Skip to main content

Main menu

  • Home
  • Content
    • First Release
    • Current
    • Archives
    • Collections
    • Audiovisual Rheum
    • COVID-19 and Rheumatology
  • Resources
    • Guide for Authors
    • Submit Manuscript
    • Author Payment
    • Reviewers
    • Advertisers
    • Classified Ads
    • Reprints and Translations
    • Permissions
    • Meetings
    • FAQ
    • Policies
  • Subscribers
    • Subscription Information
    • Purchase Subscription
    • Your Account
    • Terms and Conditions
  • About Us
    • About Us
    • Editorial Board
    • Letter from the Editor
    • Duncan A. Gordon Award
    • GDPR Policy
    • Accessibility
  • Contact Us
  • JRheum Supplements
  • Services

User menu

  • My Cart
  • Log In

Search

  • Advanced search
The Journal of Rheumatology
  • JRheum Supplements
  • Services
  • My Cart
  • Log In
The Journal of Rheumatology

Advanced Search

  • Home
  • Content
    • First Release
    • Current
    • Archives
    • Collections
    • Audiovisual Rheum
    • COVID-19 and Rheumatology
  • Resources
    • Guide for Authors
    • Submit Manuscript
    • Author Payment
    • Reviewers
    • Advertisers
    • Classified Ads
    • Reprints and Translations
    • Permissions
    • Meetings
    • FAQ
    • Policies
  • Subscribers
    • Subscription Information
    • Purchase Subscription
    • Your Account
    • Terms and Conditions
  • About Us
    • About Us
    • Editorial Board
    • Letter from the Editor
    • Duncan A. Gordon Award
    • GDPR Policy
    • Accessibility
  • Contact Us
  • Follow jrheum on Twitter
  • Visit jrheum on Facebook
  • Follow jrheum on LinkedIn
  • Follow jrheum on RSS
LetterLetter

Bias in the Methodology: Sleep Quality Is Related to Worsening Knee Pain in Those With Widespread Pain

Chieh-Chun Yang and Po-Cheng Hung
The Journal of Rheumatology February 2021, 48 (2) 303; DOI: https://doi.org/10.3899/jrheum.201165
Chieh-Chun Yang
1School of Medicine, Chung Shan Medical University, Taichung City, Taiwan.
Roles: Medical student
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Chieh-Chun Yang
  • For correspondence: jason80035@gmail.com
Po-Cheng Hung
1School of Medicine, Chung Shan Medical University, Taichung City, Taiwan.
Roles: Medical student
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Po-Cheng Hung
  • Article
  • References
  • Info & Metrics
  • PDF
  • eLetters
PreviousNext
Loading

To the Editor:

We read with great interest the article in The Journal entitled, “Sleep Quality Is Related to Worsening Knee Pain in Those with Widespread Pain: The Multicenter Osteoarthritis Study” by Dai, et al1. The authors reported the association between sleep quality and odds of developing knee pain, and how widespread pain modified this relationship. We highly appreciate the great efforts the authors did by using a prospective cohort while simultaneously considering the potential effect of body pain at other sites. However, there are some methodologies and interpretations in the study that need more clarification.

First, the questionnaires conducted at baseline may not be able to fully represent the sleeping quality of patients during the 2-year follow-up. Since there was no evidence illustrating that sleep quality would be consistently unchanged, questionnaires for the past 7 days before baseline would not be able to assess the sleep quality of the entire 2 years. Seven days seemed not to be long enough to represent the actual status, for instance, if a patient experienced bad sleep quality during the week of assessment, but had good sleep quality for the next 2 years. In this case, they could be misclassified into the “poor sleep quality” group, causing information bias. We suggest that sleep quality assessment should be investigated continually in the follow-up period, and the definition of categorization should be more detailed.

Second, we are worried about the pain-relieving treatments of patients, which might present as residual confounders in the study. Although the study has stated that the information of medication use was collected at the 60-month visit, only nonsteroidal antiinflammatory drugs were taken into account when it came to the adjustments of confounders in the statistical analysis. In general, medical treatments such as tramadol2, acetaminophen3,4, steroid joint injection4, and hyaluronic acid joint injection4,5 are commonly used to treat knee pain clinically. However, they were not included in the adjustments of the Dai, et al study1, which may lead to confounding bias. We recommend these treatments should be considered as potential confounders and included in the multivariable adjustments.

Last but not the least, we had queries about the causality of sleep quality and knee pain. Did good sleep improve knee pain, or might it be possible that persons with better knee conditions tend to have better sleep quality? This study suggested that better sleep quality could have lower odds in developing worsening knee pain1. In a previous study, however, persons with knee pain tended to experience more sleep disturbance than others6. In the Dai, et al study1, the relationship between sleep quality and knee pain was only statistically significant in the cross-sectional analysis, but not in the longitudinal one. Therefore, we wondered if the results would only represent a correlation rather than causality. More investigation and research are expected to verify the relationship.

Hence, we are convinced that a continual sleep quality assessment during the follow-up as well as the consideration of several pain-relieving treatments are essential to enhance credibility. Finally, advanced studies are recommended to prove the correlation or causality corresponding to the work of Dai, et al1.

  • Copyright © 2021 by the Journal of Rheumatology

REFERENCES

  1. 1.↵
    1. Dai Z,
    2. Neogi T,
    3. Brown C,
    4. Nevitt M,
    5. Lewis CE,
    6. Torner J, et al.
    Sleep quality is related to worsening knee pain in those with widespread pain: the multicenter osteoarthritis study. J Rheumatol 2020;47:1019-25.
    OpenUrlAbstract/FREE Full Text
  2. 2.↵
    1. Hochberg MC,
    2. Altman RD,
    3. April KT,
    4. Benkhalti M,
    5. Guyatt G,
    6. McGowan J, et al; American College of Rheumatology
    . American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res 2012;64:465-74.
    OpenUrlCrossRefPubMed
  3. 3.↵
    1. McAlindon TE,
    2. Bannuru RR,
    3. Sullivan MC,
    4. Arden NK,
    5. Berenbaum F,
    6. Bierma-Zeinstra SM, et al.
    OARSI guidelines for the non-surgical management of knee osteoarthritis. Osteoarthritis Cartilage 2014;22:363-88.
    OpenUrlCrossRefPubMed
  4. 4.↵
    1. Sinusas K.
    Osteoarthritis: diagnosis and treatment. Am Fam Physician 2012;85:49-56.
    OpenUrlPubMed
  5. 5.↵
    1. Buendía-López D,
    2. Medina-Quirós M,
    3. Fernández-Villacañas Marín M.
    Clinical and radiographic comparison of a single LP-PRP injection, a single hyaluronic acid injection and daily NSAID administration with a 52-week follow-up: a randomized controlled trial. J Orthop Traumatol 2018;19:3.
    OpenUrl
  6. 6.↵
    1. Wilcox S,
    2. Brenes GA,
    3. Levine D,
    4. Sevick MA,
    5. Shumaker SA,
    6. Craven T.
    Factors related to sleep disturbance in older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis. J Am Geriatr Soc 2000;48:1241-51.
    OpenUrlCrossRefPubMed
PreviousNext
Back to top

In this issue

The Journal of Rheumatology
Vol. 48, Issue 2
1 Feb 2021
  • Table of Contents
  • Table of Contents (PDF)
  • Index by Author
Print
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for your interest in spreading the word about The Journal of Rheumatology.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Bias in the Methodology: Sleep Quality Is Related to Worsening Knee Pain in Those With Widespread Pain
(Your Name) has forwarded a page to you from The Journal of Rheumatology
(Your Name) thought you would like to see this page from the The Journal of Rheumatology web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Bias in the Methodology: Sleep Quality Is Related to Worsening Knee Pain in Those With Widespread Pain
Chieh-Chun Yang, Po-Cheng Hung
The Journal of Rheumatology Feb 2021, 48 (2) 303; DOI: 10.3899/jrheum.201165

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero

 Request Permissions

Share
Bias in the Methodology: Sleep Quality Is Related to Worsening Knee Pain in Those With Widespread Pain
Chieh-Chun Yang, Po-Cheng Hung
The Journal of Rheumatology Feb 2021, 48 (2) 303; DOI: 10.3899/jrheum.201165
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One
Save to my folders

Jump to section

  • Article
    • REFERENCES
  • References
  • Info & Metrics
  • PDF
  • eLetters

Related Articles

Cited By...

More in this TOC Section

  • What It Means to Me to Have Juvenile Arthritis: One Patient’s Definition
  • COVID-19 in Patients With Connective Tissue Disease-related Interstitial Lung Disease
  • Clinical and Radiological Remission of Osteoarticular and Cutaneous Lesions in SAPHO Patients Treated With Secukinumab: A Case Series
Show more Letter

Similar Articles

Content

  • First Release
  • Current
  • Archives
  • Collections
  • Audiovisual Rheum
  • COVID-19 and Rheumatology

Resources

  • Guide for Authors
  • Submit Manuscript
  • Author Payment
  • Reviewers
  • Advertisers
  • Classified Ads
  • Reprints and Translations
  • Permissions
  • Meetings
  • FAQ
  • Policies

Subscribers

  • Subscription Information
  • Purchase Subscription
  • Your Account
  • Terms and Conditions

More

  • About Us
  • Contact Us
  • My Alerts
  • My Folders
  • RSS Feeds
The Journal of Rheumatology
The content of this site is intended for health care professionals.
Copyright © 2016 by The Journal of Rheumatology Publishing Co. Ltd.
Print ISSN: 0315-162X; Online ISSN: 1499-2752
Powered by HighWire