Title: Global parental acceptance, attitudes, and knowledge regarding human papillomavirus
vaccinations for their children: A systematic literature review and meta-analysis
Version: 2 Date: 21 Jun 2024
Reviewer's report:
Global parental acceptance, attitudes, and knowledge regarding human papillomavirus
vaccinations for their children: A systematic literature review and meta-analysis
The topic of the article is very interesting, and the application of qualitative and quantitative
synthesis of studies focused on parents' acceptance, attitudes, and knowledge towards HPV
vaccination of their offspring is very beneficial. As a result, valuable insight into this issue was
gained.
A pitfall of this work was the simple fact that the authors did not conduct a pooled quantitative
synthesis (meta-analysis) independent of the sex of parents and their offspring, although this
is the focus of the study as stated in the title. It would certainly be useful to conduct such a
synthesis. Stratification by sex of offspring or parent should be considered a sensitivity analysis
rather than the main outcome.
Further, stratification by the year of the survey conducted is missing. All other areas of interest,
such as parental attitudes and parental knowledge of HPV or HPV vaccination, should be
analyzed independently of the sex of the parent and their offspring. This approach (independent
of sex) could enable a general synthesis of existing knowledge with respect to the site and time
of the survey, as well as the general knowledge and attitudes of parents.
Moreover, the sex-related stratification significantly reduced the number of studies (fewer
than 10 in the sub-analyses), which did not contribute to robust results. Therefore, additional
stratification by sex should be conducted as a sensitivity analysis and presented in a supplement.
Given that the authors conducted a meta-analysis, they completely overlooked significant
parameters for assessing the quality of the pooled results, such as publication bias, the impact
of small studies, the summary effect of asymmetry with the estimation of potentially missing
studies using the trim-and-fill method, and the prediction interval estimated. Furthermore,
the assessment of the quality of results using the Grading of Recommendations Assessment,
Development, and Evaluation (GRADE) criteria was also neglected.
Re-analyses and additional analyses, including GRADE, will need to be completed for the results
to be considered justified.
Manuscript requires major revision!!!
Abstract:
The abstract must be structured according to the journal's requirements.
Introduction:
It would be appropriate to specify the manufacturers of HPV vaccines so that it is clear where
each vaccine may be available, or at least the year and site of availability.
Furthermore, it would be appropriate to state an important insight: the risk of CIN2+ recurrence
in women after conization is reduced in those who were HPV vaccinated during adolescence, as
evidenced by a new meta-analysis from 2023 (https://doi.org/10.1136/sextrans-2023-055793).
The introduction is unnecessarily long and contains a lot of information more suitable for the
discussion section. It needs to be shortened.
Materials and methods:
In section 2.2, it is stated that studies published between January 1, 2006, and August 31, 2023,
were considered. However, this contradicts what is reported in PROSPERO, where this study
was registered.
In section 2.3, the authors state that studies were included if they met the study setting. It is
necessary to better explain what is meant by „study setting“.
In section 2.4, longitudinal (prospective) studies are mentioned. It is highly likely that these were
cohort studies. Therefore, the authors should clarify this. Since the RoB of these studies was
evaluated according to the NOS cohort studies, they should consistently and correctly report the
cohort studies (including tables) throughout the entire text of the paper.
The Statistics subsection is missing. This section should be reported and should include
additional analyses such as publication bias, the effect of small studies, etc. See above.
Results:
The authors used one Medline database on two platforms, WoS and PubMed, not two databases.
This is a very common mistake and needs to be stated correctly.
The authors report that they found an additional 34 publications using the hand search method.
How this method was conducted needs to be specified
The text of the results section is extremely long and unintelligible to the reader. The authors
should shorten it, create a clear table with the results, and supplement the absolute number of
studies with percentage proportions.
The authors make a major mistake in this section by referring to specific studies. This is allowed
in the discussion, not in the results. They naively describe the range of the 95% CI and vaguely
outline the results (e.g., for almost half of the studies), which is not acceptable in this section.
Additionally, they do not address the inconsistency index at all, and there are missing additional
analyses needed to properly describe the results found. The entire section needs to be rewritten
so that the description of the results is clear, understandable, and acceptable to the reader.
Discussion + Conclusion
The discussion section should better evaluate the overall result of parents' attitudes towards HPV
vaccination of their offspring, which the authors completely neglected. This evaluation is crucial
to align with the title of the article.
Furthermore, the strength and robustness of the study outcomes are insufficiently assessed,
which is understandable given the absence of additional analyses. Therefore, the authors should
provide the additional analyses mentioned above.
Moreover, the limitations of this study are markedly underestimated. For instance, the modified
score for cross-sectional studies ranges from 0 to 10 stars, while for cohort studies it ranges
from 0 to 9 stars. This substantial limitation affects the quality assessment of eligible studies
significantly.
Tables
Tables 2 and 3 showed that not all eligible studies contained the required parameters.
Unfortunately, this discrepancy is not mentioned in the Results and Discussion sections at all.
The tables imply a bias in this study, suggesting that the authors selectively included studies.
Therefore, this discrepancy needs to be described and discussed as a limitation of this study.
Figures
Figure 1
What do 'wrong study year,' 'wrong study population,' and 'wrong study design' mean? These
need to be explained more clearly.
Figure 2 and 3 - The usual reporting details of the forest plot are missing, such as diamonds
indicating pooled effectiveness, with the lateral points indicating the 95% CI; dashed lines
indicate the point of pooled acceptability rate etc.
In figures 2 and 3, it is not clear what 'events' means; this needs to be clarified.