Children’s Nutrition Research Center Staff Publications
Language
English
Publication Date
1-13-2023
Journal
BMC Psychiatry
DOI
10.1186/s12888-022-04491-0
PMID
36639614
PMCID
PMC9840303
PubMedCentral® Posted Date
1-13-2023
PubMedCentral® Full Text Version
Post-print
Abstract
Ayudhaya et al. examined the effect of Behavioral Activation on daily step count and heart rate variability among older adults with depression in a study labeled a cluster randomized controlled trial (cRCT). However, only one cluster was assigned to either of the study conditions. Such a design would have zero degrees of freedom for inferential testing, because the variation due to cluster membership cannot be estimated apart from the variation due to treatment assignment. Thus, the intervention effect is completely confounded with the cluster effect. The study should be labeled a quasi-experimental study, not a cRCT. Accordingly, the numerical results should be interpreted as associations but not evidence for causal relationships.
Keywords
Humans, Aged, Depression, Thailand, Heart Rate, Behavior Therapy, Cluster randomized trial, Degrees of freedom, Inferential testing, Nesting
Published Open-Access
yes
Recommended Citation
Jamshidi-Naeini, Yasaman; Golzarri-Arroyo, Lilian; Siddique, Abu Bakkar; et al., "Only One Cluster per Condition Is an Invalid Design for a Cluster Randomized Trial and Should Be Re-Labeled a Quasi-Experimental Study. Response To: “Effect of Behavioral Activation on Time and Frequency Domain Heart Rate Variability in Older Adults With Subthreshold Depression: A Cluster Randomized Controlled Trial in Thailand”" (2023). Children’s Nutrition Research Center Staff Publications. 214.
https://digitalcommons.library.tmc.edu/staff_pub/214
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Biochemical Phenomena, Metabolism, and Nutrition Commons, Dietetics and Clinical Nutrition Commons, Endocrinology, Diabetes, and Metabolism Commons, Nutrition Commons