Physical and Psychological Effects of Nasogastric Tube (NGT) Use in Adolescents with Anorexia Nervosa: An Exploratory Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript addresses an important and clinically relevant issue: the physical and psychological tolerance of enteral feeding via nasogastric tube (NGT) in adolescents with anorexia nervosa. This topic is timely, and data on the subjective experience of paediatric patients are limited in the literature, which is a clear strength of this work.

However, the study has serious methodological limitations that significantly weaken the strength of its conclusions. In its current form, the manuscript is clearly exploratory, yet the authors' narrative at times suggests far-reaching clinical implications that are not fully justified by the data presented.

The study is observational, single-arm, and involves a small sample (n = 57) of hospitalised patients, with a clear predominance of girls (96.5%). The lack of a control group (e.g., patients treated exclusively orally) makes it impossible to determine whether the observed changes are specific to the use of NGT or reflect the general effects of hospitalisation, renutrition, and intensive therapeutic care.

Additionally, the sample comes from a single centre, patients were recruited consistently but without information on the number of refusals to participate, and there is no analysis of the representativeness of the sample.

These factors significantly limit the generalisability of the results.

The authors used a proprietary 21-item VAS questionnaire, developed for the study and approved by the bioethics committee. This is an interesting initiative; however, there is no psychometric validation of the tool, its reliability (e.g., internal consistency, test-retest) has not been assessed, no structural (factor) analysis has been performed, and it is not known whether the individual items measure consistent psychological constructs.

As a result, the interpretation of individual items in the questionnaire and their changes over time remains descriptive and hypothetical, rather than based on established measurement principles.

The authors used numerous statistical tests: multiple t-tests for dependent samples, ANOVA for repeated measurements, and an extensive correlation analysis with many psychometric variables.

Despite the use of Bonferroni correction, there remains a high risk of type I error, especially in the correlation analyses, where the number of tests is very large relative to the sample size, potential covariates (e.g., degree of malnutrition, length of hospitalisation, pharmacotherapy) were not considered, and there are no multivariate models to allow for a more controlled interpretation of the relationships.

Many correlations, although statistically significant, may be random or indirect and should not be interpreted as causal relationships.

The authors report an improvement in subjective psychological and physical tolerance of NGT during treatment, which is consistent with the observed improvement in somatic condition (increase in body weight and BMI). However, it cannot be unequivocally stated that this improvement is due to “adaptation to NGT” rather than a general improvement in nutritional status and mental functioning. The narrative regarding the “strengthening of the therapeutic alliance” is interesting but is not supported by direct measurement of this construct, and at times the interpretations are speculative and go beyond the scope of the empirical data.

The authors mention some of the limitations (small sample size, lack of a control group, learning effect, Hawthorne effect), which is positive. Nevertheless, the final conclusions remain relatively optimistic and could be more clearly tempered to better reflect the exploratory nature of the study.

Strengths of the study include a clinically relevant topic, focus on the subjective experience of adolescents, multiple measurements during treatment, and an attempt to integrate psychological, family, and clinical data.

Weaknesses include the absence of a control group, a small and unrepresentative sample, lack of validation of the authors' tool, risk of overinterpretation of numerous correlations, and limited possibility of causal inference.

The manuscript requires a clearer emphasis on the exploratory nature of the study, further moderation of psychological and clinical interpretations, reduction of speculative conclusions, and consideration of shortening and simplifying the discussion section.

After significant revisions, the article may make a valuable contribution to further, better-controlled research on the experience of using NGT in adolescents with anorexia nervosa.

Author Response

The authors thank the referee for the positive consideration given to the paper and for the suggestions which improved the quality of the paper and its publicability.

 

Referee 1 

The manuscript addresses an important and clinically relevant issue: the physical and psychological tolerance of enteral feeding via nasogastric tube (NGT) in adolescents with anorexia nervosa. This topic is timely, and data on the subjective experience of paediatric patients are limited in the literature, which is a clear strength of this work.

 

The authors thank the referee for the recognition of the value of the paper.

 

However, the study has serious methodological limitations that significantly weaken the strength of its conclusions. In its current form, the manuscript is clearly exploratory, yet the authors' narrative at times suggests far-reaching clinical implications that are not fully justified by the data presented.

 

We recognise the exploratory nature of the study.

 

The study is observational, single-arm, and involves a small sample (n = 57) of hospitalised patients, with a clear predominance of girls (96.5%). The lack of a control group (e.g., patients treated exclusively orally) makes it impossible to determine whether the observed changes are specific to the use of NGT or reflect the general effects of hospitalisation, renutrition, and intensive therapeutic care.

The authors used a proprietary 21-item VAS questionnaire, developed for the study and approved by the bioethics committee. This is an interesting initiative; however, there is no psychometric validation of the tool, its reliability (e.g., internal consistency, test-retest) has not been assessed, no structural (factor) analysis has been performed, and it is not known whether the individual items measure consistent psychological constructs.

As a result, the interpretation of individual items in the questionnaire and their changes over time remains descriptive and hypothetical, rather than based on established measurement principles.

The authors used numerous statistical tests: multiple t-tests for dependent samples, ANOVA for repeated measurements, and an extensive correlation analysis with many psychometric variables.

Despite the use of Bonferroni correction, there remains a high risk of type I error, especially in the correlation analyses, where the number of tests is very large relative to the sample size, potential covariates (e.g., degree of malnutrition, length of hospitalisation, pharmacotherapy) were not considered, and there are no multivariate models to allow for a more controlled interpretation of the relationships.

Many correlations, although statistically significant, may be random or indirect and should not be interpreted as causal relationships.

 

The authors incorporated the abovementioned limits of the study in the limits section of the paper.

 

Additionally, the sample comes from a single centre, patients were recruited consistently but without information on the number of refusals to participate, and there is no analysis of the representativeness of the sample.

These factors significantly limit the generalisability of the results.

 

The authors underlined that no patient refused the inclusion in the study and thus evidenced the regional representativeness of the sample in the discussion.

 

The authors report an improvement in subjective psychological and physical tolerance of NGT during treatment, which is consistent with the observed improvement in somatic condition (increase in body weight and BMI). However, it cannot be unequivocally stated that this improvement is due to “adaptation to NGT” rather than a general improvement in nutritional status and mental functioning. 

 

The authors are aware that the overall psychological improvement could be linked to the factors that are indicated in the paragraph and not only to the NGT adaptation, nevertheless the greater ‘physical tolerance’ of the NGT was probably due also to a physical adaptation to the instrument (in most cases their throat ceased to perceive it before the BMI increased). To give consideration to the referee the authors stated that this was a ‘possible’ interpretation (line 292). 

 

The narrative regarding the “strengthening of the therapeutic alliance” is interesting but is not supported by direct measurement of this construct, and at times the interpretations are speculative and go beyond the scope of the empirical data.

 

The authors modified the content of the paragraph in a more hypothetical way.

 

The authors mention some of the limitations (small sample size, lack of a control group, learning effect, Hawthorne effect), which is positive. Nevertheless, the final conclusions remain relatively optimistic and could be more clearly tempered to better reflect the exploratory nature of the study.

Strengths of the study include a clinically relevant topic, focus on the subjective experience of adolescents, multiple measurements during treatment, and an attempt to integrate psychological, family, and clinical data.

Weaknesses include the absence of a control group, a small and unrepresentative sample, lack of validation of the authors' tool, risk of overinterpretation of numerous correlations, and limited possibility of causal inference.

 

The authors included these weaknesses in the limits section.

 

The manuscript requires a clearer emphasis on the exploratory nature of the study, further moderation of psychological and clinical interpretations, reduction of speculative conclusions, and consideration of shortening and simplifying the discussion section.

 

The authors gave emphasis to the exploratory nature of the study indicating it in the title and then in methods, discussion and conclusion sections. The authors revised discussion moderating their clinical interpretations, reducing the speculative conclusions, shortening and simplifying the section.

 

After significant revisions, the article may make a valuable contribution to further, better-controlled research on the experience of using NGT in adolescents with anorexia nervosa.

 

The authors evidenced this point in the conclusion.

Reviewer 2 Report

Comments and Suggestions for Authors

From clinical point of view, this is a very relevant topic. AN lethality rate is high, therefore, a complex approch is needed to treatment.

Abstract:

Clearly written, with well defined rationale and research aim, a nice description of methods and detailed results. Conclusion is also adequate and based on the findings.

Introduction

The authors start with an exact definition of AN based on DSM.

The epidemiological data: Ref2 and Ref6, although nice articles, but are outdated, when refer to epidemiological data it is important to apply the most recent information.

The multidisciplinarty approach to treatment is welcome, in particular the psychological aspect of nasogastric tube feeding.

Lines 79-81: "Moreover, studies on the effects of NG tube feeding ..." here a reference (or more) is needed.

Lines 83-84: "Based on the data 83 available to us and previous literature on the subject..." Here also would be appropriate some references used above.

Description of the sample and methods. Approrpiate. Cronbach alpha values of reliability for the scales with the current sample is missing, please add them.

Results: The presentation of results are adequate.

Discussion: Well structured and provides substantial evaluation of the findings. .

Conclusion: line 413: More concrete suggestions for psychoeducation would be useful. Also, are there any previous experiences about it reported by other studies?

Thank you for letting me read this valuable study.

 

 

 

 

Author Response

The authors thank the referee for the positive consideration given to the paper and for the suggestions which improved the quality of the paper and its publicability.

Referee 2

From clinical point of view, this is a very relevant topic. AN lethality rate is high, therefore, a complex approch is needed to treatment.

 

Thank you for the consideration given to our research.

 

Abstract:

Clearly written, with well defined rationale and research aim, a nice description of methods and detailed results. Conclusion is also adequate and based on the findings.

 

Thank you.

 

Introduction

The authors start with an exact definition of AN based on DSM.

The epidemiological data: Ref2 and Ref6, although nice articles, but are outdated, when refer to epidemiological data it is important to apply the most recent information.

 

The authors agree with the referee, but unfortunately no more recent paper was found to replace the Ref2, since it is a very extensive revision of the literature. Ref6 was replaced with a more recent and exhaustive paper.

 

The multidisciplinarty approach to treatment is welcome, in particular the psychological aspect of nasogastric tube feeding.

 

Thank you.

 

Lines 79-81: "Moreover, studies on the effects of NG tube feeding ..." here a reference (or more) is needed.

 

The references are given.

 

Lines 83-84: "Based on the data 83 available to us and previous literature on the subject..." Here also would be appropriate some references used above.

 

The references are given.

 

Description of the sample and methods. Approrpiate. Cronbach alpha values of reliability for the scales with the current sample is missing, please add them.

 

The Cronbach alpha was given for all measures.

 

Results: The presentation of results are adequate.

Discussion: Well structured and provides substantial evaluation of the findings. .

 

Thank you.

 

Conclusion: line 413: More concrete suggestions for psychoeducation would be useful. Also, are there any previous experiences about it reported by other studies?

 

The authors inserted these suggestions:

In particular, psychoeducation should be addressed especially to younger patients, it should precede the NGT positioning but should be continued until its dismissal. It should empathise with prejudices related to the NGT but evidence the future adaptation and benefits perceived by many patients, and should be oriented to the reinforcement of therapeutic alliance to reduce the sense of coercion. 

 

Thank you for letting me read this valuable study.

 

We sincerely appreciate your consideration of our paper.