Clinical risk-scoring algorithm to forecast scrub typhus severity

Abstract

PurposeTo develop a simple risk-scoring system to forecast scrub typhus severity.Patients and methodsSeven years’ retrospective data of patients diagnosed with scrub typhus from two university-affiliated hospitals in the north of Thailand were analyzed. Patients were categorized into three severity groups: nonsevere, severe, and dead. Predictors for severity were analyzed under multivariable ordinal continuation ratio logistic regression. Significant coefficients were transformed into item score and summed to total scores.ResultsPredictors of scrub typhus severity were age >15 years, (odds ratio [OR] =4.09), pulse rate >100/minute (OR 3.19), crepitation (OR 2.97), serum aspartate aminotransferase >160 IU/L (OR 2.89), serum albumin ≤3.0 g/dL (OR 4.69), and serum creatinine >1.4 mg/dL (OR 8.19). The scores which ranged from 0 to 16, classified patients into three risk levels: non-severe (score ≤5, n=278, 52.8%), severe (score 6–9, n=143, 27.2%), and fatal (score ≥10, n=105, 20.0%). Exact severity classification was obtained in 68.3% of cases. Underestimations of 5.9% and overestimations of 25.8% were clinically acceptable.ConclusionThe derived scrub typhus severity score classified patients into their severity levels with high levels of prediction, with clinically acceptable under- and overestimations. This classification may assist clinicians in patient prognostication, investigation, and management. The scoring algorithm should be validated by independent data before adoption into routine clinical practice.

Clinical score to differentiate scrub typhus and dengue: A tool to differentiate scrub typhus and dengue

“…[ 3 ] Predictors of severity of scrub typhus and dengue and scoring systems to identify severe illness have been described by many researchers in the past. [ 15 16 17 18 ] A systematic review identified 15 studies that have examined the differences in clinical and laboratory features between dengue and other febrile illnesses. [ 19 ] Chrispal et al .…”

Validation of a clinical risk-scoring algorithm for severe scrub typhus

“…The overall proportion of correct classifications was somewhat lower (61.0% vs 68.3%), but overestimation was higher (27.0% vs 25.8%), which may be considered more beneficial to the patients. 17 …”

“…Data were retrieved retrospectively from the medical files of scrub typhus patients. The criteria for inclusion were similar to those used in the previous study 17 and were based on history of disease exposure and presentation with acute fever and at least one of the following signs and symptoms: myalgia, headache, conjunctival injection, cough, profuse sweating, maculopapular rash, and/or lymphadenopathy accompanied by the presence of eschar, and/or a positive immuno-chromatographic test for scrub typhus. 18…”

“…The patient risk scores were assigned following the scoring scheme previously developed ( Table 1 ). 17 Patients were categorized into three severity groups: 1) non-severe, 2) severe, and 3) fatal, as described. The predictive performance of the scores was compared by analysis of the area under the receiver-operating characteristic curve (AuROC).…”

“…Previously, we developed a clinical risk-scoring algorithm for scrub typhus severity comprising six predictors from routine practice. 17 The objective of the study reported here was to validate the risk-scoring algorithm developed earlier with an independent dataset obtained from similar patients from a few years later.…”