Table 2.

Hazard ratios and 95% confidence intervals for associations of recreational physical activity and outcomes after first invasive breast cancer diagnosis in the Prospective Family Study Cohort

Categorization of RPA	All-cause mortality (n = 4610)				Second breast cancer event (n = 4356)
	No. of women	No. of events	Person-years	HR (95% CI)a	No. of women	No. of events	Person-years	HR (95% CI)a
RPA categorized as any vs none
None	750	226	7541	1.00 (Referent)	720	67	6981	1.00 (Referent)
Any	3860	986	43 331	0.84 (0.72 to 0.98)	3636	406	38 609	1.05 (0.81 to 1.38)
RPA categorized by intensity level
None	750	226	7541	1.00 (Referent)	720	67	6981	1.00 (Referent)
Moderate RPA only	1737	446	20 025	0.82 (0.70 to 0.97)	1646	193	18 007	1.17 (0.88 to 1.56)
Strenuous RPA	2123b	540	23 306	0.86 (0.73 to 1.02)	1990c	213	20 602	0.93 (0.69 to 1.24)
RPA categorized by national and international guidelinesd
None	750	226	7541	1.00 (Referent)	720	67	6981	1.00 (Referent)
Some, but less than guidelinese	1045	263	11 949	0.83 (0.69 to 0.99)	992	108	10 764	1.12 (0.82 to 1.53)
Met guidelinesf	1581	431	17 282	0.87 (0.73 to 1.03)	1505	184	15 522	1.10 (0.82 to 1.47)
Exceeded guidelinesg	1234	292	14 100	0.81 (0.67 to 0.98)	1 to139	114	12 to323	0.92 (0.67 to 1.27)
RPA categorized by quintiles of total metabolic equivalents
< 4 MET-hrs/wk	857	250	8839	1.00 (Referent)	821	79	8140	1.00 (Referent)
4-11 MET-hrs/wk	910	231	10 267	0.88 (0.73 to 1.06)	865	92	9255	1.09 (0.81 to 1.49)
12-20 MET-hrs/wk	1193	325	12 959	0.92 (0.78 to 1.10)	1133	135	11 653	1.05 (0.79 to 1.40)
21-34 MET-hrs/wk	781	210	8771	0.88 (0.73 to 1.07)	738	84	7846	0.98 (0.71 to 1.34)
> 34 MET-hrs/wk	869	196	10 036	0.83 (0.68 to 1.01)	799	83	8696	0.94 (0.68 to 1.31)
Ptrendh across quintiles of MET-hrs/wk				.13				.45

^aHazard ratio and 95% confidence interval adjusted for age group at diagnosis (younger than 40, 40-49, 50-59, 60 years or older), study center (Australia, Canada, kConFab, New York, Northern California, Philadelphia, Utah), decade of birth year (<1950, 1950-1959, 1960-1969, ≥1970), race and ethnicity (Asian, Hispanic, non-Hispanic Black, non-Hispanic White, other), education (high school graduate or less, some college, Bachelor degree or higher), cigarette smoking (never, former, current), alcohol consumption (never, former, current), postmenopausal hormone therapy use (never vs otherwise), body mass index (<25, 25 to <30, ≥30 kg/m²), stage at diagnosis (1, 2, 3 or 4, unknown), chemotherapy for first invasive breast cancer (yes vs otherwise) radiation treatment for first invasive breast cancer (yes vs otherwise), and surgery for first invasive breast cancer (mastectomy, lumpectomy, otherwise). CI = confidence interval; HR = hazard ratio; MET = metabolic equivalents; RPA = recreational physical activity.

^bIncludes 106 women who engaged in only strenuous RPA and 2017 women who engaged in strenuous and moderate RPA.

^cIncludes 100 women who engaged in only strenuous RPA and 1890 who engaged in strenuous and moderate RPA.

^dBased on the Physical Activity Guidelines for Americans (2018) and the World Health Organization’s 2020 Physical Activity Guidelines, which recommend adults engage in 150-300 minutes per week of moderate physical activity or 75-150 minutes per week of strenuous physical activity, or some combination.

^eLess than 150 minutes per week of moderate RPA and less than 75 minutes per week of strenuous RPA.

^f150-300 minutes per week of moderate RPA or 75-150 minutes per week of strenuous RPA.

^g>300 minutes per week of moderate or >150 minutes per week of strenuous RPA.

^h P value reported from 2-sided Wald test.