Care trajectories and transitions at the end of life: a population-based cohort study.

BACKGROUND: End-of-life periods are often characterised by suboptimal healthcare use (HCU) patterns in persons aged 65 years and older, with negative effects on health and quality of life. Understanding care trajectories (CTs) and transitions in this period can highlight potential areas of improvement, a subject yet only little studied. OBJECTIVE: To propose a typology of CTs, including care transitions, for older individuals in the 2 years preceding death. DESIGN: Retrospective cohort study. METHODS: We used multidimensional state sequence analysis and data from the Care Trajectories-Enriched Data (TorSaDE) cohort, a linkage between a Canadian health survey and Quebec health administrative data. RESULTS: In total, 2080 decedents were categorised into five CT groups. Group 1 demonstrated low HCU until the last few months, whilst group 2 showed low HCU over the first year, followed by a steady increase. A gradual increase over the 2 years was observed for groups 3 and 4, though more pronounced towards the end for group 3. A persistent high HCU was observed for group 5. Groups 2 and 4 had higher proportions of cancer diagnoses and palliative care, as opposed to comorbidities and dementia for groups 3 and 5. Overall, 68.4% of individuals died in a hospital, whilst 27% received palliative care there. Care transitions increased rapidly towards the end, most notably in the last 2 weeks. CONCLUSION: This study provides an understanding of the variability of CTs in the last two years of life, including place of death, a critical step towards quality improvement.

Care trajectories around a first dementia diagnosis in patients with serious mental illness.

AIM: To develop a typology of care trajectories (CTs) 1 year before and after a first dementia diagnosis in individuals aged ≥65 years, with prevalent schizophrenia or bipolar disorder. METHODS: This was a longitudinal, retrospective cohort study using health administrative data (1996-2016) from Quebec (Canada). We selected patients aged ≥65 years with an incident diagnosis of dementia between 1 January 2014 and 31 December 2016, and a diagnosis of schizophrenia and/or or bipolar disorder. A CT typology was generated by a multidimensional state sequence analysis based on the "6 W" model of CTs. Three dimensions were considered: the care setting ("where"), the reason for consultation ("why") and the specialty of care providers ("which"). RESULTS: In total, 3868 patients were categorized into seven distinct types of CTs, with varying patterns of healthcare use and comorbidities. Healthcare use differed in terms of intensity, but also in its distribution around the diagnosis. For instance, whereas one group showed low healthcare use, healthcare use abruptly increased or decreased after the diagnosis in other groups, or was equally distributed. Other significant differences between CTs included mortality rates and use of long-term care after the diagnosis. Most patients (67%) received their first dementia diagnosis during hospitalization. CONCLUSIONS: Our innovative approach provides a unique insight into the complex healthcare patterns of people living with serious mental illness and dementia, and provides an avenue to support data-driven decision-making by highlighting fragility areas in allocating care resources. Geriatr Gerontol Int 2024; 24: 577-586.

Treatment with psychostimulants and atomoxetine in people with psychotic disorders: reassessing the risk of clinical deterioration in a real-world setting.

BACKGROUND: Although attention-deficit hyperactivity disorder (ADHD) is often comorbid with schizophrenia spectrum and other psychotic disorders (SZSPD), concerns about an increased risk of psychotic events have limited its treatment with either psychostimulants or atomoxetine. AIMS: To examine whether the risk of hospital admission for psychosis in people with SZSPD was increased during the year following the introduction of such medications compared with the year before. METHOD: This was a retrospective cohort study using Quebec (Canada) administrative health registries, including all Quebec residents with a public prescription drug insurance plan and a diagnosis of psychotic disorder, defined by relevant ICD-9 or ICD-10 codes, who initiated either methylphenidate, amphetamines or atomoxetine, between January 2010 and December 2016, in combination with antipsychotic medication. The primary outcome was time to hospital admission for psychosis within 1 year of initiation. State sequence analysis was also used to visualise admission trajectories for psychosis in the year following initiation of these medications, compared with the previous year. RESULTS: Out of 2219 individuals, 1589 (71.6%) initiated methylphenidate, 339 (15.3%) amphetamines and 291 (13.1%) atomoxetine during the study period. After adjustment, the risk of hospital admission for psychosis was decreased during the 12 months following the introduction of these medications when used in combination with antipsychotics (adjusted HR = 0.36, 95% CI 0.24-0.54; P < 0.0001). CONCLUSIONS: These findings suggest that, in a real-world setting, when used concurrently with antipsychotic medication, methylphenidate, amphetamines and atomoxetine may be safer than generally believed in individuals with psychotic disorders.

Care trajectories of individuals with anxiety disorders: A retrospective cohort study.

BACKGROUND: Anxiety disorders (ADs) are associated with increased healthcare use (HCU), and individuals may seek healthcare through various pathways according to clinical and individual characteristics. This study aimed to characterize care trajectories (CTs) of individuals with ADs. METHODS: This is a retrospective cohort study using the Care Trajectories - Enriched Data cohort, a linkage between the Canadian Community Health Surveys (CCHS), and health administrative data from Quebec. The cohort included 5143 respondents reporting ADs to the CCHS between 2009 and 2016. We measured CTs over 5 years before CCHS using a state sequence analysis. RESULTS: The cohort was categorized into five types of CTs. Type 1 (52.7 %) was the lowest care-seeking group, with fewer comorbidities. Type 2 (24.0 %) had higher levels of physical and mental health comorbidities and moderate HCU, mainly ambulatory visits to general practitioners. Type 3 (13.1 %) represented older patients with the highest level of physical illnesses and high HCU, predominantly ambulatory consultation of specialists other than psychiatrists. Types 4 and 5 combined young and middle-aged patients suffering from severe psychological distress. HCU of type 4 (6.7 %) was high, mainly consultations of ambulatory psychiatrists, and HCU of type 5 (3.5 %), was the highest and mostly in acute care. LIMITATIONS: Administrative and survey data may have coding errors, missing data and self-report biases. CONCLUSION: Five types of CTs showed distinct patterns of HCU often modulated by physical and mental health comorbidities, which emphasizes the importance of considering ADs when individuals seek care for other mental health conditions or physical illness.

Trajectories of care of community-dwelling people living with dementia: a multidimensional state sequence analysis.

BACKGROUND: The type and level of healthcare services required to address the needs of persons living with dementia fluctuate over disease progression. Thus, their trajectories of care (the sequence of healthcare use over time) may vary significantly. We aimed to (1) propose a typology of trajectories of care among community-dwelling people living with dementia; (2) describe and compare their characteristics according to their respective trajectories; and (3) evaluate the association between trajectories membership, socioeconomic factors, and self-perceived health. METHODS: This is an observational study using the data of the innovative Care Trajectories -Enriched Data (TorSaDE) cohort, a linkage between five waves of the Canadian Community Health Survey (CCHS), and health administrative data from the Quebec provincial health-insurance board. We analyzed data from 690 community-dwelling persons living with dementia who participated in at least one cycle of the CCHS (the date of the last CCHS completion is the index date). Trajectories of care were defined as sequences of healthcare use in the two years preceding the index date, using the following information: 1) Type of care units consulted (Hospitalization, Emergency department, Outpatient clinic, Primary care clinic); 2) Type of healthcare care professionals consulted (Geriatrician/psychiatrist/neurologist, Other specialists, Family physician). RESULTS: Three distinct types of trajectories describe healthcare use in persons with dementia: 1) low healthcare use (n = 377; 54.6%); 2) high primary care use (n = 154; 22.3%); 3) high overall healthcare use (n = 159; 23.0%). Group 3 membership was associated with living in urban areas, a poorer perceived health status and higher comorbidity. CONCLUSION: Further understanding how subgroups of patients use healthcare services over time could help highlight fragility areas in the allocation of care resources and implement best practices, especially in the context of resource shortage.

Machine learning to improve frequent emergency department use prediction: a retrospective cohort study.

Frequent emergency department use is associated with many adverse events, such as increased risk for hospitalization and mortality. Frequent users have complex needs and associated factors are commonly evaluated using logistic regression. However, other machine learning models, especially those exploiting the potential of large databases, have been less explored. This study aims at comparing the performance of logistic regression to four machine learning models for predicting frequent emergency department use in an adult population with chronic diseases, in the province of Quebec (Canada). This is a retrospective population-based study using medical and administrative databases from the Régie de l'assurance maladie du Québec. Two definitions were used for frequent emergency department use (outcome to predict): having at least three and five visits during a year period. Independent variables included sociodemographic characteristics, healthcare service use, and chronic diseases. We compared the performance of logistic regression with gradient boosting machine, naïve Bayes, neural networks, and random forests (binary and continuous outcome) using Area under the ROC curve, sensibility, specificity, positive predictive value, and negative predictive value. Out of 451,775 ED users, 43,151 (9.5%) and 13,676 (3.0%) were frequent users with at least three and five visits per year, respectively. Random forests with a binary outcome had the lowest performances (ROC curve: 53.8 [95% confidence interval 53.5-54.0] and 51.4 [95% confidence interval 51.1-51.8] for frequent users 3 and 5, respectively) while the other models had superior and overall similar performance. The most important variable in prediction was the number of emergency department visits in the previous year. No model outperformed the others. Innovations in algorithms may slightly refine current predictions, but access to other variables may be more helpful in the case of frequent emergency department use prediction.

Association between sustained opioid prescription and frequent emergency department use: a cohort study.

BACKGROUND: Chronic non-cancer pain (CNCP) is common among frequent emergency department (ED) users, although factors underlying this association are unclear. This study estimated the association between sustained opioid use and frequent ED use among patients with CNCP. METHODS: Retrospective cohort study using a Canadian provincial health insurer database (Régie d'Assurance Maladie du Québec). The database included adults with both ≥1 chronic condition and ≥ 1 ED visit in 2012 or 2013. Inclusion in the study further required a CNCP diagnosis, public drug insurance coverage and 1-year survival after the first ED visit in 2012 or 2013 (index visit). Multivariable logistic regression was used to derive ORs of frequent ED use (≥5 visits in the year following the index visit) subsequent to sustained opioid use (≥60 days opioids prescription within 90 days preceding the index visit), adjusting for important covariables. RESULTS: From 576 688 patients in the database, 58 237 were included in the study. Of these, 4109 (7.1%) had received a sustained opioid prescription and 4735 (8.1%) were frequent ED users in the follow-up year. Sustained opioid use was not associated with frequent ED use in the multivariable model (OR: 1.06, 95% CI 0.94 to 1.19). Novel associated covariables were benzodiazepine prescription (OR: 1.21, 95% CI 1.12 to 1.30) and polypharmacy (OR: 1.23, 95% CI 1.13 to 1.34). CONCLUSIONS: Due to confounding by social and medical vulnerability, patients with CNCP with sustained opioid use appear to have a higher propensity for frequent ED use in unadjusted models. However, sustained opioid use was not associated with frequent ED use in these patients after adjustment.

Profiles of frequent emergency department users with chronic conditions: a latent class analysis.

OBJECTIVES: Frequent emergency department users represent a small proportion of users while cumulating many visits. Previously identified factors of frequent use include high physical comorbidity, mental health disorders, poor socioeconomic status and substance abuse. However, frequent users do not necessarily exhibit all these characteristics and they constitute a heterogeneous population. This study aims to establish profiles of frequent emergency department users in an adult population with chronic conditions. DESIGN: This is a retrospective cohort study using administrative databases. SETTING: All adults who visited the emergency department between 2012 and 2013 (index date) in the province of Quebec (Canada), diagnosed with at least one chronic condition, and without dementia were included. Patients living in remote areas and who died in the year following their index date were excluded. We used latent class analysis, a probability-based model to establish profiles of frequent emergency department users. Frequent use was defined as having five visits or more during 1 year. Patient characteristics included sociodemographic characteristics, physical and mental comorbidities and prior healthcare utilisation. RESULTS: Out of 4 51 775 patients who visited emergency departments at least once in 2012-2013, 13 676 (3.03%) were frequent users. Four groups were identified: (1) 'low morbidity' (n=5501, 40.2%), (2) 'high physical comorbidity' (n=3202, 23.4%), (3) 'injury or chronic non-cancer pain' (n=2313, 19.5%) and (4) 'mental health or alcohol/substance abuse' (n=2660, 16.9%). CONCLUSIONS: The four profiles have distinct medical and socioeconomic characteristics. These profiles provide useful information for developing tailored interventions that would address the specific needs of each type of frequent emergency department users.

Multidimensional analysis of adult patients' care trajectories before a first diagnosis of schizophrenia.

For patients at high-risk for developing schizophrenia, a delayed diagnosis could be affected, among many reasons, by their patterns of healthcare use. This study aims to describe and generate a typology of patients' care trajectories (CTs) in the 2 years preceding a first diagnosis of schizophrenia, over a medico-administrative database of 3712 adults with a first diagnosis between April 2014 and March 2015 in Quebec, Canada. This study applied a multidimensional approach of State Sequence Analysis, considering together sequences of patients' diagnoses, care settings and care providers. Five types of distinct CTs have emerged from this data-driven analysis: The type 1, shared by 77.6% of patients, predominantly younger men, shows that this group sought little healthcare, among which 17.5% had no healthcare contact for mental disorders. These individuals might benefit from improved promotion and prevention of mental healthcare at the community level. The types 2, 3 and 4, with higher occurrence of mental disorder diagnoses, represent together 19.5% of the study cohort, mostly middle-aged and women. These CTs, although displaying roughly similar profiles of mental disorders, revealed very dissimilar sequences and levels of care providers encounters, primary and specialized care use, and hospitalizations. Surprisingly, patients of these CTs had few consultations with general practitioners. An increased attentiveness for middle-aged patients and women with high healthcare use for mental disorders could help to reduce delayed diagnosis of schizophrenia. This calls for further consideration of healthcare services for severe mental illness beyond those offered to young adults.

Antipsychotic utilization trajectories three years after initiating or reinitiating treatment of schizophrenia: A state sequence analysis approach.

OBJECTIVE: This study aims to describe the utilization patterns of antipsychotic (AP) medication in patients with schizophrenia (SCZ), three years after initiating or reinitiating a given AP. METHODS: Based on medico-administrative information on patients living in Quebec (Canada), this retrospective cohort study included 6444 patients with a previous diagnosis of SCZ initiating or reinitiating AP medication between January 1, 2012, and December 31, 2014, with continuous coverage by public drug insurance. For each day of follow-up (1092 days), patient was either exposed to one of the chosen categories of APs, or to none. This patient's sequence of AP exposure overtime has been referred to as the "antipsychotic utilization trajectory". These trajectories were analyzed using a State Sequence Analysis, an innovative approach which provides useful visual information on the continuation and discontinuation patterns of use over time. RESULTS: Clozapine and long-acting injectable second-generation APs had the best continuation and discontinuation patterns over 3 years among all other groups, including less switching of APs, while oral first-generation APs had the poorest patterns. These findings were comparable among incident and non-incident cohorts. Oral second-generation antipsychotics, excluding clozapine, had a poorer continuation and discontinuation pattern than long-acting injectable antipsychotics. CONCLUSION: State Sequence Analysis provides a clear representation of treatment adherence in comparison with dichotomous indicators of adherence or discontinuation. Consequently, this innovative method has shed light on the impact of the AP chosen to initiate or reinitiate treatment in SCZ, which has been identified as a key factor for long-term treatment continuation and discontinuation.

Comparative effectiveness and safety of antipsychotic drugs in patients with schizophrenia initiating or reinitiating treatment: A Real-World Observational Study.

OBJECTIVE: To compare the effectiveness and safety of various second-generation antipsychotics (SGAs), newer oral and long-acting injectable (LAI) SGAs, and first-generation antipsychotics (FGAs) treatments in patients with schizophrenia or schizoaffective disorder (SCZ). METHODS: This retrospective cohort study included medical administrative information for patients with a diagnosis of SCZ living in Quebec (Canada), initiating or reinitiating at least one antipsychotic (AP) drug (with a clearance baseline period of 12 months without any APs). Effectiveness was defined by a reduced risk of hospitalization for mental disorder and discontinuation, and safety by a reduced risk of all-cause death and hospitalization for non-mental disorder, 2 years after AP initiation or reinitiation. Cox proportional hazard models were used to estimate the events associated with different antipsychotics compared with oral olanzapine. RESULTS: The study cohort included 19,615 patients initiating or reinitiating an antipsychotic drug between January 2006 and December 2015. Results showed better effectiveness of clozapine (adjusted HR 0.36, 95% CI 0.30-0.42, p < 0.0001) and LAI SGAs (adjusted HR 0.56, 95% CI 0.51-0.61, p < 0.0001) compared with oral olanzapine when adding discontinuation to hospitalizations for mental disorder as a composite measure of effectiveness, as opposed to oral FGAs (adjusted HR 1.36, 95% CI 1.27-1.46, p < 0.0001) and LAI FGAs (adjusted HR 1.22, 95% CI 1.12-1.32, p < 0.0001). Most APs were as safe as oral olanzapine. CONCLUSION: The effectiveness of LAI SGAs and clozapine appears to justify their use and are as safe as a recognized treatment (oral olanzapine) in Quebec (Canada).

Association between previous and future antipsychotic adherence in patients initiating clozapine: real-world observational study.

BACKGROUND: Although recognised as the most effective antipsychotic for treatment-resistant schizophrenia, clozapine remains underused. One reason is the widespread concern about non-adherence to clozapine because of poor adherence before initiating clozapine. AIMS: To determine if prior poor out-patient adherence to treatmentbefore initiating clozapine predisposes to poor out-patient adherence to clozapine or to any antipsychotics (including clozapine) after its initiation. METHOD: This cohort study included 3228 patients with schizophrenia living in Quebec (Canada) initiating (with a 2-year clearance period) oral clozapine (index date) between 2009 and 2016. Using pharmacy data, out-patient adherence to treatment was measured by the medication possession ratio (MPR), over a 1-year period preceding and following the index date. Five groups of patients were formed based on their prior MPR level (independent variable). Two dependent variables were defined after clozapine initiation (good out-patient adherence to any antipsychotics and to clozapine only). Along with multiple logistic regressions, state sequence analysis was used as a visual representation of antipsychotic-use trajectories over time, before and after clozapine initiation. RESULTS: Although prior poor adherence to antipsychotics was associated with poor adherence after clozapine initiation, the absolute risk of subsequent poor adherence remained low, regardless of previous adherence level. Most patients adhered to their treatment after initiating clozapine (>68% to clozapine and >84% to any antipsychotics). CONCLUSIONS: Despite the fact that poor adherence prior to initiating clozapine is widely recognised by clinicians as a barrier for the prescription of clozapine, the current study supports the initiation of clozapine in all eligible patients.

Profiles of Frequent Geriatric Users of Emergency Departments: A Latent Class Analysis.

BACKGROUND/OBJECTIVES: Frequent geriatric users of emergency departments (EDs) represent a complex and heterogeneous population. Identifying their specific subgroups would allow the development of interventions better customized to their needs and characteristics. Thus, this study aimed to develop profiles of frequent geriatric ED users using the individual characteristics of patients. DESIGN: This was a retrospective cohort study. SETTING: Databases from the Régie de l'assurance maladie du Québec (RAMQ) were utilized. PARTICIPANTSThis study included individuals aged 65 years or older living in the community in the Province of Quebec (Canada), who consulted in an ED at least four times in the year after an ED index date (an ED visit, chosen randomly, during an index period of January 1, 2012 to December 31, 2013) and who had received a diagnosis of ambulatory care-sensitive conditions (ACSCs) in the 2 years preceding the index date. MEASUREMENTS: A latent class analysis was used to identify subgroups of frequent geriatric ED users according to their individual characteristics, including ACSC type, dementia, mental health disorders, cancer diagnosis, and comorbidity index. RESULTS: The study cohort consisted of 21,393 frequent geriatric ED users. Four groups of frequent geriatric ED users were identified: people with low comorbidity (39.0%), comprising the individuals with the lowest number of physical and mental health conditions; people with cancer (32.7%); people with pulmonaryand cardiac diseases (18.1%); and people with dementia or mental health disorders (10.2%), composed of individuals with the highest proportion of common and severe mental health disease, as well as dementia. This group accounts for the highest use of overall healthcare services. CONCLUSION: These profiles will be useful in developing customized interventions addressing the needs of each subgroup of frequent geriatric ED users. More research is needed to bridge the remaining gaps, especially regarding the healthiest frequent geriatric users of EDs.

Healthcare utilization after a first hospitalization for COPD: a new approach of State Sequence Analysis based on the '6W' multidimensional model of care trajectories.

BACKGROUND: Published methods to describe and visualize Care Trajectories (CTs) as patterns of healthcare use are very sparse, often incomplete, and not intuitive for non-experts. Our objectives are to propose a typology of CTs one year after a first hospitalization for Chronic Obstructive Pulmonary Disease (COPD), and describe CT types and compare patients' characteristics for each CT type. METHODS: This is an observational cohort study extracted from Quebec's medico-administrative data of patients aged 40 to 84 years hospitalized for COPD in 2013 (index date). The cohort included patients hospitalized for the first time over a 3-year period before the index date and who survived over the follow-up period. The CTs consisted of sequences of healthcare use (e.g. ED-hospital-home-GP-respiratory therapists, etc.) over a one-year period. The main variable was a CT typology, which was generated by a 'tailored' multidimensional State Sequence Analysis, based on the "6W" model of Care Trajectories. Three dimensions were considered: the care setting ("where"), the reason for consultation ("why"), and the speciality of care providers ("which"). Patients were grouped into specific CT types, which were compared in terms of care use attributes and patients' characteristics using the usual descriptive statistics. RESULTS: The 2581 patients were grouped into five distinct and homogeneous CT types: Type 1 (n = 1351, 52.3%) and Type 2 (n = 748, 29.0%) with low healthcare and moderate healthcare use respectively; Type 3 (n = 216, 8.4%) with high healthcare use, mainly for respiratory reasons, with the highest number of urgent in-hospital days, seen by pulmonologists and respiratory therapists at primary care settings; Type 4 (n = 100, 3.9%) with high healthcare use, mainly cardiovascular, high ED visits, and mostly seen by nurses in community-based primary care; Type 5 (n = 166, 6.4%) with high healthcare use, high ED visits and non-urgent hospitalisations, and with consultations at outpatient clinics and primary care settings, mainly for other reasons than respiratory or cardiovascular. Patients in the 3 highest utilization CT types were older, and had more comorbidities and more severe condition at index hospitalization. CONCLUSIONS: The proposed method allows for a better representation of the sequences of healthcare use in the real world, supporting data-driven decision making.

Frequent emergency department use by older adults with ambulatory care sensitive conditions: A population-based cohort study.

AIM: To identify factors associated with frequent emergency department (ED) use among older adults with ambulatory care sensitive conditions. METHODS: This was a retrospective cohort study using databases from the Régie de l'assurance maladie du Québec. We included community-dwelling individuals aged ≥65 years in the Province of Quebec (Canada), who consulted in ED at least once between 2012 and 2013 (index period), and were diagnosed with at least one ambulatory care sensitive condition in the 2 years preceding and including the index date (n = 264 473). We used a multivariate logistic regression model to evaluate the association between independent variables and being a frequent geriatric ED user, defined as four or more visits during the year after the index date. RESULTS: Out of the total study population, 17 332 (6.6%) individuals were considered frequent ED users in the year after the index date, accounting for 38% of ED uses for this period. The main variables associated with frequent geriatric ED use were older age, presence of chronic obstructive pulmonary disorder or diabetes, higher comorbidity index, common mental health disorders, polypharmacy, higher number of past ED and specialist visits, rural residence, and higher material and social deprivation. Dementia was inversely associated with frequent ED use. CONCLUSIONS: Frequent geriatric ED users constitute a complex population whose characteristics need to be managed thoroughly in order to enhance the quality and efficiency of their care. Further studies should address their description in administrative databases so as to combine self-perceived and professionally evaluated variables. Geriatr Gerontol Int 2020; 20: 317-323.

Risk of Frequent Emergency Department Use Among an Ambulatory Care Sensitive Condition Population: A Population-based Cohort Study.

BACKGROUND: A small fraction of patients use a disproportionately large amount of emergency department (ED) resources. Identifying these patients, especially those with ambulatory care sensitive conditions (ACSC), would allow health care professionals to enhance their outpatient care. OBJECTIVE: The objectives of the study were to determine predictive factors associated with frequent ED use in a Quebec adult population with ACSCs and to compare several models predicting the risk of becoming an ED frequent user following an ED visit. RESEARCH DESIGN: This was an observational population-based cohort study extracted from Quebec's administrative data. SUBJECTS: The cohort included 451,775 adult patients, living in nonremote areas, with an ED visit between January 2012 and December 2013 (index visit), and previously diagnosed with an ACSC but not dementia. MEASURES: The outcome was frequent ED use (≥4 visits) during the year following the index visit. Predictors included sociodemographics, physical and mental comorbidities, and prior use of health services. We developed several logistic models (with different sets of predictors) on a derivation cohort (2012 cohort) and tested them on a validation cohort (2013 cohort). RESULTS: Frequent ED users represented 5% of the cohort and accounted for 36% of all ED visits. A simple 2-variable prediction model incorporating history of hospitalization and number of previous ED use accurately predicted future frequent ED use. The full model with all sets of predictors performed only slightly better than the simple model (area under the receiver-operating characteristic curve: 0.786 vs. 0.759, respectively; similar positive predictive value and number needed to evaluate curves). CONCLUSIONS: The ability to identify frequent ED users based only on previous ED and hospitalization use provides an opportunity to rapidly target this population for appropriate interventions.

Persistent frequent emergency department users with chronic conditions: A population-based cohort study.

BACKGROUND: Frequent emergency department users are patients cumulating at least four visits per year. Few studies have focused on persistent frequent users, who maintain their frequent user status for multiple consecutive years. This study targets an adult population with chronic conditions, and its aims are: 1) to estimate the prevalence of persistent frequent ED use; 2) to identify factors associated with persistent frequent ED use (frequent use for three consecutive years) and compare their importance with those associated with occasional frequent ED use (frequent use during the year following the index date); and 3) to compare characteristics of "persistent frequent users" to "occasional frequent users" and to "users other than persistent frequent users". METHODS: This is a retrospective cohort study using Quebec administrative databases. All adult patients who visited the emergency department in 2012, diagnosed with chronic conditions, and living in non-remote areas were included. Patients who died in the three years following their index date were excluded. The main outcome was persistent frequent use (≥4 visits per year during three consecutive years). Potential predictors included sociodemographic characteristics, physical and mental comorbidities, and prior healthcare utilization. Odds ratios were computed using multivariable logistic regression. RESULTS: Out of 297,182 patients who visited ED at least once in 2012, 3,357 (1.10%) were persistent frequent users. Their main characteristics included poor socioeconomic status, mental and physical comorbidity, and substance abuse. Those characteristics were also present for occasional frequent users, although with higher percentages for the persistent user group. The number of previous visits to the emergency department was the most important factor in the regression model. The occasional frequent users' attrition rate was higher between the first and second year of follow-up than between the second and third year. CONCLUSIONS: Persistent frequent users are a subpopulation of frequent users with whom they share characteristics, such as physical and mental comorbidities, though the former are poorer and younger. More research is needed in order to better understand what factors can contribute to persistent frequent use.