Authors: S. Monty Ghosh, Khokan C. Sikdar, Adetola Koleade, Jordan Ross, William Rioux, Eddy S. Lang, Geoff Messier, Robert Tanguay, Stephen E. Congly, Stephanie Van den Berg, Karen L. Tang
Categories: Original Paper, complexity of health, evaluation, health services research, public health, qualitative methods
Source: Journal of Evaluation in Clinical Practice
Doi: 10.1111/jep.14236
Individuals experiencing homelessness (IEH) tend to have increased length of stay (LOS) in acute care settings, which negatively impacts health care costs and resource utilisation. It is unclear however, what specific factors account for this increased LOS. This study attempts to define which diagnoses most impact LOS for IEH and if there are differences based on their demographics.
A retrospective cohort study was conducted looking at ICD‐10 diagnosis codes and LOS for patients identified as IEH seen in Emergency Departments (ED) and also for those admitted to hospital. Data were stratified based on diagnosis, gender, and age. Statistical analysis was conducted to determine which ICD‐10 diagnoses were significantly associated with increased ED and inpatient LOS for IEH compared to housed individuals.
Homelessness was associated with increased LOS regardless of gender or age group. The absolute mean difference of LOS between IEH and housed individuals was 1.62 h [95% CI 1.49–1.75] in the ED and 3.02 days [95% CI 2.42–3.62] for inpatients. Males age 18–24 years spent on average 7.12 more days in hospital, and females aged 25–34 spent 7.32 more days in hospital compared to their housed counterparts. Thirty‐one diagnoses were associated with increased LOS in EDs for IEH compared to their housed counterparts; maternity concerns and coronary artery disease were associated with significantly increased inpatient LOS.
Homelessness significantly increases the LOS of individuals within both ED and inpatient settings. We have identified several diagnoses that are associated with increased LOS in IE; these should inform the prioritisation and development of targeted interventions to improve the health of IEH.
Keywords: complexity of health, evaluation, health services research, public health, qualitative methods
Homelessness has significant health implications. Individuals experiencing homelessness (IEH) present with increased disease complications compared to their housed counterparts due to factors such as poor diet, inability to afford medications, and irregular access to primary care [1]. IEH are at higher risk for uncontrolled chronic diseases and have a higher prevalence of mental health concerns, addictions, and infectious diseases like Human Immunodeficiency Virus and Hepatitis C [2, 3]. IEH also use acute care services more frequently, with 71% using Emergency Department (ED) services over a 6‐month period [4, 5] with utilisation rates between 1.63 and 18.75 times higher than the general population [6]. They also have increased rates of hospitalisations due not only to acute medical needs but also due to complex social barriers [7]. Despite increased rates of hospitalisations, the effectiveness of IEH's hospital stay is diminished by their return to homelessness [8]. Long‐term outcomes remain poor for IEH, with mortality rates being up to 9 times higher than the average population [8].
Not only are IEH hospitalised more often than housed individuals, they also have longer lengths of stay (LOS) in hospital, which presents an additional burden on both the individual and on society. In general, IEH spend between 2.3 and 4.1 more days in hospital [8, 9, 10] than housed individuals. Hwang et al. noted that in Canada, even after adjustment for age, gender, and resource intensity weight, hospitalisations for IEH cost over 1000 more for IEH after adjusting for length of stay [11].
Aside from the presence of mental health conditions, it remains unclear whether specific medical conditions are more likely to lead to an increased LOS in IEH compared to their housed counterparts. It is often believed that IEH may require longer stays in the hospital due to a lack of community support; for example, IEH may spend increased time in acute care setting to receive antibiotics for endocarditis and osteomyelitis due to lack of medication coverage or outpatient parenteral options [13]. In contrast to hospital LOS, there is variable evidence on the impact of homelessness on LOS for emergency department visits. Previous studies showed increased ED LOS for IEH [14, 15], while another study specifically examining patients with mental health concerns noted no differences in ED LOS in homeless versus housed individuals [16]. Most studies of ED utilisation do not specifically compare LOS, or the differences in ED diagnoses, between IEH and housed individuals [17, 18]. A better understanding of how medical diagnoses and needs impact the increased use of both inpatient and ED care can help to identify gaps in our current inpatient and outpatient health service delivery to ultimately inform the development of interventions to address these specific illness‐specific needs.
In this cohort study, we aimed to determine the diagnoses most responsible for impacting ED and inpatient LOS among IEH. To our knowledge, this study is the first to assess diagnosis‐modifying LOS in this population. This study will deepen our understanding on health issues faced by IEH and help to prioritise and determine disease management strategies in the community.
We designed a retrospective cohort study examining IEH who accessed four tertiary care hospitals and one urgent care centre in Calgary, Canada, from 1 April 2017 to 31 March 2018. The exposure was homelessness (operational definition described below). Ethnicity is not recorded within the health region's data set. If an individual was seen or admitted multiple times, only the first interaction with acute care (ED or inpatient) was utilised for our analysis. The primary outcomes were differences in LOS between IEH and housed individuals within both ED and inpatient settings, with the specific aim of examining which diagnoses and demographics contributed to these differences. The authors did not have access to information that could identify individual patients during or after data collection. Data were accessed from 1 May 2019 to 31 July 2019.
Administrative data for individuals aged 18 years or greater was provided by the provincial health authority, and consisted of the Discharge Abstract Database (for hospitalisations) and National Ambulatory Care Reporting System database (for ED visits). A unique ICD‐10 code (International Classification of Diseases, 10th Revision) for homelessness was utilised to identify IEH. As this code was only available from 2017 onwards, and as the code for homelessness is optional, additional information regarding homelessness was obtained through individual addresses. If the address was labeled as 'no fixed address' or the postal code provided corresponded to one of Alberta's homeless shelters, the patient was included into the study cohort. Because Calgary homeless shelters tend to be located in the downtown business districts with few residential developments, very few residences share postal codes similar to those of the shelters. This method of identifying cohorts of IEH has been used in previous studies [7, 8]. Due to limitations in identifying homelessness using administrative databases, individuals who are precariously housed, those with low‐income housing, and those who were couch surfing were classified as being housed.
IEH were excluded if their health care identification was missing. If a particular ICD‐10 category had fewer than five individuals with that diagnosis, they were also omitted due to difficulties with measuring statistical significance. Additionally, significant data outliers defined as individuals who were admitted to hospital for 90 days or more were excluded. The rationale for this latter exclusion criterion is that the extended lengths of stay for these individuals likely represent alternate level of care days, where they are medically stable with their admission being no longer attributable to acute care management.
The mean LOS for IEH and housed individuals within the ED and inpatient settings were calculated separately, and mean differences between these two were calculated by subtracting the mean LOS for IEH by the mean LOS for housed individuals. ICD‐10 codes were used for the classification of the primary diagnosis. ICD‐10 codes were combined for closely related diagnoses, and/or if individual diagnoses had a small sample size. Mean differences in LOS were adjusted for age group, sex as well as diagnosis based on principal diagnosis using analysis of covariance to limit confounding effects [19, 20]. Ninety five percent confidence intervals (CI) for the difference in mean LOS were determined using the Student t statistic. Statistical Analysis Software (SAS) version 9.3 was used to perform all statistical analyses.
The study received ethics approval at the University of Alberta research ethics board (PRO 00091280) as well as internal research review by Alberta Health Services.
A total of 3620 unique IEH accessed an acute care facility in 2017–18; 858 of these individuals were admitted to the hospital. Our comparator group consisted of 375,271 housed individuals.
The majority of individuals assessed in both the ED and inpatient settings were male across all age groups (Table 1). The mean age of IEH using acute care resources was 38.6 years, and 48.5 years for housed individuals. Most IEH who used acute services were between the ages of 25–49, whereas age ranges were more evenly spread for housed individuals. Among IEH who accessed acute care, the average number of ED visits over 1 year was 3.19 compared to 1.28 visits for housed individuals. On average, homeless and housed individuals had a similar number of hospital admissions over the 1 year period; however, the LOS for IEH was over 1.5‐fold that for housed individuals (10.27 vs. 6.70 days, p < 0.0001).
Table 2 shows the adjusted mean LOS, stratified by age and sex. There were 2.84 times more males seen in the ED and 2.97 times more males admitted to hospital than females, which reflects the Calgary homeless population baseline demographic of 2.77 times more males than females [21]. IEH in almost all age groups spent statistically significantly more time in both the ED and in the hospital than housed individuals. There was no statistically significant difference in LOS for IEH and housed individuals older than 65 years of age. Males experiencing homelessness between the ages of 18 and 25 had the highest mean difference in their LOS, spending 2.79 [CI 2.30–3.27] more hours in EDs on average, as well as 7.12 [CI 4.55–9.69] more days in hospital compared to their housed counterparts. Similarly, females experiencing homelessness between 18 and 25 years of age had the highest mean difference in ED LOS, at 3.28 [CI 2.79–3.78] more hours compared to housed individuals. Females experiencing homelessness between 25 and 34 years of age spent 7.32 [CI 6.41–8.22] more days admitted to inpatient wards compared to their housed counterparts. On average, IEH spent 1.62 [CI 1.49–1.75] more hours in the ED and 3.02 [CI 2.42–3.62] more days in hospital compared to housed individuals.
Table 3 shows all primary diagnoses that were found to be associated with a statistically significant increase in LOS for IEH in the ED compared to their housed counterparts. Some key diagnoses that were associated with an increased ED LOS in IEH were fever with chills (mean difference of 9.81 h [95% CI 5.01–14.61]) and synovitis/tenosynovitis (mean difference of 6.19 h [95% CI 5.01–7.38]). IEH who presented with unspecified organic psychosis and schizophrenia had a mean difference in LOS of 15.47 [95% CI 13.30–17.65] and 15.33 [95% CI 13.43–17.22] more hours, respectively, compared to housed individuals.
There were two diagnoses found to incur statistically significantly longer ED LOS for housed individuals compared to IEH; these included depression (mean difference of −2.56 h [95% CI −4.78 to −0.34] hours) and blood alcohol and blood drug test (−0.93 h [95% CI −1.49 to −0.38]).
Within the inpatient population, only two diagnoses demonstrated a statistically significant increased LOS in IEH compared to housed individuals. IEH diagnosed with atherosclerotic cardiovascular disease had an average of 25.33 [6.55–44.12] more days in hospital compared to housed individuals. The mean LOS for IEH with this diagnosis was 33.4 days versus 8.07 days for housed individuals. IEH with a principal diagnosis of preterm delivery spent an average of 6.45 [4.33–8.57] more days in hospital.
In Calgary, the average cost of an emergency visit is approximately 1181. In this study, IEH had an approximate acute care cost of 2.06 million being associated with ED visits. As compared to housed patients, there would be an additional cost of 3750 more per stay versus a housed patient.
To our knowledge, this is the first study that explores differences in LOS between IEH and housed individuals in both the ED and inpatient setting. It is also the first study to explore how these differences vary by demographics and the principal diagnoses that prompted acute care use. In keeping with previous studies, we found that a disproportionately high prevalence of IEH in the ED and admitted to hospital were men between the ages of 25 and 34. Most were admitted to hospital for substance‐related concerns. On average, IEH spent 1.62 more hours in the ED and 3.02 more days in hospital than housed individuals. This average increase in inpatient LOS for IEH is slightly lower than a previous study from New York (where LOS for IEH was 4.1 more days than for housed individuals) but is in keeping with a Canadian study which found a mean difference of 2.32 days in LOS between IEH and those who are housed [12, 13].
The trend towards increased ED and hospital LOS was consistent across many diagnoses, many of which have little physiologic or clinical overlap. This suggests that the increased LOS in IEH may be more attributable to their underlying state of homelessness rather than factors related to the particular medical diagnoses. There were surprisingly two diagnoses that were associated with increased LOS for housed individuals compared to IEH including depression, and blood alcohol and drug tests. These differences appear small and of questionable clinical significance.
By exploring the differences in ED LOS, our study highlights potential points of intervention to optimise ED workflow and bed occupancy. Within the ED, IEH contributes to reduced workflow, leading to ED crowding, which is associated with decreased quality of care, delays in treatment commencement, and increased mortality [22]. The majority of the primary diagnoses that are most frequently seen in the ED in the homeless population might be managed in an outpatient setting, though we are limited by the lack of severity data captured in administrative databases. For example, both cellulitis and epilepsy were associated with an increased ED LOS for IEH. These are ambulatory care sensitive conditions (ACSC) [23] where acute care use might be avoided if they are able to be optimally managed in the outpatient setting. A large number of diagnoses associated with increased ED LOS are related to mental health and addiction concerns. Further investment into community‐based mental health and addiction resources may be warranted.
When looking at diagnosis associated with increased LOS within inpatients; coronary atherosclerotic disease (CAD) is associated with almost 25 more days spent admitted to hospital compared to housed individuals. While CAD is not classified as an ACSC, risk factors for CAD such as hypertension and diabetes, as well as their consequences such as angina and heart failure, are included in ACSC. Furthermore, smoking is a known risk factor for CAD. There is a very high prevalence of smoking amongst IEH (57%) compared to housed individuals (27%) [24]. Our results highlight the need for interventions targeting CAD and their risk factors in IEH, such as focusing on resources for smoking cessation, hypertension, and diabetes. Maternal concerns associated with homelessness also demonstrated increased LOS with 6.45 more days spent in the hospital, again demonstrating specific needs for community prenatal and foetal‐maternal care for IEH. Given longer stays in hospital for IEH, the lack of housing security has a direct economic impact on acute care; our findings also support previous work showing increased hospital costs for IEH [11]. The major driver to costs is length of stay given similar rates of hospitalisation. Although longer stays in the ED do have economic impacts, these are more challenging to estimate and play a smaller role cost wise as compared to the additional days in hospital Previous research into 'specialist homeless discharge' suggests that these services may be more cost‐effective than traditional discharge methods [25]. The results from this study can be applied to current and future post‐discharge accommodation programes such as Edmonton, respite to recovery program [26] to improve post‐discharge outcomes, and reduce length of stay and subsequent healthcare costs.
The strengths of our study include detailed hospitalisation and ED data collected from multiple acute care facilities. Furthermore, our findings are in keeping with prior evidence, suggesting that they are generalisable. The demographics of the Calgary population experiencing homelessness has also been demonstrated to be similar to IEH across the country [27, 28].
There are limitations to our study. Due to our cohort identification methods, a small number of IEH were excluded from our study. For example, individuals without identification were excluded, though this comprised only 1/30 of our sample size. Furthermore, as we could not identify individuals who were precariously housed such as those who were couch surfing, our cohort likely represents individuals with more severe or chronic homelessness. Another limitation was our inability to account for illness severity, despite matching IEH and controls based on demographics and primary diagnoses, as this information is not captured within the administrative databases. That is, IEH may present to acute care facilities with similar diagnoses as housed individuals, but at a later stage and/or with increased severity, which could also explain their increased lengths of stay.
Homelessness is associated with increased ED and hospital inpatient LOS. No one diagnosis or diagnosis group could explain the increased LOS for IEH, suggesting that underlying homelessness itself contributes to this issue. Efforts to reduce homelessness and address the social determinants of health are likely necessary to have any impact on reducing acute care utilisation in this population.
The authors declare no conflicts of interest.
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.