ABSTRACT
Objective To investigate the risk factors of severe hand,foot and mouth disease (HFMD).Methods 175 severe cases of HFMD and 183 mild cases of HFMD in the same period were randomly selected.Single factor analysis was first performed between severe and mild cases on age,gender,residence,symptoms,signs and laboratory examinations,etc,to screen out the related risk factors which P value ＜ 0.05.Then,binary logistic regression analysis was carried out to determine risk factors most related to severe HFMD.Finally,receiver operating characteristic curve (ROC) analysis was performed on severe HFMD related risk factors.Results Single factor analysis showed that there were obvious differences between children with mild HFMD and those with severe HFMD in the factors like difficulty in breathing,walking instability,vomiting,limb shaking,disturbance of consciousness,convulsions,cold sweat and weakness,thermal process,the degree of fever,pulmonary rales,heart rate,serum EV71 antibody,circulatory failure,leukocyte count,platelet count,neutrophil ratio,CRP,blood glucose,etc (x2 =15.236,19.819,33.823,52.670,12.984,10.180,29.318,52.932,34.544,14.615,46.633,31.407 and 5.303,t =3.184,3.144,2.256,2.244 and 2.828,,all P ＜0.05).Binary logistic regression analysis showed that the thermal process,startle tremor or limb jitter,serum EV71 antibody,vomiting,fever,neutrophil ratio were the related risk factors of severe HFMD (B value =2.605,2.129,1.409,1.185,0.841 and 0.103,all P ＜ 0.05).ROC analysis showed that the areas under the curve of the predicted probability and thermal process were larger than any other risk factors [(95％ CI (0.888 ～ 0.961) and (0.818 ～ 0.920)],and thus had better diagnostic values.Conclusion Children under 3 years old were the high risk population of HFMD.Such clinical symptoms as persistent high fever,vomiting,startle tremor orlimb jitter,EV71 antibody in serum and increasing neutrophil ratio were risk factors for severe HFMD.The predicted probability had more diagnostic value than any other risk factors.