Table 3

Meta-regression results

MediatorsCoefficient2.50%97.50%P value
Study year−0.002−
Mean age−0.039−
% males0.004−
Study length in weeks0.04−
Risk of bias (low is the reference level)Some concerns−0.094−0.550.360.68
Stage (curative is the reference level)Palliative−0.307−0.710.100.14
Number of sites0.003−
Type of study (parallel arms trial is the reference level)X-over−0.009−0.520.510.97
Subjects in the placebo arm (categorical variable, 0–50 is the reference level)51–1990.117−0.0.530.58
Subjects in the placebo arm (continuous variable)0−0.0020.0030.74
Tool item (single is the reference level)Multidimensional−0.102−0.730.530.75
Placebo dosage regimen (fixed dose is the reference level)Flexible dose−0.001−0.440.430.99
Type of drug (other is the reference level)Psychostimulants0.157−0.220.530.41