Introduction As the focus of the Royal Air Force (RAF) shifts from sustained to contingency operations and the number of personnel is reduced, the burden of retained, medically downgraded personnel may affect operational readiness. The main aims were: to define the prevalence of morbidity leading to permanent medical downgrading; to determine at risk populations and identify areas for improvement.

Method Database of personnel referred to the RAF Medical Board was analysed from January 2012 to October 2013 and January 2017 to December 2019. Patients were excluded if they did not require a formal medical board; incomplete and duplicate entries were also excluded. The primary reason for medical downgrade was categorised with an ICD-10 code. Further subanalysis compared musculoskeletal disease with age, individual trade groups and anatomic region.

Results 2% of RAF service personnel were permanently downgraded annually. Musculoskeletal disease was the leading cause for permanent downgrade across both periods: 58% and 49%. Female personnel were at a greater risk of musculoskeletal downgrade compared with males. Spinal and knee pathology were the leading cause for downgrading among ‘high risk’ personnel. Personnel downgraded due to musculoskeletal pathology were often retained in a limited role with 10% and 5% retained as medically fully deployable. 14% and 12% of personnel downgraded due to musculoskeletal pathology were medically discharged.

Conclusion Musculoskeletal disease was the leading cause for permanent medical downgrades in the RAF. A greater proportion of downgraded personnel with musculoskeletal conditions were retained in service with medical limitations rather than medically discharged.