Defining Pediatric Failure to Thrive in the Developed World: Validation of a Semi-Objective Diagnosis Tool

There is no concordance between current diagnostic criteria for failure to thrive (FTT). We analyzed validity of the Semi-Objective Failure to Thrive (SOFTT) diagnosis tool, which uses a combination of subjective and objective components to make the diagnosis of FTT. The tool was used to diagnose FTT in 94 patients who met 1 of 7 accepted criteria for FTT. Concurrent and predictive validity were demonstrated using anthropometric z-scores and change in anthropometric z-scores, respectively. SOFTT results correlated with differences in anthropometric z-scores for length ( P = .011), weight, weight-for-length, body mass index, mid-upper arm circumference, and triceps skinfold thickness ( P < .0001) between those diagnosed as normal and those with FTT. At follow-up, children with FTT compared with children rated as normal had significantly higher change in weight ( P ≤ .001) and body mass index ( P = .026) z-scores. The SOFTT tool leads to the accurate diagnosis of FTT demonstrated by concurrent and predictive validity.