What Matters in Population Health and How We Count It Among People With Intellectual and Developmental Disabilities.

The authors looked at how the U.S. counts adults with intellectual or developmental disabilities in health data.

They read every major national survey and hospital record system.

They found big holes in how we track this group.

Most health surveys miss adults with IDD or lump them into broad categories.

This makes it hard to know if they get fair healthcare.

Better case definitions and linking records across systems would fix most gaps.

Lifshitz et al. (2014) said the same thing about medication studies — poor definitions hurt data quality.

Jackson et al. (2025) shows the fix works. Their Ontario study linked health records for 2.5 million adults and tracked IDD status through COVID-19.

Matson et al. (2009) and Kozma et al. (2009) found poor community and housing outcomes, but used small samples. The target paper explains why bigger, linked data sets are needed to confirm those patterns.

Hsieh et al. (2009) linked nursing-home records to death records — exactly the kind of data marriage the target urges for all U.S. adults with IDD.

If your state or clinic cannot see adults with IDD in its data, you cannot prove they need more services. Ask your IT team to add the federal IDD flag to electronic records. Push local hospitals to share de-identified data with your agency. Better counts today mean stronger funding requests tomorrow.