Exploring patterns of daily physical and sedentary behaviour in community-dwelling older adults.
BACKGROUND
recent evidence suggests that the interaction between periods of sedentary and activity behaviour is important for health; providing distinctive information to assessment of activity alone. This study quantified activity and sedentary behaviour in older, community-dwelling adults.


METHODS
fifty-six community-dwelling older adults with an average age 79 (SD) years wore an ActivPAL accelerometer for 7 days and were assessed for a range of motor, cognitive and affective characteristics. Seven variables derived from accelerometry considered to represent four characteristics of habitual behaviour (volume, frequency, intensity and variability) were submitted to principal components factor analysis (PCA). Factor scores were retained and used as dependent variables in regression analysis.


RESULTS
three significant orthogonal factors emerged from the PCA, accounting for 80% of the variance in test scores: 'walking behaviour' which accounted for 39% of variance in the model; 'sedentary behaviour' explaining 24.3% of total variance; and 'postural transitions' which accounted for 16.7% of total variance. For the regression analysis, younger age and lower body mass index (BMI) emerged as significant predictors of physical behaviour, explaining 36% of the total variance. For postural transitions, lower BMI was the unique contributor, explaining 15% of total variance. Significant predictors of sedentary behaviours were not identified.


CONCLUSIONS
walking, sedentary and transitory behaviours are distinct from each other, and together explain daily function. Further research on a larger sample is indicated to explore the characteristics that explain these behaviours, in particular the interplay between sedentary behaviour and periods of physical activity.
Institute for Ageing and Health, Newcastle University, Clinical Ageing Research Unit, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
Sue
S
Lord
Sebastien Francois Martin
SF
Chastin
Lynn
L
McInnes
Linda
L
Little
Pam
P
Briggs
Lynn
L
Rochester
D056044:Actigraphy / Q000295:instrumentation; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015992:Body Mass Index; D003071:Cognition; D005163:Factor Analysis, Statistical; D005260:Female; D006184:Habits; D006801:Humans; D057187:Independent Living; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D025341:Principal Component Analysis; D012044:Regression Analysis; D057185:Sedentary Behavior; D013997:Time Factors; D006113:United Kingdom; D016138:Walking