Extended self-certification period and its relation to sickness absence in the public sector

Background Extended self-certification of sickness absence has been promoted in Finland during the past years. It is anticipated to reduce the number of sickness absence episodes and the length of sickness absence, but there is little scientific evidence on the issue.

Methods In this natural experiment, we analysed longitudinal register and survey data collected in the Finnish Public Sector Study during 2013–2017. In the exposed municipalities (n = 19711 participants) the ­
self-certification period was extended from 1–3 to 1–5 days in 2015. In the reference municipalities (n = 15698 participants) the practice remained unchanged (1–3 days).

Difference-in-differences analysis with generalized estimation equation models was applied to estimate the difference in pre-post differences between the exposed and reference groups. Sex, age, occupational group, type of work contract and, in sensitivity analyses, chronic diseases and health behaviours were adjusted for.

Results There was an increase of 2–15% in the risk of the number and length of sickness absence spells in both exposed and reference groups during the follow-up. No difference in differences between these groups was detected.

Conclusions Extending the self-certification period from 1–3 to 1–5 days was not associated with the length or frequency of sickness absence in the examined municipalities. Effects on the costs of health care should be examined in future studies.