[Development of a risk assessment scale and test of its validity and reliability for venous thromboembolism in adult burn patients].

Objective: To develop a venous thromboembolism (VTE) risk assessment scale for adult burn patients and to test its reliability and validity. Methods: The scale research method and multi-center cross-sectional survey method were used. Based on the results of literature analysis method and brain-storming method, the letter questionnaire for experts was formulated. Then 27 experts (9 doctors of burn department, 9 vascular surgeons, and 9 nurses) were performed with two rounds of correspondences by Delphi method, and the reliability of the experts was analyzed. The weight of each item was determined by optimal sequence diagram method and expert importance evaluation to form the VTE Risk Assessment Scale for Adult Burn Patients. A total of 223 adult burn inpatients, who were admitted to 5 tier Ⅲ grade A general hospitals including the Affiliated Hospital of Southwest Medical University, West China Hospital of Sichuan University, the Affiliated Hospital of North Sichuan Medical College, Nanchong Central Hospital, and the Second People's Hospital of Yibin City from October 1st 2019 to January 1st 2020, were selected as respondents by convenience sampling method. The first assessment was performed with the VTE Risk Assessment Scale for Adult Burn Patients within 24 hours of admission of patients, and real-time assessment was performed as the patients' condition and treatment changed. The highest value was taken as the result. Correlation coefficient method and critical ratio method were used for item analysis; Cronbach's α coefficient was used to test the internal consistency of scale; content validity index was used to analyze the content validity of the scale, and receiver's operating characteristic (ROC) curve was drawn to test the predictive validity of the scale. Data were statistically analyzed with chi-square test, Pearson correlation analysis, independent sample t test, and Z test. Results: As four questionnaires in the first round of correspondence were rejected as unqualified, and another 4 experts were selected for the 2 rounds of correspondence. Most of them were aged 41 to 50 years with postgraduate degrees, engaging in the current profession for 11 to 30 years, and all of them had professional titles of associate senior or above. The scale, constructed through literature analysis, group brainstorming, and two rounds of correspondence, includes 3 primary items and 50 secondary items. In the first round of correspondence, the recovery rate of valid questionnaires and the ratio with expert opinions were 85.2% (23/27) and 47.8% (11/23), respectively. In the second round of correspondence, the recovery rate of valid questionnaires and the ratio with expert opinions were 100% (27/27) and 11.1% (3/27), respectively. The average collective authority coefficients of experts were both 0.90 in the 2 rounds of correspondence. The mean values of importance assignment, full score rate, and selection rate above 4 were 4.21, 52.5%, and 77.2%, respectively, in the first round of correspondence, and 4.28, 45.2%, and 85.8%, respectively, in the second round of correspondence. The mean coefficients of variation and the mean value of Kendall's coefficient of harmony for each item were 0.21 and 0.30 in the first round of correspondence, respectively, and 0.16 and 0.36 in the second round of correspondence, respectively. In the first and second rounds of correspondence, the Kendall's coefficients of harmony of 3 primary items (age and underlying diseases, burn injury factors, and burn treatment factors) and total secondary items were statistically significant (with χ2 values of 121.46, 107.09, 116.00, 331.97, 169.97, 152.12, 141.54, and 471.70, P<0.01). The weights of primary items for age and underlying diseases, burn injury factors, and burn treatment factors were 0.04, 0.05, and 0.07, respectively. The weights of secondary items ranged from 0.71 to 0.99, with assigned values of 3 to 6. The total burn area of 223 patients ranged from 1% to 89% total body surface area, and the patients were aged from 19 to 96 years, with the risk assessment score from 0 to 98. Nine patients developed VTE, with a risk assessment score of 41 to 90. The scores of 37 items were significantly positively correlated with the total score of scale (with r values of 0.14 to 0.61, P<0.05 or P<0.01), and the items were retained. There were 36 secondary items with statistically significant differences between the patients in high-score group and low-score group (with Z values of -4.88 to -2.09, t values of -11.63 to -2.09, P<0.05 or P<0.01), and the items were retained. The total Cronbach's α coefficient of scale was 0.88. The total content validity index of scale was 0.95. The optimal threshold of the scale for the diagnosis of VTE was 40, at which the sensitivity was 88.9%, the specificity was 87.4%, the Youden index was 0.87, and the area under the ROC curve was 0.96 (with 95% confidence interval of 0.93 to 0.99, P<0.01). Conclusions: The age and underlying diseases, burn injury factors, and burn treatment factors are the risk factors for VTE in adult burn patients. The VTE risk assessment scale for adult burn patients developed based on these factors has good reliability and validity, and provide good reference value for clinical VTE risk assessment.目的： 研制成年烧伤患者静脉血栓栓塞（VTE）风险评估量表并检验其信效度。 方法： 采用量表研究法及多中心横断面调查法。以文献分析法和头脑风暴法结果为基础，制订专家函询问卷。对27名专家（烧伤科医师、血管外科医师、护士各9名）行2轮德尔菲法函询并分析专家可靠性，采用优序图法和专家重要性评价确定各条目的权重，形成成年烧伤患者VTE风险评估量表。采用便利抽样法，将2019年10月1日—2020年1月1日在西南医科大学附属医院、四川大学华西医院、川北医学院附属医院、南充市中心医院及宜宾市第二人民医院5所三级甲等综合医院住院的223例成年烧伤患者作为调查对象。在患者入院24 h内采用成年烧伤患者VTE风险评估量表进行首次评估，在患者病情、治疗变化时进行实时评估，结果取最高值。采用相关系数法和临界比法进行量表项目分析，采用克龙巴赫α系数检验量表的内部一致性，采用内容效度指数分析量表的内容效度，绘制受试者操作特征（ROC）曲线检验量表的预测效度。对数据行χ2检验、Pearson相关分析、独立样本t检验、Z检验。 结果： 因第1轮函询中有4份问卷不合格予剔除，重新遴选4名专家进行2轮函询。27名专家年龄以41~50岁居多，绝大多数为研究生学历，均为副高级及以上专业技术职称，从事当前专业年限多在11~30年之间。通过文献分析、小组头脑风暴和2轮函询构建的量表包括3个一级条目、50个二级条目。第1轮函询的有效问卷回收率为85.2%（23/27）、专家提出意见比例为47.8%（11/23），第2轮函询的有效问卷回收率为100%（27/27），专家提出意见比例为11.1%（3/27）。专家集体权威程度均值在2轮函询中均为0.90。各条目重要性赋值均值、满分率均值、4分以上选择率均值在第1轮函询中分别为4.21、52.5%、77.2%，在第2轮函询中分别为4.28、45.2%、85.8%。各条目的变异系数均值、肯德尔和谐系数均值在第1轮函询中分别为0.21、0.30，在第2轮函询中分别为0.16、0.36。第1、2轮函询中，3个一级条目（年龄与基础疾病、烧伤伤情因素、烧伤救治因素）和总二级条目的肯德尔和谐系数检验均具有统计学意义（χ2值分别为121.46、107.09、116.00、331.97，169.97、152.12、141.54、471.70，P<0.01）。年龄与基础疾病、烧伤伤情因素、烧伤救治因素的一级条目权重分别为0.04、0.05和0.07，二级条目权重为0.71~0.99、赋值为3~6分。223例患者烧伤总面积为1%~89%体表总面积，年龄为19~96岁，风险评估得分为0~98分。9例患者有VTE形成，风险评估得分为41~90分。37个条目得分与量表总得分呈明显正相关（r值为0.14~0.61，P<0.05或P<0.01），予以保留。高分组和低分组患者有36个二级条目得分差异明显（Z值为-4.88~-2.09，t值为-11.63~-2.09，P<0.05或P<0.01），予以保留。本量表总的克龙巴赫α系数为0.88。该量表总的内容效度指数为0.95。该量表评分诊断VTE的最佳阀值为40分，此时敏感度为88.9%、特异度为87.4%、约登指数为0.87，ROC曲线下面积为0.96（95%置信区间为0.93~0.99，P<0.01）。 结论： 年龄与基础疾病、烧伤伤情及烧伤救治因素是成年烧伤患者发生静脉血栓的危险因素，基于这些因素研制的成年烧伤患者VTE风险评估量表具有良好的信效度，对临床VTE风险评估具有较好的参考价值。.