Evaluation of Construct and Criterion Validity for the ‘Liverpool Osteoarthritis in Dogs’ (LOAD) Clinical Metrology Instrument and Comparison to Two Other Instruments

Abstract

ObjectiveTo test the ‘Liverpool Osteoarthritis in Dogs’ (LOAD) questionnaire for construct and criterion validity, and to similarly test the Helsinki Chronic Pain Index (HCPI) and the Canine Brief Pain Inventory (CBPI).DesignProspective Study.Animals222 dogs with osteoarthritis.ProcedureOsteoarthritis was diagnosed in a cohort of dogs on the basis of clinical history and orthopedic examination. Force-platform analysis was performed and a “symmetry index” for peak vertical force (PVF) was calculated. Owners completed LOAD, CBPI and HCPI instruments. As a test of construct validity, inter-instrument correlations were calculated. As a test of criterion validity, the correlations between instrument scores and PVF symmetry scores were calculated. Additionally, internal consistency of all instruments was calculated and compared to those previously reported. Factor analysis is reported for the first time for LOAD, and is compared to that previously reported for CBPI and HCPI.ResultsSignificant moderate correlations were found between all instruments, implying construct validity for all instruments. Significant weak correlations were found between LOAD scores and PVF symmetry index, and between CBPI scores and PVF symmetry index.Conclusion and Clinical RelevanceLOAD is an owner-completed clinical metrology instrument that can be recommended for the measurement of canine osteoarthritis. It is convenient to use, validated and, as demonstrated here for the first time, has a correlation with force-platform data.

Development of a scale to evaluate mobility in dogs

“…Although clinical metrology has received relatively little attention in veterinary medicine, there are some dog owner questionnaires that compare scores either with some form of disease severity or surgical outcome, some of them having proved to correlate to veterinary assessment and force platforms data (HIELM-BJORKMAN et al, 2011;BROWN et al, 2013;CHRISTOPHER et al, 2013;WALTON et al, 2013). As with the creation of the DMS, the main concern of these instruments is to focus on the domain studied.…”

Mavacoxib and meloxicam for canine osteoarthritis: a randomised clinical comparator trial

“…A blood sample was collected for routine health screening and orthogonal view radiographs of the index joint were examined. Owners completed three CMIs: the Liverpool Osteoarthritis in Dogs (LOAD) (Hercock and others 2009, Walton and others 2013), the Canine Brief Pain Inventory (CBPI) (Brown and others 2007) and the Helsinki Chronic Pain Index (HCPI) (Hielm-Bjorkman and others 2009). …”

“…These instruments, to varying degrees, capture aspects of pain, activity levels and mobility (Walton and others 2013). …”

‘How do I know my animal got better?’ – measuring outcomes in small animal orthopaedics

“…All of these CMIs come with published evidence for most aspects of validity, but criterion validity has only been demonstrated for LOAD, CBPI (by comparison to asymmetry in PVF) (Walton and others 2013), and for the Texas A and M questionnaire (demonstrated as a predictor for ground reaction forces)(Hudson and others 2004). …”