Reliability of patient-reported complications following hip or knee arthroplasty procedures

Table 4 Validity and agreement values for PRC when compared with surgeons’ notes, categorised by surgeon, joint and follow-up time

Complication	n ^a	TT^b	TF^c	FT^d	FF^e	Sens	Spec	PPV	NPV	Agree %	kappa
Surgeon
Surgeon A	1386	3	12	39	1332	0.20	0.97	0.07	0.99	96.32	0.09
Surgeon B	1606	6	16	32	1552	0.27	0.98	0.16	0.99	97.01	0.19
Surgeon C	1122	3	16	17	1086	0.16	0.98	0.15	0.99	97.06	0.14
Surgeon D	1166	4	52	11	1099	0.07	0.99	0.27	0.95	94.60	0.09
Surgeon E	1056	1	13	26	1016	0.07	0.98	0.04	0.99	96.31	0.03
Surgeon F	1144	4	25	17	1098	0.14	0.98	0.19	0.98	96.33	0.14
Joint
Hip	2244	5	46	16	2177	0.10	0.99	0.24	0.98	97.24	0.13
Knee	5236	16	88	126	5006	0.15	0.98	0.11	0.98	95.91	0.11
Follow-up time
<6 weeks	506	1	1	15	489	0.50	0.97	0.06	0.99	96.84	0.10
6–8 weeks	2662	3	19	44	2596	0.14	0.98	0.06	0.99	97.63	0.08
3–5 months	880	2	18	21	839	0.01	0.98	0.09	0.98	95.57	0.07
6 months	2838	13	82	50	2693	0.14	0.98	0.21	0.97	95.35	0.14
6–12 months	572	2	14	12	544	0.12	0.98	0.14	0.97	95.45	0.11

^aThe denominator for the combined complications is the number of subjects in each subgroup multiplied by the number of individual complications (22) assessed for each subgroup
^bTT = True positives: both surgeons reported the complication
^cTF = False negatives: surgeons reported the complication, patients did not
^dFT = False positives: surgeons did not report the complication, but patients did
^eFF = True negatives: neither surgeons nor patients reported the complication

ISSN: 1471-2288