Table 3

SDHR and 95% CI for the relationship between eCRF and breast cancer among postmenopausal women in the UK Biobank

Exposure†Unadjusted‡
(N=17 840)		Minimally adjusted‡ (N=17 840)Fully adjusted§ (N=17 840)Adjusted & restricted to protocol 1§ (N=15 147)
Three category fitness 1
 Low (<20th percentile) (N=3566)RefRefRefRef
 Moderate (20th to <80th percentile) (N=10 704)0.95 (0.77 to 1.18)0.94 (0.76 to 1.17)0.94 (0.76 to 1.16)1.03 (0.81 to 1.32)
 High (>80th percentile) (N=3570)0.75 (0.57 to 0.99)*0.74 (0.56 to 0.98)*0.73 (0.55 to 0.97)*0.79 (0.57 to 1.08)
Low Fitness
 No (N=14 274)RefRefRefRef
 Yes (N=3566)1.11 (0.90 to 1.36)1.12 (0.91 to 1.38)1.13 (0.91 to 1.39)1.03 (0.81 to 1.31)
High fitness
 No (N=14 720)RefRefRefRef
 Yes (N=3570)0.78 (0.62 to 0.98)*0.77 (0.61 to 0.98)*0.76 (0.60 to 0.97)*0.77 (0.60 to 0.99)*

  • Fine and Gray regression analysis with other cancer, and all-cause mortality treated as competing risks was used to produce SDHRs. Age was used as a timescale to anchor findings to a clinically meaningful time point instead of arbitrary time point (ie, time since CRF assessment).

  • *Statistically significant (p<0.05).

  • †Sample sizes are based on the whole sample (ie, all those with an eCRF assessment using any of the three protocols).

  • ‡Estimates adjusted for ethnicity (white, black, other), smoke status (never, current, previous), alcohol use frequency (never, special occasions only, 1–3 times a month, once or twice a week, 3 or 4 times a week, daily) and physical activity (categorised as <50th percentile vs >50th percentile of MET minutes per week).

  • §Estimates are adjusted for all variables in the minimally adjusted model and education (secondary, postsecondary, missing), family history of breast cancer, age at menarche (<or≥13 years of age), number of live births (nulliparous, 1, 2, 3 or more children) and protocol (1, 2, 3) if relevant.

  • BMI, body mass index; CI, confidence interval; eCRF, estimated cardiorespiratory fitness; SDHR, subdistribution HR.