Background: People with intellectual disabilities (ID) frequently experience poorer health and lower treatment coverage compared to those without ID, yet differences in hypertension prevalence and treatment coverage remain unclear.
Objective: To estimate the pooled prevalence ratio (PR) of hypertension and hypertension treatment coverage comparing adults with and without ID.
Methods: We searched MEDLINE, Embase, PsychINFO, Global Health and Global Index Medicus on June 6, 2024. We included observational and intervention studies that estimated the prevalence of hypertension and/or treatment coverage. The risk of bias was assessed using the Newcastle-Ottawa Scale tool. We undertook a random-effects meta-analysis to estimate the pooled PR with 95 % confidence intervals (CI). Sources of heterogeneity were explored through sensitivity and subgroup analyses, and meta-regression.
Results: 21 studies from 10 countries across three regions were included. The pooled PR were 0.71 (95 % CI: 0.47-1.05) for hypertension and 0.61 (95 % CI: 0.47-0.81) for hypertension treatment coverage. Only one study adjusted for age; most reported unadjusted estimates, making them prone to confounding. 14 studies were rated as high risk of bias. Subgroup analysis and meta-regression revealed variability in the methods used to diagnose ID, with sample size emerging as the primary source of variability in the effect estimates.
Conclusions: This systematic review showed that adults with ID have a similar prevalence of hypertension, but lower hypertension treatment coverage compared to those without disabilities. However, these results should be interpreted with caution due to the lack of adjustment for confounding in the association and variability in the diagnosis of ID.

