Children and Families Policy Research Unit


NIHR Children and Families Policy Research Unit


Measuring child development at the 2-2½ year health and development review in England

Responsive Facility: Measuring child development at the 2-2½ year health and development review in England: available tools, stakeholder priorities and feasibility of implementation

Final Report

Please find the final report here:


October 2022 – October 2023

Research Team

Dr Jenny Woodman - UCL (project lead), Professor Pasco Fearon and Dr Jo Lysons - University of Cambridge, Professor Sally Kendall - University of Kent, Ms Jennifer Kirman - Oxford Brookes University, Dr Ryc Aquino - University of Newcastle, Ms Hannah Cann - UCL and Southampton City Council 

Why we did this study

Every child in England should be offered a health and development review aged 2-2½ years by their health visiting team, which includes the Ages & Stages Questionnaire (ASQ®; 3rd Edition, licensed from Brookes, the developers). The DHSC has selected ASQ®-3 as the population measure of early child development in England, but ASQ®-3 is also used to inform practitioners’ decisions about which children should receive extra developmental support. The DHSC commissioned us to investigate the feasibility and accuracy of tools to measure child development at the 2-2½ year health and development review, including ASQ®-3, and to gather stakeholder priorities for measuring child development at this review.

What we did

We carried out a mixed methods study with two key components:

  1. A rapid review of the literature to identify and assess the evidence on measures of early child development for use at 2-2½ year health and developmental review. We considered tools with additional versions for use before ages 2-2½ which could be used flexibly and repeatedly to measure child development over time
  2. Fifteen focus groups with 63 stakeholders to identify priorities for measuring child development aged 2-2½ years.  

What we found

Two tools (ASQ®-3 and CREDI Long Form (LF)) appeared feasible for use at the 2-2½ year health and developmental review, although we found no research evidence on the accuracy of these tools to measure or detect early developmental delay within a UK population. CREDI LF is open source (free to use). Both tools seem suitable for use to collect population-level data, but research is needed on both tools for a UK context. As an individual-level assessment tool, ASQ®-3 detects severe developmental delay with good to high accuracy but is only moderately able to detect mild developmental delay amongst general populations of children aged 2-2½ years (non-UK studies). No equivalent information is yet available about CREDI. Parents and practitioners wanted a tool that facilitated a holistic conversation about development, health, and wellbeing with direct observation of the child by the professional. There was a widespread lack of clarity about the purpose of using a tool to measure child development at the 2-2½ year health and developmental review.  Policy colleagues at DHSC saw the benefit in a tool that serves both purposes but cautioned against separating population-level data collection from the broader developmental review. Parents, practitioners, and policy colleagues at DHSC identified some aspects of the current tool as needing improvement and questioned its appropriateness for use with children from ethnic minority groups and children with disabilities. Our qualitative study generated findings relevant to workforce and skill mix, but we have not made recommendations in these areas.

Why this is important?

There are two robustly developed tools which could feasibly be used at the 2-2½ year health and development review to measure child development, one of which is the currently used (ASQ®-3). The other measure (CREDI) has the advantage of being free to use, unlike ASQ®-3. However, the health visiting infrastructure is under strain and under the wrong circumstances, implementing a new tool may exacerbate strain on the service, undermine morale and lead to patchy up-take. The delivery of the measure and the service pathways it triggers were more important to the parents and practitioners we spoke to than the specific tool used to measure child development.

What are the implications?

A tool to measure child development at 2-2½ years in England might best be embedded within an in-person holistic review of child and wider family health which includes the parent, as is currently the case. Stakeholders told us that using the tool to facilitate a holistic conversation takes professional experience and skill. The most suitable tool will have clinical utility for individual assessment of a child and collect population-level data which means we need new evidence to establish population distributions of child development in England and cut-offs for whichever tool is used (including ASQ®-3). The NHS England training on ASQ®-3 at the 2-2½ years, it might not be filtering through to practitioners and parents.