Reasons why osteoarthritis predicts mortality:Path analysis within a Cox proportional hazards model


Objectives To identify potentially modifiable factors that mediate the association between symptomatic osteoarthritis (OA) and premature mortality. Methods A population-based prospective cohort study; primary care medical record data were linked to self-report information collected by questionnaire in adults aged 50 years and over (n=10 415). OA was defined by primary care consultation and moderate-to-severe pain interference in daily life. A Cox proportional hazards analysis determined the total effect (TE) of OA on mortality after adjustment for potential confounders. Within the Cox model, path analysis was used to decompose the TE to assess the indirect and direct effects for selected potential mediators (anxiety, depression, unrefreshed sleep and walking frequency). Results are expressed as HRs with 95% CIs derived from bootstrap resampling. Results OA was significantly associated with mortality (TE-adjusted HR 1.14; 95% CI 1.00 to 1.29). The indirect effects for walking frequency were 1.05 (95% CI 1.04 to 1.06), depression 1.02 (95% CI 1.02 to 1.03), anxiety 1.01 (95% CI 1.00 to 1.02) and unrefreshed sleep 1.01 (95% CI 1.00 to 1.01). Conclusions The analysis indicates that encouraging people to walk and get out and about' in addition to targeting OA could be protective against excessive mortality. The findings also suggest that depression, anxiety and unrefreshed sleep have a role in premature mortality for people with OA; however, this has low clinical significance.

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Divisions: College of Health & Life Sciences > School of Psychology
College of Health & Life Sciences
Funding Information: Funding this study is supported financially by a programme grant awarded by the Medical research council, UK (grant code: g9900220), and by funding secured from the north Staffordshire Primary care r&D consortium for nHS service support costs. MJt is supp
Additional Information: © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:
Uncontrolled Keywords: epidemiology,health services research,osteoarthritis,outcomes research,Immunology and Allergy,Rheumatology,Immunology
Publication ISSN: 2044-6055
Last Modified: 17 Jun 2024 07:46
Date Deposited: 05 Dec 2019 12:38
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2019-11-01
Accepted Date: 2019-10-23
Authors: Wilkie, Ross
Parmar, Simran Singh
Blagojevic-Bucknall, Milica
Smith, Diane
Thomas, Martin J.
Seale, Bethany Jane
Mansell, Gemma (ORCID Profile 0000-0002-5479-2678)
Peat, George


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