POS0011 COMPARISON OF PSYCHOMETRIC PROPERTIES OF FOUR GLOBAL MEASURES OF PRESENTEEISM IN PATIENTS WITH OSTEOARTHRITIS AND INFLAMMATORY ARTHRITIS: A EULAR-PRO STUDY

Abstract

BackgroundWork is an important outcome for people with inflammatory arthritis (IA including PsA, RA, AxSpA) and osteoarthritis (OA). It is known that people with IA and OA are at increased risk of sick leave and have to stop working early due to ill health. In addition to being at increased risk of becoming work disabled and increased absenteeism, high levels of presenteeism (i.e. reduced productivity/limited ability to work due to ill health whilst at work) have also been reported. Several instruments exist to measure presenteeism, including single-item global measures and multi-item instruments. In some studies using single-item global instruments may be more feasible. However, available global instruments differ in concept, recall period and reference. It is important to understand which of the measures have good psychometric properties before using them in clinical studies.ObjectivesTo assess the psychometric properties of four global presenteeism instruments.MethodsPatients with IA or OA were recruited via rheumatology outpatient clinics to a large international, longitudinal observational study including 8 European countries and Canada. Participants completed a survey at baseline, 1, 2, 3, 4 wks, 2 months and 3 months. The four global measures of presenteeism included: Work Productivity and Activity Impairment Questionnaire (WPAI), Work Productivity Scale–Rheumatoid Arthritis (WPS-RA), Work Ability Index (WAI) and the Quality*Quantity questionnaire (QQtotal/10) scale. To facilitate score interpretation the WAI and QQtotal were reversed. Pain was measured using an 11-point Likert scale. Spearman correlations were calculated between the presenteeism measures and the Workplace Activity Limitations Scale (WALS), a validated multi-item measure of presenteeism, and HAQ to evaluate construct validity (validity: r <0.50=low; r >0.50-<0.70=moderate; r >0.70=high). Test-retest reliability of the 4 presenteeism scales (baseline-1wk) was measured applying ICC in patients with stable disease (i.e. same pain score at baseline and 1wk) (reliability: ICC<0.40=poor; ICC 0.40-0.75=fair to good; ICC >0.75=excellent). Responsiveness during 3 months was measured comparing patients with improvement in pain score (>1 point improvement in pain score (~MCID pain)) with patients with no change or worsening in pain score. The two groups were compared applying Mann Whitney U test.ResultsThis international study included 550 patients with a mean age of 47.8 (SD 9.9) yrs and 61.4% were female. Mean (SD) disease duration since diagnosis was 10.8 (10.4) yrs and 91.2% had IA. Mean (SD) presenteeism scores at baseline were: WPAI=2.9 (2.7); WPS-RA=3.4 (2.7); WAI=2.7 (2.4); and QQtotal=3.1 (3.2). The correlations between the global measures and with WALS and HAQ were moderate to good, except for QQtotal and HAQ which was low (Table 1). In patients with the same stable pain scores at baseline-1wk (n=141) ICC scores were good to excellent, respectively: WPAI (0.771), WPS-RA (0.752), WAI (0.663), and QQtotal (0.650). An improvement in pain during the 3 month study duration was observed in 145/381 (38%) of the patients. In these patients a significant reduction in mean (SD) change presenteeism was observed for all four presenteeism scales compared to those with no change or worsening of the pain score: WPAI (-1.0 (2.37) vs 0.68 (2.40), p<0.01); WPS-RA (-0.76 (2.57) vs 0.43 (2.10), p<0.001); WAI (-0.09 (2.34) vs 0.41 (2.46), p<0.001); QQtotal (-0.57 (3.16) vs 0.79 (3.1), p<0.01).Table 1.WPAIWPS-RAWAIQQtotalWALSHAQWPAI-0.81640.59920.51840.62690.5592WPS-RA-0.58360.52170.60550.5669WAI-0.58660.52310.5168QQtotal-0.50250.4367ConclusionThe psychometric properties of all 4 global presenteeism scales were moderate to good, with slightly better scores for both the WPS-RA and WPAI instruments both measuring the impact of OA and IA on productivity.Disclosure of InterestsSuzanne Verstappen Consultant of: EUOSHA, Grant/research support from: AbbVie, BMS. EULAR, Annelies Boonen Speakers bureau: Abbvie / Galapagos, Consultant of: Galapagos, Sarah Wilkinson: None declared, Dorcas Beaton: None declared, Ailsa Bosworth: None declared, José Canas da Silva: None declared, Gloria Crepaldi: None declared, Sabrina Dadoun: None declared, Cathie Hofstetter: None declared, Carina Mihai Speakers bureau: Boehringer-Ingelheim, Mepha, MED Talks Switzerland, Consultant of: Boehringer-Ingelheim, Janssen, Grant/research support from: Roche, Boehringer-Ingelheim, Sofia Ramiro Consultant of: AbbVie, Eli Lilly, MSD, Novartis, Pfizer, UCB, Sanofi, Grant/research support from: Grant: AbbVie, Galapagos, Novartis, Pfizer, UCB, Garifallia Sakellariou Consultant of: Abbvie, BMS and Galapagos., Grant/research support from: Abbvie, BMS and Galapagos., Sandra Meisalu: None declared, Johan K Wallman Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Novartis, Grant/research support from: AbbVie, Amgen, Eli Lilly, Novartis, Pfizer., Diane Lacaille: None declared