugs—was scored as 6. Active participation, ready acceptance, and taking some responsibility for treatment was scored 7.

All ratings were repeated before discharge and after the intervention. Three months later social functioning was evaluated on the global assessment of function scale.23 A composite compliance measure was obtained by using our seven point scale and was based on corroboration from as many sources as possible (mean 2), including relatives, the psychiatrist at the outpatient clinic, the community psychiatric nurse, and the general practitioner. The evaluations at three months were all repeated at six months with the addition of an abridged brief psychiatric rating scale of seven items (including main psychosis items, negative symptoms, and depression). The evaluations at six months were carried out by an independent assessor (GA, a community psychiatric nurse) blind to intervention.

ANALYSIS

The BMDP:5V program was used to construct models for repeated measures analyses for each response variable of interest. The program makes maximum use of data, taking account of missing variables.29 Apart from intervention, time, and the interaction of group and time, the appropriate preintervention score, age, IQ, and chronicity were considered for possible inclusion in the fitted models. Such an analysis is more powerful than simply examining the change in scores before and after intervention.30 The final models take into account baseline data. They do not include effects found to be non-significant in the preliminary model fitting process.

CHARACTERISTICS OF PATIENT SAMPLE

The characteristics of the sample are shown in table 1. Thirty three patients had a non-affective psychosis. Sociodemographic variables were similar in the two groups. Of the 21 patients who refused to enter the study, 14 were women, 16 were non-white, and 16 were detained under the Mental Health Act.

Before intervention the compliance therapy group had significantly higher symptom scores than the control group—that is, they were more ill—on the brief psychiatric rating scale (64.1 v 55.4, t=2.09, P<0.04). This was reflected in non-significantly higher doses of neuroleptic drugs (mean (SD) 977 (797) mg v 698 (521) mg in chlorpromazine equivalents). Twelve patients in each group were receiving intramuscular depot antipsychotics. The two groups had similar scores for insight, attitudes to treatment, and compliance. Compliance was 3.4 in the group receiving compliance therapy and 4.0 for the control group (t=1.35, P=0.18), indicating rather poor initial compliance.

OUTCOME IMMEDIATELY AFTER INTERVENTION

Both groups had substantially improved symptom scores over the two assessments. The mean changes were 38.7 (10.5) and 35.4 (6.9), with no significant difference between them (table 2). Insight and compliance improved by about 10% in controls and by about 40% in the intervention group (P<0.001).

FOLLOW UP

Eight subjects were lost to follow up, four from each group. The background characteristics and ratings before intervention did not differentiate subjects who dropped out from those who completed the trial. Five patients refused to continue, one patient was uncontactable, one patient had moved out of the area, and one 65 year old man with hypertension had died of a stroke. Four patients in the intervention group and six in the control group were readmitted during the follow up period (odds ratio 2.0 (95% confidence interval 0.48 to 8.2)).

PSYCHIATRIC SYMPTOMS

Total scores on the brief psychiatric rating scale improved significantly after intervention, but scores for the abridged version of seven items deteriorated slightly in both groups by six months. Analysis with schizophrenia diagnosis as a covariate showed no differences in outcome in any of the main outcome variables.

COMPLIANCE WITH AND ATTITUDES TO TREATMENT

For compliance a significant effect was found for intervention, and it was sustained during follow up. The mean difference between the intervention group and controls on the seven point compliance scale was 1.6 (1.2 to 2.4), which is equivalent to a 23% improvement. IQ was found to exert a small but significant effect on compliance—the higher the IQ the better.

For the symptom scores, group and the interaction between group and time had no effect. The drug attitudes scores showed an effect for group, with a mean difference of 4.7 (2.4 to 9.2) in favour of the intervention group. Scores in both groups fell slightly but at the same rate at the one month follow up. Age exerted a significant influence on scores on the drug attitudes inventory, with older patients tending to have better scores, though length of history and IQ exerted no influence. Similar results were found for the other attitudes to medication scale, which showed a significant advantage for the intervention group immediately after compliance therapy (mean difference 3.6 (95% confidence interval 2 to 6)). The results are illustrated in figure 1.

Fig 1

Attitudes to treatment (drug attitudes inventory) and compliance over time in patients receiving compliance therapy or non-specific counselling (controls)

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There was no significant difference between the two groups in dose of antipsychotic drugs; both showed large reductions over the six months of follow up.

INSIGHT

For the expanded schedule for the assessment of insight scale there was again a significant effect for group but no significant effect of time or of the group by time interaction at follow up. Therefore, patients who received compliance therapy had significantly greater insight after intervention (mean difference 16.1% (15% to 33%)) and retained this improvement six months later.

GLOBAL FUNCTION

Global function scores were not significantly better immediately after the intervention. However, there was a significant group by time interaction, with the intervention group tending to improve more as time went by (fig 2).

Fig 2

Global functioning over time in patients receiving compliance therapy or non-specific counselling

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To further highlight the efficacy of compliance therapy, table 3 shows odds ratios calculated on an intention to treat basis, with patients who dropped out being assigned the worse outcome. The compliance results were highly significant (χ², P<0.005) when a stringent criterion outcome score of at least 5 on our compliance scale (passive compliance or better) was considered. When improvement was defined categorically as a score of 50 or more on the global assessment of functioning scale the odds ratio was 3.0 but failed to reach significance at the 5% level.

PREDICTORS OF OUTCOME

To establish which measures were most predictive of compliance at six months in the group given compliance therapy we performed stepwise linear regression with backward elimination, entering the preintervention scores for psychiatric and other symptoms, IQ, age, detention under the Mental Health Act, insight, and attitudes to treatment. This showed significant effects of detention under the Mental Health Act (voluntary patients complied better; β=0.38, t=2.71, P<0.02), extrapyramidal symptoms (more symptoms, worse compliance; β=-0.38, t=2.83, P<0.02), and attitudes to treatment (β=0.35, t=2.64, P<0.02 for drug attitudes inventory scores). These variables accounted for 62.5% of the variance in compliance.

METHODOLOGICAL CONSIDERATIONS

Several points require additional clarification. The first deals with the measure of compliance. This was an indirect composite measure based on information from a number of sources. There are problems associated with more direct measures such as urine tests since these may overestimate compliance when drugs have a long half life.34 Serum assays, when available, are invasive and are of limited value in assessing partial compliance.35 Pill counts are widely considered a useful measure,4 despite the potential for dissimulation and inaccuracy. We used an observer rated measure of compliance, which correlated strongly at each time point with self reported measures of attitudes to drug treatment (r>0.68), lending it some concurrent validity.

Observer bias was another potential problem. Most of the ratings of functioning and compliance initially and at three months were made by a research psychiatrist (RK), who was not blind to intervention group. However, the compliance ratings were based on information from impartial sources, including community psychiatric nurses and outpatient doctors on the clinical teams. By contrast, the ratings at six months were carried out by a researcher (GA) trained in the use of all the ratings, who was blind to intervention group. The results show consistency between ratings at the two time points. We believe that, despite these short-comings, compliance therapy does have a measurable and positive effect on adherence to treatment.

IMPLICATIONS

Are these findings generalisable? Around a third of the sample refused to enter the study and some dropped out. However, these figures must be interpreted in the light of the minimal selection criteria and the severe illness in our patient population. We believe that compliance therapy is eminently suited for adaptation to typical busy clinics, and we intend to examine the ease with which the technique may be taught to a range of health professionals. Psychotic patients, largely because of their illness, are often reluctant to acknowledge the need for the very treatment that might give them some relief. Given the high human and social costs of relapse and persisting symptoms, any proved means of counteracting this reluctance has important implications for management.

We thank the East Lambeth clinical teams and the nursing staff on Eileen Skellern III ward, Maudsley Hospital, especially John Hartley, for their continuing cooperation. Glyn Lewis kindly commented on the manuscript.