Table 1.

25 Selected studies related to clinical coding accuracy augmented with six independent variables

Case no.	Author’s	Data source	Random sampling (A)	90 % sampled data available (B)	Trained coders (C)	Coder reliability (D)	Coder awareness of codes (E)	Definition of accuracy (F)
1	Sellar et al. (1990)	X	No	Yes	Unclear	No	Yes, aware	Unclear
2	Smith et al. (1991)	Y1	Yes	Yes	No	No	Unclear	Unclear
3	Yeoh and Davies (1993)	Y1	Yes	No	Unclear	Yes	No, unaware	Unclear
4	Panayiotou (1993)	Y1	Unclear	Yes	Yes	No	Yes, aware	Three digit
5	Cleary et al. (1994)	Y1	Unclear	Unclear	Yes	Yes	Unclear	Four digit
6	Drennan (1994)	Y1	Yes	Yes	Yes	No	No, unaware	Unclear
7	Gibson and Bridgman (1998)	Y1	Yes	No	Unclear	No	Unclear	Four digit
8	Dixon et al. (1998)	Y1	Yes	Yes	Yes	Yes	Unclear	Four digit
9	Kirkman et al. (2009)	Z	Yes	Unclear	Unclear	No	Unclear	Four digit
10	Reddy-Kolanu and Hogg (2009)	Y1	Yes	Yes	Yes	No	Unclear	Unclear
11	Nouraei et al. (2009)	Y1	Yes	Yes	Yes	Unclear	Unclear	Four digit
12	Mitra et al. (2009)	Y1	Yes	Unclear	Yes	No	Unclear	Four digit
13	Beckley et al. (2009)	Y1	Yes	Unclear	Yes	No	Unclear	Unclear
14	Audit Commission (2010)	Y1	Yes	Unclear	Yes	Unclear	Unclear	Four digit
15	Murchison et al. (1991)	Y1	No	Yes	Unclear	No	Unclear	Unclear
16	Park et al. (1992)	Y1	No	Yes	No	No	Unclear	Unclear
17	McGonigal et al. (1992)	Y1	No	Yes	No	No	Yes, aware	Four digit
18	Pears et al. (1992)	Y1	Unclear	No	Unclear	Unclear	No, unaware	Four digit
19	Samy et al. (1994)	Y1	Yes	Unclear	Unclear	Unclear	Unclear	Unclear
20	Dornan et al. (1995)	Y1	Yes	Yes	Yes	No	Yes, aware	Unclear
21	Harley and Jones (1996)	Y1	Yes	Yes	Yes	No	Unclear	Three digit
22	Davenport et al. (1996)	Y2	No	Yes	Unclear	No	Yes, aware	Unclear
23	Kohli and Knill-Jones (1992)	Y1	Yes	Yes	Unclear	No	Yes, aware	Four digit
24	Hasan et al. (1995)	Y1	Yes	Yes	Yes	No	Unclear	Four digit
25	Colville and Laing (2000)	Y3	Yes	Yes	No	No	No, unaware	Four digit