TY - JOUR T1 - Dr. Griffiths et al reply JF - The Journal of Rheumatology JO - J Rheumatol SP - 1075 LP - 1075 DO - 10.3899/jrheum.220120 VL - 49 IS - 9 AU - Jo Leadbetter AU - Hedley Griffiths Y1 - 2022/09/01 UR - http://www.jrheum.org/content/49/9/1075.abstract N2 - To the Editor:We thank Dr. Schou for her insightful comments.1 The interpretation of data from an observational study such as this is complex, and the conclusions are by necessity less robust than in a randomized controlled trial. As noted in our manuscript,2 there were differences in the underlying characteristics between the groups of patients receiving the different treatments at baseline. As Dr. Schou has noted,1 this included the length of follow-up, which is important in determining the stability of the Kaplan-Meier (KM) estimate.3 The follow-up time was calculated as the time from index until the time of last follow-up, censored at the time of the discontinuation for those who discontinued treatment. The median follow-up was estimated using KM methods. This is the “time to censoring” method as recommended by Betensky.3 In particular, golimumab (GOL) is a much more recent entrant onto the … Address correspondence to Dr. H. Griffiths, Barwon Rheumatology Service, 156 Bellerine Street, Geelong, 3220 VIC, Australia. Email: hedley{at}brservice.com.au. ER -