Self-efficacy (SE) questionnaire data from the DWECS study in 2000 and 2005, age, sex, and transfer of sickness absence compensation data from the DREAM register. Men: sickness absence for more than 12 weeks and one and three absence spells are associated with decline in SE; women: decline in SE is associated with sickness absence for more than 52 weeks and two sickness absence spells. For both sexes SE declines at age 40-50 years. SE declines with length of sickness and sickness absence spells.