Epidemiology and Public Health
The Burden of Comorbidity in Patients with RA, PsA or SPA in a General Practice Registry
Diederik De Cock, PhD
KU Leuven, Leuven, Belgium
In general practice, prescribers should be aware of the high burden of cardiovascular diseases and depression along with the relatively high use of opioid-based medications in patients with RA and PsA.
Rheumatoid arthritis (RA), psoriatic arthritis (PsA) and spondylarthritis (SPA) are the most common inflammatory rheumatic diseases, and associated with a high burden of comorbidities and polypharmacy, especially analgesics. 
Compare comorbidity burden and usage of pain-related medication in patients with RA, PsA and SPA versus controls in a general practitioner (GP) setting.
Type of study, patients, and inclusion criteria
Data were obtained from Intego, a Flemish GP-based morbidity registration network that covers 2% of the Flemish general population from 1999-2012.
Codes on the International Classification of Primary Care (iCPC) were selected:
L188 (rheumatoid/seropositive arthritis)
L199 (musculoskeletal disease other)
The ICPC codes were verified for RA/SPA/PsA diagnosis by rheumatologists.
Control selection was 4 controls per case, matched by age, gender, GP practice, and date of diagnosis.
Outcomes were based on:
3-year comorbidity incidence rates using the Rheumatic Disease Comorbidity Index (RDCI) score to map comorbidities;
prevalent use of analgesic medication.
Over the 13-year period, 738, 229, and 167 patients were included with a diagnosis of RA, SPA, and PsA, respectively.
Mean RDCI at baseline was 1.2, 0.6, and 1.0 for RA, SPA or PsA respectively.
After 3 years, the mean RDCI was 1.5, 0.8, and 1.3 for RA, SPA, and PsA respectively.
The RDCI differed after 3 years between RA and controls (1.5 vs. 1.4, p=0.008), and PsA and controls (1.3 vs. 1.0), p=0.009).
In RA, at baseline 58% of individuals had an RDCI score ≥1 (vs. 53% of controls, p=0.01) and after 3 years, 66% of individuals had an RDCI score ≥1 (vs. 60% of controls, p=0.004).
In SPA, at baseline 36% of individuals had an RDCI score ≥1 (vs. 34% of controls, p=0.6) and after 3 years, 45% of individuals had an RDCI score ≥1 (vs. 41% of controls, p=0.4).
In PsA, at baseline 52% of individuals had an RDCI score ≥1 (vs. of 42% controls, p=0.03) and after 3 years, 60% of individuals had an RDCI score ≥1 (vs. 48% controls, p=0.003).
All analgesics were statistically significantly prescribed more in patients with a musculoskeletal disease compared to controls (
This study highlights the issue of multimorbidity in patients with musculoskeletal diseases, especially for those with RA and PsA.
The high cardiovascular burden is substantial in these two populations.
The high prevalence of opioid and tramadol use in about 20% of patients with an inflammatory rheumatic disease deserves to be noted.
Key messages/Clinical perspectives
Patients with RA and PsA have a high burden of high cardiovascular and relatively high use of opioid-based medications.
Presenter disclosure: The presenter has reported that no relationships exist relevant to the contents of this presentation.
Written by: Patrick Moore, PhD
Reviewed by: Alessia Alunno, MD, PhD
Local reviewers: Alessia Alunno, MD, PhD (Italian); Aurélie Najm, MD (French); Yukinori Okada, MD, PhD (Japanese); Fabian Proft, MD (German); Javier Rodríguez-Carrio, MD, PhD (Spanish); Priscilla Wong, MD (Chinese)
Scientific Editor: Leonard H. Calabrese, DO