Development Of Extracorporeal Circulation Coagulation Risk Assessment Scale For Continuous Blood Purification Patients

Objective:To develop an extracorporeal circulation coagulation risk assessment scale for patients with continuous blood purification,and test its reliability and validity and determine the risk level of coagulation,in order to offer a scientific and reliable assessment tool for clinical personnel to precisely identify and quantify the risk of extracorporeal circulation coagulation in patient with continuous blood purification.Methods:1.Preliminary construction and selection of the scale item pool: based on literature review,Meta analysis and clinical practice experience of the subject group,the item pool of continuous blood purification extracorporeal circulation coagulation risk assessment scale was initially developed.Objective sampling method was adopted to select clinical medical and nursing experts in the field of blood purification to carry out two rounds of expert consultation.After collating data and feedback,the project team prepared a draft of extracorporeal circulation coagulation risk assessment scale for patients with continuous blood purification.2.Reliability and validity test of scale: 270 patients who met the inclusion and exclusion criteria in a tertiary class A general hospital of Taiyuan city were retrospectively analyzed by using the draft of continuous blood purification extracorporeal circulation coagulation risk assessment scale.The critical ratio,correlation coefficient,Cronbach’s α coefficient and factor analysis were used to test the identification degree of items.Internal consistency reliability,content validity and structure validity were used to test the reliability and validity of the scale.The diagnostic threshold of the scale was determined by ROC curve,and the clotting risk level was defined by quartile method,and finally the extracorporeal circulation coagulation risk assessment scale for continuous blood purification patients was formed.Results:1.Results of the initial construction and screening of scale entries:(1)Fourteen risk factors were identified by meta-analysis,including age,agitation due to impaired consciousness,blood platelet count,hematocrit,serum ionized calcium concentration,activated partial thromboplastin time,prothrombin time,no anticoagulant,post-dilution modality,intermittent saline flush,ultrafiltration rate,transmembrane pressure,blood flow rate,moderate-severe access outflow dysfunction events.After discussion based on clinical experience,the subject group added items including BMI,CVVH treatment mode,infusion of blood products,pre-flush saline without heparin injection,major surgery within one month,underlying disease(multiple injuries,sepsis,hypertension,diabetes mellitus,coronary artery disease,malignant tumor,hyperlipidemia,severe pneumonia),the scale item pool consists of 27 items in 5 dimensions.(2)Results of expert consultation: the effective recall rate of the questionnaire after two rounds of consultation was 84.2% and 100%,the authority coefficients of expert comments were 0.887 and 0.903,and the coordination coefficients of expert views of scale dimensions and items were 0.324 and 0.400 and 0.332 and 0.432,respectively,significance test P<0.001.Four items(" hypertension ","diabetes mellitus","coronary artery disease" and "malignant tumor")were excluded in the two rounds of expert letter consultation,and two new items were added("disseminated intravascular coagulation","catheter patency assessment"),four items were retained after adjustment(" agitation due to impaired consciousness " was adjusted to " Richmond Agitation-Sedation Score";"Prothrombin Time grade entry ≥12s,<12s " changed to " ≥15s,<15 s ","major surgery within a month" changed to "major surgery within a month(>3 hours)";"infusion of blood products" was changed to "infusion of blood products(within 48 hours)",forming the first draft of continuous blood purification extracorporeal circulation coagulation risk assessment scale consisting of 25 items in 5 dimensions.2.Results of scale reliability and validity test: the formal scale included 21 items from 5 dimensions.The Cronbach’s α coefficients of the total scale were 0.881,and the Cronbach’s α coefficients of each dimension were 0.725,0.831,0.863,0.838 and 0.856,respectively.The content validity index of the scale was 0.960,and the content validity index of each item was 0.83～1.Exploratory factor analysis of structural validity extracted five common factors,and the cumulative variance contribution rate was66.164%.The area under ROC curve of the scale was 0.862(0.817-0.906),the diagnostic threshold was 9 points,and the corresponding sensitivity and specificity were 74.2% and85%,respectively.The risk of coagulation was defined as: 9～11 as low risk,12～20 as medium risk,and 21 or more as high risk.Conclusion:The extracorporeal circulation coagulation risk assessment scale for continuous blood purification patients includes 5 dimensions and 21 items with good reliability and validity,which can be used as a tool to assess the coagulation risk of extracorporeal circulation in patients with continuous blood purification and offer a scientific basis for clinical early pre-warning and intervention.