Patient factors associated with duration of certified sickness absence and transition to long-term incapacity

Despite a considerable increase in claims for long-term sickness benefits, and the impact of certifying sickness upon general practitioner (GP) workload, little is known about transition to long-term incapacity for work.

To explore the relationship between patient factors and the transition from short-term to long-term work incapacity, in particular focusing on mild mental health and musculoskeletal problems.

Nine practices comprising the Mersey Primary Care R&D Consortium.

Prospective data collection and audit of sickness certificate details.

GPs issued carbonised sickness certificates for a period of 12 months. The resulting baseline dataset included claimant diagnosis, age, sex, postcode-derived deprivation score, and sickness episode duration. Associations of patient factors with sickness duration outcomes were tested.

Mild mental disorder accounted for nearly 40% of certified sickness. Relatively few claimants had their diagnosis changed during a sickness episode. Risk factors for longer-term incapacity included increasing age, social deprivation, mild and severe mental disorder, neoplasm, and congenital illness. For mild mental disorder claimants, age, addiction, and deprivation were risk factors for relatively longer incapacity. For musculoskeletal problems, the development of chronic incapacity was significantly related to the nature of the problem. Back pain claimants were likely to return to work sooner than those with other musculoskeletal problems.

In addition to the presenting diagnosis, a range of factors is associated with the development of chronic incapacity for work, including age and social deprivation. GPs should consider these when negotiating sickness certification with patients.