Table 4. Association between daily lifting load and bodily fatigue after work and on the following morning. [LSM=least squares means; CI=confidence intervals].

Lifting load (kg		N	Minimally adjusted a			P-value	Fully adjusted b			P-value
			LSM		LSM differences		LSM		LSM differences
			Estimates		Difference (95% CI)		Estimates		Difference (95% CI)
After work
	0–499	439	3.31		Reference		2.90		Reference
	500–1999	143	3.54		0.24 (-0.26–0.74)	0.355	3.16		0.26 (-0.24–0.76)	0.307
	2000–3499	118	3.61		0.30 (-0.30–0.90)	0.327	3.20		0.30 (-0.29–0.90)	0.317
	3500–4999	191	3.67		0.36 (-0.30–1.02)	0.285	3.25		0.35 (-0.31–1.01)	0.302
	≥5000	50	3.94		0.63 (-0.16–1.43)	0.117	3.53		0.63 (-0.16–1.42)	0.118
The following morning
	0–499	439	2.22		Reference		2.03		Reference
	500–1999	143	2.26		0.04 (-0.44–0.53)	0.862	2.10		0.06 (-0.42–0.55)	0.795
	2000–3499	118	2.55		0.34 (-0.25–0.92)	0.261	2.36		0.32 (-0.27–0.91)	0.283
	3500–4999	191	2.56		0.34 (-0.30–0.98)	0.299	2.34		0.31 (-0.34–0.95)	0.353
	≥5000	50	2.95		0.74 (-0.08–1.55) c,d	0.076	2.79		0.75 (-0.07–1.57) c,d	0.071

^a Minimally adjusted model: Adjusted for age, sex, job title, years of employment, daily working hours, low-back pain intensity the preceding 4 weeks prior to baseline, chronic low-back pain, and perceived stress during the two weeks prior to baseline. ^b Fully adjusted model: Minimally adjusted + BMI, leisure-time physical activity, smoking status, influence at work, access to work tools, role clarity, guidance, community and cohesion between colleagues, recognition, respectful relationship between leader and employees, and fairness. ^c Tendency (P=0.07-0.08) towards a statistically significant difference from 0-499 kg (reference). ^d Tendency (P=0.06-0.07) towards a statistically significant difference from 500–1999 kg.