{"doi":"10.2147/cia.s400881","title":"Inappropriate Analysis of a Cluster Randomized Controlled Trial Due to Not Accounting for Nesting and Clustering: Comment on “A Home-Based Dyadic Music-with-Movement Intervention for People with Dementia and Caregivers: A Hybrid Type 2 Cluster-Randomized Effectiveness-Implementation Design” [Letter]","abstract":"Cheung et al accepted an important challenge by conducting a cluster randomized controlled trial (cRCT) primarily designed to assess the effect of a music-with-movement (MM) intervention on psychosocial wellbeing of patients with dementia and their caregivers. 1 Due to identified barriers in applying MM, the secondary aim of their experiment was to determine implementation strategy effectiveness of the home-based, dyadic MM intervention. 1 To appropriately assess outcomes using a cluster randomized design requires that intracluster dependency, typically as quantified by the intracluster correlation coefficient (ICC), be accounted for in the statistical analysis. 2Accounting for non-independence allows for comparison between individuals in the clusters assigned to intervention or control conditions because it accounts for potential non-independence of model residuals within clusters. 2Given this, there are concerns within the publication by Cheung et al.Most importantly, the authors did not explain how clustering was accommodated within the statistical analysis used, suggesting that it was not.Additionally, accounting for nesting in cRCTs is critical, especially with a small number of clusters (K), because if K is small, the available degrees of freedom for estimating effect sizes must also be small. 2Ignoring either non-independence or limited degrees of freedom often inflates type I error rate. 2 We also highlight a concern with the article's reported sample size calculations.The cRCT CONSORT guidelines require that authors report the methods used for sample size calculation, number of clusters (K), size of clusters (m), whether equal or unequal cluster sizes were assumed, assumed ICC, and an indication of the ICC uncertainty.The authors did include the assumed ICC (0.01) for sample size calculation of their trial registration's statistical analysis plan (NCT03575026).However, they reported a sample size calculation only with respect to the number of individual participants, not accounting for the number of clusters required to reach statistical power.The number of clusters has greater impact on statistical power in cRCTs than does the number of individual participants.","journal":"Clinical Interventions in Aging","year":2023,"id":384604,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9436,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":797347,"name":"Yasaman Jamshidi‐Naeini","orcid":"0000-0003-4769-2764","position":1,"is_corresponding":false},{"id":528482,"name":"Colby J. Vorland","orcid":"0000-0003-4225-372X","position":2,"is_corresponding":false},{"id":501096,"name":"Lilian Golzarri‐Arroyo","orcid":"0000-0002-1221-6701","position":3,"is_corresponding":false},{"id":71622,"name":"Brian P. Shaw","orcid":"0000-0002-6152-6001","position":4,"is_corresponding":false},{"id":71621,"name":"David B. Allison","orcid":"0000-0003-3566-9399","position":5,"is_corresponding":false},{"id":1126585,"name":"Marleigh Hefner","orcid":null,"position":0,"is_corresponding":true}],"reference_count":4,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T01:17:37.110513Z","pmid":"36755746","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}