Table 4.

Associations of exercise over the first 36 months after breast cancer diagnosis with total mortality and relapse/disease-specific mortality, stratified by menopausal status, QOL, and BMI

	Total mortality			Relapse/disease-specific mortality
	Total	Events	HR (95% CI)	Total	Events	HR (95% CI)
Stratified by menopausal status ^a
Premenopause	2,359	186		2,202	208
MET-hours per week^b
No exercise	835	76	1.00	773	81	1.00
<8.3	764	49	0.87 (0.58–1.10)	714	55	0.59 (0.39–0.89)
≥8.3	760	61	0.86 (0.58–1.26)	715	72	0.69 (0.47–1.00)
P_trend			0.317			0.631
Postmenopause	2,467	250		2,309	242
MET-hours per week^b
No exercise	876	109	1.00	807	93	1.00
<8.3	802	73	0.82 (0.59–1.14)	754	73	0.63 (0.44–0.91)
≥8.3	789	68	0.55 (0.40–0.77)	748	76	0.52 (0.36–0.74)
P_trend			<0.001			0.001
P_interaction			0.233			0.300
Stratified by QOL ^c
QOL < median	2,278	205		2,138	222
MET-hours per week^b
No exercise	902	101	1.00	827	99	1.00
<8.3	723	56	0.63 (0.44–0.90)	681	59	0.45 (0.31–0.65)
≥8.3	653	48	0.50 (0.35–0.71)	630	64	0.47 (0.33–0.66)
P_trend			<0.001			0.006
QOL ≥ median	2,548	231		2,373	228
MET-hours per week^b
No exercise	809	84	1.00	753	75	1.00
<8.3	843	66	1.06 (0.73–1.55)	787	69	0.80 (0.53–1.21)
≥8.3	896	81	0.83 (0.58–1.21)	833	84	0.74 (0.50–1.10)
P_trend			0.111			0.289
P_interaction			0.294			0.218
Stratified by BMI ^d
BMI<25	3,128	267		2,914	266
MET-hours per week^b
No exercise	1,102	113	1.00	1,015	98	1.00
<8.3	999	76	0.76 (0.55–1.05)	932	81	0.70 (0.47–0.96)
≥8.3	1,027	78	0.62 (0.45–0.85)	967	87	0.66 (0.47–0.94)
P_trend			0.002			0.033
BMI ≥ 25	1,698	169		1,597	184
MET-hours per week^b
No exercise	609	72	1.00	565	76	1.00
<8.3	567	46	0.91 (0.60–1.38)	536	47	0.53 (0.35–0.81)
≥8.3	522	51	0.70 (0.46–1.05)	496	61	0.50 (0.38–0.74)
P_trend			0.027			0.095
P_interaction			0.642			0.704
Stratified by Charlson comorbidity index
Charlson comorbidity index <1	3,869	339		3,601	350
MET-hours per week^b
No exercise	1,360	138	1.00	1,253	133	1.00
<8.3	1,258	98	0.89 (0.66,1.18)	1,172	101	0.65 (0.47–0.89)
≥8.3	1,251	103	0.68 (0.50–0.90)	1,176	116	0.66 (0.49–0.90)
P_trend			0.003			0.162
Charlson comorbidity index ≥1	957	97		910	100
MET-hours per week^b
No exercise	351	47	1.00	327	41	1.00
<8.3	308	24	0.63 (0.36–1.10)	296	27	0.49 (0.26–0.78)
≥8.3	298	26	0.62 (0.37–1.05)	287	32	0.39 (0.23–0.66)
P_trend			0.050			0.009
P_interaction			0.198			0.651

^aAdjusted for date of birth, BMI at baseline, waist-to-hip ratio at baseline, income, education, QOL, cruciferous vegetable intake, soy protein intake, tea consumption, chemotherapy, radiotherapy, tamoxifen use, TNM status, and ER/PR receptor status.
^bExercise was treated as a time-dependent variable.
^cFurther adjusted for TNM status instead of QOL.
^dFurther adjusted for QOL instead of BMI.