Table 3

Elixhauser Index inter-rater agreement

Elixhauser Index	Coded records (n)	Audited records (n)	% agreement	κ value	95% CI	Prob >Z
Congestive heart failure	15	28	85.0	0.57	0.38 to 0.75	<0.001
Cardiac arrhythmia	17	21	76.0	0.22	−0.00 to 0.45	0.013
Valvular disease	2	10	92.0	0.31	−0.02 to 0.64	<0.001
Pulmonary circulation disorder	3	2	97.0	0.39	−0.17 to 0.94	<0.001
Peripheral vascular disease	6	12	88.0	0.28	−0.02 to 0.57	<0.001
Hypertension	33	43	74.0	0.49	0.28 to 0.63	<0.001
Paralysis	1	2	97.0	−0.01	−0.01 to 0.02	0.557
Other neurological disorder	13	21	80.0	0.30	0.07 to 0.53	0.009
Chronic pulmonary disease	13	30	79.0	0.40	0.21 to 0.60	<0.001
Diabetes, uncomplicated	7	15	86.0	0.30	0.03 to 0.56	<0.001
Diabetes with complications	30	13	81.0	0.46	0.27 to 0.65	<0.001
Hypothyroidism	1	7	94.0	0.24	−0.15 to 0.62	<0.001
Renal failure	22	33	81.0	0.53	0.35 to 0.71	<0.001
Liver disease	6	20	80.0	0.15	−0.06 to 0.36	0.029
Peptic ulcer disease	0	19	81.0	0.00	–	–
Lymphoma	0	3	97.0	0.00	–	–
Metastatic cancer	4	9	93.0	0.43	0.09 to 0.77	<0.001
Solid tumour without metastases	16	13	85.0	0.40	0.15 to 0.65	<0.001
Rheumatoid arthritis	0	4	95.0	0.00	–	–
Coagulopathy	7	3	92.0	0.16	−0.02 to 0.41	0.035
Obesity	4	20	82.0	0.20	−0.04 to 0.33	0.003
Weight loss	12	1	89.0	0.14	−0.11 to 0.38	0.003
Fluid and electrolyte disorders	30	29	73.0	0.35	−0.15 to 0.55	<0.001
Blood loss anaemia	0	9	91.0	0.00	–	0.500
Deficiency anaemia	6	10	94.0	0.60	0.30 to 0.89	<0.001
Alcohol abuse	8	10	88.0	0.27	−0.03 to 0.57	0.003
Drug abuse	4	9	93.0	0.43	0.09 to 0.77	<0.001
Psychosis	2	8	94.0	0.38	0.00 to 0.76	<0.001
Depression	5	17	86.0	0.31	0.06 to 0.56	<0.001
AIDS	0	0	/	/	/	/

Inter-rater agreement in Elixhauser Index as specified by kappa (κ) values between audited data and coded data by disease.