[Study on the score criteria of severe hand, foot and mouth disease cases]

To explore the score criteria of severe hand, foot and mouth disease (HFMD) cases and to provide evidence for unified criteria and treatment on severe HFMD cases.

All severe cases and partial mild cases reported by two designated hospitals of HFMD in Fuyang during March to June, 2008 were scored by the methods of criteria constructed in advance. ROC curve was adopted to evaluate the score criteria and the gold standard was defined according to ICU, intubation and clinical outcomes, etc. Sensitivity, specificity and Youden's index were used to determine the division scores on critical, severe and mild cases.

97% of the cases (34 cases) were scored less than 6 points. 88% of cases (24 cases) who were intubated or mechanical ventilated had the scores of 6 points or higher. 79% of deaths (11 cases) were scored 10 points or higher. The area of receiver operation characteristic (ROC) curve was 0.90 (95%CI: 0.83 - 0.98) between severe and mild cases and the area of ROC curve was 0.95 (95%CI: 0.92 - 0.98) between critical and severe, mild cases. When comprehensively considering the sensitivity and specificity, severe cases were best judged when score was 4 points (sensitivity, specificity and Youden's index were 0.94, 0.68 and 0.62 respectively). When score was 6 points, critical cases were judged very well (sensitivity, specificity and Youden's index were 0.92, 0.84 and 0.76 respectively).

Score criteria could be quantified to determine the degree of seriousness and with high-value for diagnosis on HFMD.