ORIGINAL ARTICLE Previous sick leaves as predictor of subsequent ones Ricardo J. Reis • Mireia Utzet • Poliana F. La Rocca • Fu ´lvio B. Nedel • Miguel Martı ´n • Albert Navarro Received: 19 April 2010 / Accepted: 26 January 2011 / Published online: 12 February 2011 Ó Springer-Verlag 2011 Abstract Purpose There is evidence that a history of sick leave (SL) increases the risk of suffering a new episode. How- ever, little is known about the effect of the number of previous SL on subsequent ones. The aim of this paper was to quantify the effect of prior episodes on the risk of experiencing a new one and the effect on the duration of episodes, by diagnosis. Methods Prospective study. Sample comprises 1,542 workers from a university hospital, whose first contract started during 2000–2007. Results The studied workers accumulated 5,138 episodes, 21,250 days of absence and 45,324.2 months of follow-up. For all the causes, recurrence density was higher than incidence density. The higher the number of prior SL, the greater is the hazard of presenting a new episode. This is particularly true for episodes due to mental and behavioral disorders, diseases of the skin and subcutaneous tissue, and diseases related to nervous system. The adjusted hazard of suffering an SL episode due to mood disorders was increased 21.44 times when the worker had previously had one SL. The corresponding figures were 14.58 and 13.92 for SL due to skin and mucous membrane diseases and due to neurotic or stress-related disorders, respectively. Conclusions The results obtained provide evidence that having suffered previous SL episodes implies a significant increase in the risk of experiencing a new one. High recurrence density of certain diagnoses should be inter- preted as a general indication that something is wrong in the occupational setting. Keywords Sick leave Á Recurrence Á Cohort studies Á Occupational health Á Risk factors Introduction Sick leave (SL) is considered an indicator of health status and functioning and it can be understood as a product of the interaction among health status, productive and reproduc- tive demands, and personal resources in terms of control over work, and social support, in a specific economic, regulatory, and social context that involves differential exposures according to social class and gender (Moncada et al. 2002). Return to work is conceptualized as a dynamic process that not only involves an off-work phase and a work re-entry phase but also includes a maintenance phase of sustainability of work performance. If phase-specific goals are not achieved, then there is risk of a relapse to the off- work phase (Young et al. 2005). Therefore, recurrence of SL could be seen as an indicator of the maintenance of the work status. Similarly, short SL with high recurrence may be indicative of the use of coping strategies by active workers wanting to protect their health, i.e., by limiting noxious occupational exposures through absences from work (Kristensen 1991). R. J. Reis Á P. F. La Rocca Servic ¸o de Atenc ¸a ˜o a ` Sau ´de do Trabalhador, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil M. Utzet Á F. B. Nedel Á M. Martı ´n Á A. Navarro (&) Grups de Recerca d’Ame `rica i d’A ` frica Llatines (GRAAL), Facultat de Medicina, Unitat de Bioestadı ´stica, Universitat Auto `noma de Barcelona, Campus UAB, Cerdanyola del Valle `s 08193, Spain e-mail: albert.navarro@uab.cat F. B. Nedel Departamento de Biologia e Farma ´cia, Universidade de Santa Cruz do Sul. GRAAL-UNISC, Santa Cruz do Sul, Brazil 123 Int Arch Occup Environ Health (2011) 84:491–499 DOI 10.1007/s00420-011-0620-0