Predictors of continuation with olanzapine during the 1-year naturalistic treatment of patients with schizophrenia in Japan

Figures & data

Table 1 Baseline univariate characteristics

Characteristic	Total N	Discontinuer (N = 588)	Continuer (N = 1262)	P
Demographics
Age (y), mean ± SD	1850	42.4 ± 15.5	45.9 ± 15.4	<0.001
Female (%)	1850	51.0	44.8	0.013
Clinical status
Outpatient status (%)	1850	49.3	40.4	<0.001
Duration of illness (y), mean ± SD	1451	15.1 ± 14.0	19.7 ± 14.9	<0.001
Tardive dyskinesia (%)	1822	5.2	7.7	0.052
BMI (kg/m^2), mean ± SD	1638	22.6 ± 4.3	22.6 ± 4.0	0.84
Any medical comorbidities (%)	1849	31.5	38.4	0.004
Clinical measures
CGI-SCH global severity, mean ± SD	1822	3.3 ± 1.0	3.4 ± 1.1	0.45
CGI-SCH positive, mean ± SD	1822	3.1 ± 1.5	2.9 ± 1.5	0.052
CGI-SCH negative, mean ± SD	1822	2.9 ± 1.4	3.2 ± 1.3	<0.001
CGI-SCH cognitive, mean ± SD	1822	2.8 ± 1.4	3.0 ± 1.3	0.004
CGI-SCH depressive, mean ± SD	1822	1.7 ± 1.4	1.6 ± 1.3	0.09
Responded at 3-month visit (%)	1822	28.9	36.0	0.003
Functional measures
EQ-5D VAS, mean ± SD	1815	43.6 ± 21.3	49.6 ± 22.8	<0.001
Working for pay (%)	1820	12.0	7.5	0.007
Social activities (%)	1820	32.7	26.8	0.027
Living independently (%)	1822	20.4	15.7	0.014
Baseline and prior medication use
Starting dose of OLZ (mg/day), mean ± SD	1847	8.4 ± 5.3	8.6 ± 5.0	0.56
Switch from atypical antipsychotic (%)	1850	21.6	20.5	0.60
Switch from typical antipsychotic (%)	1850	13.3	15.2	0.27
Prior anticholinergic use (%)	1823	35.7	41.8	0.012
Prior antidepressant use (%)	1823	7.7	4.4	0.005
Prior anxiolytic/hypnotic use (%)	1823	57.6	60.5	0.24
Prior mood stabilizer use (%)	1823	13.0	12.9	0.93
Prior other medication use (%)	1823	32.2	44.9	<0.001

Abbreviations: BMI, body mass index; CGI-SCH, Clinical Global Impression-Schizophrenia; EQ-5D VAS, European Quality of Life 5-Dimensions Visual Analog Scale; OLZ, olanzapine; SD, standard deviation.

Figure 1 Proportion of patients continuing olanzapine for 1 year. Most patients (68.2%, 1262/1850) continued with olanzapine treatment for the full 1-year study.

Note: The mean duration of olanzapine treatment was 265.5 ± 119.4 days.

Figure 2 Significant predictors of treatment continuation in the stepwise logistic regression analysis. This figure presents the odds ratios and 95% confidence intervals for each of the predictors of continuation in the final stepwise logistic regression model. Each predictor in the final model was a continuous variable; therefore, the odds ratios represent the change in odds of continuation for every one-unit increase in the predictor variable.

Abbreviations: CGI-SCH, Clinical Global Impression-Schizophrenia; EQ-5D VAS, European Quality of Life 5-Dimensions Visual Analog Scale.