Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
Chin Med J (Engl). 2019 Jun 20;132(12):1441-1447. doi: 10.1097/CM9.0000000000000261.
Diagnosis of heparin-induced thrombocytopenia (HIT) is challenging. This study aimed to compare the diagnostic performance of HIT expert probability (HEP) and 4T scores, and to evaluate the inter-observer reliability for the 4T score in a clinical setting.
This prospective study included HIT-suspected patients between 2016 and 2018. Three hematologists assessed the HEP and 4T scores. Correlations between scores and anti-platelet factor 4 (anti-PF4)/heparin antibodies were evaluated. Receiver operating characteristic curves and area under the curve (AUC) were used to assess the predictive accuracy of these two scoring models. The intraclass correlation coefficient (ICC) was used to assess the inter-observer agreement of 4T scores between residents and hematologists.
Of the 89 subjects included, 22 (24.7%) were positive for anti-PF4/heparin antibody. The correlations between antibody titer and either HEP or 4T scores were similar (r = 0.392, P < 0.01 for the HEP score; r = 0.444, P < 0.01 for the 4T score). No significant difference in the diagnostic performance was displayed between these two scores (AUC for the HEP score: 0.778 vs. AUC for the 4T score: 0.741, P = 0.357). Only 72 4T scores were collected from the residents, with a surprisingly low percentage of observers (43.1%) presenting the four individual item scores which made up their 4T score. The AUC of 4T score assessed by residents and hematologists was 0.657 (95% confidence interval [CI]: 536-0.765) and 0.780 (95% CI: 0.667-0.869, P < 0.05), respectively. The ICC of 4T score between residents and hematologists was 0.49 (95% CI: 0.29-0.65, P < 0.01), demonstrating a fair inter-observer agreement.
The HEP score does not display a better performance for predicting HIT than the 4T score. With the unsatisfactory completion rate, the inter-observer agreement of 4T score in a tertiary hospital is fair, underscoring the necessity for continuing education for physicians.
肝素诱导的血小板减少症（HIT）的诊断具有挑战性。本研究旨在比较 HIT 专家概率（HEP）和 4T 评分的诊断性能，并评估 4T 评分在临床环境中的观察者间可靠性。
这项前瞻性研究纳入了 2016 年至 2018 年间疑似 HIT 的患者。三位血液科医生评估了 HEP 和 4T 评分。评估了评分与抗血小板因子 4（抗 PF4）/肝素抗体之间的相关性。使用受试者工作特征曲线和曲线下面积（AUC）评估这两种评分模型的预测准确性。使用组内相关系数（ICC）评估住院医师和血液科医生之间 4T 评分的观察者间一致性。
在 89 例受试者中，有 22 例（24.7%）抗 PF4/肝素抗体阳性。抗体滴度与 HEP 评分或 4T 评分之间的相关性相似（HEP 评分：r=0.392，P<0.01；4T 评分：r=0.444，P<0.01）。这两种评分之间的诊断性能无显著差异（HEP 评分的 AUC：0.778 与 4T 评分的 AUC：0.741，P=0.357）。仅从住院医师那里收集了 72 个 4T 评分，令人惊讶的是，只有 43.1%的观察者报告了构成其 4T 评分的四个单独项目评分。住院医师和血液科医生评估的 4T 评分 AUC 分别为 0.657（95%置信区间[CI]：0.536-0.765）和 0.780（95%CI：0.667-0.869，P<0.05）。住院医师和血液科医生之间的 4T 评分 ICC 为 0.49（95%CI：0.29-0.65，P<0.01），表明观察者间一致性尚可。
HEP 评分在预测 HIT 方面的表现并不优于 4T 评分。由于完成率不理想，三级医院 4T 评分的观察者间一致性尚可，这突显了对医生进行继续教育的必要性。
