Recurrence of sickness absence episodes certified by general practitioners in the UK

Compared to other areas of sickness certification, recurrence of certified sickness absence has been relatively under-researched.

This study aims to report the extent and patterns of recurrence and to identify factors associated with higher rates of recurrence.

Sickness certification ('fit note') data were collected from 68 general practices in eight regions of the UK for 12 months.

Twenty percent of 31,453 patients in the study had a recurrent certified sickness episode, with over half of these having the second episode in the same diagnostic category as their first. Mental health problems accounted for over a half of all days certified in same-diagnosis recurrent episodes. Male gender, residing in an area of social deprivation, a longer episode of initial certified sickness absence, not having return to work ('may be fit') advice in the first episode, having a mental disorder or musculoskeletal (particularly back) problem were all independently associated with a higher incidence of recurrence.

Differential risk of recurrence needs to be considered when designing return-to-work interventions. Evaluation of effectiveness of interventions (particularly for sickness absentees with mental health problems) has to consider the sustainability of employment after a return to work.