Table 2.

Effect of per cent sitting time at work on trajectories of neck–shoulder pain intensity (scale 0–10) in the Danish PHysical ACTivity cohort with Objective measurements (DPHACTO) study population

				95% CI
	Estimate	SE	p Value	Lower	Upper
Model 1 (n=625)
Intercept	2.976	0.179	<0.01	2.624	3.327
Time	−0.020	0.010	0.053	−0.040	0.000
Sitting	0.000	0.005	0.966	−0.009	0.010
Interaction (sitting×time)	−0.001	0.000	0.020	−0.001	0.000
Model 2 (n=610)
Intercept	1.280	0.695	0.066	−0.085	2.645
Time	−0.019	0.010	0.072	−0.039	0.002
Sitting	0.003	0.005	0.582	−0.007	0.012
Interaction (sitting×time)	−0.001	0.000	0.020	−0.001	0.000
Model 3 (n=595)
Intercept	3.020	1.084	0.006	0.891	5.149
Time	−0.019	0.010	0.065	−0.040	0.001
Sitting	0.012	0.006	0.055	0.000	0.025
Interaction (sitting×time)	−0.001	0.000	0.027	−0.001	0.000

Model 1: unadjusted.

Model 2: adjusted for gender, age and body mass index.

Model 3: adjusted for the covariates in model 2 and occupational sector, lifting/carrying time at work, sitting time at leisure, physical activity at work and leisure, upper arm elevation >60° at work.

‘Time’ indicates the 14 pain ratings over 12 months, starting at baseline; ‘sitting’ represents sitting time in percentage of working hours; ‘interaction’ indicates the effect of sitting on the rate of change in pain intensity over time.