Observer agreement on pen level prevalence of clinical signs in finishing pigs

Four observers performed a standard clinical examination of finisher pigs in two commercial finisher herds. In herd 1, 600 finisher pigs in 44 pens were examined. The observers assessed clinical signs of lameness, umbilical hernia and tail bite according to a standardized procedure. The prevalence of the clinical signs was estimated at the pen level. The procedure was repeated after 3 months in another herd, where 730 finisher pigs in 69 pens were examined. The agreement between observer pairs was assessed using prevalence-adjusted bias-adjusted kappa (PABAK) and proportionate-agreement estimates (P_pos and P_neg).

Observer bias was present despite training and standardization of the participating observers. The highest pen level agreement for the observer pairs was found for pens that had one or more pigs with tail bite (PABAK = 0.82–1.00) and umbilical hernia (PABAK = 0.77–1.00). The agreement was fair-to-moderate for identification of pens holding one or more lame pigs (PABAK = 0.27–0.71). In general, the average agreement of observer pairs on absence of clinical signs (P_neg) was higher than for presence (P_pos). The observer bias varied between observer pairs and with the clinical signs.     

Evaluation of Intra‐ and Interobserver Variability and Repeatability of Tibial Plateau Angle Measurements with Digital Radiography Using a Novel Digital Radiographic Program

Objective— To compare the intra‐ and interobserver variability occurring when observers with differing experience levels measure tibial plateau angles (TPAs) with a novel digital radiographic projection program (tibial plateau leveling osteotomy [TPLO] planning program), the Kodak Picture Archiving and Communications System (PACS), and standard sized printed films (SF). Study Design— Cross‐sectional study. Sample Population— Dogs (n=36) with cranial cruciate ligament (CCL) rupture that had a TPLO. Methods— Six observers, divided into 3 equal groups based on experience level, measured TPA on 36 digitally captured radiographic images of tibiae of dogs clinically affected with CCL rupture. Each observer used 3 methods of measuring TPA and repeated the measurements 3 times with each method. The intra‐ and interobserver variability was compared using the coefficient of variation. Results— Averaged over all replications and images, there was no significant difference (P>.05) in the average variability occurring with each method for all but 1 observer. There was no effect of experience level on measurement variability; however, interobserver variability was significantly less with measurements made with the PACS and TPLO planning program compared with measurements made from SF (P<.05). Conclusions— Repeated measurements of TPA made using digital images and computer‐based measurement programs were significantly less variable between observers than those made from images printed on standard radiographic films. Clinical Relevance— Digital radiography and computer‐based measurement programs are effective for determining the TPA, allowing less variability in measurements compared with SF. The ability to manipulate the image may allow better identification of anatomic landmarks.     

Comparison of three two-dimensional echocardiographic methods of assessing left ventricular size in Doberman Pinschers

IntroductionCompare three methods of obtaining linear left ventricular dimensions within the same Doberman Pinscher (DP).AnimalsOne hundred and thirty-nine client-owned DP.Materials and MethodsLinear left ventricular dimensions were measured using two-dimensional short-axis (Sx-2D), motion-mode short-axis (Sx-MM), and motion-mode long-axis (Lx-MM) methods, then left ventricular volumes were obtained using monoplane Simpson's method of discs (SMOD). A Friedman test with Dunn's multiple comparisons was used to compare differences between methods. Bias and correlation were evaluated via Bland-Altman and Spearman's correlation. Sensitivity and specificity for diagnosing occult dilated cardiomyopathy (DCM) compared to SMOD were determined. Coefficients of variation (CVs) were calculated for intra- and inter-observer measurement variability.ResultsThere were significant differences between all linear dimensions in diastole and systole. Short-axis 2D measurements had significant bias compared with Sx-MM (diastole +1.19 mm, systole +1.65 mm) and Lx-MM (diastole +4.36 mm, systole +3.87 mm) as did Sx-MM compared with Lx-MM (diastole +3.17 mm, systole +2.22 mm). All linear dimensions had a moderate positive correlation with SMOD. The sensitivity and specificity of linear measurements to detect DCM were: Sx-2D (sensitivity 72.0%, specificity 88.5%), Sx-MM (sensitivity 52.0%, specificity 92.0%), and Lx-MM (sensitivity 37.5%, specificity 99.1%). All methods had acceptably low CV for intra- and inter-observer measurement variability.ConclusionsResults of this study suggest that linear measurements are repeatable and correlate with reference standard; however, there is a significant bias between measurements, and they should not be used interchangeably.     

INTRA‐ AND INTEROBSERVER VARIABILITY OF ULTRASONOGRAPHIC MEASUREMENTS OF THE ADRENAL GLANDS IN HEALTHY BEAGLES

The aim of the present study was to establish which adrenal gland measurement was characterized by the least variations. To do this, we quantified the variability of seven different size measurements of the canine adrenal gland (maximal length, maximal height at the cranial and caudal poles on longitudinal and transverse images, and maximal width of the cranial and caudal poles) within observer, between observer, and between dogs based on three different measurements made by each of the three observers in six healthy Beagle dogs. The height of the caudal pole of both adrenal glands measured on longitudinal images had the lowest intra‐ and interobserver variability, while measurements of the length had the highest intra‐ and interobserver variability. Other measurements that were characterized by low intra‐ and interobserver variability were: height and width of the caudal pole on transverse images and height of the cranial pole on longitudinal images only. These results provide a basis for further study of the changes in adrenal gland size in dogs with pituitary‐dependent hyperadrenocorticism.     

Analgesic efficacy of intra‐articular morphine in experimentally induced radiocarpal synovitis in horses

ObjectiveTo compare the analgesic effect of intra-articular (IA) and intravenous (IV) morphine in horses with experimentally induced synovitis.AnimalsEight adult horses.Study designRandomized, observer blinded, double dummy trial with sequential crossover design.MethodsRadiocarpal synovitis was induced by IA injection of lipopolysaccharide on two occasions separated by a 3-week washout period. In one study period horses received treatment IA; morphine IA (0.05 mg kg^?1) plus saline IV and in the other study period they received treatment IV; saline IA plus morphine IV (0.05 mg kg^?1). Lameness and pain were evaluated repeatedly by two observers throughout each of the two 168-hour study periods. Pain was evaluated by use of a visual analogue scale of pain intensity (VAS) and a composite measure pain scale (CMPS). Comparison of treatments was performed by analysis of variance with repeated measurements. Significance level was set to p ≤ 0.05. Inter-observer agreement and agreement between the VAS and CMPS was assessed by use of the Bland–Altman method.ResultsIntra-articular injection of LPS elicited a marked synovitis resulting in lameness and pain. IA morphine resulted in significantly less lameness than IV morphine (p = 0.03). CMPS (p = 0.09) and VAS (p = 0.10) pain scores did not differ significantly between treatments. Inter-observer agreement of the CMPS was classified as good, but only fair for the VAS. Agreement between the two pain scales was considered fair.Conclusions and clinical relevanceAn analgesic effect of IA morphine was demonstrated by significantly reduced lameness scores. The results support the common practice of including IA morphine in a multimodal analgesic protocol after arthroscopic surgery, although further studies in clinical cases are needed. The employed CMPS had good reproducibility, and was easy to use, but may have limited sensitivity at mild intensity pain.     

Prognostic value of selected one-, two- and three-dimensional and Doppler echocardiographic methods to assess severity in dogs with myxomatous mitral valve disease

IntroductionAlthough challenging, predicting outcomes in dogs with myxomatous mitral valve disease (MMVD) is of importance to owners and veterinarians. Our aim was to compare the prognostic value of selected one-, two-, and three-dimensional and Doppler echocardiographic methods to predict cardiac-related and all-cause mortality in MMVD dogs. We hypothesize that three-dimensional methods would better predict prognosis than one- and two-dimensional methods.AnimalsOne-hundred thirty-eight privately-owned dogs with MMVD.Materials and methodsCox proportional Hazard analyses and Kaplan–Meier curves were used to investigate the predictive value of 14 variables; left atrial (LA) volume indexed to body weight (BW) measured by real-time three-dimensional echocardiography (RT3DE) and calculated using Simpson's modified method of discs (SMOD) and the area-length method; LA diameter in short-axis and long-axis to aortic in short-axis ratio, effective regurgitant orifice area indexed to body surface area measured in RT3DE en face view and calculated using four-chamber (4Ch) and two-chamber views alone or in combination; percentage increase in left ventricular end-diastolic and systolic internal diameters; fractional shortening; E wave velocity; regurgitant jet area/LA area.ResultsAll 14 variables were significantly predictive of cardiac-related mortality, and 11 were predictive of all-cause mortality. The prognosis was best predicted by LA volume/BW estimated by SMOD or RT3DE, consistently showing the highest predictive value in all analyses.ConclusionsLeft atrial volume calculated by SMOD showed a similar predictive value compared to RT3DE. Performing SMOD from apical 4Ch images should be considered an alternative to RT3DE for echocardiographic examinations where prognostication of disease outcome is sought.     

Intraobserver and interobserver agreement, reproducibility, and accuracy of computed tomographic measurements of pituitary gland dimensions in healthy dogs

OBJECTIVE: To determine the reproducibility and accuracy of computed tomographic (CT) measurements of pituitary gland dimensions in healthy dogs. ANIMALS: 35 healthy sexually intact adult dogs. PROCEDURES: 2 observers independently viewed CT images of the skull in 35 dogs twice. Pituitary gland height, width, length, and volume and pituitary gland height-to-brain area ratio (P:B ratio) were measured or calculated. Intraobserver and interobserver agreement indexes (AIs) were calculated for pituitary gland dimensions. Computed tomography was performed also on 5 phantoms, and both observers measured phantom dimensions twice. True-value AIs were calculated for the phantom study. RESULTS: The mean +/- SD interobserver AI between observer 1 and 2 for pituitary gland height and the P:B ratio was 0.90 +/- 0.07. The intraobserver AI for pituitary gland height and the P:B ratio was 0.97 +/- 0.04 for observer 1 and 0.94 +/- 0.04 for observer 2. The intra and interobserver AIs for the other dimensions were lower than those for pituitary gland height and the P:B ratio. All phantom dimensions on CT images were underestimated significantly, compared with their true values. CONCLUSIONS AND CLINICAL RELEVANCE: The intra- and interobserver AIs for pituitary gland dimension measurements on CT images were high. However, the same observer preferably should perform serial measurements. Window settings influence pituitary gland dimension measurements, and predetermined window settings are recommended to make comparisons among dogs. Pituitary gland dimension measurements made from CT images in our study underestimated the true values.     

REPEATABILITY AND RELIABILITY OF GLOMERULAR FILTRATION RATE DETERMINATION VIA GAMMA CAMERA UPTAKE OF TC‐99M‐DTPA IN CATS WITH CHRONIC KIDNEY DISEASE

Measurement of glomerular filtration rate (GFR) via gamma camera uptake of 99mTc‐diethylenetriaminepentaacetic acid is a standard method for quantifying renal function. Aims of this retrospective, observer agreement study were to determine intra‐ and interobserver variation in GFR values for cats with chronic kidney disease and to determine whether renal insufficiency classification changed between observers. Guideline cut‐points were established for the difference in repeated GFRs to differentiate changes caused by therapeutic effect vs. inherent variation. Included cats had a diagnosis of chronic kidney disease and had undergone GFR examinations between the years of 2010 and 2013. Twenty‐nine GFR studies were sampled. Each study was read twice, 6 months apart, by two veterinary radiologists and one radiology resident. Modified Bland–Altman plots were used to investigate differences between readings 1 and 2 by observer and between pairs of observers by reading. Reliability of clinical classification was assessed through comparisons between readings and observers. Measurements were not systematically different between readings for the experienced observers but were higher in reading 1 than reading 2 for the inexperienced observer. Measurements were not systematically different between the experienced observers in reading 1 or between any two observers in reading 2. Reliability for GFR measurements was high among experienced observers; variations in GFR measurements rarely led to differences in clinical classification. Results suggested that, for experienced observers, changes in GFR values following treatment in cats with chronic kidney disease between ?0.4 and 0.4 mL/min/kg may be due to inherent variability rather than treatment effect.     

Two-dimensional echocardiographic assessment of the feline left atrium

Atrial size determined by echocardiography provides a surrogate measure of the hemodynamic burden of cardiac disease. Linear atrial dimensions often are indexed to aortic diameter. Whereas quantitative variables obtained from healthy cats, using 2-dimensional echocardiography (2DE), have been reported, indices from 2DE, have not. Using 2DE and M-mode echocardiography, we calculated indices of left atrial size and a single index of atrial function, left atrial fractional shortening, in 17 healthy cats. Specifically, left atrial dimensions from short- and long-axis 2DE planes were indexed to aortic diameter and also to end-diastolic left ventricular dimension. Additionally, left atrial circumference and area were indexed to aortic circumference and area, respectively. The same variables were obtained from 20 cats with hypertrophic cardiomyopathy (HCM), so that agreement between 2DE indices and indices from M-mode echocardiography could be evaluated over a clinically relevant range of atrial sizes. Atrial dimensions and indices of atrial size from cats with HCM exceeded those of healthy cats. Left atrial dimension from 2D short-axis images indexed to aortic diameter generally was less than the analogous index obtained from M-mode (mean bias, [95% limits of agreement] -0.13, [-0.42, 0.17]). Left atrial dimension from 2D long-axis images indexed to aortic diameter generally was greater than the index obtained from M-mode (0.15, [-0.28, 0.58]). We conclude that ratios of left atrial size and aortic diameter, from 2DE and M-mode echocardiography, are not interchangeable. Normative data that may serve as reference intervals for 2DE assessment of atrial size are presented.     

Investigations of the reliability of observational gait analysis for the assessment of lameness in horses

The objectives of this study were to assess the reliability of a numerical rating scale (NRS) and a verbal rating scale (VRS) for the assessment of lameness in horses and to determine whether they can be used interchangeably. Sixteen independent observers graded the severity of lameness in 20 videotaped horses, and the agreement between and within observers, correlation and bias were determined for each scale. The observers agreed with each other in 56 per cent of the observations with the NRS and in 60 per cent of the observations with the VRS, and the associated Kendall coefficient of concordance was high. Similar trends were evident in the agreement between two observations by each observer. The correlation between and within observers was high for both scales. There were no significant differences (bias) among the observers' mean scores when using either scale. There was a significant correlation between the lameness scores attributed when using the two scales, but the differences between the scores when plotted against their overall mean were unacceptable for clinical purposes. The results indicate that the NRS and VRS are only moderately reliable when used to assess lameness severity in the horse, and that they should not be used interchangeably.     

A clinical comparison between a non‐invasive blood pressure monitor using high definition oscillometry (Memodiagnostic MD 15/90 Pro) and invasive arterial blood pressure measurement in anaesthetized dogs

ObjectiveTo compare high definition oscillometry (HDO) to invasive blood pressure measurement in anaesthetized dogs.Study designProspective, clinical trial.AnimalsFifty dogs weighing 1.95–79 kg (mean 23.5 kg).Materials and methodsAnaesthetic and peri–anaesthetic management was chosen according to each dog's physical status and anaesthetist's preference. Direct arterial blood pressure measurements were performed using a catheter placed in the dorsal pedal artery and an electronic pressure transducer connected to a multiparameter monitor. Non–invasive blood pressure measurements were performed using an appropriately sized cuff placed around the tail base. Comparisons between the two methods were made using Bland and Altman plots. The data are reported as mean bias (lower, upper limits of agreement). Further analysis was performed after separating the data into the following categories based on invasive mean arterial blood pressure (MAP): high (MAP > 100 mmHg), medium (70 mmHg < MAP < 100 mmHg) and low (MAP < 70 mmHg) blood pressure (BP). The two methods were compared as used clinically.ResultsEight hundred measurement pairs for invasive and HDO BP readings were compared. Overall, the HDO measured lower values for SAP and DAP but higher for MAP than the invasive method. The lowest bias (upper, lower limits of agreement) were obtained for MAP, ?1 (?22, 19) mmHg. The biggest discrepancy between the methods was reflected by a large bias (limits of agreement) 5 (?34, 45) mmHg, was for SAP. The results for DAP were between those for SAP and MAP with a bias (limits of agreement) of 3 (?20, 27) mmHg. When the values were separated into the pressure range categories the HDO measured higher in the high, medium and low BP groups, with the exception of SAP in the low BP group.ConclusionsWhen considering the mean bias, the accuracy of HDO compared well with direct arterial blood pressure, but the precision was poor, as determined by wide limits of agreement.Clinical relevanceUsing trends and serial measurements rather than a single measurement for clinical decision making is recommended with both methods, when used as reported here.     

Interobserver agreement in the diagnosis of canine hip dysplasia using the standard ventrodorsal hip-extended radiographic method

OBJECTIVES: To determine the agreement between observers and to investigate the effect of observer experience in diagnosing canine hip dysplasia and providing final scoring of hips using the standard ventrodorsal hip-extended radiographic method. The agreement of the final scoring, with a presumed correct assessment based on the Norberg angle, is also investigated. METHODS: Thirty observers were requested to read 50 ventrodorsal hip-extended radiographs of 25 dogs according to Federation Cynologique International criteria. Groups of experienced (nine members) and inexperienced (21 members) observers were used. RESULTS: For providing the distinction between dysplastic versus non-dysplastic dogs, the average interobserver agreement was 72 per cent and was significantly higher (P<0.0001) than the score that could be expected by chance without any agreement between observers. For providing the final score (A, B, C, D or E), an average interobserver agreement of 43.6 per cent was found. In the experienced group, an agreement score of 76 per cent was found for the distinction between AB versus non-AB and an agreement score of 81 per cent was found for the distinction between C versus non-C. The agreement score was significantly higher (P<0.0001) for the experienced group than for the inexperienced group in all cases. Agreement between the presumed correct assessment based on the Norberg angle and the observer's evaluation was low (P=0.35), irrespective of whether the observers were experienced (71.8 per cent correct assessments) or inexperienced (69 per cent correct assessments). CLINICAL SIGNIFICANCE: Although interobserver agreement is low, observer experience increases agreement.     

COMPARABILITY OF LEFT VENTRICULAR M-MODE ECHOCARDIOGRAPHY IN DOGS PERFORMED IN LONG-AXIS AND SHORT-AXIS

The purpose of this prospective study was to determine comparability of left ventricular (LV) M-mode echocardiographic indices derived from right parasternal long-axis and short-axis imaging planes. In 104 dogs (37 healthy dogs and 67 dogs with heart disease), LV M-mode echocardiograms were recorded from both long-axis and short-axis views and interventricular septum thickness (IVS), left ventricular internal dimensions (LVD), left ventricular posterior wall thickness (LVPW), and LV shortening fraction (FS) were measured. Statistical analysis included paired t-test and graphical analysis to assess agreement between the two methods of data acquisition. Mean LVD in systole and diastole and mean IVS in systole were significantly (P<0.001) larger when measured from short-axis recordings compared to long-axis measurements. An increased magnitude of measurement resulted in increased differences between the methods for LV dimensions and fractional shortening. Differences between the two methods were small and within clinically acceptable limits in normal dogs. However, in 23 (34%) of the dogs with cardiac abnormality, one or more LV M-mode derived dimension obtained from one imaging plane did not agree sufficiently closely with the same measure from the other plane. Only for measurement of FS was there good agreement between methods in dogs with cardiac disease. Therefore, with the exception of FS, data gained from LV short-axis and long-axis M-mode recordings should not be used interchangeably in dogs with cardiac disease.     

Evaluation of intra- and interobserver reliability and image reproducibility to assess usefulness of high-resolution ultrasonography for measurement of anterior segment structures of canine eyes

OBJECTIVE: To evaluate the usefulness of high-resolution ultrasonography (HRUS) for measurements of anterior segment structures in canine eyes. ANIMALS: 4 clinically normal Beagles. PROCEDURE: Images were obtained from 8 eyes with a handheld 20-MHz transducer. Eleven anterior segment structures on each image were measured 5 times by 2 independent observers. Coefficients of variation (CVs) for measurements were used to assess intraobserver reliability. Interobserver reliability was assessed by comparing measurements obtained by the 2 observers from the same images. Five images were sequentially obtained from 2 locations (ie, superior and temporal) to evaluate image reproducibility. Anterior segment structures were measured once on each image; image reproducibility was assessed by use of the CV for each parameter measured. Imaging location was assessed by comparison of CV for measurements from each location. RESULTS: CVs were < 10% for observer A for all measurements except the ciliary cleft area (11.63%). The CVs were > 10% for observer B for measurements of the angle recess area (18.51%) and ciliary cleft width (17.44%) and area (16.01%). Significant differences in measurements between observers were found for 5 of 11 anterior segment structures. Imaging the superior aspect of the globe provided the most reproducible images, although image reproducibility was still somewhat variable, with the highest and lowest CVs for measurements of 33.01% and 11.32%, respectively, in the superior position. CONCLUSIONS AND CLINICAL RELEVANCE: High-resolution ultrasound images can be used to reliably measure various anterior segment structures. Clinically relevant findings in the anterior segment of canine eyes may be detectable by use of HRUS.     

Observations of variable inter-observer agreement for clinical evaluation of faecal consistency in grow-finishing pigs

Inter-observer agreement for assessment of faecal consistency in pigs was evaluated using a scoring system with 3 categories. In a pilot study, 3 observers performed an examination of faecal samples post-collection. The samples were obtained from pigs (12-13 weeks old) in 4 herds with a history of diarrhoea associated with Lawsonia intracellularis, Brachyspira spp. and/or Porcine Circovirus Type 2. Observer 1 examined all the faecal samples from the 4 herds. Observer 2 only examined the faecal samples from herds 1 and 2. Observer 3 only examined the faecal samples from herds 3 and 4. We observed a substantial agreement in faecal consistency scores between Observers 1 and 3 (kappa=0.64, 95% CI: 0.51-0.78). In contrast, only a fair agreement was observed between Observers 1 and 2 (kappa=0.24, 95% CI: 0.14-0.34). The variations in inter-observer agreement detected in the current study suggest that misclassification error can be a problem in studies assessing faecal consistency. Solutions may include developing a standardized system for scoring the consistency of pig faeces, calibration when more than one observer is involved in clinical studies and using a more objective measure of faecal consistency.     

COMPARISON OF NONCONTRAST COMPUTED TOMOGRAPHY AND HIGH‐FIELD MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF GREAT DANES WITH CERVICAL SPONDYLOMYELOPATHY

Computed tomography (CT) provides excellent bony detail, whereas magnetic resonance (MR) imaging is superior in evaluating the neural structures. The purpose of this prospective study was to assess interobserver and intermethod agreement in the evaluation of cervical vertebral column morphology and lesion severity in Great Danes with cervical spondylomyelopathy by use of noncontrast CT and high‐field MR imaging. Fifteen client‐owned affected Great Danes were enrolled. All dogs underwent noncontrast CT under sedation and MR imaging under general anesthesia of the cervical vertebral column. Three observers independently evaluated the images to determine the main site of spinal cord compression, direction and cause of the compression, articular process joint characteristics, and presence of foraminal stenosis. Overall intermethod agreement, intermethod agreement for each observer, overall interobserver agreement, and interobserver agreement between pairs of observers were calculated by use of kappa (κ) statistics. The highest overall intermethod agreements were obtained for the main site of compression and direction of compression with substantial agreements (κ = 0.65 and 0.62, respectively), whereas the lowest was obtained for right‐sided foraminal stenosis (κ = 0.39, fair agreement). For both imaging techniques, the highest and lowest interobserver agreements were recorded for the main site of compression and degree of articular joint proliferation, respectively. While different observers frequently agree on the main site of compression using both imaging techniques, there is considerable variation between modalities and among observers when assessing articular process characteristics and foraminal stenosis. Caution should be exerted when comparing image interpretations from multiple observers.     

The inter- and intra-observer reliability of a locomotion scoring scale for sheep

A seven point locomotion scoring scale, ranging from 0=normal locomotion to 6=unable to stand or move, has been developed. To test the between and within observer reliability of the scale, 65 movie clips of sheep with normal and varying degrees of abnormal locomotion were made. Three observers familiar with sheep locomotion were trained to read the movie clips. Thirty clips were randomly selected and used to test between and within observer agreement. There was high inter-(intra-class correlation coefficient [ICC]=0.93, weighted kappa [kappa(w)]=0.93) and intra-(ICC=0.90, kappa(w)=0.91) observer reliability, with no evidence of observer bias. The main between score differences were for scores 0 (normal) and 1 (uneven posture and shortened stride but no head movement). The results indicate that the locomotion scoring scale using groups of defined observations for each point on the scale was reliable and may be a useful research tool to identify and monitor locomotion in individual sheep when used by trained observers.     

Intra- and interobserver measurement variability of tibial plateau slope from lateral radiographs in dogs

Measurement of the tibial plateau slope from lateral hind-limb radiographs is a preoperative requirement when performing tibial plateau leveling osteotomy (TPLO) for repair of the cruciate-deficient stifle in dogs. Two measurements of the tibial plateau slope in 312 stifles of 156 dogs were taken from lateral radiographs by each of three observers with varying degrees of experience in the measurement method. Intraobserver variability was +/-3.4 degrees, and interobserver variability was +/-4.8 degrees. No significant differences were identified for the intraobserver measurements; however, in evaluating interobserver variability, a significant difference was found between the inexperienced observer and the two experienced observers.     

TWO-DIMENSIONAL ECHOCARDIOGRAPHY IN THE NORMAL CAT

Two-dimensional echocardiography (2DE) and M-mode echocardiography were used to image the heart of 13 clinically healthy cats. Seven awake cats and six cats tranquilized with a combination of acetylpromazine and ketamine were studied. Six cats were studied by 2DE on 3 consecutive days to assess repeatability of the study. Long-axis and short-axis echocardiographic tomograms were obtained from the right parasternal location, and these images were used to determine internal cardiac dimensions, ventricular and septal wall thicknesses, repeatability of the study, and interobserver variability. Some but not all parameters were significantly (P < 0.05) related to body weight. Significant correlations (P <0.05) were found between measurements obtained by long-axis and by short-axis image planes. Comparison of parameters measured by 2DE and M-mode echocardiography demonstrated minimal differences between mean values. Repeatability of the 2DE study was good with 14 of 16 parameters having a mean percent error less than 10%. Interobserver variability was acceptable for some but not all parameters. The study indicates that repeatable 2DE tomograms can be obtained in the cat and that quantitation of cardiac anatomy is possible with this imaging technique.     

Assessment of the variation in American Society of Anaesthesiologists Physical Status Classification assignment in small animal anaesthesia

ObjectiveTo evaluate the interobserver variability in the assignment of the American Society of Anesthesiologists Physical Status Classification (ASA-PSC) to compromised small animal patients amongst a group of veterinary anaesthetists.Study designAnonymous internet survey.AnimalsHypothetical case presentations.MethodsSixteen hypothetical small animal cases with differing degrees of physiological or patho-physiological compromise were presented as part of an internet survey. Respondents were asked to assign a single ASA-PSC to each case and also to answer a number of demographic questions. ASA-PSC scores were considered separately and then grouped as scores of I–II and III–V. Agreement was analysed using the modified kappa statistic for multiple observers. Data were then sorted into various demographic groups for further analysis.ResultsThere were 144 respondents of which 60 (～42%) were anaesthesia diplomates, 24 (～17%) were post-residency (nondiploma holders), 24 (～17%) were current anaesthesia residents, 21 (～15%) were general practitioners, 12 (～8%) were veterinary nurses or technicians, and 3 (～2%) were interns. Although there was a majority agreement (>50% in a single category) in 15 of the 16 cases, ASA-PSC were spread over at least three ASA-PS classifications for every case. Overall agreement was considered only fair (κ = 0.24, mean ± SD agreement 46 ± 7%). When comparing grouped data (ASA-PSC I–II versus III-V) overall agreement remained fair (κ = 0.36, mean ± SD agreement 69 ± 19%). There was no difference in ASA-PSC assignment between any of the demographic groups investigated.Conclusions and clinical relevanceThis study suggests major discrepancies can occur between observers given identical information when using the ASA-PSC to categorise health status in compromised small animal patients. The significant potential for interobserver variability in classification allocation should be borne in mind when the ASA-PSC is used for clinical, scientific and statistical purposes.