Reviewer’s report
Title: 
Night-shift work duration and breast cancer risk: an updated systematic
review and meta-analysis
Version: 
1 
Date: 
20 Nov 2020
Reviewer's report:
THE RELATIONSHIP BETWEEN NIGHT-SHIFT WORK DURATION AND
BREAST CANCER RISK: AN UPDATE SYSTEMATIC REVIEW AND
META-ANALYSIS 
Manuscript number: BMWH-D-20-00966R1
Comments 
Abstract
* "…until September 1, 2019." Kindly indicate the starting date.
Discussion
* "The results of these studies were contradictory with regards to the effect of
night-shift work on BC. Jia et al. (2013) showed an overall positive association
concerning 1.20 (95% CI 1.08-1.33; 13 studies) between the risk of BC and
night-shift work (never versus ever) (73), which 229 is also consistent with the
study of Wang et al. (2013) (17), He et al. (2014) (18) and Yuan et al (2018)
(27)." 
* There appears to be some disconnection in the sentence above which starts
from lines 227 to 230. Kindly check and correct.
* "Ijaz et al. (2013) (72) observed a 9% risk increase per five years of night-shift
work exposure in case-control studies (RR=1.09, 95% CI: 1.02-1.20)…"
* Are the reported ratios (above) for the case-control studies relative risk (RR) or
Odds ratio (OR)?
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