Research Report

Comparing the Performance of Comorbidity Indices in Predicting Functional Status, Health-Related Quality of Life, and Total Health Care Use in Older Adults With Back Pain

Journal of Orthopaedic & Sports Physical Therapy

Published Online:February 29, 2020Volume50Issue3Pages143-148

https://www.jospt.org/doi/10.2519/jospt.2020.8764

Abstract

Objective

To determine how well the functional comorbidity index (FCI) predicts outcomes in older adults with back pain compared to Quan's modification of the Charlson comorbidity index (Quan-Charlson comorbidity index) and the Elixhauser comorbidity index.

Design

Secondary analysis of a prospective cohort study.

Methods

We included 5155 adults 65 years of age or older with new primary care visits for back pain. Comorbidity was measured using diagnosis codes 12 months prior to the new visit. Outcomes of functional limitation (Roland-Morris Disability Questionnaire), health-related quality of life (European Quality of Life-5 Dimensions [EQ-5D]), and total health care use (sum of relative value units) were measured 12 months after the new visit. We compared multivariable models containing preselected prognostic factors.

Results

Spearman correlation coefficients among the indices were 0.70 or greater. Multivariable models for the Roland-Morris Disability Questionnaire had similar R² and root-mean-square error (RMSE) of prediction when using the FCI (R² = 0.190; RMSE, 6.19), Quan-Charlson comorbidity index (R² = 0.185; RMSE, 6.20), or Elixhauser comorbidity index (R² = 0.189; RMSE, 6.19). Multivariable models for the EQ-5D score showed small differences in R² and RMSE when using the FCI (R² = 0.157; RMSE, 0.163), Quan-Charlson comorbidity index (R² = 0.148; RMSE, 0.164), or Elixhauser comorbidity index (R² = 0.154; RMSE, 0.163). Multivariable models for health care use had similar Akaike information criterion (AIC) values when using the FCI (AIC = 10.04), Quan-Charlson comorbidity index (AIC = 10.04), or Elixhauser comorbidity index (AIC = 10.01).

Conclusion

All indices performed similarly in predicting outcomes. There does not seem to be an advantage to using one index over another for older adults with back pain. There is still a need to develop better function-based risk-adjustment models that improve prediction of functional outcomes versus standard comorbidity indices. J Orthop Sports Phys Ther 2020;50(3):143–148. Epub 23 Jul 2019. doi:10.2519/jospt.2020.8764

References

1. American Physical Therapy Association. Physical Therapy Outcomes Registry. Available at: http://www.ptoutcomes.com/home.aspx?navID%20=%2010737435589. Accessed June 1, 2015. Google Scholar
2. Barton GR, , Sach TH, , Avery AJ, , et al.. A comparison of the performance of the EQ-5D and SF-6D for individuals aged ± 45 years. Health Econ. 2008; 17: 815– 832. https://doi.org/10.1002/hec.1298 Crossref Medline Google Scholar
3. Burwell SM. and Setting value-based payment goals—HHS efforts to improve U.S. health care. N Engl J Med. 2015; 372: 897– 899. https://doi.org/10.1056/NEJMp1500445 Crossref Medline Google Scholar
4. Delitto A, , George SZ, , Van Dillen L, , et al.. Low back pain. J Orthop Sports Phys Ther. 2012; 42: A1– A57. https://doi.org/10.2519/jospt.2012.42.4.A1 Link Google Scholar
5. Dominick CH, , Blyth FM, , Nicholas MK. and Unpacking the burden: understanding the relationships between chronic pain and comorbidity in the general population. Pain. 2012; 153: 293– 304. https://doi.org/10.1016/j.pain.2011.09.018 Crossref Medline Google Scholar
6. Dominick KL, , Dudley TK, , Coffman CJ, , Bosworth HB. and Comparison of three comorbidity measures for predicting health service use in patients with osteoarthritis. Arthritis Rheum. 2005; 53: 666– 672. https://doi.org/10.1002/art.21440 Crossref Medline Google Scholar
7. Edwards TC, , Lavallee DC, , Bauer Z, , et al.. Problem areas identified as important to older adults with lumbar spinal stenosis. Spine J. 2015; 15: 1636– 1644. https://doi.org/10.1016/j.spinee.2015.03.008 Crossref Medline Google Scholar
8. Gold LS, , Bryan M, , Comstock BA, , et al.. Associations between relative value units and patient-reported back pain and disability. Gerontol Geriatr Med. 2017; 3: 2333721416686019. https://doi.org/10.1177/2333721416686019 Crossref Google Scholar
9. Gozalo PL, , Resnik LJ, , Silver B. and Benchmarking outpatient rehabilitation clinics using functional status outcomes. Health Serv Res. 2016; 51: 768– 789. https://doi.org/10.1111/1475-6773.12344 Crossref Medline Google Scholar
10. Groll DL, , To T, , Bombardier C, , Wright JG. and The development of a comorbidity index with physical function as the outcome. J Clin Epidemiol. 2005; 58: 595– 602. https://doi.org/10.1016/j.jclinepi.2004.10.018 Crossref Medline Google Scholar
11. Jarvik JG, , Comstock BA, , Heagerty PJ, , et al.. Back pain in seniors: the Back pain Outcomes using Longitudinal Data (BOLD) cohort baseline data. BMC Musculoskelet Disord. 2014; 15: 134. https://doi.org/10.1186/1471-2474-15-134 Crossref Medline Google Scholar
12. Jarvik JG, , Gold LS, , Tan K, , et al.. Long-term outcomes of a large, prospective observational cohort of older adults with back pain. Spine J. 2018; 18: 1540– 1551. https://doi.org/10.1016/j.spinee.2018.01.018 Crossref Medline Google Scholar
13. Kumar A, , Graham JE, , Resnik L, , et al.. Examining the association between comorbidity indexes and functional status in hospitalized Medicare fee-for-service beneficiaries. Phys Ther. 2016; 96: 232– 240. https://doi.org/10.2522/ptj.20150039 Crossref Medline Google Scholar
14. Kumar A, , Graham JE, , Resnik L, , et al.. Comparing comorbidity indices to predict post–acute rehabilitation outcomes in older adults. Am J Phys Med Rehabil. 2016; 95: 889– 898. https://doi.org/10.1097/PHM.0000000000000527 Crossref Medline Google Scholar
15. Patel KV, , Guralnik JM, , Dansie EJ, , Turk DC. and Prevalence and impact of pain among older adults in the United States: findings from the 2011 National Health and Aging Trends Study. Pain. 2013; 154: 2649– 2657. https://doi.org/10.1016/j.pain.2013.07.029 Crossref Medline Google Scholar
16. Patrick DL, , Deyo RA, , Atlas SJ, , Singer DE, , Chapin A, , Keller RB. and Assessing health-related quality of life in patients with sciatica. Spine (Phila Pa 1976). 1995; 20: 1899– 1908; discussion 1909. https://doi.org/10.1097/00007632-199509000-00011 Crossref Medline Google Scholar
17. Quan H, , Sundararajan V, , Halfon P, , et al.. Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Med Care. 2005; 43: 1130– 1139. https://doi.org/10.1097/01.mlr.0000182534.19832.83 Crossref Medline Google Scholar
18. Sharabiani MT, , Aylin P, , Bottle A. and Systematic review of comorbidity indices for administrative data. Med Care. 2012; 50: 1109– 1118. https://doi.org/10.1097/MLR.0b013e31825f64d0 Crossref Medline Google Scholar
19. Steyerberg EW, , Moons KG, , van der Windt DA, , et al.. PROGnosis RESearch Strategy (PROGRESS) 3: prognostic model research. PLoS Med. 2013; 10: e1001381. https://doi.org/10.1371/journal.pmed.1001381 Crossref Medline Google Scholar
20. Yurkovich M, , Avina-Zubieta JA, , Thomas J, , Gorenchtein M, , Lacaille D. and A systematic review identifies valid comorbidity indices derived from administrative health data. J Clin Epidemiol. 2015; 68: 3– 14. https://doi.org/10.1016/j.jclinepi.2014.09.010 Crossref Medline Google Scholar

Volume 50, Issue 3March 2020

Pages: 113-168

Keywords

Correspondence

Address correspondence to Dr Sean Rundell, University of Washington, Box 356490, 1959 NE Pacific Street, Seattle, WA 98195. E-mail: [email protected]

Disclosure

The Back pain Outcomes using Longitudinal Data study received Internal Review Board approval from the University of Washington Human Subjects Division (application number 39051). This research was supported by the Foundation for Physical Therapy Research's Center on Health Services Training and Research Pilot Study Program grant. The Back pain Outcomes using Longitudinal Data study was supported by grants 1R01HS01922201 and 1R01HS022972-01 from the Agency for Healthcare Research and Quality. Dr Jarvik is a founder and stockholder of Physiosonix (an ultrasound company), consults for HealthHelp (a utilization review service), is a section editor for UpToDate (Wolters Kluwer Health; medical resource software), and is a coeditor of the book Evidence-Based Neuroimaging Diagnosis and Treatment (Springer). The other authors certify that they have no affiliations with or financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the article.

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Comparing the Performance of Comorbidity Indices in Predicting Functional Status, Health-Related Quality of Life, and Total Health Care Use in Older Adults With Back Pain

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Conclusion

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