BACKGROUND Unstimulated whole saliva (UWS) flow rate is one of the ACR/EULAR 2016 criteria for primary Sjögren's syndrome (pSS). With a single threshold of ≤ 0.1 mL/min, UWS flow does not take into account the age- and sex-related physiological variations. Furthermore, it has a low sensitivity for the diagnosis of pSS (about 50%), contrary to the screening test for xerophthalmia, Schirmer's test (sensitivity of about 70%). We aimed to identify UWS thresholds allowing better performances for a screening test for pSS comparable to Schirmer's test, and considering age- and sex-related variations. METHODS A prospective cohort of 185 patients with oral and/or ocular dryness was classified into 3 groups: men, women < 50 (< 50 years old), and women ≥ 50 (≥ 50 years old). The diagnostic performances of UWS flow rate in these groups were compared in terms of sensitivity, specificity, positive and negative predictive values, and ROC curves. The identification of thresholds that optimize diagnostic performances was carried out using Youden's index. RESULTS The diagnostic performances of UWS flow rate varied according to age and sex. UWS had poor diagnostic performances whatever the threshold in the women ≥ 50 group. The threshold of 0.2 mL/min had a sensitivity of ≥ 70% and a specificity of ≥ 50% in both men and women < 50 groups. In the whole population and compared to the current cutoff, a threshold of 0.2 mL/min increased sensitivity (+ 19.8%) and positive (+ 2.3%) and negative (+ 7.0%) predictive values, with a better specificity (65.2%) than Schirmer's test. CONCLUSION For objective assessment of xerostomia, raising the threshold of the UWS flow rate to 0.2 mL/min would optimize its screening performances for pSS.

中文翻译：

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不加刺激的全唾液流量用于诊断原发性干燥综合征：是否需要重新检查阈值？

背景技术未刺激的全唾液（UWS）流速是ACR / EULAR 2016年原发性干燥综合征（pSS）的标准之一。单一阈值≤0.1 mL / min，UWS流量​​不考虑与年龄和性别相关的生理变化。此外，它对pSS的诊断敏感性较低（约50％），与对干眼症的筛查试验，席尔默氏试验（敏感性约70％）相反。我们的目标是确定UWS阈值，以使pSS筛查测试的性能与Schirmer的测试相当，并考虑与年龄和性别相关的差异。方法将185名口腔干燥和/或眼部干燥患者的前瞻性队列分为3组：男性，女性<50岁（<50岁）和女性≥50岁（≥50岁）。在敏感性，特异性，阳性和阴性预测值以及ROC曲线方面比较了UWS流速在这些组中的诊断性能。使用Youden指数确定优化诊断性能的阈值。结果UWS流量​​的诊断性能随年龄和性别而变化。无论女性≥50组的阈值如何，UWS的诊断性能均较差。在<50组的男性和女性中，阈值0.2 mL / min的敏感性≥70％，特异性≥50％。在整个人群中，与当前临界值相比，阈值0.2 mL / min可提高灵敏度（+ 19.8％）和阳性（+ 2.3％）和阴性（+ 7.0％）预测值，特异性更高（65.2％）比Schirmer的测试要好。