Cover: A Psychometric Study of the Modified Bridges for Newborns Screening Tool

A Psychometric Study of the Modified Bridges for Newborns Screening Tool

Published Feb 6, 2017

by Brian D. Stucky, Victoria K. Ngo, Ashley M. Kranz, Chandra Garber, Gabriela Castro, Wenjing Huang, Joyce S. Marks

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Research Questions

  1. Do hospital liaisons assign similar scores when using the Modified Bridges?
  2. Does the Modified Bridges identify a level of risk that is similar to those that other well-validated measures of psychosocial and medical risk identify in the same women?
  3. Does the Modified Bridges accurately distinguish between low- and moderate-risk mothers and high-risk mothers?

Welcome Baby, a program that First 5 Los Angeles (First 5 LA) sponsors, provides new mothers with supportive services intended to create enriching environments for their children. To identify mothers in need of these services, First 5 LA employs hospital liaisons who administer a maternal risk assessment tool, the Modified Bridges for Newborns screening tool, during postpartum interviews of mothers. First 5 LA uses risk assessment scores from the Modified Bridges to classify mothers as low, moderate, or high risk; high-risk mothers are eligible for additional supportive services that are not available to low- and moderate-risk mothers. This report describes RAND Corporation work evaluating the psychometric characteristics of the Modified Bridges.

Key Findings

Liaisons Perform at Acceptable Levels

  • Liaisons provide similar risk scores to one another (interrater reliability) and that their assessments were similar over time (test–retest reliability). Liaison interrater reliabilities are highest for the Demographics/Basic Needs subscale and somewhat lower for the Medical subscale.
  • Experience as a liaison and use of liaison training materials improved performance.

The Modified Bridges Might Overidentify Mothers as Being High Risk

  • The Modified Bridges' ability to distinguish similar levels of risk compared with that ability in other widely used tools would improve if a higher risk threshold were implemented.

The Current Risk Threshold of 50 May Not Be Able to Distinguish Between the Highest Levels of Risk

  • The current reliability of the Modified Bridges indicates, in practical terms, that First 5 LA can have only limited confidence that the given risk score for a mother reflects that mother's true level of risk. The current scoring protocol and item weights used for the Modified Bridges have a moderate level of reliability (0.65), below the widely used reliability threshold of 0.70, while scoring the tool without the current item weights would improve its reliability to a more acceptable level (0.74).


  • Given the relationship between the item weight and items' ability to distinguish between risk levels, we propose increasing the weight of seven items and decreasing the weight of three items.
  • In addition to these changes, we recommend removing two items: infant medical problems, which is redundant with another item on the Modified Bridges that performs better, and mother's use of English, which does not distinguish between maternal risk levels.

The research described in this report was conducted by RAND Health.

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