title: Increased risk of lost workdays prior to the diagnosis of sleep apnea.
abstract: BACKGROUND
  The impact of sleep apnea on work disability, in terms of sickness absence and disability pension, is unclear. We sought to estimate the total number of lost workdays caused by sleep apnea either due to medically certified sickness absences or disability pensions during the 5 years prior to the year of a sleep apnea diagnosis.
  
  
  METHODS
  This is a register-linkage case-control study of Finnish public sector employees who had received a diagnosis of sleep apnea between 1995 and 2005 (n = 957) and randomly selected control subjects who had not received a diagnosis of sleep apnea (n = 4,785), matched for age, gender, socioeconomic position, type of employment, and organization. The annual sum of lost workdays, due to either medically certified sickness absences or disability pensions prior to diagnosis, was calculated for each participant (mean follow-up time, 5 years).
  
  
  RESULTS
  After adjustment for comorbid conditions (eg, hypertension, ischemic heart disease, diabetes, asthma/other chronic lung disease, and depression), an increased risk of lost workdays was found in employees in whom sleep apnea developed compared to control subjects (rate ratio [RR], 1.61; 95% confidence interval [CI], 1.24 to 2.09 in men; and RR, 1.80; 95% CI, 1.43 to 2.28 in women). In women, the excess risk was already pronounced 5 years prior to the year of diagnosis, whereas in men the highest risk was noticed 1 year before the year of diagnosis.
  
  
  CONCLUSIONS
  Sleep apnea may severely threaten work ability years before diagnosis. These results emphasize the importance of the early identification and treatment of employees with sleep apnea.
authors.affiliation: Finnish Institute of Occupational Health, Turku Finland, Finland. Electronic address: noora.sjosten@ttl.fi.
authors.forename: Noora
authors.initials: N
authors.lastname: Sjösten
authors.affiliation: Finnish Institute of Occupational Health, Turku Finland, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Vahtera
authors.affiliation: Finnish Institute of Occupational Health, Turku Finland, Finland.
authors.forename: Paula
authors.initials: P
authors.lastname: Salo
authors.affiliation: Finnish Institute of Occupational Health, Turku Finland, Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Oksanen
authors.affiliation: Department of Pulmonary Diseases and Sleep Research Unit, Department of Physiology, University of Turku, Turku, Finland.
authors.forename: Tarja
authors.initials: T
authors.lastname: Saaresranta
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Marianna
authors.initials: M
authors.lastname: Virtanen
authors.affiliation: Finnish Institute of Occupational Health, Turku Finland, Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Pentti
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki