Diagnostic accuracy of Sultan's scoring criteria in confirmed cases of measles

Abstract

World Health Organization (WHO) clinical case definition for the diagnosis of measles lacks diagnostic accuracy. We thus propose two separate scoring criteria for the diagnosis of acute and post measles cases. This study was conducted to determine the diagnostic accuracy of scoring criteria in confirmed cases of measles. This cross-sectional validation study was conducted in the Department of Paediatrics Unit-I, King Edward Medical University, Lahore, Pakistan, from March-August 2009. Sixty-one cases fulfilling the WHO clinical case definition of measles were included in the study, and divided into Group A (Acute measles) and Group B (Post measles). A separate criterion was used for each. Positive Serology (IgM) was taken as confirmed cases. At scores ≥ 3, ≥ 4 and ≥ 5, the sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) were calculated. Appropriate statistical tests were applied. In Group A, out of 36 cases, 28 (78%) had total score ≥ 4, whereas IgM was positive in 24 (67%). The scoring criteria had sensitivity, specificity, PPV and NPV of 100%, 66.7%, 86% and 100% respectively. In Group B, out of 25 cases, 23 (92%) had a total score ≥ 4 whereas IgM was positive in 22 (88%) cases. The scoring criteria had sensitivity, specificity, PPV and NPV of 100%, 66.7%, 96% and 100% respectively. The measure and strength of association were statistically significant for both Groups. At scores ≥ 3 and ≥ 5, sensitivity, specificity and predictive values were not statistically significant in either group. This study has shown that the criteria for the diagnosis of acute and post measles cases at a score ≥ 4 are valid to make a clinical diagnosis.

Keywords

Acute measles - measles IgM - post measles - scoring criteria