Data on these benefits, both the ones covered by the employer and NAV, was obtained from NAV's register, which contains information on the start and stop dates of sickness benefits given from 1992 and onward for the entire Norwegian population.
As only the month of measurement of satisfaction with psychosocial work conditions was known the 15th was chosen as the start date of measurement of sickness absence.
3) The Social Insurance Agency SIAA): Micro-data for analyses of social insurance (MiDAS) with information on date, grade and diagnosis of sickness absence and disability pension.
Information on symptomatic episodes was augmented through sickness absenteeism rates and staff medical records for details such as dates of illness and tests to confirm pandemic (H1N1) 2009 infection.
For each of the 213 individuals in the cohort, data were obtained on all sickness absence (including date of start and end of sick leave) and the diagnoses for each sick-leave period (n = 7,878) in each sick-leave spell (n = 4,610) from 1st January 1985 to 1st September 1996.
Data on official date of retirement, longstanding illness or disability, and sickness absence came from company records.
In addition, we retrieved starting and ending dates of all compensated sickness absence periods during the follow-up.
Follow-up continued through 2004 (suicide) or 2003 (disability, sickness absence), or date of death, emigration or study outcome, whichever came first.
In each questionnaire participants were asked to report the number of sickness absence spells during the past six months, the starting and end date of each spell, including embedded non-working days and weekend days.
The date of each illness episode was defined as the earliest symptom onset date or sickness absenteeism if onset dates were unavailable.
