Table 4. Odds ratios (OR) and 95% confidence intervals (CI) of sickness absence 3 and 5 years following a diagnosis of stage I-IIb breast cancer.

	Sickness absence after 3 years						Sickness absence after 5 years
	Yes	Model 1		Model 2		Yes	Model 3		Model 4
	No./Total	%	OR	95% CI	OR	95% CI	No./Total	%	OR	95% CI	OR	95% CI
Sickness absence 1 year prior
Yes	933/1169	79.8	1.00	(ref.)	1.00	(ref.)	685/868	78.9	1.00	(ref.)	1.00	(ref.)
No	946/2925	32.3	0.12	0.10–0.15	0.12	0.10–0.14	863/2375	36.3	0.16	0.13–0.19	0.15	0.13–0.19
Education 1 year before
Low	528/1006	52.5	1.00	(ref.)	1.00	(ref.)	461/841	54.8	1.00	(ref.)	1.00	(ref.)
Middle	857/1881	45.6	0.88	0.75–1.05	0.89	0.75–1.06	691/1451	47.6	0.85	0.71–1.03	0.86	0.71–1.03
High	490/1197	40.9	0.84	0.70–1.02	0.83	0.68–1.00	394/943	41.8	0.77	0.63–0.94	0.76	0.61–0.93
Unknown	4/11	36.4	0.57	0.14–2.25	0.49	0.12–2.00	2/8	25.0	0.50	0.10–2.49	0.44	0.09–2.23
Tumour size
1–10	336/819	41.0	1.00	(ref.)	1.00	(ref.)	284/639	44.4	1.00	(ref.)	1.00	(ref.)
11–20	907/2047	44.3	1.15	0.96–1.38	1.01	0.84–1.22	755/1632	46.3	1.09	0.90–1.34	1.02	0.83–1.26
21–50	610/1183	51.6	1.66	1.36–2.03	1.14	0.91–1.42	490/933	52.2	1.49	1.20–1.86	1.18	0.93–1.51
50+	26/46	56.5	2.19	1.15–4.18	1.47	0.76–2.88	19/39	48.7	1.25	0.62–2.50	0.98	0.48–2.02
Lymph nodes
N0	1189/2732	43.5	1.00	(ref.)	1.00	(ref.)	992/2165	45.8	1.00	(ref.)	1.00	(ref.)
N+ (Yes)	690/1363	50.6	1.49	1.29–1.72	1.00	0.83–1.21	556/1078	51.6	1.36	1.16–1.59	1.08	0.88–1.33
Sentinel node
Sentinel node only	116/278	41.2	1.00	(ref.)			25/56	44.6	1.00	(ref.)
Axillary dissection (1–9)	661/1525	43.3	1.26	0.94–1.69			630/1313	48.0	1.41	0.78–2.54
Axillary dissection (10+)	1096/2279	48.1	1.59	1.20–2.12			889/1863	47.7	1.44	0.80–2.59
Missing	6/13	46.2	1.18	0.33–4.24			4/11	36.4	0.68	0.15–3.04
Surgery
Mastectomy	629/1193	52.7	1.00	(ref.)	1.00	(ref.)	503/955	52.7	1.00	(ref.)	1.00	(ref.)
Breast-conserving	1241/2881	43.7	0.62	0.53–0.72	0.71	0.59–0.86	1038/2272	45.7	0.72	0.61–0.85	0.77	0.63–0.95
None or missing	9/21	42.9	-	-	-	-	7/16	43.8	-	-	-	-
Received radiotherapy
Yes	1605/3539	45.4	0.90	0.74–1.10	0.99	0.78–1.26	1332/2796	47.6	1.03	0.83–1.28	1.12	0.86–1.44
No	274/556	49.3	1.00	(ref.)	1.00	(ref.)	216/447	48.3	1.00	(ref.)	1.00	(ref.)
Received chemotherapy
Yes	777/1483	52.4	1.74	1.51–2.01	1.55	1.29–1.86	558/1083	51.5	1.42	1.22–1.67	1.23	1.00–1.50
No	1102/2612	42.2	1.00	(ref.)	1.00	(ref.)	990/2160	45.8	1.00	(ref.)	1.00	(ref.)
Received hormonal therapy (Tamoxifen)
Yes	822/1629	50.5	1.35	1.17–1.55	1.25	1.08–1.46	537/1055	50.9	1.20	1.02–1.40	1.08	0.90–1.29
No	1057/2466	42.9	1.00	(ref.)	1.00	(ref.)	1911/2188	46.2	1.00	(ref.)	1.00	(ref.)

Model 1: Adjustment for sickness absence 1 year before diagnosis, education.

Model 2: Adjustment for sickness absence 1 year before diagnosis, education, tumour size, having lymph nodes, stage, and treatment.

Model 3: Adjustment for sickness absence 1 year before diagnosis, education.

Model 4: Adjustment for sickness absence 1 year before diagnosis, education, tumour size, having lymph nodes, stage, and treatment.