Table 5.

Within-individual association between multisite pain and sickness absence days

Pain	All	High occupational class	Low occupational class	P value for the occupational class interaction†
	IRR (95% CI)	IRR (95% CI)	IRR (95% CI)
Short-term association
Pain (ref group: no pain)
One pain location	1.22*** (1.10 to 1.36)	1.11 (0.95 to 1.29)	1.38*** (1.20 to 1.60)	0.012
Two pain locations	1.35*** (1.19 to 1.54)	1.30** (1.07 to 1.58)	1.46*** (1.21 to 1.75)	0.293
Three or more pain locations	1.21* (1.04 to 1.40)	1.19 (0.95 to 1.50)	1.26* (1.03 to 1.55)	0.706
Number of observations	10 849	6181	4668
Long-term association
Pain (ref group: no pain)
One pain location	1.16** (1.05 to 1.27)	1.15 (1.00 to 1.33)	1.19* (1.04 to 1.37)	0.529
Two pain locations	1.23*** (1.09 to 1.39)	1.16 (0.97 to 1.40)	1.27**(1.08 to 1.51)	0.528
Three or more pain locations	1.36*** (1.19 to 1.55)	1.17 (0.94 to 1.45)	1.55*** (1.30 to 1.86)	0.042
Number of observations	8214	4600	3614

All models adjusted for common mental disorders, long-standing illness, physical and mental work environments, job control, survey wave, marital status, night/shift work and part-time work.

*p<0.05; **p<0.01; ***p<0.001.

†Interaction terms for variables differed in the stratified models included to a single model.

Short-term, within the survey year; long-term, during 2 years after the survey year.

IRRs, incidence rate ratios and their 95% CIs.