Title
Statistical power of articles published in three health psychology-related journals
Document Type
Article
Date of Original Version
1-1-2001
Abstract
Power was calculated for 8,266 statistical tests in 187 journal articles published in the 1997 volumes of Health Psychology (HP), Addictive Behaviors (AB), and the Journal of Studies on Alcohol (JSA). Power to detect small, medium, and large effects was .34, .74, and .92 for HP; .34, .75, and .90 for AB; and .41, .81, and .92 for JSA. Mean power estimates are .36, .77, and .91, giving a good estimation for the field of health psychology. J. Cohen (1988) recommended that power to detect effects should be approximately .80. Using this criterion, the articles in these journals have adequate power to detect medium and large effects. Intervention studies have much less power to detect effects than nonintervention studies do. Results are encouraging for this field, although studies examining small effects are still very much underpowered. This issue is important, because most intervention effects in health psychology are small.
Publication Title, e.g., Journal
Health Psychology
Volume
20
Issue
1
Citation/Publisher Attribution
Maddock, Jason E., and Joseph S. Rossi. "Statistical power of articles published in three health psychology-related journals." Health Psychology 20, 1 (2001): 76-78. doi: 10.1037/0278-6133.20.1.76.