Hewetson Michael, Venner Monica, Volquardsen Jan, Sykes Ben William, Hallowell Gayle Davina, Vervuert Ingrid, Fosgate Geoffrey Theodore, Tulamo Riitta-Mari
Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire, AL9 7TA, UK.
Acta Vet Scand. 2018 Apr 13;60(1):24. doi: 10.1186/s13028-018-0377-5.
Equine gastric ulcer syndrome is an important cause of morbidity in weanling foals. Many foals are asymptomatic, and the development of an inexpensive screening test to ensure an early diagnosis is desirable. The objective of this study was to determine the diagnostic accuracy of blood sucrose for diagnosis of EGUS in weanling foals.
45 foals were studied 7 days before and 14 days after weaning. The diagnostic accuracy of blood sucrose for diagnosis of gastric lesions (GL); glandular lesions (GDL); squamous lesions (SQL) and clinically significant gastric lesions (CSL) at 45 and 90 min after administration of 1 g/kg of sucrose via nasogastric intubation was assessed using ROC curves and calculating the AUC. For each lesion type, sucrose concentration in blood was compared to gastroscopy; and sensitivities (Se) and specificities (Sp) were calculated across a range of sucrose concentrations. Cut-off values were selected manually to optimize Se. Because of concerns over the validity of the gold standard, additional Se, Sp, and lesion prevalence data were subsequently estimated and compared using Bayesian latent class analysis. Using the frequentist approach, the prevalence of GL; GDL; SQL and CSL before weaning was 21; 9; 7 and 8% respectively; and increased to 98; 59; 97 and 82% respectively after weaning. At the selected cut-off, Se ranged from 84 to 95% and Sp ranged from 47 to 71%, depending upon the lesion type and time of sampling. In comparison, estimates of Se and Sp were consistently higher when using a Bayesian approach, with Se ranging from 81 to 97%; and Sp ranging from 77 to 97%, depending upon the lesion type and time of sampling.
Blood sucrose is a sensitive test for detecting EGUS in weanling foals. Due to its poor specificity, it is not expected that the sucrose blood test will replace gastroscopy, however it may represent a clinically useful screening test to identify foals that may benefit from gastroscopy. Bayesian latent class analysis represents an alternative method to evaluate the diagnostic accuracy of the blood sucrose test in an attempt to avoid bias associated with the assumption that gastroscopy is a perfect test.
马胃溃疡综合征是断奶幼驹发病的重要原因。许多幼驹没有症状，因此开发一种廉价的筛查试验以确保早期诊断很有必要。本研究的目的是确定血液蔗糖检测断奶幼驹马胃溃疡综合征（EGUS）的诊断准确性。
对45匹幼驹在断奶前7天和断奶后14天进行了研究。通过鼻胃管给予1g/kg蔗糖后45分钟和90分钟时，使用ROC曲线并计算AUC，评估血液蔗糖检测胃病变（GL）、腺性病变（GDL）、鳞状病变（SQL）和具有临床意义的胃病变（CSL）的诊断准确性。对于每种病变类型，将血液中的蔗糖浓度与胃镜检查结果进行比较，并在一系列蔗糖浓度范围内计算敏感性（Se）和特异性（Sp）。手动选择临界值以优化敏感性。由于担心金标准的有效性，随后使用贝叶斯潜在类别分析估计并比较了额外的敏感性、特异性和病变患病率数据。采用频率学派方法，断奶前GL、GDL、SQL和CSL的患病率分别为21%、9%、7%和8%；断奶后分别增至98%、59%、97%和82%。在选定的临界值下，敏感性范围为84%至95%，特异性范围为47%至71%，具体取决于病变类型和采样时间。相比之下，使用贝叶斯方法时，敏感性和特异性的估计值始终较高，敏感性范围为81%至97%；特异性范围为77%至97%，具体取决于病变类型和采样时间。
血液蔗糖检测是检测断奶幼驹EGUS的一种敏感试验。由于其特异性较差，预计蔗糖血液检测不会取代胃镜检查，但它可能是一种临床上有用的筛查试验，用于识别可能从胃镜检查中受益的幼驹。贝叶斯潜在类别分析是评估血液蔗糖检测诊断准确性的一种替代方法，旨在避免因假设胃镜检查是完美检测而产生的偏差。
