A statistical model for interpreting computerized dynamic posturography data

Alan H. Feiveson, E. Metter, William H. Paloski

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Computerized dynamic posturography (CDP) is widely used for assessment of altered balance control. CDP trials are quantified using the equilibrium score (ES), which ranges from zero to 100, as a decreasing function of peak sway angle. The problem of how best to model and analyze ESs from a controlled study is considered. The ES often exhibits a skewed distribution in repeated trials, which can lead to incorrect inference when applying standard regression or analysis of variance models. Furthermore, CDP trials are terminated when a patient loses balance. In these situations, the ES is not observable, but is assigned the lowest possible score - zero. As a result, the response variable has a mixed discrete-continuous distribution, further compromising inference obtained by standard statistical methods. Here, we develop alternative methodology for analyzing ESs under a stochastic model extending the ES to a continuous latent random variable that always exists, but is unobserved in the event of a fall. Loss of balance occurs conditionally, with probability depending on the realized latent ES. After fitting the model by a form of quasi-maximum-likelihood, one may perform statistical inference to assess the effects of explanatory variables. An example is provided, using data from the NIH/NIA Baltimore Longitudinal Study on Aging.

Original languageEnglish (US)
Pages (from-to)300-309
Number of pages10
JournalIEEE Transactions on Biomedical Engineering
Volume49
Issue number4
DOIs
StatePublished - Apr 3 2002
Externally publishedYes

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Stochastic models
Analysis of variance (ANOVA)
Random variables
Maximum likelihood
Statistical methods
Aging of materials
Statistical Models

All Science Journal Classification (ASJC) codes

  • Biomedical Engineering

Cite this

A statistical model for interpreting computerized dynamic posturography data. / Feiveson, Alan H.; Metter, E.; Paloski, William H.

In: IEEE Transactions on Biomedical Engineering, Vol. 49, No. 4, 03.04.2002, p. 300-309.

Research output: Contribution to journalArticle

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