RT Journal Article
SR Electronic
T1 Post hoc power analysis: is it an informative and meaningful analysis?
JF General Psychiatry
JO Gen Psych
FD BMJ Publishing Group Ltd
SP e100069
DO 10.1136/gpsych-2019-100069
VO 32
IS 4
A1 Zhang, Yiran
A1 Hedo, Rita
A1 Rivera, Anna
A1 Rull, Rudolph
A1 Richardson, Sabrina
A1 Tu, Xin M
YR 2019
UL http://gpsych.bmj.com/content/32/4/e100069.abstract
AB Power analysis is a key component for planning prospective studies such as clinical trials. However, some journals in biomedical and psychosocial sciences ask for power analysis for data already collected and analysed before accepting manuscripts for publication. In this report, post hoc power analysis for retrospective studies is examined and the informativeness of understanding the power for detecting significant effects of the results analysed, using the same data on which the power analysis is based, is scrutinised. Monte Carlo simulation is used to investigate the performance of posthoc power analysis.