The High Cost of Psoriatic Arthritis Save

New research confirms that patients with psoriatic arthritis (PsA) face significant healthcare and socioeconomic hurdles.

For instance, healthcare costs for PsA patients increased from less than €2000 ($2,137) annually 5 years prior to diagnosis to over €5000 ($5,344)/year at the time of diagnosis, Danish researchers reported. At all time points, total healthcare costs were higher for patients than for controls.

he study, published in Annals of the Rheumatic Diseases, also found that compared with the general population, PsA patients not only have increased healthcare costs, but also lower income, higher unemployment, greater risk for disability, and more comorbidities, both before and after their diagnosis.

"The results of our study are highly suggestive of significant health inequity for the PsA patients compared to a matched general population," the study's lead author, Lars Erik Kristensen, MD, PhD, chief scientific officer of the Parker Institute of Copenhagen University Hospital in Denmark, told MedPage Today.

"More studies are needed to investigate the role of lower socioeconomic status and the risk for developing PsA."
The study is the first to assess healthcare and societal costs as well as comorbidities in PsA patients compared with matched controls, the authors noted.

Using nationwide Danish databases, Kristensen and his colleagues identified a population-based cohort of PsA patients. For each of these patients, the team selected two individuals from the general population without PsA, matched for age, gender, time, and marital status.

The analysis included 10,525 PsA patients and 20,777 controls; the median age of both groups was 52 years, and 41% were male.

The study showed that at the time of diagnosis, PsA patients already had significantly more comorbidities, including neoplasms, cardiovascular disease, respiratory disease, infectious diseases, and hematological diseases compared with controls.

Average yearly income was lower for PsA patients at all time points from 5 years prior to diagnosis until 10 years after, although the difference was markedly increased around and after the year of diagnosis.

The relative risk for being on disability pension 5 years prior to the PsA diagnosis was 1.36 (95% CI 1.24-1.49) compared with controls, and it increased to 1.60 (95% CI 1.49-1.72) at the time of diagnosis and to 2.69 (95% CI 2.40-3.02) 10 years after diagnosis.

The relative risk for being unemployed was 1.21 (95% CI 1.09-1.34) for patients versus controls 5 years before diagnosis, increasing to 1.72 (95% CI 1.58-1.87) at diagnosis.

Not only do patients have an increased risk of receiving other diagnoses before being diagnosed with PsA, but the odds ratios were also significantly increased in the 3 years after the diagnosis. The likelihood of having mental or behavioral disorders became significant after receiving a PsA diagnosis compared with controls (OR 1.21, 95% CI 1.04-1.41).

The increased socioeconomic burden and frequency of comorbidities many years before the diagnosis of PsA raises the possibility that these factors may contribute to development of the condition, the authors suggested. But they noted that the differences in socioeconomic and health status are accentuated in the years after diagnosis, illustrating a potential bi-directional causality.

"Thus, poor health contributes to significant individual, social, and economic costs, and the lower an individual's socioeconomic position, the higher their risk of poor health," the authors wrote.

Although further study is needed to "disentangle" the relative roles of poor health from lower socioeconomic position, or an interaction of the two with regard to risk for developing PsA, the mechanisms together create a "classic downward spiral," the team said.

The results "call for increased awareness of the impact of PsA and should stimulate preventive measures for the individual, as well as overall societal action," said Kristensen.

Although patients with rheumatoid arthritis and other chronic arthritis diseases also face increased healthcare and socioeconomic inequities, "the magnitude and significance already 5 years prior to diagnosis" of PsA uncovered by this new study "are exceptional."

The researchers said they are not able to rule out some degree of residual confounding and bias. For example, it is possible that relying on diagnostic codes may have meant inclusion of more severe cases and missing of mild cases managed entirely in primary care.

Asked for his opinion of the research, Petros Efthimiou, MD, associate chief of rheumatology at New York Presbyterian/Brooklyn Methodist Hospital and Weill Cornell Medical College in New York City, said that this is one of the largest epidemiological studies to examine comorbidities and the burden of psoriatic arthritis.

"The study confirms the severe impact that psoriatic arthritis may have to society, including high medical costs, increased risk of disability for individuals, and inhibition of upward social movement."

Increased awareness, and organized efforts to diagnose the condition early and treat it appropriately may diminish that negative impact, he added.