[Diagnosis coding of the musculoskeletal system in general practice]

Danish general practitioners are encouraged to code diagnoses according to the Danish version of ICPC. In order to evaluate feasibility, we aimed to estimate sensitivity of ICPC coding of patients with symptoms from the musculoskeletal system (ICPC L01-20 and 83-99) in general practice compared to health information from other sources.

We identified patients connected to one general practice in July 2005. We retrieved information on referred care by specialists in neurology, rheumatology, and orthopaedic surgery as well as treatments by physiotherapists from the Danish Health Insurance. We received ICD10 codes within chapter 8 (diseases of the musculoskeletal system and connective tissue) from the Danish Hospital Register. Sensitivity was calculated according to criteria based on whether the patients had received an ICD10 code or other public health services.

Of 2649 patients registered in the general practice, 496 had recorded an ICPC code in chapter L (the musculoskeletal system). Sensitivity was calculated to 0.83. Of all patients with musculoskeletal diseases 82.5% were identified by ICPC codes, but only 45% by other health sources.

The coding of ICPC in a general practice had an acceptable sensitivity and constitutes a useful opportunity to identify a group of patients with musculoskeletal diseases. An optimal identification of specific patient subgroups, by using ICPC coding, requires the construction of a national registry of the ICPC coding made in all Danish general practices.