Variability in comorbidites and health services use across homeless typologies: multicenter data linkage between healthcare and homeless systems

Abstract

Background Homelessness is associated with substantial morbidity. Data linkages between homeless and health systems are important to understand unique needs across homeless populations, identify homeless individuals not registered in homeless databases, quantify the impact of housing services on health-system use, and motivate health systems and payers to contribute to housing solutions. Methods We performed a cross-sectional survey including six health systems and two Homeless Management Information Systems (HMIS) in Cook County, Illinois. We performed privacy-preserving record linkage to identify homelessness through HMIS or ICD-10 codes captured in electronic medical records. We measured the prevalence of health conditions and health-services use across the following typologies: housing-service utilizers stratified by service provided (stable, stable plus unstable, unstable) and non-utilizers (i.e., homelessness identified through diagnosis codes—without receipt of housing services). Results Among 11,447 homeless recipients of healthcare, nearly 1 in 5 were identified by ICD10 code alone without recorded homeless services (n = 2177; 19%). Almost half received homeless services that did not include stable housing (n = 5444; 48%), followed by stable housing (n = 3017; 26%), then receipt of both stable and unstable services (n = 809; 7%). Setting stable housing recipients as the referent group, we found a stepwise increase in behavioral-health conditions from stable housing to those known as homeless solely by health systems. Compared to those in stable housing, prevalence rate ratios (PRR) for those without homeless services were as follows: depression (PRR = 2.2; 95% CI 1.9 to 2.5), anxiety (PRR = 2.5; 95% CI 2.1 to 3.0), schizophrenia (PRR = 3.3; 95% CI 2.7 to 4.0), and alcohol-use disorder (PRR = 4.4; 95% CI 3.6 to 5.3). Homeless individuals who had not received housing services relied on emergency departments for healthcare—nearly 3 of 4 visited at least one and many (24%) visited multiple. Conclusions Differences in behavioral-health conditions and health-system use across homeless typologies highlight the particularly high burden among homeless who are disconnected from homeless services. Fragmented and high use of emergency departments for care should motivate health systems and payers to promote housing solutions, especially those that incorporate substance use and mental health treatment.

Privacy‐preserving record linkage across disparate institutions and datasets to enable a learning health system: The national COVID cohort collaborative (N3C) experience

“…Prior nationwide studies have had benefits ours lacked: being conducted, for example, within a national health service (Scotland) in which all patients have a unique identifier across datasets 24 or in a country (Switzerland) where patients agreed to use their social security numbers in record linkages 25 . Other studies have used PPRL to link datasets in specific parts of the US: within one county's services, for instance, 26 or in a state‐based clinical research network, 27 or focused on a single disease in one state 28 or on deduplication across multiple sites in a large metropolitan area 29 or between national government indices and national surveys 30 . Because our project, with its broad and diverse national scope, has established and validated ways to link EHR data from many healthcare institutions across the United States and to link widely varying datasets (from EHR data to images to population‐based data), these PPRL methods hold great potential for use beyond the N3C initiative.…”

Representation of marginalised populations in digital surveillance for notifiable conditions in Australia: a systematic review

“… 56 One aspect of digital technology which is showing promise to assist with surveillance in homeless populations is data linkage. 57 However, this has not yet been used for communicable disease surveillance. There are further challenges for data collection as participation in digital reporting would require a phone or computer and homeless individuals have reduced access to digital technology.…”

Homelessness and health-related outcomes in the Republic of Ireland: a systematic review, meta-analysis and evidence map

“…Moving forward, the usage of unique identifiers and linkage of health and social care data should be prioritized, as should the routine recording of housing status in primary care, hospital datasets, and national disease registries. Examples of successful linkages of homelessness and health datasets exist from Scotland and the US (Waugh et al 2018 ; Trick et al 2021 ).…”