Skip to main content

Table 3 Effect sizes for olanzapine oral or long-acting injection vs. placebo or non-therapeutic olanzapine (1 mg)

From: Efficacy of olanzapine long-acting injection in patients with acutely exacerbated schizophrenia: an insight from effect size comparison with historical oral data

Study and Treatment

N

Mean Modal Dose/ Corresponding Daily Dose (mg/day)

PANSS Total LS Mean Change

PANSS Total Effect Sizea(category)b

BPRS Total LS Mean Change

BPRS Total Effect Sizea(category)b

OLZ LAI Study

      

405 mg/4 weeks olanzapine LAI

100

14.5

−22.5

.75 (moderate)

−14.2

.71 (moderate)

210 mg/2 weeks olanzapine LAI

106

15.0

−22.8

.80 (large)

−14.4

.77 (moderate)

300 mg/2 weeks olanzapine LAI

100

21.4

−24.8

.88 (large)

−15.4

.82 (large)

vs. Placebo

98

0.0

−8.7

--

−6.1

--

Oral Study 1

      

5 ± 2.5 mg/day olanzapine

65

6.6

--

--

−6.4

.17 (small)

10 ± 2.5 mg/day olanzapine

64

11.6

--

--

−12.2

.50 (moderate)

15 ± 2.5 mg/day olanzapine

69

16.3

--

--

−15.2

.67 (moderate)

15 ± 5.0 mg/day haloperidol

69

16.4

--

--

−12.8

.57 (moderate)

vs. Placebo

68

0.0

--

--

−3.7

--

Oral Study 2

      

5 ± 2.5 mg/day olanzapine

87

6.7

−21.4

.17 (small)

−13.4

.19 (small)

10 ± 2.5 mg/day olanzapine

86

11.3

−22.7

.20 (small)

−13.8

.19 (small)

15 ± 2.5 mg/day olanzapine

89

16.4

−26.7

.37 (moderate)

−16.4

.38 (moderate)

15 ± 5.0 mg/day haloperidol

81

17.6

−20.0

.12 (small)

−12.4

.12 (small)

vs. 1.0 mg/day olanzapine

88

0.0

−16.8

--

−10.5

--

Oral Study 3

      

10 mg/day olanzapine (vs. placebo)

50

10.0

−12.3

.71 (moderate)

−7.7

.60 (moderate)

10 mg/day olanzapine (vs. 1 mg)

50

10.0

−12.3

.48 (moderate)

−7.7

.45 (moderate)

1 mg/day olanzapine (vs. placebo)

52

1.0

−1.9

.22 (moderate)

−2.0

.14 (small)

Placebo

50

0.0

2.8

--

−0.2

--

  1. a All effect sizes were calculated from baseline-to-endpoint LOCF mean change scores at 6 weeks of treatment (OLZ LAI study was 8 weeks, whereas the 3 oral studies were only 6 weeks)
  2. b Effect sizes were categorized using Cohen’s general effect size thresholds [19]
  3. Abbreviations: BPRS: Brief Psychiatric Rating Scale; LOCF: last observation carried forward; LS: least squares; OLZ LAI: olanzapine long-acting injection; PANSS: Positive and Negative Syndrome Scale