TY  - JOUR
PY  - 2010//
TI  - The effect of population heterogeneity on statistical power in the design and evaluation of interventions
JO  - International journal of behavioral development
A1  - Depeng Jiang, 
A1  - Pepler, Debra
A1  - Hongxing Yao, 
SP  - 473
EP  - 480
VL  - 34
IS  - 5
N2  - Do interventions work and for whom? For this article, we examined the influence of population heterogeneity on power in designing and evaluating interventions. On the basis of Monte Carlo simulations in Study 1, we demonstrated that the power to detect the overall intervention effect is lower for a mixture of two subpopulations than for a homogeneous population with the same average effect size. We also examined how obtaining covariate information for the outcome and risk status (i.e., latent subclass membership) affects power. For Study 2, we moved from the simulation to assess power in the design and evaluation of an intervention for antisocial children. We illustrated the importance of considering population heterogeneity because interventions have different impacts on different ‘‘classes’’ of participants. We also illustrated that power increases by including covariates that are correlated with risk status. The results provide guidelines for the design and evaluation of interventions.<p />
LA  - 
SN  - 0165-0254
UR  - http://dx.doi.org/10.1177/0165025410375912
ID  - ref1
ER  -