Quantification of the Fragmentation of Rest-Activity Patterns in Elderly Individuals Using a State Transition Analysis

Abstract

Probabilistic analyses of the transition dynamics of rest-activity data provide a high-throughput, automated, quantitative, and noninvasive method of assessing the fragmentation of behavioral states suitable for large scale human and animal studies; these methods reveal age-associated changes in the fragmentation of rest-activity patterns akin to those described using polysomnographic methods.

0934 Evaluating the Effects of General Anesthesia on Sleep in Children Undergoing Elective Surgery

“…The plot is generally divided into 3 regions: a falling region where a rapid decline is observed, followed by a constant non-zero probability region, and ending with a rising region where a slow increase occurs at the end of the longest runs. Similar to Lim and colleagues, we found that the rising regions were identified based on a relatively small number of data points and may represent an artifact (Lim et al, 2011 "usually" if the sleep behaviour occurred five to seven times a week, "sometimes" for two to four times a week, and "rarely" for zero to one time a week. Specific items are scored in a reverse order in order to make a higher score indicative of more disturbed sleep.…”

“…As older age tends to be associated with more fragmented runs of activity, children would be expected to show a reduced tendency towards fragmented runs of activity compared to older individuals (Lim et al, 2011). In contrast, mean kRA was higher in the control group and surgical group compared to the elderly, indicating that children have an increased tendency towards fragmented runs of rest.…”

“…however there remains a lack of normative data for children (Lim et al, 2011). Thus, the application of the transition probabilities algorithm in a pediatric population is new and relevant to this thesis.…”

“…An additional tool involves a state-transition analysis that quantifies the degree of fragmentation during runs of rest and activity in a 24-hour day. Lim and colleagues constructed an algorithm that computes transition probabilities between periods of rest and activity using raw actigraphy epoch data, but the algorithm has previously only been applied to an elderly population (Lim et al, 2011). This algorithm had not been applied in children.…”

Regional neocortical gray matter structure and sleep fragmentation in older adults

“…[25][26][27] Briefly, k RA is the probability per 15-sec period of having an arousal, as indicated by movement (a nonzero activity count) after a sustained (≥ ~5 min) period of rest (i.e., sleep). A higher k RA indicates greater sleep fragmentation.…”