Sex- and Age-Specific Utilization Patterns of Nuclear Medicine Procedures at a Public Tertiary Hospital in Jamaica

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors examine the patterns of NM procedure utilization by sex and age at a major public hospital in Jamaica. This study found that 1,135 scans were conducted for 1,098 patients over the two-year period and indicated significant sex- and age-specific differences in NM service demand. The authors conclude that NM procedures at this institution are primarily driven by cancer-related and cardiovascular indications, especially among the elderly population. They emphasize that understanding these age/sex utilization patterns is important for health policy and resource allocation planning to ensure the sustainability of NM services in Jamaica. Overall, this manuscript addresses an important and under-researched topic in healthcare delivery. While the study’s data are valuable and the manuscript has many strengths, revisions are needed to improve its clarity and scientific rigor.

 

Specific Issues:

1. The treatment of patients with multiple scans is unclear and appears inconsistent. The abstract mentions that “repeat visits were excluded from the analysis”, suggesting that each patient would only be counted once. However, the Results report 1,135 scans for 1,098 patients, implying some patients had more than one scan during the study period. In the Methods, it is later clarified that repeat visits were excluded “from the inferential statistical analysis”, but all scans were counted in the descriptive totals. The authors should explicitly clarify this in the text.

 

2. The statistical methods used, particularly the Spearman’s correlation, require justification and/or revision. According to the Methods, the authors employed Spearman’s rho to assess relationships between scan types, age, and sex. However, scan type is a nominal categorical variable (e.g. bone scan, thyroid scan, etc.), which has no natural numeric order. Using a rank-based correlation in this context is statistically questionable, as any numeric coding of scan types would be arbitrary. The results indeed report a Spearman correlation finding (e.g., “type of scan had [a] significant negative correlated with age” and positive with sex), but it’s unclear how to interpret this meaningfully. Additionally, the reporting of p-values should follow standard conventions. For instance, the manuscript gives “p = 0.000” for extremely significant results, but P values should generally be rounded and never written as 0.000 – it should be reported as “p < 0.001”. Please ensure consistency in decimal places and significance notation throughout (e.g., one result in the abstract is reported as p=0.005 with three decimals, while others are given as p=0.01 with two decimals; a uniform format such as p = 0.01 or p < 0.05 would be clearer). Overall, the manuscript would benefit from a brief explanation of all statistical tests used and why they are suitable, to reassure readers that the analysis is sound.

 

3. Some of the descriptions of the results, especially the age- and sex-specific differences, are hard to follow or ambiguous and should be rewritten for clarity. For example, the abstract states, “There was a significantly greater demand for services from females 60 years and older for cardiac amyloid scans”. Similarly, the Results section notes “a significant difference in the proportion of female patients in the 60 and older age group who underwent a cardiac amyloid scan (χ²=6.40, p=0.01)”.

Comments on the Quality of English Language

The quality of English in the manuscript is generally acceptable, but there are several instances of grammatical errors and awkward phrasing that require attention. For example, one sentence reads: “The age for 50 patients were missing from the data.” This is grammatically incorrect. It could be corrected to “The ages of 50 patients were missing from the data” or “Age data were missing for 50 patients.”  The authors are encouraged to revise the identified sentences and perform a careful edit to eliminate typos, fix verb tenses and pluralization, and ensure that the narrative reads smoothly for the reader.

Author Response

Dear Sir/Madam,

Please see the attachment.

 

Best Regards

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This is a valuable and well-structured retrospective observational study assessing sex- and age-specific patterns in nuclear medicine (NM) service utilization at the University Hospital of the West Indies (UHWI) from June 2022 to May 2024. The work fills an important gap in regional data and provides crucial insight into resource allocation for NM services in a resource-limited, Caribbean public health context.

The manuscript is well written and strutured. Nevertheless,  have some minor revisions in order to improve the manuscript:

1) The abstract could better emphasize the implications of findings, especially the potential policy impacts and sustainability considerations.

2) Multivariate analysis (e.g., logistic regression) could provide more insight into predictors of scan type and sex/age interaction effects.

3) For the discussion section:

- Incorporate Health Systems Implications. The findings have clear policy relevance, but these implications are not fully developed.

- While some limitations are discussed, they should be more explicitly listed in a separate section or paragraph, including: Generalizability (single institution, urban setting); Lack of clinical outcome data; Absence of socioeconomic or comorbidity information.

Overall considered, the manuscript is acceptable with minor revisions. It provides important and timely data that will benefit researchers, practitioners, and policymakers in global and Caribbean health. Enhancing clarity around data limitations and improving the discussion of generalizability and multivariate potential will strengthen its impact.

Author Response

Dear Sir/Madam,

Please see the attachment.

 

Best Regards.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript is a retrospective analysis of the nuclear medicine activity carried out at the only hospital in the public sector of Jamaica.

The manuscript is certainly interesting and the analysis and description of the data seems to be done in a correct and orderly manner; in fact, I have no critical issues for the results paragraph.

However, I believe that some major revisions should be made that are necessary to frame the work itself.

The introductory paragraph is not exhaustive and does not provide information on the functioning of public health in Jamaica.

Since this is a work that perform an epidemiological analysis based on access to a specific facility, it is necessary to preface what the methods of access to it are, in order to understand and describe (in the discussion) the potential biases on the analysis of the results.

I review from Europe and in my country access to public facilities can be either completely free, associated with the payment of a ticket that is always approximately the same even for expensive procedures, or paid with a cost linked to the specific procedure.

How does it work in Jamaica? Are there differences between public and private health care? Are there differences in access to preliminary health services for MN in the public sector? Are there differences in access to the various MN services.

It is also appropriate to describe how the Nuclear Medicine Department is organised: how are services managed during the working week? Are there predetermined agendas?

The diagnostic activity of a nuclear medicine department must certainly be managed considering the activity and decay of the 99mTc generator, which determines how many and which procedures can be performed.

Another element to consider is the number of gamma cameras available, the model and the year of production. I believe that a paragraph dedicated to the equipment should be included in the Materials and Methods (you must specify in this section that you have a single SPECT/CT and which one) and to the supply of Mo generator and cold kit (some things are already written between lines 45-58; they should be moved and integrated).

I reiterate that the analysis of the results is good and in line with the specified objective.

In the discussion I disagree with the statement on lines 191-194: it is not justified by the data presented; to talk about trends, the data presented must be compared with the same data from a previous period.

However, I believe the entire discussion should be rewritten in order to support the considerations of paragraph 4.5 on lines 273-288, which are very valid but not supported by what is described in the previous paragraphs.

To support the activity of nuclear medicine, also related to the variables of sex and age, I believe it is necessary to describe the demographic characteristics of the Jamaican population with numbers; I assume that a census is periodically carried out, or that in any case there are reports that describe an estimate.

The conclusions should be rewritten in light of the considerations made in the introduction and discussion.

Author Response

Dear Sir/Madam,

Please see the attachment.

 

Best Regards.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed the concerns raised and the manuscript is improved significantly.

Reviewer 3 Report

Comments and Suggestions for Authors

The paper entitled "Sex-and Age-Specific Utilization Patterns of Nuclear Medicine Procedures at a Public Tertiary Hospital in Jamaica" was resubmitted after major revision.
I believe the paper can be published in its current form because it has been significantly improved following the suggestions of me and further reviewers.
My suggestions have been completely understood and incorporated correctly, and I thank the authors for it, also because my suggestions were complex and requested further information on the topic of the paper.
I also noticed that further modifications have been introduced made by other reviewers who identified other deficiencies, which were appropriately amended.
The topic is certainly interesting even if for a niche sector of the scientific community, and I believe it could be an excellent starting point for the development of nuclear medicine with gamma-emitting radiopharmaceuticals in countries where adequate development is not yet possible.