Health-related QoL less impacted in radiographic vs. nonradiographic axial SpA
Radiographic axial spondyloarthritis, or axSpA appears to have less impact on patient-reported outcome measures than the nonradiographic form of the disease, regardless of sex, according to data published in Arthritis Research & Therapy.
“Little is known of the differential clinical expression of axSpA between males and females,” Rikke A. Andreasen, MD, of Odense University Hospital, in Denmark, and colleagues wrote. “However, female axSpA patients are more likely to have shorter disease duration and less objective signs of inflammation but demonstrate a high burden of illness due to disease activity and impairment of health-related quality of life (HR-QoL).”
“Despite some studies suggesting that this is due to the concomitant widespread pain syndrome (eg, fibromyalgia), this notion as well as any speculation around cause and effect is still regarded as controversial,” they wrote. “Few studies have analyzed sex differences in axSpA patients, and thus, there is a need to determine the actual distribution of these descriptive characteristics and the association with the self-reported burden of disease in a real-world setting (ie, pragmatic and unbiased enrollment).”
To evaluate the effects of sex and disease classification on outcomes in patients with axial SpA, Andreasen and colleagues conducted a noninterventional descriptive prospective cross-sectional study of 100 participants seen at the Odense University Hospital, in either Svendborg or Odense, Denmark. These participants included 30 males and 10 females with radiographic axial SpA, as well as 25 males and 35 females with nonradiographic axial SpA.
The researchers examined impacts on patient-reported outcome measures, using general linear models to assess any links or interactions between continuous variables and each of the main characteristics of interest — sex and disease classification. In addition, they used logistic regression with the same fixed effects to analyze categorical outcome measures, and examined the relationship between tender point count and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Extra-articular manifestations and the Charlson Comorbidity Index (CCI) were also evaluated.
According to the researchers, BASDAI scores appeared higher among female patients with non-radiographic axial SpA (median [Q1; Q3] = 47 [21; 60]), compared with the three other subgroups (combined median = 25 [12; 25]). In addition, female sex was associated with a higher tender point count (P<0.001). Overall, tender point count and BASDAI were correlated for female (r=0.44; P=.008) and male (r=0.56; P=0.003) patients with non-radiographic axial SpA.
A nonradiographic axial SpA disease classification was associated with a lower SF-36 Mental Component Summary. In addition, extra-articular manifestations were frequent, with an incidence rate of up to 50%. The Charlson Comorbidity Index (CCI) was low in all subgroups, with no differences observed across the groups (P=.14). However, male sex appeared to have a significant impact on CCI (P=.03).
“This is to our knowledge the first extensive study performed comparing the clinical characteristics and [patient-reported outcome measures (PROMs)] in axSpA patients with an explicit objective regarding sex and type of clinical diagnosis,” Andreasen and colleagues wrote.
“We observed that patients with [radiographic] axSpA are less affected on most PROMs, especially regarding generic HR-QoL measures when compared with axSpA patients not fulfilling the [radiographic] axSpA (ie, AS) criteria,” they added. “Moreover, HR-QoL is more negatively impacted in [nonradiographic] axSpA females compared with [nonradiographic] axSpA males. The number of tender points is associated with sex-related differences in self-reported disease activity in patients classified as [nonradiographic] axSpA.” – by Jason Laday
Disclosure: The researchers report no relevant financial disclosures.