A Cost-Analysis of Risperidone in the Treatment of Chronic Schizophrenia with Predominating Negative Symptoms in Hong Kong

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ABSTRACT

A comparative study of risperidone and conventional anti-psychotic therapy was performed for out-patients with schizophrenia with predominantly negative symptoms. After 3 months, there was a significant change in the Brief Psychiatric Rating Scale, Scale for Assessment of Negative Symptoms and Clinical Global Impression scores in the patients receiving risperidone, together with a better employment status. Both treatments appeared to be cost-beneficial, but risperidone was more cost-effective compared with conventional anti-psychotic therapy for this group of patients. Various limitations of the study are discussed and some clinical implications that warrant further studies to confirm the present findings have been suggested.

Keywords: Chronic Disorder; Cost-analysis; Negative Symptoms; Risperidone; Schizophrenia

INTRODUCTION

Patients with schizophrenia exhibit both positive and negative symptoms. The latter appears to be more associated with structural abnormalities, (1) but is not particularly responsive to conventional neuroleptic medications. (2) Those patients with predominant negative symptoms are particularly difficult to treat, (3) and usually experience a chronic deteriorating course with poor prognosis and severe multiple handicaps, creating a burden to their families and society.

The underlying neuro-biochemistry of schizophrenia is quite exciting, with involvement of both the 'dopamine' or DA system (4) and the 'serotonin' or 5HT system. (5) Atypical neuroleptic drugs such as clozapine (6) and risperidone (7) have recently appeared in the market and the manufacturers claim that they have both DA and 5HT antagonistic properties. However, clozapine has the notorious toxic potential of agranulocytosis and thus requires close white-cell monitoring. This procedure has frightened many potential patients who may benefit from the drug. On the other hand, risperidone appears to be much safer, (8) even if taken in excessive amounts. Overseas studies show that risperidone has therapeutic effects for both positive and negative symptoms. (9,10) There are few studies in Chinese populations and, so far, none have been performed in Hong Kong Chinese. Yu et al. (11) prescribed risperidone to 60 schizophrenic patients in Beijing for eight weeks and found an 88% improvement (with 64% marked improvement) in patients with positive or negative symptoms, with an optimal dosage of 5 to 6.5 mg per day. Zhang et al. (12) compared risperidone with clozapine in a randomised sample of 64 schizophrenic patients in Harbin, Heilongjiang, and found risperidone superior for treating patients with positive or negative symptoms, with minimal side-effects. Besides the cross-cultural or genetic differences between Chinese and non-Chinese schizophrenic patients, it would be useful to conduct a study to assess its efficacy locally, and to look especially on the effects of the medication on negative symptoms and the process of rehabilitation.

OBJECTIVE

An open clinical prospective trial was performed to compare the effects of the atypical neuroleptic, risperidone, with those of conventional anti-psychotic medications in the treatment of chronic schizophrenic patients with predominantly negative symptoms. The study also provided a cost-benefit analysis, modified to a cost-effectiveness comparison between risperidone and conventional neuroleptics. An intent-to-treat approach was used to reflect the actual clinical situation.

METHODOLOGY

SUBJECT SELECTION

Between September and December 1997, all consecutive schizophrenic patients attending the Western Psychiatric Centre in Hong Kong were screened. The eligibility criteria included the following:

* Inclusion criteria

--schizophrenic patients (diagnosed using International Classification of Diseases/Diagnostic and Statistical Manual of Mental Disorders criteria)

--taking regular neuroleptic therapy for at least 2 years (criterion for chronicity)

--a score of at least 35 on the Scale for the Assessment of Negative Symptoms (SANS) (13)

--informed consent

* Exclusion criteria

--aggressive, drug-abusing patients

--co-existing organic disorders or mental retardation

--those taking other novel anti-psychotics such as olanzapine or clozapine

--those receiving special treatment regimens such as case management or family therapy

--in-patients with schizophrenia. …