Skip to main content

Table 3 Characteristics of the selected cohort studies on breast cancer and night-shift work

From: Night-shift work duration and breast cancer risk: an updated systematic review and meta-analysis

Author Total size/cases sample size Follow up length (years) Exposure data source Adjusted confounders Definition of night shift NSW category Quality score (%)
Koppes [72] 285,723/2531 7 Labor Force Survey Age, origin, children in the household, education, occupational group, contractual working hours, and job tenure Work at nights, meaning between midnight and 6 am Short/long High
Pronk et al. [74] 73,049/717 9 In-person occupational history plus job exposure matrix Age, age at first childbirth, parity, family history, education, work-related PA Starting work after 10 PM at least 3 times a month for over 1 year Short/long High
Åkerstedt et al. [70] 13,656/463 12 Swedish Twin registry, with follow-up in the Swedish Cancer Registry Age, education, parity, Tobacco use, BMI, PA, Alcohol consumption, coffee consumption, menopause status, hormone use, previous cancer, time to BC diagnosis Working hours in nights at least now and then Short/long High
Wegrzyn [73] 78,516/5971 24 Nurses’ Health Study Age, height, current BMI and BMI at age 18 years, adolescent body size, age at menarche and at first birth, parity, BF history, type of menopause, age at menopause, MHT use, duration of use of estrogen-only MHT, duration of use of combined estrogen and progesterone MHT, first-degree family history of BC, history of benign breast disease, alcohol consumption, PA level, and current mammography use At least 3 nights/month in addition to days/evenings in that month Short/long High
Wegrzyn [73] 114,559/3570 24 Nurses’ Health Study II Age, height, current BMI and BMI at age 18 years, adolescent body size, age at menarche and at first birth, parity, BF history, type of menopause, age at menopause, MHT use, duration of use of estrogen-only MHT, duration of use of combined estrogen and progesterone MHT, first-degree family history of BC, history of benign breast disease, alcohol consumption, PA level, and current mammography use At least 3 nights/month in addition to days/evenings in that month Short/long High
Jones et al. [71] 102,869/2059 9.5 Generations Study Alcohol use, parity, OC use, MHT use, and menopausal status Any jobs that regularly involved work in the late evening or night (between 10 pm and 7 am) Short/long Moderate
Travis et al. [28] 522 246/ 4809 Established 1996 to 2001. Analyzed at December 2013 Million woman study Age, SES, marital status, nulliparity, age at first birth, number of children, obesity, PA, alcohol consumption, smoking, first-degree relative with BC, OC use, MHT use, amount of sleep, take medication to sleep, more evening than morning type Any time between midnight and 06:00 h, for at least 3 nights per month Short/long High
Travis et al. [28] 22,559/181 Recruited 1993–1999. Analyzed at December 2013 EPIC-Oxford study Age, SES, marital status, nulliparity, age at first birth, number of children, obesity, PA, alcohol consumption, smoking, first-degree relative with BC, OC use, MHT use, amount of sleep, take medication to sleep, more evening than morning type Any job lasting for at least one year, and occurring on a regular basis for at least one night per month or 12 nights per year Ever/long High
Sweeney et al. [75] 48,451/3191 Recruited 2003–2009. Analyzed at September 2017 Sister study cohort Age, race/ethnicity, education, marital status and parity 1 h between 12:00 and 2:00 AM) for ≥ 2 years Short/long High
  1. NSW night shift work, PA physical activity, BMI body mass index, BC breast cancer, BF breastfeeding, MHT menopausal hormone therapy, SES socioeconomic status, OC oral contraceptive