| Nonlinear Dynamics, Psychology, and Life Sciences, Vol. 20, Iss. 3, Jul, 2016, pp. 319-352 @2016 Society for Chaos Theory in Psychology & Life Sciences "How do I feel today?" An Analysis of HRQOL Variability among Institutionalized Older Adults Abstract: Intra-individual variability is a central topic in Nonlinear Dynamical Systems (NDS)
studies of human development, because the theory predicts that particular forms or
properties of intra-individual variability will serve as indicators or predictors of
bifurcations, and stable states in individual development. Currently,
there are almost no studies that address intra-individual changes and variability of
Health Related Quality of Life in old age. The main aim of this paper is to
analyze the role of day-to-day HRQOL variability and long term HRQOL and
disability development in a sample of institutionalized older adults.
22 older adults took part in this longitudinal study. Daily diary-based assessments
were made for a period of 100 days. Furthermore, monthly assessments of HRQOL and
disability with validated questionnaires were performed. The intra individual variability
on a day-to-day basis was found to be related to HRQOL and disability development.
Furthermore, life events as operationalized by extreme values in HRQOL were related to the
level of day-to-day HRQOL variability. As predicted by NDS theory, day-to-day variability emerges
as an important indicator of levels of and changes in HRQOL and disability and as such,
it may be an important indicator of developmental processes in old age. Keywords: intra-individual variability, diary method, disability, institutionalized older adults, health related quality of life, perturbation |