Higher mortality rates associated with rheumatoid arthritis in Saskatchewan, Canada, 2001–2019

Abstract

Objectives

To estimate provincial all-cause mortality rates of Saskatchewan people with rheumatoid arthritis (RA) for comparison with the general population over time and between different geographic regions.

Methods

Saskatchewan provincial administrative health databases (2001–2019) were utilized as data sources. Two RA case definitions were employed: (1) ≥ 3 physician billing diagnoses, at least 1 from a specialist (rheumatologist, general internist or orthopaedic surgeon) within 2 years; (2) ≥ 1 hospitalization diagnosis (ICD-9 code 714, and ICD-10-CA codes M05, M06). Data from these definitions were combined to create an administrative data RA cohort. All-cause mortality rates across geographic regions, between rural/urban residences and between sexes were examined.

Results

Over an 18-year span, between fiscal-year 2001–2002 and fiscal-year 2018–2019, age- and sex-adjusted mortality rates ranged from 17.10 to 21.04 (95% CI 14.77, 19.44; 18.03, 24.05)/1000 RA person-years, compared with mortality rates for the general Saskatchewan population without RA, which ranged from 9.37 to 10.88 (95% CI 9.23, 9.51; 10.72, 11.05)/1000 person-years. Fiscal-year mortality rate ratios ranged from 1.82 to 2.13 (95% CI 1.56, 2.13; 1.83, 2.46). Provincial mortality rates were higher in men than in women for both general and RA populations. Northern Saskatchewan mortality rates were significantly higher in the general population but did not achieve significance compared with other provincial regions for the RA population. Regression analysis identified age, male sex, RA and geographic region as factors contributing to increased mortality. A trend towards lower mortality rates over time was observed.

Conclusion

Higher mortality rates were observed in the RA population overall. Men had higher mortality rates, as did residents of Northern Saskatchewan compared with residents of other regions for the general population.

Résumé

Objectifs

Estimer les taux de mortalité provinciaux, toutes causes confondues, des habitants de la Saskatchewan atteints de polyarthrite rhumatoïde (PR) pour les comparer aux taux dans la population générale au fil du temps et entre différentes régions géographiques.

Méthode

Nos données sont extraites des bases de données administratives sur la santé de la Saskatchewan (2001–2019). Deux définitions de cas ont été employées pour la PR : 1) ≥ 3 factures de diagnostic médical, dont au moins une d’un(e) spécialiste (rhumatologue, interniste général[e] ou chirurgien[ne] orthopédiste) en l’espace de deux ans; 2) ≥ 1 diagnostic d’hospitalisation (code CIM-9 714 et codes CIM-10-CA M05 et M06). Les données de ces définitions ont été combinées pour créer une cohorte de personnes atteintes de PR dans les données administratives. Les taux de mortalité toutes causes confondues entre les régions géographiques, entre les lieux de résidence urbains et ruraux et entre les sexes ont été examinés.

Résultats

En l’espace de 18 ans, entre les exercices 2001-2002 et 2018-2019, les taux de mortalité rajustés selon l’âge et le sexe ont varié entre 17,10 et 21,04 (IC de 95 % : 14,77-19,44; 18,03-24,05)/1000 personnes-années pour les personnes atteintes de PR, tandis que les taux de mortalité de la population générale de la Saskatchewan non atteinte de PR se sont situés entre 9,37 et 10,88 (IC de 95 % : 9,23-9,51; 10,72-11,05)/1000 personnes-années. Les rapports de taux de mortalité par exercice ont varié entre 1,82 et 2,13 (IC de 95 % : 1,56-2,13; 1,83-2,46). Les taux de mortalité provinciaux des hommes étaient supérieurs à ceux des femmes, tant dans la population générale que chez les personnes atteintes de PR. Les taux de mortalité dans le Nord de la Saskatchewan étaient sensiblement plus élevés que dans les autres régions de la province pour la population générale, mais pas sensiblement plus élevés pour la population atteinte de PR. Selon les analyses de régression, l’âge, le sexe masculin, la PR et la région géographique étaient des facteurs contribuant à une mortalité accrue. Une tendance à la baisse des taux de mortalité au fil du temps a été observée.

Conclusion

Dans la population atteinte de PR, des taux de mortalité plus élevés ont été observés globalement. Dans la population générale, les taux de mortalité des hommes et ceux des résidents du Nord de la Saskatchewan étaient plus élevés que ceux des résidents des autres régions.

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Data availability

Data for this study were derived from Saskatchewan health administration databases.

References

  1. Bernatsky, S., Dekis, A., Hudson, M., Pineau, C. A., Boire, G., Fortin, P. R., et al. (2014). Rheumatoid arthritis prevalence in Quebec. BMC Research Notes, 19(7), 937.

    Article  Google Scholar 

  2. Canada: Metropolitan Areas (Population Estimates). https://www.citypopulation.de/php/canada-metro.php. Accessed 14 July 2020.

  3. Dadoun, S., Zeboulon-Ktorza, N., Combescure, C., Elhai, M., Rozenberg, S., Gossec, L., & Fautrel, B. (2013). Mortality in rheumatoid arthritis over the last fifty years: Systematic review and meta-analysis. Joint, Bone, Spine, 80(1), 29–33.

    Article  Google Scholar 

  4. Gonzalez, A., Maradit Kremers, H., Crowson, C. S., et al. (2007). The widening mortality gap between rheumatoid arthritis patients and the general population. Arthritis and Rheumatism, 56(11), 3583–3587.

    Article  Google Scholar 

  5. Jean, S., Hudson, M., Gamache, P., Bessette, L., Fortin, P. R., Boire, G., et al. (2017). Temporal trends in prevalence, incidence and mortality for rheumatoid arthritis in Quebec, Canada: A population-based study. Clinical Rheumatology, 36, 2667–2671.

    Article  Google Scholar 

  6. Kroeker, K., Widdifield, J., Muthukamarana, S., Jiang, D., & Lix, L. (2017). Model-based methods for case definitions from administrative health data: Application to rheumatoid arthritis. BMJ Open, 6, e016173. https://doi.org/10.1136/bmjopen-2017-016173.

    Article  Google Scholar 

  7. Lacaille, D., Avina-Zubieta, J. A., Sayre, E. C., & Abrahamowicz, M. (2017). Improvement in 5-year mortality in incident rheumatoid arthritis compared with the general population—Closing the mortality gap. Annals of the Rheumatic Diseases, 76(6), 1057–1063.

    Article  Google Scholar 

  8. Law, M. R., & Morris, J. K. (1998). Why is mortality higher in poorer areas and in more northern areas of England and Wales. Journal of Epidemiology and Community Health, 52(6), 344–352.

    CAS  Article  Google Scholar 

  9. Maradit-Kremers, H., Nicola, P. J., Crowson, C. S., Ballman, K. V., & Gabriel, S. E. (2005). Cardiovascular death in rheumatoid arthritis: A population-based study. Arthritis and Rheumatism, 52(3), 722–732.

    Article  Google Scholar 

  10. Myasoedova, E., Crowson, C. S., Kremers, H. M., Therneau, T. M., & Gabriel, S. E. (2010). Is the incidence of rheumatoid arthritis rising? Results from Olmsted County, Minnesota, 1955-2007. Arthritis and Rheumatism, 62(6), 1576–1582.

    Article  Google Scholar 

  11. Nair, B. V., Schuler, R., Stewart, S., & Taylor-Gjevre, R. M. (2016). Self-reported barriers to healthcare access for rheumatoid arthritis patients in rural and northern Saskatchewan: A mixed methods study. Musculoskeletal Care, 14(4), 243–251.

    CAS  Article  Google Scholar 

  12. Nair, B. V., Taylor-Gjevre, R. M., Wu, L., Jin, S., & Quail, J. M. (2019). Incidence and prevalence of rheumatoid arthritis in Saskatchewan, Canada: 2001-2014. BMC Rheumatology, 3, 28.

    Article  Google Scholar 

  13. Ogdie, A., Maliha, S., Shin, D., Love, T. J., Baker, J., Jiang, Y., et al. (2017). Cause-specific mortality in patients with psoriatic arthritis and rheumatoid arthritis. Rheumatology (Oxford), 56(6), 907–911.

    Article  Google Scholar 

  14. Population Health Unit. Northern Saskatchewan. Northern Saskatchewan Health Indicators Report 2011. http://www.mcrhealth.ca/media/files/Northern%20Saskatchewan%20Health%20Indicators%20Report%202011.pdf. Accessed 2 Oct 2020.

  15. Romanow, R. J. (2002). Building on values: The future of health care in Canada. Final report. The Romanow Commission report. Ottawa: Health Canada.

  16. Statistics Canada: Census metropolitan area (CMA) and Census agglomeration (CA). http://www.statcan.gc.ca/pub/92-195-x/2011001/geo/cma-rmr/cma-rmr-eng.htm. Accessed 12 June 2016.

  17. Statistics Canada: Deaths and age-standardized mortality rate, by province and territory. https://www.statcan.gc.ca/tables-tableaux/sum-som/l01/cst01/hlth86b-eng.htm. Accessed 31 Dec 2017.

  18. Statistics Canada: Saskatchewan annual population report calendar year 2019. https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=1710000901. Accessed 20 Oct 2020.

  19. Taylor-Gjevre, R. M., Nair, B. V., Jin, S., & Quail, J. M. (2018). Geographic variation in incidence and prevalence rates for rheumatoid arthritis in Saskatchewan, Canada 2001-2014. Canadian Journal of Public Health, 109(3), 427–435.

    Article  Google Scholar 

  20. Tjepkema, M., Bushnik, T., Bougie, E. Life expectancy of First Nations, Metis and Inuit household populations in Canada Health Reports: Statistics Canada. https://www150.statcan.gc.ca/n1/pub/82-003-x/2019012/article/00001-eng.htm. Accessed 2 Oct 2020.

  21. van den Hoek, J., Boshuizen, H. C., Roorda, L. D., Tijhuis, G. J., Nurmohamed, M. T., et al. (2017). Mortality in patients with rheumatoid arthritis: A 15-year prospective cohort study. Rheumatology International, 37(4), 487–493.

    Article  Google Scholar 

  22. Widdifield, J., Bernatsky, S., Paterson, J. M., Tu, K., Ng, R., Thorne, J. C., et al. (2013). Accuracy of Canadian health administrative databases in identifying patients with rheumatoid arthritis: A validation study using the medical records of rheumatologists. Arthritis Care and Research, 65(10), 1582–1591.

    PubMed  Google Scholar 

  23. Widdifield, J., Paterson, J. M., Bernatsky, S., Tu, K., Tomlinson, G., Kuriya, B., Thorne, J. C., & Bombardier, C. (2014). The epidemiology of rheumatoid arthritis in Ontario, Canada. Arthritis and Rheumatism, 66(4), 786–793.

    Article  Google Scholar 

  24. Widdifield, J., Bernatsky, S., Paterson, J. M., Tomlinson, G., Tu, K., Kuriya, B., et al. (2015). Trends in excess mortality among patients with rheumatoid arthritis in Ontario, Canada. Arthritis Care & Research, 67(8), 1047–1053.

    Article  Google Scholar 

  25. Wolfe, F., Mitchell, D. M., Sibley, J. T., Fries, J. F., Bloch, D. A., Williams, C. A., et al. (1994). The mortality of rheumatoid arthritis. Arthritis and Rheumatism, 37(4), 481–494.

    CAS  Article  Google Scholar 

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Funding

This work was supported by the Noreen Sutherland— Rheumatoid Arthritis—Royal University Hospital Foundation Endowment Fund.

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All the authors participated in the study design, interpretation of findings and preparation/review of the final manuscript.

Corresponding author

Correspondence to Regina M. Taylor-Gjevre.

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The authors declare that they have no conflict of interest.

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This study complies with the Declaration of Helsinki and was approved by the University of Saskatchewan Biomedical Research Ethics Board (BIO-REB 13-336).

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Taylor-Gjevre, R.M., Nair, B.V., Jin, S. et al. Higher mortality rates associated with rheumatoid arthritis in Saskatchewan, Canada, 2001–2019. Can J Public Health (2021). https://doi.org/10.17269/s41997-021-00476-w

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Keywords

  • Rheumatoid arthritis
  • Mortality
  • Northern
  • Rural

Mots-clés

  • Polyarthrite rhumatoïde
  • mortalité
  • population nordique
  • population rurale