Later-Life Outcomes of Aging Parents of Individuals with and without Intellectual and Developmental Disabilities: A Systematic Review and Meta-Analysis

Background and Purpose:
Parents of individuals with intellectual and developmental disabilities (IDD) often provide support across the life course and may continue caregiving into later life. Although research on these parents has grown, comparative studies examining aging parents of individuals with IDD with those who not have IDD remain limited. This gap in research limits understanding of the various pathways of lifelong parenting their children with IDD and the potential connections with disparities in later-life outcomes. This systematic review and meta-analysis aimed to: (1) summarize comparative studies on aging parents of individuals with versus without IDD; (2) identify outcome domains in which disparities are consistently observed; and (3) examine potential moderators, including sex, age, and race.

Methods:
This review was preregistered in PROSPERO and followed PRISMA guidelines. Four databases (MEDLINE, PsycINFO, AgeLine, and Social Work Abstracts) were searched in December 2025 without publication-date restrictions. Studies were included if they were published in English, examined parents aged 50 years or older, and compared parents of individuals with IDD with parents of individuals without IDD. Two reviewers independently screened records, assessed full texts, and resolved disagreements through consensus. Data extraction was completed by two reviewers. Study quality was assessed using an adapted 10-item risk-of-bias tool. Random-effects meta-analyses with restricted maximum likelihood estimation (REML) and Knapp-Hartung adjustment were conducted on pre-calculated Cohen’s d effect sizes. Outcomes were grouped into seven domains, and subgroup analyses examined sample sex composition, age group, and racial composition.

Results:
Among 537 identified studies, 15 studies met inclusion criteria. 13 studies were conducted in the United States and relied on secondary data sources, including the Midlife in the United States (MIDUS), Wisconsin Longitudinal Study (WLS), and National Health Interview Survey (NHIS). 2 studies from Canada and Israel collected primary data and recruited participants through a linked-sample procedure. Compared with parents of individuals without IDD, aging parents of individuals with IDD showed significantly poorer outcomes in general health (d = -0.20, 95% CI [-0.35, -0.05]), physical health (d = -0.26, 95% CI [-0.46, -0.07]), psychological health (d = -0.42, 95% CI [-0.73, -0.12]), social participation (d = -0.18, 95% CI [-0.32, -0.05]), and social attainment (d = -0.26, 95% CI [-0.50, -0.16]). No significant differences were found for health behaviors or healthcare utilization. Subgroup findings suggested variation by sex, age, and race, although several subgroup estimates were based on a small number of studies and should be interpreted cautiously.

Conclusions and Implications:
Aging parents of individuals with IDD experience consistent disadvantages across multiple later-life health and social domains. Findings support the need for long-term supports, including health and mental health services, peer support, counseling, and future care planning. Because these parents may not differ in healthcare utilization despite poorer outcomes, proactive outreach beyond clinical settings may be warranted. Future research should use more diverse samples and more nuanced measures of caregiving context and intensity.