Inter-observer agreement for clinical examinations of foot lesions of sheep.
In sheep, the diagnosis of foot lesions is routinely based on physical examination of the hoof. Correct diagnosis is important for the effective treatment, prevention and control of both infectious and non-infectious causes of lameness. Therefore, the aim of this study was to evaluate the level of inter-observer agreement for clinical examination of ovine foot lesions. Eight observers of varying experience, training and occupation performed foot examinations on a total of 1158 sheep from 38 farms across North England and Wales. On each farm, a group of two to four observers independently examined a sample of 24 to 30 sheep to diagnose the presence or absence of specific foot lesions including white line lesions (WL), contagious ovine digital dermatitis (CODD), footrot (FR), inter-digital dermatitis (ID) and toe granuloma (TG). The inter-observer agreement of foot lesion assessments was examined using Fleiss kappa (κ), and Cohen's κ examined the paired agreement between the test standard observer (TSO) and each observer. Scoring differences with the TSO were examined as the percentage of scoring errors and assessed for evidence of systematic scoring bias. With the exception of WL (maximum error rate 33.3%), few scoring differences with the TSO occurred (maximum error rate 3.3%). This suggests that observers can achieve good levels of reliability when diagnosing most of the commonly observed foot conditions associated with lameness in sheep.
Department of Epidemiology, Institute of Global Health and Infection, and Population Health, University of Liverpool, Leahurst, Neston CH64 7TE, UK; Section for Small Ruminant Research, Norwegian University of Life Sciences (NMBU), Høyland, 4325 Sandnes, Norway. Electronic address: clare.phythian@nmbu.no.
C J
CJ
Phythian
Department of Epidemiology, Institute of Global Health and Infection, and Population Health, University of Liverpool, Leahurst, Neston CH64 7TE, UK.
P J
PJ
Cripps
Department of Epidemiology, Institute of Global Health and Infection, and Population Health, University of Liverpool, Leahurst, Neston CH64 7TE, UK.
D
D
Grove-White
Department of Epidemiology, Institute of Global Health and Infection, and Population Health, University of Liverpool, Leahurst, Neston CH64 7TE, UK.
E
E
Michalopoulou
Department of Epidemiology, Institute of Global Health and Infection, and Population Health, University of Liverpool, Leahurst, Neston CH64 7TE, UK.
J S
JS
Duncan
D000818:Animals; D058066:Digital Dermatitis / Q000175:diagnosis* / Q000453:epidemiology; D004739:England / Q000453:epidemiology; D005528:Foot / Q000473:pathology; D005534:Foot Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D005535:Foot Rot / Q000175:diagnosis* / Q000453:epidemiology; D006724:Hoof and Claw / Q000473:pathology; D015588:Observer Variation; D010808:Physical Examination; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000453:epidemiology; D014852:Wales / Q000453:epidemiology
Clinical diagnosis; Foot lesions; Observer agreement; Sheep