Review for 10.1186/s12876-025-03606-7 (2025)

Title: Association of Daily Step Counts and Step Intensity with Mortality Among US Adults:
a cross–sectional study of NHANES 2005–2006
Version: 0 Date: 10 Dec 2024
Reviewer:  Amira A A Othman
Reviewer's report:
First of all
I want to congratulate the authors on their work. In this study, Peng et al. used data from the 2005
and 2006 National Health and Nutrition Examination Survey (NHANES) for adult Americans.
This research aims to identify associations between total steps per day and the intensity
of steps with mortality among adult US individuals with MASLD. The focus on physical
activity, specifically step count and intensity, and its association with all-cause mortality among
individuals with metabolic dysfunction-associated Steatotic liver disease (MASLD) is a valuable
contribution to public health and clinical management.
While the widely promoted 10,000-steps-per-day goal lacks strong evidence, prior research has
shown that higher step counts correlate with lower mortality *. However, most studies have
focused on older adults, people with chronic conditions, or small populations, limiting their
generalizability **. Evidence on whether step intensity independently affects health outcomes
remains conflicting. Some studies suggest step intensity improves health, while others find no
significant effect after accounting for total steps.
(*: https://doi.org/10.1136/bjsports-2017-098733, **: https://doi.org/10.1378/chest.10-2521,
***: doi: 10.1001/jama.2020.1382 )
The authors tried to contribute to this field of research with new findings, nevertheless, there is
an observation for which sufficient justification must be obtained.
In general:
1. The English writing level is shallow, and it is necessary to seek help from an English language
specialist to correct spelling and grammatical errors in the entire text.
2. Abbreviations must be fully written at their first appearance
In Title:
3. The authors may consider indicating the locality at which the National Health and Nutrition
Examination Survey (NHANES) was performed.
I suggest “Association of Daily Step Count and Step Intensity with Mortality Among US Adults:
a cross-sectional study of NHANES 2005–2006”.
In Abstract section
4. In method: please use “Using data from the National Health and Nutrition Examination
Survey (NHANES) database spanning from 2005 to 2006, a cross-sectional study included 1108
participants was performed to assess the relationship …….”.
5. Why only the 2005-2005 cycle? Could you expand for broader results?
6. It would help if you described the aim of your statistical analysis used throughout the study.
7. Nothing was mentioned about the participant’s age, sex, ethnicity, etc.
8. The type of study: a population-based study.
In the Introduction section:
9. Try to provide a summarized description of The National Health and Nutrition Examination
Survey (NHANES) in the background section. You may use the following
“NHANES (www.cdc.gov/nchs/nhanes) is designed to assess the health and nutritional status
of adults and children in the United States. The survey is distinctive in that it incorporates
both physical examinations and interviews. Several cross-sectional, nationally representative
health examination surveys are part of the NHANES program. Questions about demographics,
health insurance status, dietary habits, acute and chronic medical issues, mental health, and
prescription drug use are all included in the health interview. Exam components can change
between survey cycles but typically include blood pressure, dental exams, vision, hearing,
dermatology, fitness, balance and strength testing, respiratory testing, taste and smell, and
body measurements (weight, height, skin folds, body composition scans). Hematology, organ
and endocrine function (e.g., thyroid, kidney), environmental exposure, dietary biomarkers,
metabolic and cardiovascular health, and infectious disease are some laboratory components.”.
In the Methods section:
10. Please move the sentences defining the NHANES to the introduction section rather than the
methodology section.
11. Please provide the participants' sociodemographic data.
12. The information on MAFLD is based on the question?
13. What was the source of the covariate data?
14. Justify the thresholds used for step count and intensity categories by referencing prior
literature or explaining their clinical relevance.
15. Expand on the exclusion and inclusion criteria.
In the Results section:
16. In Tables: You can title the statistical test column as “Test of significance” and use U= for
the Mann–Whitney U test, T= for the T-test, and #2 = for the Chi-square test, etc.
17. Subgroup analyses must be performed to evaluate the effect of studied variables on mortality
rate and their stability in different populations. Subgroup analyses based on differences in
diagnostic components were performed to elaborate correlations. The results were presented in
forest plots using odds ratios (ORs) and 95% confidence intervals (CIs).
18. Log2 logarithmic transformation shall be analyzed.
19. The marital status category should be categorized into cohabitation (married/living with a
partner) and solitude (widowed/divorced/separated/unmarried).”
In the Discussion section:
20. The discussion section is one of the final parts of a research paper, in which an author
describes, analyzes, and interprets their findings. They explain the significance of those results
and tie everything back to the research question(s). In this manuscript, there is confusion between
what should be written in the introduction section and the discussion section. Please reconstruct
the discussion section.
21. Discuss potential physiological reasons why higher step intensities might not correlate with
lower mortality (e.g., overexertion or inaccuracies in accelerometer data for peak intensity).
22. The bias associated with using a self-reported outcome variable was not mentioned by the
authors.
23. Improve the limitations section such as the impact of missing data, cultural differences in
disease reporting, and assumptions in APC modeling.
24. Discuss the novelty of your study. Compare findings to related studies on step counts and
mortality in other populations (e.g., older adults or general populations) to highlight the novelty
of MASLD-specific results. (https://doi.org/10.1001/jama.2020.1382, https://doi.org/10.1093/
eurjpc/zwad263 ).
25. Reliance on accelerometer data from 2005–2006 (outdated technology) is a critical limitation
in your study.
26. Discuss future studies concerning the associations between total steps per day and the
intensity of steps with mortality among adult US individuals with MASLD.
27. Discuss the practical implications of your study.
In the conclusion section:
28. The conclusion should restate your main points and provide closure.