Does being physically active prevent future disability in older people?: attenuated effects when taking time-dependent confounders into account

Causal experimental evidence that physical activity prevents disability in older people is sparse. Being physically active has nonetheless been shown to be associated with disability-free survival in observational studies. Observational studies are, however, prone to bias introduced by time-dependen...

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Main Authors: Kreisel, Stefan H. (Author) , Blahak, Christian (Author) , Bäzner, Hansjörg (Author) , Hennerici, Michael G. (Author)
Format: Article (Journal)
Language:English
Published: 21 December 2017
In: BMC geriatrics
Year: 2017, Volume: 17, Pages: 290
ISSN:1471-2318
DOI:10.1186/s12877-017-0657-3
Online Access:Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1186/s12877-017-0657-3
Verlag, kostenfrei, Volltext: https://doi.org/10.1186/s12877-017-0657-3
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Author Notes:Stefan H. Kreisel, Christian Blahak, Hansjörg Bäzner and Michael G. Hennerici
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Summary:Causal experimental evidence that physical activity prevents disability in older people is sparse. Being physically active has nonetheless been shown to be associated with disability-free survival in observational studies. Observational studies are, however, prone to bias introduced by time-dependent confounding. Time-dependent confounding occurs when an exposure (e.g. being physically active at some time-point) potentially affects the future status of a confounder (such as depression sometime later), and both variables have an effect on latter outcome (i.e. disability). “Conventional” analysis with e.g. Cox-regression is the mainstay when analyzing longitudinal observational studies. Unfortunately, it does not provide unbiased estimates in the presence of time-dependent confounding. Marginal structural models (MSM) - a relatively new class of causal models - have the potential to adequately account for time-dependent confounding.
Item Description:Gesehen am 06.06.2018
Physical Description:Online Resource
ISSN:1471-2318
DOI:10.1186/s12877-017-0657-3