PoopMD, a Mobile Health Application, Accurately Identifies Infant Acholic Stools

<div><p>Biliary atresia (BA) is the leading cause of pediatric end-stage liver disease in the United States. Education of parents in the perinatal period with stool cards depicting acholic and normal stools has been associated with improved time-to-diagnosis and survival in BA. PoopMD is a mobile application that utilizes a smartphone’s camera and color recognition software to analyze an infant’s stool and determine if additional follow-up is indicated. PoopMD was developed using custom HTML5/CSS3 and wrapped to work on iOS and Android platforms. In order to define the gold standard regarding stool color, seven pediatricians were asked to review 45 photographs of infant stool and rate them as acholic, normal, or indeterminate. Samples for which 6+ pediatricians demonstrated agreement defined the gold standard, and only these samples were included in the analysis. Accuracy of PoopMD was assessed using an iPhone 5s with incandescent lighting. Variability in analysis of stool photographs as acholic versus normal with intermediate rating weighted as 50% agreement (kappa) was compared between three laypeople and one expert user. Variability in output was also assessed between an iPhone 5s and a Samsung Galaxy S4, as well as between incandescent lighting and compact fluorescent lighting. Six-plus pediatricians agreed on 27 normal and 7 acholic photographs; no photographs were defined as indeterminate. The sensitivity was 7/7 (100%). The specificity was 24/27 (89%) with 3/27 labeled as indeterminate; no photos of normal stool were labeled as acholic. The Laplace-smoothed positive likelihood ratio was 6.44 (95% CI 2.52 to 16.48) and the negative likelihood ratio was 0.13 (95% CI 0.02 to 0.83). kappa_user was 0.68, kappa_phone was 0.88, and kappa_light was 0.81. Therefore, in this pilot study, PoopMD accurately differentiates acholic from normal color with substantial agreement across users, and almost perfect agreement across two popular smartphones and ambient light settings. PoopMD may be a valuable tool to help parents identify acholic stools in the perinatal period, and provide guidance as to whether additional evaluation with their pediatrician is indicated. PoopMD may improve outcomes for children with BA.</p></div

Example of stool photographs presented to panel of pediatricians for development of gold standard.

<p>Example of stool photographs presented to panel of pediatricians for development of gold standard.</p

RGB hexcodes denoting the spectrum of abnormal and normal stool colors.

<p>RGB hexcodes denoting the spectrum of abnormal and normal stool colors.</p

Laboratory findings in DF and DHF.

<p>Cases compared using chi-square test, <i>p</i>- value <0.05 considered significant.</p

Cytokine levels (pg/ml) in early and late days of illness in DF and DHF patients.

<p>Scatter plot of levels of cytokine (pg/ml) in early (2–5) and late (6–15) days of illness. A) IFN-γ, B) TNF-α, C) IL-6 and D) IL-8. The two panels show DF and DHF cases. The mean levels are indicated with the red line. The cut-off (mean levels in healthy controls+2SD) for each cytokine is shown with a dashed line.</p

Demographics, Serotypes detected and disease categories.

<p>Demographics, Serotypes detected and disease categories.</p

Association of cytokine levels with clinical parameters of dengue patients.

<p>A. Association of levels of IFN-γ with ALT levels. B. Association of levels of IL-8 with ALT levels. C. Tukey box-whisker plot with median, range with the upper and lower quartiles and outliers of IL-8 levels in thrombocytopenic (platelet count <100,000) and non- thrombocytopenic (platelet count >100,000) dengue patients. A & B] Pearson correlation used for analysis, <i>p</i><0.05 considered significant. C] <i>p</i>-value calculated by ANOVA, <i>p</i><0.05 considered significant. Outliers showed as dots and those above the axis limit not shown in graph but included in analysis.</p

Levels of IFN-γ, TNF-α, IL-6 and IL-8 in DF and DHF patients.

<p>A. Mean with SEM levels (pg/ml) of cytokines. B. Number (%) of cases with increased (above cut-off) values of cytokines in DF/DHF. Analysis of variance was carried out for log transformed values of each cytokine and differences in groups analysed by using Tukey test.*<i>p</i>-value <0.05 when compared with controls. *<i>p</i>-value <0.05 when compared between DF and DHF. Comparison between number of cases for DF and DHF done using chi-square test. <i>p</i>-value <0.05 is shown.</p

Cytokine levels in primary and secondary DENV infections.

<p>Mean with SEM levels of four cytokines (pg/ml) in primary and secondary infections. Patients with IgM/IgG ≥1.78 had primary infections; IgM/IgG<1.78 had secondary infections. p-value calculated by analysis of variance of log transformed levels of cytokines. p<0.05 considered significant.</p

Age-wise distribution of DF and DHF cases.

<p>Number of dengue cases plotted according to age – groups.</p