Björk M, Thyberg I, Rikner K, Balogh I, Gerdle B. Sick leave before and after diagnosis of rheumatoid arthritis — A report from the Swedish TIRA Project. J Rheumatol 2009;36:1170–9; doi:10.3899/jrheum.080523. In the Discussion, page 1175, the part “In an earlier report from the Swedish TIRA project based on self-reported sick leave data 28% of the total study group were on sick leave at time of diagnosis. The rate remained mainly unchanged during the following 3 years7. In our study, the rate of sick leave at time of diagnosis was 53% and also remained stable after. The differences in sick leave rates in the 2 studies may reflect the difficulty of comparing self-reported and register-based sick leave data...” should read, “In an earlier report from the Swedish TIRA project based on self-reported sick leave data, almost 50% of the total study group were on sick leave at time of diagnosis. The rate remained mainly unchanged during the following 3 years7. In our study, the rate of sick leave at time of diagnosis was 53% and also remained stable after, indicating no difference between self-reported and register-based sick leave data in the TIRA cohort.”
This has unfortunately also led to a false statement in the related editorial, Eberhardt K, J Rheumatol 2009; 36:1104–6 (page 1104): “The variation in results obtained by different data collection methods is well illustrated by a previous TIRA study, where the corresponding figure for self-reported sick leave was 28%.” We regret the error.