Daytime use of general practice and use of the Out-of-Hours Primary Care Service for patients with chronic disease: a cohort study

Table 1 Sources and codes for identification of chronically ill patients

	National registries in Denmark	Variables
Heart disease	Danish National Registry of Patients	ICD-10: I20, I21
Lung disease	Danish National Registry of Patients	ICD-10: J40-J47, or J96
Lung disease	Danish National Health Service Register	Service codes: 7113, 7121 (spirometries)
	Danish National Prescription Registry	ATC codes: R03AC, R03AK, R03BA, R03BB, R03CC, R03DA, R03DC, V03AN01 (oxygen)
Diabetes	Danish National Diabetes Register	Civil registration numbers (CPR) corresponding registry data
Psychiatric disease	Danish Psychiatric Central Registry	ICD-10: F20, F25, F30, F31
Cancer	Danish Cancer Registry	ICD-10: C00-C97 (excl. C44)

ISSN: 2731-4553