Quality of Life, Anxiety, and Depression in Peruvian Patients with Acute Coronary Syndrome

Round 1

Reviewer 1 Report

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Manuscript ID: sustainability-1932579

Quality of life, anxiety and depression in Peruvian patients with acute coronary syndrome

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The manuscript entitled “Quality of life, anxiety and depression in Peruvian patients with acute coronary syndrome” studies factors associated with anxiety and depression in Peruvian patients with acute coronary syndrome (ACS). After reading the manuscript, several issues must be addressed before I can recommend its publication. Therefore, I suggest the authors to revise the paper. There are some comments I would like to offer to the authors.

Abstract and keywords

Abstract: “These patients are isolated due to fear of 35 SARS-CoV-2 infection, which has a negative impact on their quality of life and mental health”. I don’t think this final statement is backed up by the data and results. Firstly, the cross-sectional nature of the design does not allow for such causal inferences. The authors have been careful about this issue for the most part of the manuscript, except for this conclusion. And then, how was fear measured as the cause of isolation? How was the isolation considered as the cause of lower quality of life and mental health? Please consider revising the statement.

COVID-19 as a factor related to anxiety is an interesting result. However, it is not a variable related to the aim of the study. In this regard, I think the term should be removed from the keywords list. If the authors want to highlight the background of the social isolation during the pandemic, it should be included in the abstract and, perhaps, in the title itself.

Introduction

Please, introduce once the term “acute coronary syndrome” in the introduction before using the abbreviation ACS.

The manuscript reviews literature regarding acute coronary syndrome (ACS) and depressive symptoms. However, anxiety (one of the main variables) is not reviewed; some background would be appreciated.

In p. 2, the manuscript states “Anxiety and depression are described in different studies related to cardiovascular disease” but not citations are provided.

Methodology

The sample size (and some sample characteristics) should be discussed somewhere in this section. How about adding a Participants section?

Variables and apparatuses

Hamilton-anxiety test. Why were those specific cut-off points considered? Are those usual cut-off values, or it was a decision made by the authors. Why not use the quantitative value as dependent variable?

Statistical analysis and Results

The sample size seems too scarce for multiple regression analysis. Can you provide a power analysis?

What is the purpose of using the same predictors in simple and multiple regression analyses? Table 3 is cumbersome, and the information reported is somewhat redundant. I would discard the simple regression analyses and stick to the multivariable models. It would make a more concise and informative Results section.

Table 3. Please specify in the footnote what “Ref.” means.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Some comments:

Methodology:

·        There is no information on the total population (ACS patients of the medical center during Nov 2019 to Dec 2020) and the response rate for the telephone survey. These details would be relevant in describing both the scope of this single-center study (are there 100/500/1000 ACS patients within a year) and the representativeness of the data in respect to the population and sample. Such info could be presented in a separate table with basic demographic characteristics for both sampled patients and responders.

·        Why was non-probability sampling preferred and how was the sample itself drawn?

·        Another potential point of concern is the variation between discharge and telephone survey (lines 138-140) – the measurements are taken in different context (with also external factors like Covid-19 pandemic factoring in). In your opinion, could this have affected the results?

·        You have listed a considerable number of covariates in the methods section, but except for anxiety, depression and QOL indices no description is provided on how these variables were measured/operationalized for the analysis. There are probably several good reasons why particular categories were grouped together (e.g. for education), but in some instances it might be debatable. For example, the variable of occupation where housekeeper (referring to economically non-actives) and employed were merged or SES variable where low socio-economic status was differentiated more than high SES. In case of SES, the indicator(s) itself is also relevant as the measures of income or wealth might have different meaning for older adults (i.e. living standards might be more dependant from accumulated wealth (house ownership etc) than direct income from pensions etc). If there is no background information provided, it is difficult to assess whether the items captures the concept is should measure.

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·        The source for Quality of life index (Mezzich et al) is not properly cited in text/reference list.

Results:

Although the results are presented in a standardized manner and cover the data presented in results tables, a few question arose:

·        Did you assess goodness-of-fit for the models? Did it change after inclusion of subsequent covariates?

·        The age is given as a binary variable, however it is very relevant for both the mental health and QOL outcomes (and for CVD of course). As no statistically significant age-effects were found during the modelling, did you consider/test another options for age-classification as well (e.g. cont. variable, 10-year age groups)?

·        The same issue is present in several other indicators as well. Most notably for QOL – where initial 0-10 scale is transformed into a binary outcome (compared to 4-levels used in Barthel index for example). Did you test the alternatives as well or not?

·         ‘**’ marking is missing from Table 3 footnotes

Discussion:

·        You list being a non-smoker and non-alcoholic the risk-factors for having depression/anxiety (lines 218-220). As both smoking and alcohol consumption are often seen as ways to relieve extensive stress, the more indepth discussion on thse behavioural correlates to mental health would be welcome. How was ‘Alcoholism’ measured in your survey?

·        Distribution of QoL scores should be presented in a graph – otherwise it is very hard to reason, why a 10-item QoL measure would be preferrable to some single-item measure (e.g. self-rated health).

·        The implications-section does sound slightly over-ambitious (given the methodological restrictions of the study). The sentence (l 339-342) “level of education can improve the conditions of people” needs rephrasing as health outcomes clearly vary by education (and other SES indicators), but increase in education (happens rather seldom at older ages) does not necessarily improve the health for those already in poor health.

The limitations-section should also be carefully revised as several point mentioned above are not considered.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I have no further comments about the contents of the manuscript. The authors have addressed my earlier suggestions. 

As a note related to formatting, easy to fix, Table 3 is now disarrayed and unreadable.