Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study

Table 2 Hazard ratios for the risk of functional disability by total sedentary time and mean sedentary bout duration quartiles (n = 1,687)^a

	No. of events/participants	Incidence rate per 1000 person-years	Model 1		Model 2		Model 3
	No. of events/participants	Incidence rate per 1000 person-years	HR (95% CI)	P value	HR (95%CI)	P value	HR (95% CI)	P value
Total sedentary time
Quartile 1 (low)	87/421	26.4	1.00		1.00		1.00
Quartile 2	104/422	33.5	1.20 (0.90‒1.60)	0.22	1.21 (0.91‒1.62)	0.19	0.94 (0.70‒1.27)	0.69
Quartile 3	133/422	44.9	1.42 (1.08–1.87)	0.01	1.45 (1.10‒1.92)	0.01	1.02 (0.76‒1.37)	0.90
Quartile 4 (high)	142/422	50.3	1.41 (1.06‒1.87)	0.02	1.40 (1.05‒1.88)	0.02	0.85 (0.61‒1.18)	0.33
P for trend				0.01		0.01		0.41
Mean sedentary bout length
Quartile 1 (low)	96/421	30.0	1.00		1.00		1.00
Quartile 2	106/422	34.1	1.06 (0.81‒1.40)	0.66	1.07 (0.81‒1.42)	0.63	0.95 (0.71‒1.25)	0.70
Quartile 3	117/422	38.7	1.06 (0.80‒1.39)	0.70	1.10 (0.83‒1.44)	0.51	0.92 (0.70‒1.22)	0.58
Quartile 4 (high)	147/422	51.5	1.22 (0.93‒1.60)	0.15	1.22 (0.93‒1.60)	0.15	0.93 (0.70‒1.23)	0.60
P for trend				0.16		0.15		0.61

Model 1 was adjusted for age and sex
Model 2 was additionally adjusted for education, living alone, body mass index, multimorbidity, having a fall in the past year, low walking ability, cognitive impairment, smoking, and drinking
Model 3 was additionally adjusted for moderate-to-vigorous physical activity
CI confidence interval, HR hazard ratio
^aValues of total sedentary time were corrected for accelerometer wear time by standardizing the total sedentary time to 16 h per day of accelerometer wear time, using the residuals obtained by regressing total sedentary time on accelerometer wear time. The quartile cut-off points were 460.1, 537.4, and 611.3 min/day for total sedentary time and 6.1, 7.5, and 9.4 min/day for mean sedentary bout duration

ISSN: 1479-5868