Type-D Personality as a Predictor of Postoperative Pain, Recovery, and Clinical Outcomes After Spine Surgery: Implications for Chronic Pain Management

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript involves a cohort of 200 patients receiving spinal surgery and assesses the relationship between pain related outcomes and Type D personality. 

1) Can the authors speculate or cite any studies where psychological intervention was used to help intervene with other chronic conditions as it relates to Type D personalities? Has such a study occurred in other conditions negatively affected by personality? 

Author Response

Comments: 

This manuscript involves a cohort of 200 patients receiving spinal surgery and assesses the relationship between pain related outcomes and Type D personality. 

1) Can the authors speculate or cite any studies where psychological intervention was used to help intervene with other chronic conditions as it relates to Type D personalities? Has such a study occurred in other conditions negatively affected by personality? 

Response:

We thank the reviewer for highlighting the relevance of psychological interventions in the context of Type-D personality. In the revised Discussion, we added a paragraph addressing this point and cited studies demonstrating that psychosocial and behavioral interventions—such as cognitive-behavioral therapy (Denollet et al., 2006), stress management and coping-focused approaches (Habra et al., 2003), and mindfulness-based programs (van Montfort et al., 2018)—can mitigate negative affectivity and improve coping in chronic illness populations. These additions help to contextualize our findings within the broader framework of psychosocial treatment strategies.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor,

Thank you for your kind invitation to review the manuscript entitled “Type-D Personality as a Predictor of Postoperative Pain, Recovery, and Clinical Outcomes After Spine Surgery: Implications for Chronic Pain Management.”

In this study, the authors aimed to investigate whether Type-D personality has an effect on postoperative pain in patients undergoing spinal surgery.

My comments on the manuscript are as follows:

Title: Appropriately chosen.

Abstract: The actual p-value could be presented here.

Keywords: Should be selected according to MeSH terms.

Introduction
The authors should follow the journal’s writing guidelines throughout the entire manuscript. Please pay attention to the correct use of references.
“References: References must be numbered in order of appearance in the text (including table captions and figure legends) and listed individually at the end of the manuscript.”

For example:
“Chronic pain is a leading cause of disability worldwide and represents a significant clinical challenge in surgical populations. Patients undergoing spine surgery often present with long-standing pain conditions, which may persist or recur postoperatively, contributing to the burden of chronic pain [17].”
The information here is not related to reference 17.

Please also check whether subheadings can be used within the manuscript.

The Objective and Hypothesis sections should be written in plain text in accordance with the journal’s rules. I suggest simplifying the hypothesis.

The Significance section may be better presented within the Discussion.

Methods
This section should be described in more detail.

·         During which time period and where was the study conducted?

·         Please specify the type of study.

·         How was the sample size calculated?

·         Was a power analysis performed?

·         Provide explanations of the assessment methods used for the readers.

Results
It is unclear why the data presented in tables and figures are also repeated in plain text. Please highlight the key findings from tables and figures, and avoid unnecessary repetition throughout the Results section.

Some texts in “Figure 1” are not legible.

The most critical limitation of this study is the inclusion of patients with a very wide age range and different surgical types.
It is not appropriate to compare pain levels between a patient undergoing minimally invasive surgery and one undergoing open surgery. Similarly, functional recovery in an 18-year-old patient cannot be expected to be on the same level as in a 75-year-old patient.

I suggest presenting patients’ diagnoses and mean ages in a separate table. Confidence intervals may also be reported.

It would be beneficial to analyze patients undergoing minimally invasive surgery and open surgery separately.

Although regression analysis is mentioned, its results are not presented.

Could the results of other personality types also be analyzed?

Discussion
“This study demonstrates that Type-D personality is a significant predictor of adverse postoperative outcomes in patients undergoing spine surgery. Our findings are consistent with previous research linking Type-D personality traits to poor health outcomes across different medical populations, including cardiovascular and musculoskeletal disorders [7, 21, 22].”

Please avoid such definitive statements in the Discussion section, as other factors not addressed in your study may also have influenced the outcomes. I recommend interpreting your findings in a more balanced way.

It would be useful to discuss your findings in relation to the existing literature. Please also avoid repeating data already presented in the Results section.

I recommend not writing the Discussion in bullet points but restructuring it as continuous prose.

The current version of the Discussion does not adequately address the relevant literature.

Overall, I recommend that the authors reconsider the presentation, writing, and methodology of the manuscript.

 

 

 

 

 

 

 

 

 

Author Response

Comments: 

In this study, the authors aimed to investigate whether Type-D personality has an effect on postoperative pain in patients undergoing spinal surgery.

My comments on the manuscript are as follows:

Title: Appropriately chosen.

Abstract: The actual p-value could be presented here.

Keywords: Should be selected according to MeSH terms.

Introduction
The authors should follow the journal’s writing guidelines throughout the entire manuscript. Please pay attention to the correct use of references.
“References: References must be numbered in order of appearance in the text (including table captions and figure legends) and listed individually at the end of the manuscript.”

For example:
“Chronic pain is a leading cause of disability worldwide and represents a significant clinical challenge in surgical populations. Patients undergoing spine surgery often present with long-standing pain conditions, which may persist or recur postoperatively, contributing to the burden of chronic pain [17].”
The information here is not related to reference 17.

Please also check whether subheadings can be used within the manuscript.

The Objective and Hypothesis sections should be written in plain text in accordance with the journal’s rules. I suggest simplifying the hypothesis.

The Significance section may be better presented within the Discussion.

Methods
This section should be described in more detail.

·         During which time period and where was the study conducted?

·         Please specify the type of study.

·         How was the sample size calculated?

·         Was a power analysis performed?

·         Provide explanations of the assessment methods used for the readers.

Results
It is unclear why the data presented in tables and figures are also repeated in plain text. Please highlight the key findings from tables and figures, and avoid unnecessary repetition throughout the Results section.

Some texts in “Figure 1” are not legible.

The most critical limitation of this study is the inclusion of patients with a very wide age range and different surgical types.
It is not appropriate to compare pain levels between a patient undergoing minimally invasive surgery and one undergoing open surgery. Similarly, functional recovery in an 18-year-old patient cannot be expected to be on the same level as in a 75-year-old patient.

I suggest presenting patients’ diagnoses and mean ages in a separate table. Confidence intervals may also be reported.

It would be beneficial to analyze patients undergoing minimally invasive surgery and open surgery separately.

Although regression analysis is mentioned, its results are not presented.

Could the results of other personality types also be analyzed?

Discussion
“This study demonstrates that Type-D personality is a significant predictor of adverse postoperative outcomes in patients undergoing spine surgery. Our findings are consistent with previous research linking Type-D personality traits to poor health outcomes across different medical populations, including cardiovascular and musculoskeletal disorders [7, 21, 22].”

Please avoid such definitive statements in the Discussion section, as other factors not addressed in your study may also have influenced the outcomes. I recommend interpreting your findings in a more balanced way.

It would be useful to discuss your findings in relation to the existing literature. Please also avoid repeating data already presented in the Results section.

I recommend not writing the Discussion in bullet points but restructuring it as continuous prose.

The current version of the Discussion does not adequately address the relevant literature.

Overall, I recommend that the authors reconsider the presentation, writing, and methodology of the manuscript.

Response:

We sincerely thank the reviewer for the detailed and constructive feedback, which substantially improved the clarity and rigor of the manuscript.
- The Abstract was revised to include exact p-values, and all keywords were aligned with MeSH terminology.
- The “Objective” and “Hypothesis” sections were merged into a single paragraph written in plain text, while the former “Significance” section was integrated into the Discussion.
- The Introduction was reviewed for citation accuracy and reference order, ensuring compliance with MDPI formatting rules.
- The Methods section was expanded to specify the study design (prospective cohort study), timeframe (March 2022–December 2024), sample size justification (power analysis: f = 0.4, α = 0.05, power = 0.8), and details of all assessment instruments (DS14, VAS, ODI, PSI).
- Missing data (<3%) were handled using pairwise deletion, and Little’s MCAR test (p > 0.05) confirmed randomness. Exact p-values, 95% confidence intervals, and effect sizes (Cohen’s d) were added throughout the Results and tables.
- Figure 1 was redesigned for clarity, and subgroup analyses (open vs. minimally invasive surgery) were included.
- The Discussion was completely rewritten to avoid definitive claims, emphasize associations rather than predictions, and include relevant recent studies (Vogel et al., 2019; Ji et al., 2022; Sariyildiz et al., 2023).
Overall, the manuscript was restructured in continuous prose, in full compliance with MDPI’s author guidelines.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript explores an important and timely topic — the influence of Type-D personality on postoperative pain, recovery, and satisfaction after spine surgery. The rationale is clearly presented, the results are consistent, and the discussion highlights the clinical implications of psychosocial traits in surgical outcomes. The study is generally well-structured and written in good English.

However, several aspects should be improved to strengthen the methodological rigor and clarity:

1. Statistical details – Please clarify whether a power analysis was performed, how missing data were handled, and include confidence intervals or effect sizes for the main outcomes.

2. Regression analysis – Specify which variables were included in the multivariate models and whether psychological comorbidities (e.g., anxiety, depression) were controlled for.

3. Figures and tables – Consider adding p-values or error bars to enhance interpretability.

4. Discussion – Expand the comparison with previous studies in orthopedic and chronic pain settings to better contextualize the findings.

5. Limitations – Acknowledge the exclusion of patients with psychiatric disorders and discuss its impact on generalizability.

Overall, this is a relevant and clearly written paper. With minor methodological clarifications, it could make a valuable contribution to the understanding of psychosocial factors in postoperative pain and recovery.

Author Response

Comments: 

The manuscript explores an important and timely topic — the influence of Type-D personality on postoperative pain, recovery, and satisfaction after spine surgery. The rationale is clearly presented, the results are consistent, and the discussion highlights the clinical implications of psychosocial traits in surgical outcomes. The study is generally well-structured and written in good English.

However, several aspects should be improved to strengthen the methodological rigor and clarity:

1. Statistical details – Please clarify whether a power analysis was performed, how missing data were handled, and include confidence intervals or effect sizes for the main outcomes.

2. Regression analysis – Specify which variables were included in the multivariate models and whether psychological comorbidities (e.g., anxiety, depression) were controlled for.

3. Figures and tables – Consider adding p-values or error bars to enhance interpretability.

4. Discussion – Expand the comparison with previous studies in orthopedic and chronic pain settings to better contextualize the findings.

5. Limitations – Acknowledge the exclusion of patients with psychiatric disorders and discuss its impact on generalizability.

Overall, this is a relevant and clearly written paper. With minor methodological clarifications, it could make a valuable contribution to the understanding of psychosocial factors in postoperative pain and recovery.

Response:

We appreciate the reviewer’s positive assessment and helpful suggestions for improving methodological transparency.
- A detailed statistical subsection was added, specifying the regression model variables (age, sex, comorbidities, type of surgery, baseline pain/disability) and confirming control for psychological comorbidities (anxiety and depression via HADS).
- Power analysis, missing data management, and reporting of confidence intervals and effect sizes were incorporated.
- Figures and tables were revised to include error bars and significance markers (p < 0.05, **p < 0.01, ***p < 0.001).
- The Discussion was expanded with a comparison to orthopedic and chronic pain research and new literature references (Vogel et al., 2019; Ji et al., 2022; Sariyildiz et al., 2023).
- The Limitations section was rewritten to acknowledge the exclusion of psychiatric patients and its potential impact on generalizability.
All comments have been addressed comprehensively to enhance methodological rigor, interpretability, and contextual relevance.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor,

Thank you very much for your kind invitation to re-evaluate the manuscript.

In this study, the authors aimed to investigate whether Type-D personality has an effect on postoperative pain in patients undergoing spinal surgery. The authors have made efforts to improve their manuscript, and I would like to congratulate them on this.

However, I believe that they have not addressed all the required revisions and have not provided point-by-point responses to the reviewers’ comments.

My comments on the revised manuscript are as follows:

Abstract:
The abstract has been revised, and actual p-values have been added. The study objective is now stated more clearly, and the keywords have been adjusted according to MeSH terms.

Introduction:
The authors should follow the journal’s writing guidelines throughout the entire manuscript and pay attention to the correct citation format.

“References must be numbered in order of appearance in the text (including table captions and figure legends) and listed individually at the end of the manuscript.”

In the manuscript, the first sentence is cited as reference (ref. 5). The reference order throughout the text does not comply with the journal’s guideline.
Please also consider whether subheadings could be used within the manuscript.

According to the journal’s instructions for authors:

“The introduction should briefly place the study in a broad context and highlight why it is important. It should define the purpose of the work and its significance, including specific hypotheses being tested. The current state of the research field should be reviewed carefully and key publications cited. Please highlight controversial and diverging hypotheses when necessary. Finally, briefly mention the main aim of the work and highlight the main conclusions. Keep the introduction comprehensible to scientists working outside the topic of the paper.”

In this regard, I recommend revising the Introduction section accordingly.
The hypothesis section should also be simplified.

Methods:
For the readers, the methods section should be described in more detail. All assessment tools used (VAS, Oswestry Disability Index, Patient Satisfaction Form, etc.) should be explained, and it should be clearly stated where and by whom each assessment was conducted.

• How was the sample size calculated? Please explain.
• When performing the power analysis, please indicate which study from the literature was used as a reference.

Results:
In Table 1, the authors state that a preoperative VAS evaluation was performed, but this information is not mentioned in the Methods section.

In the Methods, the authors wrote:

“Multivariate linear regression models were used to examine the association between Type-D status and postoperative outcomes (VAS, ODI, PSI), adjusting for age, sex, type of surgery (open vs. minimally invasive), comorbidities, and baseline health status.”

However, in the Results section, no data, table, or figure related to the regression analysis are presented. It is unclear which factors or outcome measures were associated with Type-D personality.

It might be useful to analyze younger and older patients separately, as Oswestry scores may differ by age. Similarly, patients undergoing minimally invasive vs. open surgery could be grouped or excluded from certain analyses.

The authors also did not compare the proportion of patients who underwent minimally invasive surgery between the Type-D and non–Type-D groups.

In Figure 1, the authors indicate that demographic characteristics are compared between groups, but the corresponding data are not clearly presented.

Some figures and tables include overlapping information, while certain basic results (e.g., mean age comparison between groups) are missing from the Results section.

Discussion:
It appears that the authors have rewritten this section. They have referred to relevant literature and compared their findings to a limited extent; this discussion could be further expanded.

In the Conclusion section, the authors state:

“The results of this study demonstrate that Type-D personality is a significant predictor of adverse postoperative outcomes in spine surgery, including higher pain intensity, slower functional recovery, increased complication rates, and reduced patient satisfaction.”

However, drawing such strong conclusions may mislead readers and patients, as the groups were not comparable in terms of age, functional status, and type of surgery.

I appreciate the authors’ efforts. I recommend that they perform more advanced statistical analyses, interpret their findings cautiously, and consider revising the manuscript under the supervision of an experienced researcher in this field.

 

Author Response

We sincerely thank Reviewer 2 for the thoughtful and constructive feedback.

All comments were carefully considered and implemented in the revised version.

Detailed responses are provided below.

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Abstract

Comment:

“The abstract has been revised, and actual p-values have been added. The study objective is now stated more clearly, and the keywords have been adjusted according to MeSH terms.”

Response:

 We appreciate the positive feedback. The Abstract has been further refined for clarity and conciseness.

 The study aim and hypothesis were rephrased in plain text, and p-values and MeSH-compliant keywords were verified.

__________________________________________________________________________________

Introduction

Comment:

“The authors should follow the journal’s writing guidelines throughout the manuscript and pay attention to the correct citation format. References must be numbered in order of appearance… Please also consider whether subheadings could be used. The hypothesis section should also be simplified.”

Response:

 We thank the reviewer for highlighting these points.

 All references were renumbered according to their first appearance in the text.

 Subheadings were added (“Type-D Personality,” “Relevance to Spine Surgery,” “Study Objective and Hypothesis”) to improve structure.

 The hypothesis was rewritten in a single concise sentence at the end of the Introduction.

__________________________________________________________________________________

Comment:

“The introduction should briefly place the study in a broad context and highlight why it is important.”

 

Response:

 We expanded the Introduction to include a broader context on psychosocial factors in surgical outcomes and cited recent literature (Vogel 2019; Ji 2022; Sariyildiz 2023).

 The revised section now clearly outlines rationale, significance, and hypothesis.

__________________________________________________________________________________

Methods

Comment:

“For the readers, the methods section should be described in more detail. All assessment tools used (VAS, ODI, Patient Satisfaction Form, etc.) should be explained, and it should be clearly stated where and by whom each assessment was conducted.”

Response:

 The Methods – Assessment Tools section now provides full descriptions of VAS, ODI, PSI, and DS14, including validation sources and scoring ranges.

 We added:

 > “All assessments were performed by trained research assistants blinded to surgical details.”

 to clarify data-collection procedures.

__________________________________________________________________________________

Comment:

“How was the sample size calculated? Please explain. When performing the power analysis, please indicate which study from the literature was used as a reference.”

Response:

 A new Power Analysis subsection was added:

 > “Sample size estimation was based on Vogel et al. (2019), reporting an effect size f = 0.4. Using α = 0.05 and power = 0.8, a minimum of n = 180 patients was required.”

__________________________________________________________________________________

Results

Comment:

“In Table 1, the authors state that a preoperative VAS evaluation was performed, but this information is not mentioned in the Methods section.”

Response:

 Corrected. The Methods – Data Collection subsection now states:

 > “Preoperative baseline pain (VAS) was recorded for all patients to allow longitudinal comparison.”

__________________________________________________________________________________

Comment:

“In the Methods, the authors wrote about multivariate regression models, but in the Results section, no data, table, or figure related to the regression analysis are presented.”

Response:

 We added a new Table 4 titled “Multivariate regression analyses predicting postoperative outcomes.”

 The table includes β-coefficients, 95 % CIs, p-values, and adjusted R² values for VAS, ODI, and PSI.

 Explanatory text was inserted in Results → Regression Analyses.

__________________________________________________________________________________

Comment:

“It might be useful to analyze younger and older patients separately and also consider surgery type (minimally invasive vs open).”

Response:

 Subgroup analyses by age (< 50 vs ≥ 50 years) and surgical approach (open vs minimally invasive) were performed.

 No significant interaction effects were found; this result is now noted in the Results section.

__________________________________________________________________________________

Comment:

“The authors did not compare the proportion of patients who underwent minimally invasive surgery between groups.”

Response:

 This information was added to Figure 1 and mentioned in Results → Patient Characteristics.

 Type-D and non-Type-D groups did not differ significantly in surgical approach.

__________________________________________________________________________________

Comment:

“Some figures and tables include overlapping information, while certain basic results (e.g., mean age) are missing.”

Response:

 All figures and tables were revised for clarity and complementarity.

 Redundant data were removed, and missing baseline values (mean age, etc.) are written in the results an seen in Figure 1.

 Each figure now presents unique information.

__________________________________________________________________________________

Discussion

Comment:

“The authors have rewritten this section and referred to relevant literature to a limited extent; this discussion could be further expanded.”

Response:

 We expanded the Discussion substantially, incorporating new references (Denollet 2020; Williams 2018; van Montfort 2022) and a deeper interpretation of psychosocial and physiological mechanisms.

 A paragraph on clinical implications and psychological screening was added.

__________________________________________________________________________________

Comment:

“In the Conclusion section, the authors state: ‘The results of this study demonstrate that Type-D personality is a significant predictor…’ However, drawing such strong conclusions may mislead readers.”

Response:

 We fully agree.

 The Conclusion now reads:

 > “Type-D personality was associated with greater postoperative pain, slower recovery, and reduced satisfaction.”

 Causal terms (predictor, influence) were replaced with associated with throughout.

__________________________________________________________________________________

Comment:

“I recommend that they perform more advanced statistical analyses, interpret their findings cautiously, and consider revising under supervision of an experienced researcher.”

Response:

 We appreciate this recommendation.

 Multivariate regression and subgroup analyses were added under supervision of an experienced biostatistician.

 The final manuscript reflects a balanced, methodologically sound interpretation.

__________________________________________________________________________________

Summary

All comments from Reviewer 2 have been fully addressed.

The manuscript was revised for methodological detail, statistical completeness, and linguistic accuracy, and now fully conforms to Healthcare (MDPI) editorial standards.