Housing instability is a social determinant of health associated with multiple negative health outcomes including substance use disorders (SUDs). Real-world evidence of housing instability is needed to improve translational research on populations with SUDs.

We identified evidence of housing instability by leveraging structured diagnosis codes and unstructured clinical data from electronic health records of 20,556 patients from 2017 to 2021. We applied natural language processing with named-entity recognition and pattern matching to unstructured clinical notes with free-text documentation. Additionally, we analyzed semi-structured addresses containing explicit or implicit housing-related labels. We assessed agreement on identification methods by having three experts review of 300 records.

Diagnostic codes only identified 58.5% of the population identifiable as having housing instability, whereas 41.5% are identifiable from addresses only (7.1%), clinical notes only (30.4%), or both (4.0%). Reviewers unanimously agreed on 79.7% of cases reviewed; a Fleiss’ Kappa score of 0.35 suggested fair agreement yet emphasized the difficulty of analyzing patients having ambiguous housing situations. Among those with poisoning episodes related to stimulants or opioids, diagnosis codes were only able to identify 63.9% of those with housing instability.

All three data sources yield valid evidence of housing instability; each has their own inherent practical use and limitations. Translational researchers requiring comprehensive real-world evidence of housing instability should optimize and implement use of structured and unstructured data. Understanding the role of housing instability and temporary housing facilities is salient in populations with SUDs.

Residential instability, including transience (i.e. unusually frequent mobility), is associated with higher risk for emotional and behavioural problems in children and young adults. However, most studies have not compared the effect of recent v. more distal moves on mental health or on mental health treatment. This study examined associations between recent (past year) and distal (past 2–4 years) residential transience and past year major depressive episode (MDE) and mental health treatment in a nationally representative sample of US adolescents aged 12–17.

Data are from the 2010–2014 National Surveys on Drug Use and Health (n = ~107 300 adolescents). T-tests were used to examine the prevalence of MDE by number of moves in the past 5 years among a nationally representative sample of adolescents. Additionally, multivariable logistic regression models were used to evaluate the adjusted association between recent (⩾2 moves in the past year) and distal (⩾4 moves in the past 5 years, but no recent transience) and (1) past year MDE and (2) past year mental health treatment among adolescents with MDE.

MDE prevalence increased linearly with number of moves in the past 5 years (p < 0.001). The adjusted odds of MDE were greater among youths with distal transience (adjusted odds ratio (AOR) = 1.25, 95% confidence interval (CI) = 1.09–1.44) and among those with proximal transience (AOR = 1.31, 95% CI = 1.17–1.46), compared with those without transience in the past 5 years. The MDE prevalence did not differ between those with distal and proximal transience (p = 0.163). In youths with past year MDE, the prevalence of past year mental health treatment was greater among those with proximal transience compared with those without transience (AOR = 1.40, 95% CI = 1.15–1.70), but there was no significant difference in treatment among those with distal v. no transience.

Distal and recent transience are associated with past year MDE among adolescents. Adolescents with MDE who had recent transience were more likely to receive past year mental health treatment compared with those without transience. However, those with only distal transience were not more likely to receive treatment. Parents, school officials and health care providers should be aware that residential mobility in the past 5 years may indicate increased odds of depression among adolescents even among adolescents whose housing stability has improved in the past year.