Sedentary Behavior and Physical Function Decline in Older Women: Findings from the Women's Health Initiative

Table 3

Multivariate analysis of change in physical function score over time between WHI-OS baseline and WHI-OSES follow up and daily sitting time and total sedentary time⁵.

Key variable	Change in mean physical function score
	Parameter estimate	95% CI	𝑃 value
Sitting time at baseline			<.0001
Q1 (≤4.5 hours/day)	1.00	(referent)
Q2 (>4.5–6.5 hours/day)	−0.96	(−1.16, −0.76)
Q3 (>6.5–8.5 hours/day)	−1.45	(−1.68, −1.22)
Q4 (>8.5 hours/day)	−2.45	(−2.69, −2.22)
Total sedentary time at baseline			<.0001
Q1 (≤6 hours/day)	1.00	(referent)
Q2 (>6–8 hours/day)	−0.78	(−0.98, −0.57)
Q3 (>8–11 hours/day)	−1.48	(−1.71, −1.25)
Q4 (>11 hours/day)	−3.13	(−3.36, −2.89)

⁵Results from linear mixed model of repeated measures assuming AR (1) covariance structure, adjusted for age race/ethnicity, education, physical activities, self-reported general health, BMI, smoking status, alcohol use, hormone use, depressed mood, living alone, activities of daily living, history of CHD, history of CHF, stroke, treated diabetes, arthritis, and history of COPD at baseline. Key variables were estimated in separated models and updated in the model with Year 3 data when available.