Fig. 4

Dose–response meta-analysis between light at night and risk of breast cancer among all women [23,24,25, 40, 43, 44, 52] and between light at night and risk of breast cancer in premenopausal [43, 44, 52] and postmenopausal women [23, 43, 44, 52]. Spline curve (black solid line) with 95% confidence limits (black dashed lines), and linear trend estimation (long-dashed gray line). RR risk ratio