Statistical power calculations for clustered continuous data

Gałecki, Andrzej T.; Chen, S.; Ashton‐Miller, James A.; Burzykowski, Tomasz

doi:10.1504/ijkesdp.2009.021983

Cited by 2 publications

(2 citation statements)

References 2 publications

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“…Methods for powering cluster analysis are not yet well established, though smaller samples have a higher likelihood of type‐2 errors than studies with larger samples, which are more generalizable. Work on the best methods of a priori power analysis for clustering methods is ongoing (Galecki, Burzykowski, Chen, Faulkner, & Ashton‐Miller, 2009; Gudicha, Tekle, & Vermunt, 2016; Tein, Coxe, & Cham, 2013).…”

Section: Discussionmentioning

confidence: 99%

A systematic review of illness representation clusters in chronic conditions

Rivera

Corte

DeVon

et al. 2020

Research in Nursing & Health

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A person's beliefs about their chronic condition (illness representations) influence health and treatment outcomes. Recently, researchers have used clustering approaches to identify subgroups with different patterns of beliefs about their illness, with some subgroups having more favorable health outcomes than others. To date, these findings have not been synthesized. The purpose of this systematic review of the literature was to synthesize results of studies that used clustering approaches to analyze illness representation in chronic disease populations, in order to characterize the clusters and their relationship to health outcomes. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines we searched CINAHL, PsycInfo, and PubMed. To be included, studies had to be (a) peer reviewed, (b) in English, (c) performing a cluster analysis (CA), latent class analysis (LCA), or latent profile analysis (LPA), (d) using only illness representation (IR) subscales to form clusters, (e) measuring illness representation with the Illness Perception Questionnaire (IPQ-R), (f) in a chronic condition sample, and (g) measuring health-related outcomes. Twelve studies were included. Across studies, the number of clusters found ranged from two to three. In all studies, an association was found between illness representation group and at least one of their health outcomes. Illness representation clusters associated with favorable outcomes usually included lower disease-related consequences, fewer symptoms, less negative emotion, and a more stable disease pattern. The results of this review indicate that the relationship between the patterns of the illness representation profiles and health outcomes transcend diseases. Additionally, some dimensions of illness representation may be more important drivers of group membership than others. K E Y W O R D S chronic condition, cluster analysis, illness perception, illness representation, systematic review

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Section: Discussionmentioning

confidence: 99%

A systematic review of illness representation clusters in chronic conditions

Rivera

Corte

DeVon

et al. 2020

Research in Nursing & Health

View full text Add to dashboard Cite

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“…Models were fitted, and computations were performed using PROC MIXED (SAS 9.1). Sample size calculations were based on the work of Galecki et al (15). The level of significance was set a priori at P Ͻ 0.05.…”

Section: Methodsmentioning

confidence: 99%

Effects of high- and low-velocity resistance training on the contractile properties of skeletal muscle fibers from young and older humans

Claflin

Larkin

Cederna

et al. 2011

Journal of Applied Physiology

118

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A two-arm, prospective, randomized, controlled trial study was conducted to investigate the effects of movement velocity during progressive resistance training (PRT) on the size and contractile properties of individual fibers from human vastus lateralis muscles. The effects of age and sex were examined by a design that included 63 subjects organized into four groups: young (20-30 yr) men and women, and older (65-80 yr) men and women. In each group, one-half of the subjects underwent a traditional PRT protocol that involved shortening contractions at low velocities against high loads, while the other half performed a modified PRT protocol that involved contractions at 3.5 times higher velocity against reduced loads. Muscles were sampled by needle biopsy before and after the 14-wk PRT program, and functional tests were performed on permeabilized individual fiber segments isolated from the biopsies. We tested the hypothesis that, compared with low-velocity PRT, high-velocity PRT results in a greater increase in the cross-sectional area, force, and power of type 2 fibers. Both types of PRT increased the cross-sectional area, force, and power of type 2 fibers by 8-12%, independent of the sex or age of the subject. Contrary to our hypothesis, the velocity at which the PRT was performed did not affect the fiber-level outcomes substantially. We conclude that, compared with low-velocity PRT, resistance training performed at velocities up to 3.5 times higher against reduced loads is equally effective for eliciting an adaptive response in type 2 fibers from human skeletal muscle.

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Statistical power calculations for clustered continuous data

Cited by 2 publications

References 2 publications

A systematic review of illness representation clusters in chronic conditions

A systematic review of illness representation clusters in chronic conditions

Effects of high- and low-velocity resistance training on the contractile properties of skeletal muscle fibers from young and older humans

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