Title: Association between oxidative balance score and rheumatoid arthritis in female: a cross-
sectional study
Version: 1 Date: 04 Mar 2024
Reviewer's report:
TOBS, DOBS, and LOBS were analyzed as continuous variables using the original scores,
which were not conducive to comparison among these three variables. Please consider perform
variable standardization for TOBS, DOBS, and LOBS, estimate the standardized beta coefficient
to calculate OR, and compare results among TOBS, DOBS, and LOBS, and to facilitate the
interpretation and understanding of study results.
Methods
1. This study excluded nearly 70% of the original subjects. 7539 subjects excluded in the first
stage were due to "without dietary OBS data". Which specific nutrients were with missing data?
Mainly because of fiber data? If yes, why should fiber data be completed two-day dietary data
(MEC and telephone)?
2. Please describe the MET score setting for these five principle activities.
3. Regarding alcohol consumption, there were considerable number of studies considering
moderate alcohol consumption (0-15g/day) as a healthy lifestyle, especially the alcohol
consumption from red wine. In this study, scored 1 point for non-alcoholics (0-15g/day). Please
cite reference to justify this score setting.
4. Were there any studies that use questionnaire data to evaluate and  score the smoking
behaviors? Please cite reference to discuss the advantages of using plasma nicotine level for
smoking behavior evaluation.
5. Please cite references for threshold effect analysis and smooth curve fitting studies.
6. SII was treated as covariate and adjusted in model 3. Would the inflammatory effect of OBS
be over-adjusted? In addition, if SII was treated as confounder, why not considered SIRI as
confounder?
Results
1. Decimal places in tables and figures:
(1) OR might be taken to three decimal places.
(2) Up to four decimal places for p value or presented as " *: <0.05; **: p<0.01; ***: p<0.0001".
2. There was a redundant table 4 in page 14.
3. The 0.8, 0.9, 1.0, 1.0, 1.0, marked at the bottom of figure 2A were wrong, they should be
0.85, 0.90, 0.95, 1.00, 1.05. The 0.9, 1.0, 1.0, 1.0, 1.1, marked at the bottom of figure 2B were
wrong, they  should be 0.90, 0.95, 1.00, 1.05, 1.10.
4. In figure 2A, 2B, and 2C, diabetes groupings were "Yes", "No", and "borderline". Why there
was not "borderline" group in hypertension?
5. How to estimate "p for trend" in table 3, table 4, and table 5? Those estimates were quite
close to those "OBS(treated as continuous variables)" estimates. Please describe your modelling
method clearly.
6. The statistical analysis in table 6 should be logistic regression, not linear regression, and the
estimates should be ORs instead of beta coefficients. And, please footnote the "AIP"?
7. It is recommended to add a supplementary table to display the original scores of 20 items of
TOBS for RA and Non-RA.
Discussion
1. This study explored the female population, and excluded nearly 70% female subjects. The
characteristics of included subjects seemed younger, less educated, and poorer in PIR, compared
to other published NHANES studies. Please discuss the issue of selection bias.
2. In line 297-326, the authors discussed: "The following points can help illuminate the latent
mechanisms between oxidative stress and RA". But the reviewer only saw "Firstly, ...." in line
298. Please state these points consequently as “firstly”, “secondly”, “thirdly”, etc.