Table 2. Conditional distributions of asthma cases and non-cases classified by self-report, the Danish National Patient Register (DNPR) and the Registry of Medicinal Product Statistics (RMPS).

	Yes/Yes	No/No	Yes/No	No/Yes	Kappa
Self-report/DNPR	2,023	46,122	4,401	1,091	0.38
RMPS/Self-report	5,499	36,209	925	11,004	0.37
DNPR/RMPS	5,211	62,867	650	24,888	0.21