Abstract
Objective To 1) identify threshold values of presenteeism measurement instruments that reflect unacceptable work state in employed RA patients and whether those thresholds can predict future adverse work outcomes (AWO); 2) to assess among patients with RA the performance of presenteeism thresholds previously established in axSpA for the same instruments.
Methods Data from the multinational RA-PROSE study was used. Thresholds to determine when patients consider themselves in an 'unacceptable work state' were calculated at baseline for four instruments assessing presenteeism and for the patient global assessment of RA related pain. Different approaches derived from the receiver operating characteristic methodology were used. Accuracy of thresholds to predict AWO throughout 12 months was assessed and recently developed presenteeism thresholds for axSpA were also tested.
Results A total of 104 employed patients were included: 17% of the patients considered themselves in an unacceptable work status and 7 (7%) had at least one AWO over 12 months. Thresholds of all instruments specifically developed in RA showed good performance vs the external criterion (AUC >0.75) except for the QQ method (AUC 0.62). The available axSpA thresholds were more accurate by reducing over-estimation. The final optimal thresholds were: WPAI-presenteeism ≥40, QQ-method<97, WALS ≥0.75, WLQ-25 ≥29 and pain intensity ≥4. For AWO over 12 months, pain and WPAI performed best in predicting AWO.
Conclusion The final thresholds to assess unacceptable presenteeism for axSpA were also chosen as most accurate for use in RA. In addition, accurate thresholds of pain reflecting unacceptable work status are available.