Table 4

Regression model predicting variability in response rates in placebo groups of clinical trials; n = 97 Studies, with prevention trials excluded; formal and diagnostic variables (ICD Coding); italics: different from full model

Beta

t (DFs = 91)

p-value

Constant

10.3

<0.000001

Disorders due to substance abuse (F1)

-0.31

-3.57

0.0006

Affective disorders (F3)

0.37

4.49

0.00002

Nervous diseases (G)

-0.20

-2.40

0.018

Digestive diseases (K)

0.29

3.65

0.0004

Diseases of the urigenital system (N)

0.16

2.09

0.039

Walach et al. BMC Medical Research Methodology 2005 5:26   doi:10.1186/1471-2288-5-26