Background While there is an increasing need to better understand the epidemiology of ankylosing spondylitis (AS), such data in France are limited1,2 or issued from cohorts, with the inherent risk of selection bias.
Objectives To estimate the prevalence of severe AS in France and the frequency of chronic, severe co-morbidities, as compared with a control group based on a national representative claims database.
Methods The EGB database is a national representative 1/97 sample of individuals covered by the 3 main French insurance schemes. This database lists all healthcare consumption and allows identification of beneficiaries eligible for full health insurance coverage due to severe conditions (list of conditions is defined by the French Sickness fund and called “ALD”). The studied population comprised adults (>18 yrs) with severe AS in 2012. Frequency of serious chronic co-morbidities, such as inflammatory bowel diseases (IBD), cardiovascular diseases and malignancies were identified based on ALD eligibility and compared with a control group without full coverage due to AS and matched by sex and age.
Results Among 470,326 adults in the database, 827 patients with severe AS were identified, corresponding to a crude prevalence rate of 0.18% and a nationwide prevalence estimate of 88,275 patients in 2012 in France. Their M/F sex ratio was 1.2, mean (±SD) age was 50.4 (±14.3) years and the time since decision for full health insurance coverage due to AS was 9.7 (±7.8) years. IBD, high blood pressure (HBP), recurrent major depressive disorders and other co-morbidities taken as a whole were significantly more frequent in AS patients than controls (Table; 3.5 vs 0.24%, p<0.0001; 4.5 vs 1.8%; p<0.0001; 3.1 vs 1.5%; p=0.003 and 24.7 vs 18.8%; p=0.0003, respectively). There was no significant difference in mortality between AS and controls as measured by annual death rate.
Conclusions Analysis of a national representative claim database provides up-to-date data on the current prevalence of severe AS in France. These initial results also indicate an increase in several co-morbidities, such as IBD, HBP and depression. No differences were seen regarding malignancies or mortality rates. Further research is needed to confirm these findings.
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Costantino F. Ann Rheum Dis 2013 [Epub ahead of print]
Acknowledgements The authors acknowledge Costello Medical Consulting for editorial assistance which was funded by UCB Pharma.
Disclosure of Interest M. Breban Consultant for: UCB Pharma, P. Claudepierre Consultant for: UCB Pharma, T. de Chalus Employee of: UCB Pharma, J. M. Joubert Employee of: UCB Pharma, C. Laurendeau Employee of: CEMKA mandated by UCB Pharma for the analysis of the database, J. Gourmelen: None declared, F. Fagnani Employee of: CEMKA mandated by UCB Pharma for the analysis of the database