Table 3

Reliability of acoustic analysis v stethoscope

	Wheeze			Rattles			Crackles
	Yes	No	Total	Yes	No	Total	Yes	No	Total
2×2 tables showing for how many infants there was agreement between the two measures; κ (95% confidence interval) given for each comparison. Rows and columns are defined as (A) and (B) observer 1 v observer 2; (C) and (D) occasion 1 v occasion 2.
A Between-observer agreement for stethoscope
Yes	13	14	27	10	4	14	3	2	5
No	2	7	9	4	18	22	3	28	31
Total	15	21	36	14	22	36	6	30	36
	κ = 0.18 (−0.08 to 0.44)			κ = 0.53 (0.21 to 0.86)			κ = 0.46 (0.14 to 0.79)
B Between-observer agreement for acoustic analysis
Yes	4	7	11	7	6	13	4	4	8
No	1	8	9	2	5	7	1	11	12
Total	5	15	20	9	11	20	5	15	20
	κ = 0.24 (−0.12 to 0.60)			κ = 0.22 (−0.18 to 0.63)			κ = 0.44 (0.03 to 0.86)
C Within-observer agreement for acoustic analysis (instrument)
Yes	29	9	38	44	4	48	15	7	22
No	3	17	20	3	7	10	4	32	36
Total	32	26	58	47	11	58	19	39	58
	κ = 0.57 (0.32 to 0.82)			κ = 0.59 (0.34 to 0.85)			κ = 0.56 (0.30 to 0.82)
D Within-observer agreement for acoustic analysis (repeat analysis)
Yes	9	1	10	16	0	16	6	1	7
No	1	8	9	1	2	3	1	11	12
Total	10	9	19	17	2	19	7	12	19
	κ = 0.79 (0.43 to 1.24)			κ = 0.77 (0.33 to 1.20)			κ = 0.77 (0.32 to 1.22)