Limitations of Dutch Growth Research Foundation Commercial Software Weight Velocity for Age Standard Deviation Score

Patient: Male, 1-year-old Final Diagnosis: Healthy Symptoms: None Medication:— Clinical Procedure: Foster care Specialty: Pediatrics and Neonatology OBJECTIVE: Rare disease BACKGROUND: The commercial software for hospitals, Weight Velocity for Age Standard Deviation Score (SDS(WVA)), claims to document the growth and development of children, although published details are unavailable. The statistics-derived parameter SDS(WVA) includes the weight velocity at age t, WV(t) (weight gained between t and (t–1.23) years, divided by 1.23), and 3 standard weight velocity curves at average age AA, defined as AA=t–1.23/2 years. SDS(WVA) denotes the number of standard deviations that WV(t) deviates from the 0 SD weight velocity at AA. WV(t) yielded erroneous outcomes when applied to weights of a seriously underweight boy with an allergy to cows’ milk who showed strong weight growth after being fed on food free of cows’ milk. The SDS(WVA) software tacitly suggests that it is more accurate than WV(t). CASE REPORT: The case of this boy was previously described in this Journal. Using SDS(WVA)(t,AA) software, his weight growth was analyzed by his third pediatrician, beginning at age 1.5 years. The diagnosis of the mother with Pediatric Condition Falsification was confirmed, adding 6 months to foster care, which totalled 8.5 months. Testing of the SDS(WVA) software on the boy’s weight curve yielded results that were complex, nontransparent, and as erroneous as WV(t), explaining the misdiagnosis by the third pediatrician. CONCLUSIONS: SDS(WVA) software should not be used for children under 3 years and during variable weight behavior. Erroneous performance, unpublished details, and an error identified in their new but untested software make the Dutch Growth Research Foundation unlikely to meet the 2020 European Union regulations for in vitro medical devices.