Comparison Of The Reliability And Validity Of Two Risk Assessment Scales Among Hip/Knee Joint Replacement Patients

Objective The objectives of this study are to compare the reliability and validity of Autar scale and Wells scale for deep vein thrombosis among orthopedic joint replacement patients through a multicenter prospective follow-up study, to provide a more accurate and efficient tool to reduce the incidence of deep vein thrombosis for the department of orthopedics,to obtain the prevention of deep vein thrombosis among orthopedics joint replacement patients from multicenter hospitals, to provide further standardize of preventive measures of deep venous thrombosis.Methods A multicenter prospective follow-up study and convenience sample was used. In November 2014-May 2015,2 trained registered nurses assessmented the Autar scale and Wells scale in 331 orthopedic joint replacement patients before the 24 hours of operation,24 hours after surgery and the discharge day independently.1 trained registered nurse collected the informations of general datas and preventive measures. After 2 weeks,1 month and 3 months of patients discharged from the hospital, a telephone followed up. The Follow-up included patients with deep vein thrombosis, which standard was ultrasound. The primary end point of follow-up was the incidence of DVT, the secondary end points was deep vein thrombosis didn’t occur after 3 months discharged from hospital.Results:A total of 325 patients form 10 hospitals had suffered from deep vein thrombosis with the incidence of 10.77%. The Cronbach’ s alpha coefficients of Autar scale lied between 0.716-0.762 while Wells’s lied between 0.580-0.603. The Cronbach’s alpha coefficients of the Autar scale set in 0.601-0.786 when removing its each item at a time, while the coefficient came to the highest 0.786 when removing the item ’special risks’. The Cronbach’s alpha coefficients of Wells scale lied between 0.526-0.594 when removing its each item at a time, the coefficient became the highest 0.594 when removing the item ’bedtime≥3 days/surgery in 1 month’. Each Pearson correlation coefficient of Autar scale and Wells scale of the 3 times all showed statistical significance (r= 0.241～0.473,p<0.01). When Autar scale and Wells scale analyzed by Varimax, the overall cumulative variance contribution rate was respectively 66.735% and 59.598%(eigenvalues> 1). The factor loadings of Autar scale and Wells scale for each item spreaded in 0.303-0.775,0.321-0.985. The factors of the two scales were basically the same with the originals. The AUC of Autar Scale was 0.726-0.798, while the area reached the maximum on the discharge day and it was the minimum before the surgery.The AUC of Wells scale ranged from 0.568-0.628,in which the area was the maximum on discharge day and it was the minimum on before the surgery. Each P value of Autar scale on AUC of the 3 times was below 0.05. However, except before the surgery, P value of Wells scale on AUC of the 2 times was above 0.05, which meant a significant importance on diagnosis of deep venous thrombosis postoperatively. When Autar scale diagnosis value was 15 points and Wells scale diagnosis value was 2 points, the sensitivity and specificity were balanced.The prevention conditions of deep venous thrombosis among rthopedic joint replacement patients:Before the surgery,3.08% patients weared elastic stockings,0.62% patients used intermittent pneumatic pressure pump, 0.31% patients used foot pump,0.92% patients take medicine, the nurses assessmented 67.08% patients, and provided basic prevention for 24.62% patients, and provided health education for 27.08% patients. After surgery,3.08% patients weared elastic stockings,37.85% patients used intermittent pneumatic pressure pump,5.85% patients used foot pump,89.54% patients took medicine, the nurses assessmented 20.31% patients for bleeding risk, observed the clinic manifestation and provided health education for 65.23% patients. The nurses provided basic prevention for 31.38% patients and avoided transfusion of lower limbs on 89.54% patients。Conclusion:1. The Cronbach’s alpha of Autar scale for overall internal consistency was higher than that of Wells scale. The ’special risks’ of Autar scale and the ’bedtime≥ 3days/surgery in 1 month’ of Wells Scale were sugguested to be adjusted.2. The factor construct of Autar Scale was nearly the same with the original, which meant Autar Scale can forecast the risk of deep vein thrombosis. When Autar scale diagnosis value was 15 points and Wells scale diagnosis value was 2 points after the surgery, the sensitivity and specificity were balance. The sensitivity, specificity and AUC were higher than Wells. Autar scale can forecast deep vein thrombosis better than Wells scale.3. The prevention was not good in the department of orthopedics patients. The nurses must strengthen the cognition of DVT, use scales assessment high risk patients, combined mechanical prevention and medicine prevention in time and targeted to reduce the incidence of deep vein thrombosis.