Title: The Role of the Dengue Severity Scale in Predicting Prognosis in Patients Admitted to the Medicine Wards of a Tertiary Care Hospital during an Epidemic
Authors: Arun Peter Pathrose, Dr Jayamohan, Dr Anna Mathew, John Michael Raj
DOI: https://dx.doi.org/10.18535/jmscr/v8i5.22
Abstract
Background: Dengue is most rapidly spreading mosquito-borne viral disease in the world with approximately 1 million cases reported annually. Ko-Chang et al developed a clinical scoring system to predict dengue severity, based on clinical characteristics and laboratory investigations. The WHO 1997 classification of Dengue is considered as the golden standard.
Objectives
- To classify patients with dengue into uncomplicated and severe dengue using the Dengue Severity Scale & WHO Classification.
- To determine the sensitivity, specificity, positive predictive value & negative predictive value of Dengue Severity Scale.
Methodology: This is a cross sectional study done in May - June 2017. Consenting patients admitted with proven dengue (NS1 antigen positive) who fulfilled the study selection criteria were enrolled in the study. Sample size calculated for a confidence level of 95% and precision of 5% was 130 patients to find the sensitivity of the Dengue Severity Scale for predicting the prognosis of dengue.
The socio-demographic and clinical data was collected, and patients were classified to Group A (mild) and B (severe) using the Dengue Severity Scale (DSS) and the traditional WHO Scale (WHOS). In the DSS, the cut-off value is 6.Maximum score is 15. The DSS scores were compared to the gold standard, the WHOS and the sensitivity, specificity and positive predictive value (PPV) and the negative predictive values (NPV) were obtained.
Results: Of the 130 patients recruited to the study, 73 (56.2%) were male and 57(43.8%) were female. Most of the participants 114 (87.7%) belonged to the lower middle or lower socio-economic group.
The DSS scoring system had a sensitivity of 91.70%, specificity of 4.80%, PPV of 83.30% and NPV of 10.00% In the DSS, 120(92.3%) patients were in the severe dengue group and 10 (7.7%) were in the uncomplicated dengue group. The upper limit of the DSS score was 13 and the lower limit was 4.
By the WHO Scale, of the 130 patients who had dengue, there were 21 (16.2%] in the uncomplicated ormild dengue group and 108 (83.4%) patients were in the severe dengue group.
Conclusions: From this study we see male patients had a greater risk of developing severe dengue. Greater number of patients were grouped as severe dengue in the DSS compared to the WHOS, making the probability of drtecting severe dengue higher with the DSS Score. The DSS scale has a higher sensitivity so it is useful in detecting severe cases of dengue but as the specificity is low it may not be as useful in ruling out other types of fever. We hope this study will evolve into a good screening tool for detecting patients who may have severe dengue so that focussed care and monitoring may be given to them.
Keywords: Dengue fever, Dengue Severity Scale, DSS, WHO Scale, Predicting prognosis.
References
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- Sample size measured using nMaster Sample Size software produced by Biostatistics Department of Biostatistics, Christian Medical College, Vellore 632 004. Tamil Nadu. India.