Aten Primaria. 2009 May 20; Alvarez Theurer E, Llergo Muñoz A, Vaquero Abellán MOBJECTIVE: To analyse the length of sick leave (SL) and its associated factors in Andalusia. DESIGN: Descriptive observational study. SETTING: Andalusia. PARTICIPANTS: A total of 1,633,405 sick leave forms issued from the 1st January 2002 to the 31st of December 2006 for any reason by Primary Health Care doctors in the Public Health Service, were analysed. MAIN MEASUREMENTS: Descriptive and bivariate analysis of SL health complaints and their length according to gender, rural or urban environment, Social Security scheme, diagnosis and reason for discharge. A model of multiple lineal regression was completed. RESULTS: The overall incidence of SL was 15.83 health complaints per 100 Social Security members per year (14.73 in males and 17.24 in women). The most frequent diagnoses for the SL were, lower back pain and the common cold. The mean length of the SL health complaint episodes in men was lower than that of women by 7 days. The majority of the SL health complaints were resolved in less than one month (71.7%). The SL complaints that lasted longer were: endocrine diseases and immune disorders, neoplasms and mental disorders. The mean length of SL is higher in the rural environment (45.4) compared to urban (36.9). The variables that predict the length of sick leave in the model were gender, age and address location. CONCLUSIONS: Different factors to the diagnosis have a large influence on the length of SL. The main variables that affect this are, age, gender and a rural environment.