Abstract
Introduction
Little is known about the burden of rheumatoid arthritis (RA) in South Africa. The aim of this study was to establish the prevalence of RA and coexisting chronic disease list (CDL) conditions in the private health sector of South Africa.
Methods
A retrospective, cross-sectional analysis was performed on medicine claims data from 1 January 2014 to 31 December 2014 to establish the prevalence of RA. The cohort of RA patients was then divided into those with and those without CDL conditions, to determine the number and type of CDL conditions per patient, stratified by age group and gender.
Results
A total 4352 (0.5%) patients had RA, of whom 69.3% (3016) presented with CDL conditions. Patients had a median age of 61.31 years (3.38; 98.51), and 74.8% were female. Patients with CDL conditions were older than those patients without (p < 0.001; Cohen’s d = 0.674). Gender had no influence on the presence of CDL conditions (p = 0.456). Men had relatively higher odds for hyperlipidemia (OR 1.83; CI 1.33–2.51; p < 0.001) and lower odds for asthma (OR 0.83; CI 0.48–1.42; p = 0.490) than women. In combination with hyperlipidemia, the odds for asthma were reversed and strongly increased (OR 6.74; CI 2.07–21.93; p = 0.002). The odds for men having concomitant hyperlipidemia, hypertension, type 2 diabetes mellitus and hypothyroidism were insignificant and low (OR 0.40; CI 0.16–1.02; p = 0.055); however, in the absence of hypothyroidism, the odds increased to 3.26 (CI 2.25–4.71; p < 0.001).
Conclusion
Hypothyroidism was an important discriminating factor for comorbidity in men with RA. This study may contribute to the body of evidence about the burden of RA and coexisting chronic conditions in South Africa.
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Acknowledgements
The authors would like to thank the Pharmaceutical Benefit Management Company for providing the data to conduct the study.
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Contributions
NO: Planning and designing of the study, interpretation of data, writing of the manuscript. JB: Supervised planning and designing of the study, development of work, helped in data interpretation, drafting manuscript and final manuscript evaluation. RJ: Supervised development of work and manuscript evaluation. ML: Performed cross-sectional and cohort analysis, and manuscript evaluation. AN: Supervised development of work and manuscript evaluation. MC: Verification of analysis performed by author (ML), cohort analysis, and manuscript evaluation.
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Some of the results of the study were presented as a poster presentation at the European Drug Utilisation Research Group (EuroDURG) Conference 2017, held on the 15th–17th November 2017, at the Technology and Innovation Centre, University of Strathclyde, Glasgow, UK. The poster was entitled “Prevalence of rheumatoid arthritis and associated chronic disease list conditions in the private health sector of South Africa”.
Conflict of interest
Author Olivier has received a master’s bursary from the North-West University (Grant no. 23465174). Authors Burger, Joubert, Lubbe, Naudé and Cockeran declare that they have no conflict of interest.
Ethical approval
The study protocol was reviewed and approved by the Health Research Ethics Committee of the Health Research Ethics Commitee of the North-West University (Potcehfstroom campus), Potchefstroom, South Africa, on the July 19, 2016 (Ethics number: NWU-00179-14-A1-02). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Human and animal participants
This study was a retrospective analysis of administrative claims data and does not contain any human participants or animals.
Informed consent
Since the PBMs database contain only retrospective depersonalized claims data, the need for informed consent from each individual patient, medical scheme, prescriber and service provider was waived by the Health Research Ethics Committee.
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Olivier, N., Burger, J., Joubert, R. et al. Chronic disease list conditions in patients with rheumatoid arthritis in the private healthcare sector of South Africa. Rheumatol Int 38, 837–844 (2018). https://doi.org/10.1007/s00296-017-3907-y
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DOI: https://doi.org/10.1007/s00296-017-3907-y