Research Article: Prevalence of intellectual and developmental disabilities among first generation adult newcomers, and the health and health service use of this group: A retrospective cohort study

Date Published: June 20, 2019

Publisher: Public Library of Science

Author(s): Anna Durbin, James K. H. Jung, Hannah Chung, Elizabeth Lin, Robert Balogh, Yona Lunsky, Sungwoo Lim.


Attention to research and planning are increasingly being devoted to newcomer health, but the needs of newcomers with disabilities remain largely unknown. This information is difficult to determine since population-level data are rarely available on newcomers or on people with intellectual and developmental disabilities (IDD), although in Ontario, Canada these databases are accessible. This study compared the prevalence of IDD among first generation adult newcomers to adult non-newcomers in Ontario, and assessed how having IDD affected the health profile and health service use of newcomers.

This population-based retrospective cohort study of adults aged 19–65 in 2010 used linked health and social services administrative data. Prevalence of IDD among newcomers (n = 1,649,633) and non-newcomers (n = 6,880,196) was compared. Among newcomers, those with IDD (n = 2,830) and without IDD (n = 1,646,803) were compared in terms of health conditions, and community and hospital service use.

Prevalence of IDD was lower in newcomers than non-newcomers (171.6 versus 898.3 per 100,000 adults, p<0.0001). Among newcomers, those with IDD were more likely than those without IDD to have comorbid physical health disorders, non-psychotic, psychotic and substance use disorders. Newcomers with IDD were also more likely to have psychiatry visits, and frequent emergency department visits and hospitalizations. First generation adult newcomers have lower rates of IDD than non-newcomers. How much of this difference is attributable to admission policies that exclude people expected to be high health service users versus how much is attributable to our methodological approach is unknown. Finding more medical and psychiatric comorbidity, and more health service use among newcomers with IDD compared to newcomers without IDD is consistent with patterns observed in adults with IDD more generally. To inform polices that support newcomers with IDD future research should investigate reasons for the prevalence finding, barriers and facilitators to timely health care access, and pathways to care.

Partial Text

Across settings newcomers tend to have better health than non-newcomers (“Healthy Immigrant Effect”)[1]. They also tend to use health care services less frequently than non-newcomers [2], although results related to their use of primary care are mixed [3]. Research and service planning attention are increasingly being devoted to newcomer health, but the needs of newcomers with disabilities remain largely unknown.

This is the first study to examine the prevalence of IDD among first generation adult newcomers. The prevalence of IDD was significantly lower among newcomers than non-newcomers in Ontario, Canada. Among newcomers, those with IDD had a higher prevalence of a range of physical and mental health conditions, with marked differences in rates of psychotic and concurrent disorders. Moreover, newcomers with IDD were also significantly more likely to use psychiatry services and have frequent ED visits and hospitalizations than newcomers without IDD.

Given the knowledge gap related to newcomers and disabilities, particularly IDD, this population-based study is an early step toward building an evidence base. Present findings suggest a much lower prevalence of IDD among newcomers compared to Canadian-born persons. Self-selection may be a contributor to these findings, however, it was not possible to estimate the effect of Canadian selection policies on the exclusion of newcomer applicants with IDD.