INTRODUCTION: The aim of this study was to investigate the distribution of International Classification of Primary Care, second edition, (ICPC-2) diagnoses in a population of individuals on long-term sick leave. Furthermore, we wanted to test if the number of diagnoses varied between assessors.

METHODS: The study population was comprised of people on sick leave aged 18-65 years attending rehabilitation appointments in Region Zealand in the period from 1 March to 31 August 2018. Five general practitioners assigned between one and three ICPC-2 diagnoses per subject. It was investigated whether there was independence between the doctors collecting the data.

RESULTS: A total of 29 diagnostic categories were established, and the three most common conditions were back pain (9.8%), musculoskeletal disorders (8.6%) and depression (7.5%). During the data collection period, a primary ICPC-2 diagnosis was made in 743 subjects, a secondary diagnosis in 371 subjects (49.9%) and a tertiary diagnosis in 101 subjects (13.6%). No significant differences were found between the number of ICPC-2 diagnoses made by the five doctors (p = 0.49).

CONCLUSIONS: The most common diagnoses were back conditions, musculoskeletal disorders and depression, and half of the study population had at least two diagnoses. The study shows that health professionals can assign ICPC-2 diagnoses for individuals on sick leave during rehabilitation sessions. This will give the municipalities the necessary knowledge to systematically track the development of diagnoses in order to plan individualised interventions.

FUNDING: none.

TRIAL REGISTRATION: not relevant.