New compounds have been introduced to treat schizophrenic
patients in the last 4 years. Their safety and efficacy
with respect to conventional treatments are well
documented, but their economic impact in a naturalistic
context is still pending.
OBJECTIVE: The purpose of the study is to evaluate new
antipsychotics in usual practice with a pragmatic Markov
Model of patients compliance under treatment.
METHODS: The model is based on a 6-month Markov
cycle tree divided into four sub-trees: M1, M2, M3, and
M4. (1) M1 identifies the drug strategies in schizophrenia:
sertindole versus olanzapine versus haloperidol. (2)
M2 enumerates the care structures. Five care management
categories are defined in function of the place where
patients live (hospital, residential, or private home) and
the intensity of care (intensive or mild residential care, intensive
or mild own-home personal care). Care management
depends on the clinical status (relapse and nonrelapse).
Long stay hospitalisation is integrated as a separate
branch. (3) M3 identifies the clinical events. Each of
the treatments has side effects determining the compliance
or noncompliance and the frequency of relapses.
Adverse events are extrapyramidal symptoms, somnolence,
weight gain, and sexual disturbance. Toxicity rates
are estimated from three integrated summaries of safety.
Compliance and relapse rates are obtained by a metaanalysis
of the literature. They are differentiated according
to the patients’ settings. (4) M4 shows the patients’
paths in the health care system. The corresponding transitional
probabilities are derived from two French cohorts
(2,747 pts), a German cohort (459 pts), and a British
cross-sectional study (1,051 pts). The model is based on
18 health states and 19,000 nodes.
RESULTS: The relative risk of relapse of haloperidol and
olanzapine with respect to sertindole is respectively equal to
1.4 and 1.2. Not only is sertindol self-financing because of
saved hospital admissions (- $12,000 compared with haloperidol
and -$6,500 compared with olanzapine), but it
produces a slight net savings compared with the two components.
Olanzapine and haloperidol are dominated strategy
with a lower effectiveness and a greater cost. A sensitivity
analysis carried out on toxicity, compliance, relapse, and
drop-out rates confirms the robustness of the results.
CONCLUSION: In schizophrenia, sertindole brings a
benefit of 5 months without relapse compared with olanzapine
and 13.5 months with respect to haloperidol. In
terms of cost-effectiveness, the study clearly shows the interest