Agreement in Infant Growth Indicators and Overweight/Obesity between Community and Clinical Care Settings

Abstract

Background: Infants from low-income backgrounds receive nutrition care from both community and clinical care settings. However, mothers accessing these services have reported receiving conflicting messages related to infant growth between settings, although this has not been examined quantitatively.

Objective: Describe the agreement in infant growth assessments between community (Special Supplemental Nutrition Program for Women, Infants, and Children) and clinical (primary care providers) care settings.

Design: A cross-sectional, secondary data analysis of infant growth measures abstracted from electronic data management systems.

Participants and setting: Participants included a convenience sample of infants (N = 129) from northeastern Pennsylvania randomized to the WEE Baby Care study from July 2016 to May 2018. Infants had complete anthropometric data from both community and clinical settings at age 6.2 ± 0.4 months. Average time between assessments was 2.7 ± 1.9 weeks.

Main outcome measures: Limits of agreement and bias in weight-for-age, length-for-age, weight-for-length, and body-mass-index-for-age z scores as well as cross-context equivalence in weight status between care settings.

Statistical analysis performed: Bland-Altman analyses were used to describe the limits of agreement and bias in z scores between care settings. Cross-context equivalence was examined by dichotomizing infants' growth indicators at the 85th and 95th percentile cut-points and cross-tabulating equivalent and discordant categorization between settings.

Results: Strongest agreement was observed for weight-for-age z scores (95% limits of agreement -0.41 to 0.54). However, the limits of agreement intervals for growth indicators that included length were wider, suggesting weaker agreement. There was a high level of inconsistency for classification of overweight/obesity using weight-for-length z scores, with 15.5% (85th percentile cut-point) and 11.6% (95th percentile cut-point) discordant categorization between settings, respectively.

Conclusions: Infant growth indicators that factor in length could contribute to disagreement in the interpretation of infant growth between settings. Further investigation into the techniques, standards, and training protocols for obtaining infant growth measurements across care settings is required.

Keywords: Anthropometry; Infant growth; Infants; Overweight and obesity; Pediatric clinical care; Special Supplemental Nutrition Program for Women; and Children.