Polypharmacy is Significantly Higher in Patients with Psoriatic Arthritis

Polypharmacy, comprised of both psoriatic arthritis (PsA)-specific medications in addition to medications for various comorbidities, was common in patients with PsA, according to a study published in Rheumatic and Musculoskeletal Diseases.¹ This was observed in similar proportions among women and men, affecting approximately half of patients.

Katinka Albrecht, MD

Image Credit: DRFZ

Drugs used for treating PsA and comorbidities increase the likelihood of polypharmacy and complicate disease management. This patient population is particularly at high risk of developing comorbidities, such as metabolic syndrome.²

“For patients with PsA, German data are available for PsA-specific pharmacotherapy and for treatment persistence but not for polypharmacy,” Katinka Albrecht, MD, associated with Epidemiology and Health Services Research at the German Rheumatism Research Center Berlin, and a team of international investigators, noted. “Since the majority of the comedications are prescribed by general practitioners, a data source containing all prescriptions is necessary to adequately analyze polypharmacy in PsA.”

Data from 11,984 adult patients with PsA who were treated with disease-modifying antirheumatic drugs (DMARDs) and continuously insured in 2021 were extracted from the German BARMER health insurance database. These patients were age- and sex-matched 1:10 with healthy controls (n = 119,840). Polypharmacy, defined as ≥5 concomitant daily drugs, was determined and compared by age, sex, and comorbidity using the Elixhauser comorbidity score and the Rheumatic Disease Comorbidity Index (RDCI). Medications were evaluated using the Anatomical Therapeutic Chemical (ATC) groups. Differences in the number of medications between patients and controls were determined using a linear regression model.

Patients with PsA were more likely to present comorbidity when compared with controls (3.6 vs 2.2, respectively) which increased from a mean RDCI of 0.4 in patients aged 18-30 years to 3.0 for those aged above 80 years. Common comorbidities were hypertension, dyslipidemia, obesity, diabetes, osteoarthritis, and depression.

ATC drug classes were significantly more frequent in patients with PsA when compared with the control group. They were most commonly seen in musculoskeletal (81% vs 30%), cardiovascular (62% vs 48%), alimentary tract/metabolic (57% vs 31%), immunomodulatory (56% vs 2.6%), and nervous system (50% vs 31%) drugs.

Polypharmacy was significantly higher in patients with PsA when compared with controls (49% vs 17%, respectively). It was also more frequently seen in women compared with men (52% vs 45%, respectively) and increased with comorbidity and age (15% in patients aged 18–30 years vs 78% in those aged >80 years).

The age-adjusted number of medications increased by 0.98 (95% confidence interval [CI] 0.95 to 1.01) units in men and 0.93 (95% CI 0.90 to 0.96) units in women for each unit increase of the RDCI. The number of medications to treat patients with PsA (mean 4.9) was 2.4 (95%CI 2.34; 2.43) units higher in female patients and 2.3 (95% CI 2.21 to 2.35) units higher in male patients when compared with the control group.

A large overlap of PsA and rheumatoid arthritis (RA) diagnoses was observed and could not be fully categorized without clinical validation as both conditions are often treated with the same medications. By evaluating prescription-only medications, investigators could not determine the full proportion of polypharmacy which led to an underestimation of polypharmacy in this patient population. However, using a broad nationwide DMARD-treated population of patients with a PsA diagnosis and including age- and sex-matched controls solidified the findings.

“Polypharmacy is a major burden for people with PsA, resulting from both PsA therapy and medication for comorbidities,” investigators concluded. “The majority of older persons with PsA are affected by polypharmacy, this applies equally to women and men. In the elderly, more frequent therapy with biologic DMARDs should be considered, which may result in reduced use of analgesics, opioids and other secondarily induced comedications.”

References

1. ^{Albrecht K, Regierer AC, Strangfeld A, Marschall U, Callhoff J. High burden of polypharmacy and comorbidity in persons with psoriatic arthritis: an analysis of claims data, stratified by age and sex. RMD Open. 2023;9(1):e002960. doi:10.1136/rmdopen-2022-002960}
2. ^{Cigolini C , Fattorini F , Gentileschi S , et al . Psoriatic arthritis: one year in review 2022. Clin Exp Rheumatol 2022;40:1611–9. doi:10.55563/clinexprheumatol/x3sfxe}