Baseline disease activity influences subsequent achievement of patient acceptable symptom state in Sjögren's syndrome.

Objectives: To investigate longitudinal changes of the EULAR SS Patient-Reported Index (ESSPRI) and EULAR SS Disease Activity Index (ESSDAI), and identify factors associated with patient acceptable symptom state (PASS) in patients with primary SS (pSS).

Methods: We assessed ESSPRI, ESSDAI, clinical ESSDAI (ClinESSDAI), EULAR Sicca Score, EuroQoL 5-dimension (EQ-5D), Fatigue Severity Score, Beck Depression Inventory, and patient global assessment (PGA) for pSS, and visual analogue scale (VAS) scores for glandular and extra-glandular symptoms at baseline and follow-up. The responses to the currently available standards of care were evaluated by the PASS, the minimal clinically important improvement (MCII) of ESSPRI and ESSDAI, and a modified SS Responder Index-30 (mSSRI-30) response.

Results: Among 115 patients enrolled, 102 (88.7%) completed a median 3-year follow-up. The ESSPRI, ClinESSDAI and EQ-5D levels remained stable, although the PGA and ESSDAI significantly improved (both P <0.05). Of the 102 patients, 52 (51.0%) patients achieved the PASS at the follow-up and tended to attain the ESSPRI-MCII and mSSRI-30 (both P < 0.001) more frequently than the non-PASS group. Multivariate analysis revealed that the PASS was significantly associated with baseline ESSPRI negatively [odds ratio (OR) 0.609] and ESSDAI positively (OR 1.224). When categorized using baseline ESSPRI and ESSDAI, a subgroup of low ESSPRI and high ESSDAI reached a PASS achievement rate of 79.3%.

Conclusion: Although longitudinal changes in ESSPRI and ClinESSDAI are stable in pSS, baseline ESSPRI and ESSDAI could provide prognostic information on the subsequent achievement of PASS, using currently available treatments. A categorization model using ESSPRI and ESSDAI may have clinical implications.