Reliabilitätsanalyse der subjektiven Beurteilung des Bizepssehnenreflexes beim gesunden Hund

Reliability-analysis of the subjective assessment of the bicipital reflex in healthy dogs

The goals of this thesis are two-folded: first the comparative quantification of the Interobserver Agreement (IA) on the evaluation of the canine bicipital (BTR) and patellar tendon (PTR) reflex in healthy dogs and second the identification of intrinsic (sex, age, fur length, weight) and extrinsic (observer´s expertise, body side, examiner) risk factors on the IA of both reflexes.
The observers are subdivided in three groups based on their expected level of expertise (neurologists = highest -, practitioners = middle – and veterinary students = lowest level of expertise). Each observer evaluates independently the reflex presence (RP(BTR), RP(PTR)) and the reflex activity (RA(BTR), RA(PTR)) of both reflexes on a videotape using a 5-point-ordinalscale. For study 1, 103 anonymized sequences of 61 forelimbs are evaluated, of which 42 sequences have been examined by both examiners (E1, E2) and 19 by one of both examiners (E1 or E2) each. For study 2 only the sequences examined by E2 in study 1 (n = 54) were analyzed and compared to the evaluation of the patellar tendon-reflex on 64 hindlimbs, which have been examined only by E2 as well.
Multiple reliability coefficients were calculated. Additionally, the amount of complete agreement-, partial (dis)agreement with difference of 1 or ≥ 2 points of the ordinalscale- and complete disagreement-evaluations are counted for all groups. The influence of the risk factors mentioned above are calculated using a mixed regression-model. The Odds Ratio for each factor was presented.
The higher the level of expertise the higher is the IA for RP(BTR) and is significant highest for neurologists. For the RA(BTR), the amount of complete agreement-evaluations was the higher the higher the level of expertise of the observer was. The IA of the RA(BTR) is significantly lowest for students. The level of expertise has a significant impact on the height of the IA in the evaluation of the bicipital tendon-reflex: for the RP(BTR) practitioners have a 3.8-way, students a 5.7-way higher risk to judge discordantly compared to the neurologists. For the RA(BTR), practitioners have a 4.4-way, students a 7.6-way higher risk of discordance. In longhaired dogs the likelihood of disagreement is 2.6-way higher compared to shorthaired dogs in the evaluation of RA(BTR). This impact is significant. Likewise, the RP(PTR) is the higher the higher the observers´ expertise is. Students have the significant lowest IA of the evaluation of the RP(PTR). The RA(PTR) is evaluated significantly more consistent by practitioners and students than the RA(BTR). For practitioners this difference is significant. For neurologists there is no difference between the IA of the RA(BTR) and RA(PTR). Neurologists have a higher amount of complete agreement-evaluations in RA(BTR) compared to the RA(PTR), while practitioners and students have a higher amount of complete agreement-evaluations in the RA(PTR). Neurologists and practitioners have the identical distribution of complete agreement- and disagreement-evaluations of RA(PTR) and show no evaluation with a difference of more than one scale-point. None of the examined risk factors has a significant impact on the height of IA in the evaluation of RP(PTR), while students have a 4.3-way higher risk of discordance when evaluating the RA(PTR) compared to the other groups. This effect is significant (p < 0,001). Neurologists can reliably assess the bicipital tendon-reflex. The level of the observer´s expertise and the fur length of the dog take an impact on the height of the IA of RA(BTR). The influence of the observer´s expertise is higher on the evaluation of the BTR than on the evaluation of the PTR.