Title: Association between depression and perceived health status in Korean adult women: A
nationwide cross-sectional study
Version: 0 Date: 18 Dec 2024
Reviewer's report:
General comment
The authors present an analysis of the relationship between depression and perceived health
status among Korean adult women, along with associated comorbidities. While the study
provides valuable data specific to the Korean population, the fundamental association between
depression and perceived health status has been well-documented in both cross-sectional and
longitudinal studies across various populations. While the topic is important, the current version
requires substantial revision before it can be considered for publication. There are several
fundamental concerns that need to be addressed:
Major comment
The rationale for using depression (assessed by PHQ-9) to predict perceived health
status requires clearer justification. The authors should explicitly articulate the clinical or
epidemiological significance of this specific predictive approach. While both variables are
important, the relationship between them needs more comprehensive explanation to demonstrate
the study's scientific merit.
The authors noted that both chronic diseases and depression are related to poor perceived health
status. However, the potential synergistic effects of chronic physical diseases and psychological
conditions (such as depression) on an individual's perceived health status warrant deeper
investigation. A more nuanced analysis exploring the joint impact of these factors would enhance
the study's depth and clinical relevance.
In line 110 to 113, While the authors used a cut-off value to diagnose depression, the PHQ-9
scores offer a more granular categorization of depression severity: "none/minimal", "mild",
"moderate", "moderately severe", and "severe". Exploring the differential impact of these
depression severity categories on perceived health status would provide more nuanced insights
into the relationship between mental health and perceived well-being.
In line 179, the exclusion of 5,875 participants without chronic disease information represents
a substantial proportion of the original sample. This significant data loss raises concerns about
potential selection bias. The authors should conduct and report a comprehensive sensitivity
analysis to address the potential biases introduced by these missing values. This analysis is
crucial for establishing the robustness and generalizability of the study's findings.
It is indeed worthwhile to explore whether there is a nonlinear relationship between PHQ-9
scores and study outcomes. Adding a Restricted Cubic Spline (RCS) analysis to the existing
research results can provide a more nuanced understanding of this relationship. If the RCS
analysis indicates a nonlinear relationship between PHQ-9 scores and study outcomes, authors
could then attempt to identify cut-off values. This would be beneficial for the practical
application of the PHQ-9 in predicting perceived health status.
Minor comment
In line 49, the abbreviation OECD should be written in full upon its first appearance, with the
abbreviation introduced in parentheses afterward.
In line 82 to 83, the authors used data from different investigation cycles spanning 8 years. Given
this extended time frame, the participants' attendance year should be carefully considered as
a potential confounding variable. Including the year of investigation in the sensitivity analysis
could help account for potential temporal variations in health status, socioeconomic conditions,
or other relevant factors.
In line 134 to 135, the description of the Korean National Health and Nutrition Examination
Survey (KNHANES) sampling method requires more detailed explanation. While the authors
note the use of a stratified, multistage, clustered probability sampling method, they should
provide a more comprehensive description of the weighting approach.
In line 141 to 142, the included confounding variables should be relevant to both the exposure
and the outcome. The selection of confounding variables should be more explicitly justified.
In line 234, the phrase "for each unit increase in depression" lacks precision. Is it “PHQ-9 score”
rather than “depression”? It should be clarified to ensure accurate interpretation.
In the discussion of depression's impact on perceived health status (lines 250-256), the authors
should emphasize the findings specific to adult women, as the analysis appears to highlight
gender-specific effects and provide a more in-depth exploration of the potential mechanisms
underlying the observed relationship in Korean women.