title: The effect of multimorbidity on sickness absence by specific diagnoses.
abstract: BACKGROUND
  As the world's population ages, the prevalence of multiple chronic and non-chronic health-related conditions is increasing. Research on multimorbidity, the co-occurrence of two or more health-related conditions, has mainly involved patient and older populations. Its effect in working populations, presumably younger and healthier, is not well known but could conceivably affect sickness absence (SA) and ability to return to work.
  
  
  OBJECTIVE
  To examine the effect of multimorbidity on the incidence and duration of SA episodes by frequent diagnostic groups.
  
  
  METHODS
  A prospective study (in 2006-2008) of workers in Spain. Information on health-related conditions was gathered with a standardized questionnaire and used to construct a sex-specific multidimensional multimorbidity score (MDMS). In order to estimate the effect of MDMS on incidence and duration of SA episodes due to cardiovascular diseases (CVD), musculoskeletal disorders (MSD) and mental health disorders (MHD), we fitted Cox models adjusted by age, occupational social class and number of prior SA episodes for both sexes.
  
  
  RESULTS
  The study population was 372370. Men with high MDMS showed a trend towards higher incidence risk for SA due to CVD and MSD [adjusted hazard ratio (aHR) = 2.03; 95% confidence interval (CI) 1.48-2.78 and aHR = 1.20; 95% CI 1.01-1.43, respectively]. Women showed a similar trend for MSD, but MHD had the strongest association (aHR = 4.78; 95% CI 1.97-11.62) for high MDMS. In both sexes, the effect of MDMS was strongest among those without a prior SA. No consistent associations with SA duration were observed.
  
  
  CONCLUSIONS
  Multimorbidity increased the risk of incident musculoskeletal, mental and cardiovascular SA episodes but not their duration.
authors: CISAL-Center for Research in Occupational Health, University Pompeu Fabra, Barcelona 08003, Spain.|CIBERESP, CIBER in Epidemiology and Public Health, Madrid 28029, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona 08003, Spain.
authors: M
authors: M
authors: Ubalde-Lopez
authors: CISAL-Center for Research in Occupational Health, University Pompeu Fabra, Barcelona 08003, Spain.|CIBERESP, CIBER in Epidemiology and Public Health, Madrid 28029, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona 08003, Spain.|Southwest Center for Occupational and Environmental Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, The University of Texas School of Public Health, Houston, TX 77225, USA.
authors: G L
authors: GL
authors: Delclos
authors: CISAL-Center for Research in Occupational Health, University Pompeu Fabra, Barcelona 08003, Spain.|CIBERESP, CIBER in Epidemiology and Public Health, Madrid 28029, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona 08003, Spain.
authors: F G
authors: FG
authors: Benavides
authors: Ibermutuamur (Mutua de Accidentes de Trabajo y Enfermedades Profesionales de la Seguridad Social 274), Madrid 28043, Spain.
authors: E
authors: E
authors: Calvo-Bonacho
authors: CISAL-Center for Research in Occupational Health, University Pompeu Fabra, Barcelona 08003, Spain.|CIBERESP, CIBER in Epidemiology and Public Health, Madrid 28029, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona 08003, Spain.|Southwest Center for Occupational and Environmental Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, The University of Texas School of Public Health, San Antonio Campus, San Antonio, TX 78229, USA.
authors: D
authors: D
authors: Gimeno
mesh_terms: D000041:Absenteeism; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006261:Headache / Q000453:epidemiology; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology*; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000453:epidemiology*; D016272:Occupational Health; D011446:Prospective Studies; D062707:Return to Work / Q000706:statistics & numerical data*; D012307:Risk Factors; D018582:Sick Leave / Q000706:statistics & numerical data*; D013030:Spain / Q000453:epidemiology
keywords: Cardiovascular disease; chronic conditions; comorbidity; mental health disorder; musculoskeletal disorders; sick leave.