Dear Editor:
We read with interest the recent paper ‘Time Trends in the Incidence of Spinal Pain in China, 1990 to 2019 and Its Prediction to 2030: The Global Burden of Disease Study 2019′ [1]. The authors present estimates for the age-standardized incidence of neck pain and low back pain in China from 1990 to 2019, and projections for 2020 to 2030. We have concerns that there are insufficient primary incidence studies to justify these estimates and projections.
To locate the primary data underpinning the estimates, we used the Global Burden of Disease (GBD) Study Data Input Tool [2] (cause: low back pain, neck pain; location: China). This revealed that the neck pain incidence estimates are based upon four studies, and the low back pain estimates are based upon eight studies. Critically, none of these studies measured incidence. Some of the studies measured prevalence, but there is only low back pain prevalence data for the years 1991, 1992, 2001, 2002, 2006, 2007 and 2009, and neck pain prevalence data for 1993, 2001, 2009 and 2011.
Providing estimates and projections for back and neck pain incidence over a 40-year period where there are no primary studies seems problematic. While the authors acknowledge the limitations of relying upon modelled data from GBD 2019, they do not make it explicit to readers that there are no primary incidence data and very limited prevalence data to inform the GBD estimates or their projections.
Understanding the global burden of low back pain and neck pain is challenging, as the data we have from China (and many other countries) are limited. In our opinion, it would be more informative for readers if the authors had stated that the burden of low back pain and neck pain in China is largely unknown, as we have very little prevalence data and no incidence data. Lack of primary data to inform GBD estimates is not confined to spinal pain and China. There are low back pain prevalence studies for only 103 of the 204 countries in the 2017 Global Burden of Disease study and incidence data for 4 of 204 countries [3]. Presenting estimates at a subnational level, as some have done, makes the problem worse [4, 5]. Therefore, it is easy to understand the challenges in having sufficient data in GBD studies to present modelled estimates.
There is a pressing need for more high-quality primary research measuring the prevalence and incidence of low back pain and neck pain. Currently, the GBD estimates for low back pain and neck pain prevalence in China are based upon a very small number of studies, which makes the estimates very uncertain. There are no incidence studies for China, so incidence estimates are even more of a concern.
Acknowledgments
Authorship
All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work as a whole, and have given their approval for this version to be published.
Author Contributions
All authors carefully read the manuscript by Wei et al. [1] and discussed the preparation and content of this letter. Christopher S Han drafted the letter. Qiuzhe Chen and Christopher G Maher revised the manuscript. All authors approved the final version.
Funding
No funding or sponsorship was received for this study/letter or publication of this article.
Data Availability
All data are described in previously published manuscripts. Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.
Declarations
Conflict of interest
None of the authors report any conflicts of interest.
Ethical Approval
This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.
References
- 1.Wei J, Chen L, Huang S, et al. Time trends in the incidence of spinal pain in China, 1990 to 2019 and its prediction to 2030: the global burden of disease study 2019. Pain Ther. 2022. 10.1007/s40122-022-00422-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
All data are described in previously published manuscripts. Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.