Background Whilst the patient-perspective burden of axial spondyloarthritis (axSpA) is well known, non-radiographic (nr)-axSpa has only recently been identified as a distinct spondyloarthritic indication with its own associated burden. As such, evidence demonstrating both humanistic and societal burden of nr-axSpa is sparse, where no multi-country controlled study of real world patients has been conducted to date.
Objectives To demonstrate the health-related quality of life (HRQoL) impact of nr-axSpa relative to general population controls, as well as the societal impact in terms of work productivity.
Methods This was a retrospective database analysis drawing on data from the Adelphi Real World 2011 and 2014 Rheumatology Disease Specific Programme (DSP®). The Rheumatology DSP is a cross sectional, observational research programme collecting data from Rheumatologists and their patients in the UK, France, Germany, Spain, and Italy. Data were collected for 880 patients, of which 252 met the inclusion criteria for a 2-arm multivariate matching model. Patient inclusion was based on physician diagnosis of axSpa for the 2014 cohort (both radial and non-radial), and using the [modified] New York criteria to exclude radiographic axSpa patients, leaving only nr-axSpa patients in the cohort. Controls were drawn from the 2012 Health Survey for England (HSE), a representative sample of 10,000 English residents, matching patients with controls 1:1 based on age, gender, Body Mass Index, comorbidities, employment and caregiver status. A Wilcoxon sign-rank test was used to quantify the relative difference in HRQoL between patients and controls, as measured by the Euroqol 5-domain HRQoL tool (EQ-5D). Work Productivity and Activity Impairment tool (WPAI) outcome was also assessed. Sub-group analyses were also conducted, comparing patients responsive and non-responsive to conventional and DMARD therapies, where response is defined by the physician's opinion based on patient symptom change between treatment initiation and most recent consultation.
Results A reasonable match balance was achieved in all analyses, matching 252 patients to 252 general public controls. HRQoL of nr-axSpa patients relative to controls was 0.109 lower (worse) on the EQ-5D scale (p<0.001), exceeding the minimally important difference threshold (0.074). Patient mean WPAI score was 29.8 descriptively, exceeding general population norms of 3.4-5.2 [Kobelt 2002]. Direct comparison was not feasible with the data in this study, as WPAI was not recorded in the comparator group. 166 responders were identified and 76 non-responders. Non-responders were 0.195 EQ-5D points lower than responders (p<0.01), with non-responders WPAI score 31.6 points higher (worse) than responders (p<0.01). All results were insensitive to change in the magnitude of an unobserved confounding factor.
Conclusions Nr-axSpa is associated with considerable detriment to HRQoL relative to general public controls, and furthermore, nr-axSpa is associated with high levels of work productivity loss. Patients non-responsive to conventional and DMARD therapies are especially burdened.
Productivity, vitality and utility in a group of healthy professionally active individuals with nocturia. G. Kobelt, F. Borgström and A. Mattiasson. October 2002. BJU International.
Disclosure of Interest T. Holbrook: None declared, R. Wood: None declared, C. Black Employee of: Merck, S. Kachroo Employee of: Merck