Intra-rater Variability of the Brussels Infants and Toddlers Stool Scale (BITSS) Using Photographed Stools

Area of Science:

• Pediatric Gastroenterology
• Clinical Assessment Tools

Background:

• Accurate stool consistency assessment is crucial for diagnosing and managing gastrointestinal issues in infants and toddlers.
• The Brussels Infants and Toddlers Stool Scale (BITSS) was developed to standardize stool consistency evaluation in non-toilet-trained children.

Purpose of the Study:

• To evaluate the intra-rater reliability of the BITSS among healthcare professionals (HCPs) and caregivers (CGs).
• To investigate potential learning effects associated with BITSS use.
• To determine the influence of photographic quality on BITSS intra-rater reliability.

Main Methods:

• HCPs and CGs assessed stool consistency from diaper photographs using the BITSS on two separate occasions.
• Intra-rater reliability was quantified using percentage of exact agreement and kappa (κ) values.
• Mixed linear models and generalized estimating equations were employed to analyze learning effects and the impact of photo quality.

Main Results:

• The BITSS demonstrated excellent intra-rater reliability for both HCPs (κ range: 0.64-0.78) and CGs (κ range: 0.68-0.94).
• A clinically insignificant learning effect was observed, with less than 1% improvement in classification accuracy per 50 photos.
• Higher agreement rates were noted for good quality photos compared to lower quality ones (HCPs: 80.3% vs 69.5%; CGs: 90.4% vs 86.3%).

Conclusions:

• The BITSS is a reliable tool for assessing stool consistency from photographs in infants and toddlers.
• Optimal photographic quality is essential for maximizing the reliability of BITSS assessments.
• The scale exhibits minimal learning curve effects, supporting its practical application by various users.