A comparison of the NIRUDAK models and WHO algorithm for dehydration assessment in older children and adults with acute diarrhoea: a prospective, observational study

Abstract

Background: Despite the importance of accurate and rapid assessment of hydration status in patients with acute diarrhoea, no validated tools exist to help clinicians assess dehydration severity in older children and adults. The aim of this study is to validate a clinical decision support tool (CDST) and a simplified score for dehydration severity in older children and adults with acute diarrhoea (both developed during the NIRUDAK study) and compare their accuracy and reliability with current WHO guidelines.

Methods: A random sample of patients aged 5 years or older presenting with diarrhoea to the icddr,b Dhaka Hospital in Bangladesh between Jan 30 and Dec 13, 2022 were included in this prospective cohort study. Patients with fewer than three loose stools per day, more than 7 days of symptoms, previous enrolment in the study, or a diagnosis other than acute gastroenteritis were excluded. Patients were weighed on arrival and assessed separately by two nurses using both our novel clinical tools and WHO guidelines. Patients were weighed every 4 h to determine their percent weight change with rehydration, our criterion standard for dehydration. Accuracy for the diagnosis of dehydration category (none, some, or severe) was assessed using the ordinal c-index (ORC). Reliability was assessed by comparing the prediction of severe dehydration from each nurse's independent assessment using the intraclass correlation coefficient (ICC).

Findings: 1580 patients were included in our primary analysis, of whom 921 (58·3%) were female and 659 (41·7%) male. The ORC was 0·74 (95% CI 0·71-0·77) for the CDST, 0·75 (0·71-0·78) for the simplified score, and 0·64 (0·61-0·67) for the WHO guidelines. The ICC was 0·98 (95% CI 0·97-0·98) for the CDST, 0·94 (0·93-0·95) for the simplified score, and 0·56 (0·52-0·60) for the WHO guidelines.

Interpretation: Use of our CDST or simplified score by clinicians could reduce undertreatment and overtreatment of older children and adults with acute diarrhoea, potentially reducing morbidity and mortality for this common disease.

Funding: US National Institutes of Health.

Translation: For the Bangla translation of the abstract see Supplementary Materials section.

Figure 1:

Patient enrolment

Figure 2:. Comparison of ORC computed for NIRUDAK full model, NIRUDAK simplified model, and WHO IMAI algorithm

Each histogram shows the distribution of ORC values derived from 1000 bootstrap samples. The bar at the top of each histogram gives the mean ORC and a 95% CI derived from the bootstraps. The grey bars signify the WHO IMAI algorithm, the light purple bars signify the full NIRUDAK model, and the blue bars signify the simplified NIRUDAK model; the dark purple colour denotes where the light purple and blue bars overlap. IMAI=Integrated Management of Adult and Adolescent Illnesses. ORC=ordinal c-index.

Figure 3:

Results of usability surveys showing the number of nurses agreeing or disagreeing with each statement based on their level of experience with the mobile health clinical decision support tool