# The Burdens of Idiopathic Developmental Intellectual Disability Attributable to Lead Exposure from 1990 to 2023 and a Projection to 2050 in the USA: Findings from the Global Burden of Disease Study 2023

## TL;DR

This study examines how lead exposure has contributed to intellectual disability in the USA from 1990 to 2023 and predicts future trends through 2050.

## Contribution

The study provides a detailed analysis and projection of lead-related intellectual disability burden in the USA using advanced statistical models.

## Key findings

- DALYs and age-standardized DALY rates for lead-related IDID have decreased from 1990 to 2023.
- Males have a higher disease burden than females, though both are expected to see declining trends through 2050.
- Bayesian analysis predicts continued decline in lead-related IDID burden, with faster improvement for males.

## Abstract

Background: Idiopathic developmental intellectual disability (IDID) is a neurodevelopmental disorder that leads to poor health status. This study analyzes the burden of IDID attributed to lead (Pb) exposure in the United States of America (USA) from 1990 to 2023 and projects trends through 2050. Methods: Measurements on Disability-adjusted life years (DALYs) and Years lived with disability (YLDs) were downloaded from the Institute for Health Metrics and Evaluation (IHME). A joinpoint regression model was employed to assess the epidemiological change in this disease. The age–period–cohort (APC) model was used to examine the age, period, and birth cohort effects on DALYs. Decomposition analysis was applied to analyze the role of population, aging, and epidemiological factors in driving changes to DALYs. Bayesian age–period–cohort (BAPC) analysis was conducted to forecast sex-specific burden trends through 2050. Results: From 1990 to 2023, DALYs and age-standardized DALY rate (ASDR) showed an overall decreasing trend. Males bore a higher disease burden than females. In the USA, the average annual percentage change (AAPC) in ASDR was −1.41 (95% CI: −1.45 to −1.37), indicating an overall decline. BAPC analysis predicted that the ASDR will continue to decline for both females and males through 2050, with males showing a faster decline. Conclusions: Consistent efforts have led to significant progress in reducing lead exposure-related IDID in the USA. Prevention strategies focus on continuing to reduce lead exposure and minimize its impact on IDID.