Background:EULAR- recommendations for management of early arthritis formulated that patients should be referred to, and seen by a rheumatologist, within 6-weeks after symptom onset. The mentioned period of ≤6-weeks after symptom onset is shorter than ≤12-weeks, the period that is generally considered as the ‘window-of-opportunity’. Because implementation provides challenges, and evidence supporting that referral ≤6-weeks is better than e.g. <12-weeks is missing, we investigated if ≤6-weeks relates to improved long-term outcomes.Objectives:We used an observational study design to investigate in two cohorts if time-to-encounter (TtE) a rheumatologist ≤6-weeks, compared to 7-12-weeks, results in better disease long-term outcomes, measured with sustained DMARD-free remission (SDFR) and radiographic progression.Methods:Consecutive 1987-RA patients of the Leiden EAC (n=1025) and ESPOIR (n=514) were studied during median 7 and 10 years follow-up. Patients were categorized on duration between symptom onset and first encounter with a rheumatologist; ≤6-, 7-12-, and >12-weeks. Multivariable Cox regression (SDFR), linear mixed models (radiographic progression), and meta-analyses were used.Results:Leiden RA-patients encountered the rheumatologist within 6-weeks obtained SDFR more often than patients seen within 7-12-weeks (HR 1·59, 95%CI:1·02-2·49), and >12-weeks (HR 1·54, 95%CI:1·04-2·29). In ESPOIR, similar but non-significant effects were observed; meta-analysis showed that within 6-weeks was better than 7-12-weeks (HR 1·69, 95%CI:1·10-2·57, Figure 1-A) and >12-weeks (HR 1·67, 95%CI:1·08-2·58). Patients encountered the rheumatologist within 6-weeks had similar radiographic progression than those seen 7-12-weeks, in any cohort, or meta-analysis (Figure 1-B).Figure 1Meta-analyses of time-to-encounter the rheumatologist and the chance of achieving sustained DMARD-free remission (A) and radiographic progression (B)Conclusion:Scientific evidence underlying the first EULAR recommendation depends on the outcome of interest; visiting a rheumatologist within 6-weeks of symptom-onset had clear benefits for achieving SDFR, but not for radiographic progression.References:None.Disclosure of Interests:Ellis Niemantsverdriet: None declared, Maxime Dougados Grant/research support from: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Speakers bureau: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Bernard Combe Grant/research support from: Novartis, Pfizer, Roche-Chugai, Consultant of: AbbVie; Gilead Sciences, Inc.; Janssen; Eli Lilly and Company; Pfizer; Roche-Chugai; Sanofi, Speakers bureau: Bristol-Myers Squibb; Gilead Sciences, Inc.; Eli Lilly and Company; Merck Sharp & Dohme; Pfizer; Roche-Chugai; UCB, Annette van der Helm - van Mil: None declared