Risk factors for avoidable hospitalizations in Canada using national linked data: A retrospective cohort study

Primary care payment models and avoidable hospitalizations in Ontario, Canada: A multivalued treatment effects analysis

Improving access to primary care physicians' services may help reduce hospitalizations due to Ambulatory Care Sensitive Conditions (ACSCs). Ontario, Canada's most populous province, introduced blended payment models for primary care physicians in the early- to mid-2000s to increase access to primary care, preventive care, and better chronic disease management. We study the impact of payment models on avoidable hospitalizations due to two incentivized ACSCs (diabetes and congestive heart failure) and two non-incentivized ACSCs (angina and asthma). The data for our study came from health administrative data on practicing primary care physicians in Ontario between 2006 and 2015. We employ a two-stage estimation strategy on a balanced panel of 3710 primary care physicians (1158 blended-fee-for-service (FFS), 1388 blended-capitation models, and 1164 interprofessional team-based practices). First, we account for the differences in physician practices using a generalized propensity score based on a multinomial logit regression model, corresponding to three primary care payment models. Second, we use fractional regression models to estimate the average treatment effects on the treated outcome (i.e., avoidable hospitalizations). The capitation-based model sometimes increases avoidable hospitalizations due to angina (by 7 per 100,000 patients) and congestive heart failure (40 per 100,000) relative to the blended-FFS-based model. Switching capitation physicians into interprofessional teams mitigates this effect, reducing avoidable hospitalizations from congestive heart failure by 30 per 100,000 patients and suggesting better access to primary care and chronic disease management in team-based practices.

Emergency Department Use Among Adults Receiving Dialysis

Importance

People with kidney failure receiving maintenance dialysis visit the emergency department (ED) 3 times per year on average, which is 3- to 8-fold more often than the general population. Little is known about the factors that contribute to potentially preventable ED use in this population.

Objective

To identify the clinical and sociodemographic factors associated with potentially preventable ED use among patients receiving maintenance dialysis.

Design, Setting, and Participants

This cohort study used linked administrative health data within the Alberta Kidney Disease Network to identify adults aged 18 years or older receiving maintenance dialysis (ie, hemodialysis or peritoneal dialysis) between April 1, 2010, and March 31, 2019. Patients who had been receiving dialysis for more than 90 days were followed up from cohort entry (defined as dialysis start date plus 90 days) until death, outmigration from the province, receipt of a kidney transplant, or end of study follow-up. The Andersen behavioral model of health services was used as a conceptual framework to identify variables related to health care need, predisposing factors, and enabling factors. Data were analyzed in March 2024.

Main Outcomes and Measures

Rates of all-cause ED encounters and potentially preventable ED use associated with 4 kidney disease-specific ambulatory care-sensitive conditions (hyperkalemia, heart failure, volume overload, and malignant hypertension) were calculated. Multivariable negative binomial regression models were used to examine the association between clinical and sociodemographic factors and rates of potentially preventable ED use.

Results

The cohort included 4925 adults (mean [SD] age, 60.8 [15.5] years; 3071 males [62.4%]) with kidney failure receiving maintenance hemodialysis (3183 patients) or peritoneal dialysis (1742 patients) who were followed up for a mean (SD) of 2.5 (2.0) years. In all, 3877 patients had 34 029 all-cause ED encounters (3100 [95% CI, 2996-3206] encounters per 1000 person-years). Of these, 755 patients (19.5%) had 1351 potentially preventable ED encounters (114 [95% CI, 105-124] encounters per 1000 person-years). Compared with patients with a nonpreventable ED encounter, patients with a potentially preventable ED encounter were more likely to be in the lowest income quintile (38.8% vs 30.9%; P < .001); to experience heart failure (46.8% vs 39.9%; P = .001), depression (36.6% vs 32.5%; P = .03), and chronic pain (60.1% vs 54.9%; P = .01); and to have a longer duration of dialysis (3.6 vs 2.6 years; P < .001). In multivariable regression analyses, potentially preventable ED use was higher for younger adults (incidence rate ratio [IRR], 1.69 [95% CI, 1.33-2.15] for those aged 18 to 44 years) and patients with chronic pain (IRR, 1.35 [95% CI, 1.14-1.61]), greater material deprivation (IRR, 1.57 [95% CI, 1.16-2.12]), a history of hyperkalemia (IRR, 1.31 [95% CI, 1.09-1.58]), and historically high ED use (ie, ≥3 ED encounters in the prior year; IRR, 1.46 [95% CI, 1.23-1.73).

Conclusions and Relevance

In this study of adults receiving maintenance dialysis in Alberta, Canada, among those with ED use, 1 in 5 had a potentially preventable ED encounter; reasons for such encounters were associated with both psychosocial and medical factors. The findings underscore the need for strategies that address social determinants of health to avert potentially preventable ED use in this population.

A study protocol for a predictive model to assess population-based avoidable hospitalization risk: Avoidable Hospitalization Population Risk Prediction Tool (AvHPoRT)

INTRODUCTION

Avoidable hospitalizations are considered preventable given effective and timely primary care management and are an important indicator of health system performance. The ability to predict avoidable hospitalizations at the population level represents a significant advantage for health system decision-makers that could facilitate proactive intervention for ambulatory care-sensitive conditions (ACSCs). The aim of this study is to develop and validate the Avoidable Hospitalization Population Risk Tool (AvHPoRT) that will predict the 5-year risk of first avoidable hospitalization for seven ACSCs using self-reported, routinely collected population health survey data.

METHODS AND ANALYSIS

The derivation cohort will consist of respondents to the first 3 cycles (2000/01, 2003/04, 2005/06) of the Canadian Community Health Survey (CCHS) who are 18-74 years of age at survey administration and a hold-out data set will be used for external validation. Outcome information on avoidable hospitalizations for 5 years following the CCHS interview will be assessed through data linkage to the Discharge Abstract Database (1999/2000-2017/2018) for an estimated sample size of 394,600. Candidate predictor variables will include demographic characteristics, socioeconomic status, self-perceived health measures, health behaviors, chronic conditions, and area-based measures. Sex-specific algorithms will be developed using Weibull accelerated failure time survival models. The model will be validated both using split set cross-validation and external temporal validation split using cycles 2000-2006 compared to 2007-2012. We will assess measures of overall predictive performance (Nagelkerke R2), calibration (calibration plots), and discrimination (Harrell's concordance statistic). Development of the model will be informed by the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) statement.

ETHICS AND DISSEMINATION

This study was approved by the University of Toronto Research Ethics Board. The predictive algorithm and findings from this work will be disseminated at scientific meetings and in peer-reviewed publications.

Virtual care use among older immigrant adults in Ontario, Canada during the COVID-19 pandemic: A repeated cross-sectional analysis

The critical role of virtual care during the COVID-19 pandemic has raised concerns about the widening disparities to access by vulnerable populations including older immigrants. This paper aims to describe virtual care use in older immigrant populations residing in Ontario, Canada. In this population-based, repeated cross-sectional study, we used linked administrative data to describe virtual care and healthcare utilization among immigrants aged 65 years and older before and during the COVID-19 pandemic. Visits were identified weekly from January 2018 to March 2021 among various older adult immigrant populations. Among older immigrants, over 75% were high users of virtual care (had two or more virtual visits) during the pandemic. Rates of virtual care use was low (weekly average <2 visits per 1000) prior to the pandemic, but increased for both older adult immigrant and non-immigrant populations. At the start of the pandemic, virtual care use was lower among immigrants compared to non-immigrants (weekly average of 77 vs 86 visits per 1000). As the pandemic progressed, the rates between these groups became similar (80 vs 79 visits per 1000). Virtual care use was consistently lower among immigrants in the family class (75 visits per 1000) compared to the economic (82 visits per 1000) or refugee (89 visits per 1000) classes, and was lower among those who only spoke French (69 visits per 1000) or neither French nor English (73 visits per 1000) compared to those who were fluent in English (81 visits per 1000). This study found that use of virtual care was comparable between older immigrants and non-immigrants overall, though there may have been barriers to access for older immigrants early on in the pandemic. However, within older immigrant populations, immigration category and language ability were consistent differentiators in the rates of virtual care use throughout the pandemic.

Childhood adversities and rate of adulthood all-cause hospitalization in the general population: A retrospective cohort study

OBJECTIVE

The study examined the association between specific childhood adversities and rate of all-cause hospitalization in adulthood in a large sample of the general population and assessed whether adult socioeconomic and health-related factors mediate those associations.

METHODS

We used linked data available from Statistics Canada i.e., the Canadian Community Health Survey (CCHS-2005) linked to Discharge Abstract Database (DAD 2005-2017) and Canadian Vital Statistics Database (CVSD 2005-2017). CCHS-2005 measured self-reported exposure to childhood adversities, namely prolonged hospitalization, parental divorce, parental unemployment, prolonged trauma, parental substance use, physical abuse, and being sent away from home for wrongdoing, from a sample of household residents aged 18 years and above (n = 11,340). The number and causes of hospitalization were derived from linkage with DAD. Negative binomial regression was used to characterize the association between childhood adversities and the rate of hospitalization and to identify potential mediators between them.

RESULTS

During the 12-year follow-up, 37,080 hospitalizations occurred among the respondents, and there were 2,030 deaths. Exposure to at least one childhood adversity and specific adversities (except parental divorce) were significantly associated with the hospitalization rate among people below 65 years. The associations (except for physical abuse) were attenuated when adjusted for one or more of the adulthood factors such as depression, restriction of activity, smoking, chronic conditions, poor perceived health, obesity, unmet health care needs, poor education, and unemployment, observations that are consistent with mediation effects. The associations were not significant among those aged 65 and above.

CONCLUSION

Childhood adversities significantly increased the rate of hospitalization in young and middle adulthood, and the effect was potentially mediated by adulthood socioeconomic status and health and health care access related factors. Health care overutilization may be reduced through primary prevention of childhood adversities and intervention on those potentially mediating pathways such as improving adulthood socioeconomic circumstances and lifestyle modifications.

Emergency department utilization and hospital admissions for ambulatory care sensitive conditions among people seeking a primary care provider during the COVID-19 pandemic

BACKGROUND

Primary care attachment improves health care access and health outcomes, but many Canadians are unattached, seeking a provider via provincial wait-lists. This Nova Scotia-wide cohort study compares emergency department utilization and hospital admission associated with insufficient primary care management among patients on and off a provincial primary care wait-list, before and during the first waves of the COVID-19 pandemic.

METHODS

We linked wait-list and Nova Scotian administrative health data to describe people on and off wait-list, by quarter, between Jan. 1, 2017, and Dec. 24, 2020. We quantified emergency department utilization and ambulatory care sensitive condition (ACSC) hospital admission rates by wait-list status from physician claims and hospital admission data. We compared relative differences during the COVID-19 first and second waves with the previous year.

RESULTS

During the study period, 100 867 people in Nova Scotia (10.1% of the provincial population) were on the wait-list. Those on the wait-list had higher emergency department utilization and ACSC hospital admission. Emergency department utilization was higher overall for individuals aged 65 years and older, and females; lowest during the first 2 COVID-19 waves; and differed more by wait-list status for those younger than 65 years. Emergency department contacts and ACSC hospital admissions decreased during the COVID-19 pandemic relative to the previous year, and for emergency department utilization, this difference was more pronounced for those on the wait-list.

INTERPRETATION

People in Nova Scotia seeking primary care attachment via the provincial wait-list use hospital-based services more frequently than those not on the wait-list. Although both groups have had lower utilization during COVID-19, existing challenges to primary care access for those actively seeking a provider were further exacerbated during the initial waves of the pandemic. The degree to which forgone services produces downstream health burden remains in question.

Characteristics of High-Resource Health System Users in Rural and Remote Regions: A Scoping Review

A small proportion of health care users are recognized to use a significantly higher proportion of health system resources, largely due to systemic, inequitable access and disproportionate health burdens. These high-resource health system users are routinely characterized as older, with multiple comorbidities, and reduced access to adequate health care. Geographic trends also emerge, with more rural and isolated regions demonstrating higher rates of high-resource use than others. Despite known geographical discrepancies in health care access and outcomes, health policy and research initiatives remain focused on urban population centers. To alleviate mounting health system pressure from high-resource users, their characteristics must be better understood within the context in which i arises. To examine this, a scoping review was conducted to provide an overview of characteristics of high-resource users in rural and remote communities in Canada and Australia. In total, 21 papers were included in the review. Using qualitative thematic coding, primary findings characterized rural high-resource users as those of an older age; with increased comorbid conditions and condition severity; lower socioeconomic status; and elevated risk behaviors.

Social disparities in unplanned 30-day readmission rates after hospital discharge in patients with chronic health conditions: A retrospective cohort study using patient level hospital administrative data linked to the population census in Switzerland

Unplanned readmissions shortly after discharge from hospital are common in chronic diseases. The risk of readmission has been shown to be related both to hospital care, e.g., medical complications, and to patients’ resources and abilities to manage the chronic disease at home and to make appropriate use of outpatient medical care. Despite a growing body of evidence on social determinants of health and health behaviour, little is known about the impact of social and contextual factors on readmission rates. The objective of this study was to analyse possible effects of educational, financial and social resources of patients with different chronic health conditions on unplanned 30 day-readmission risks. The study made use of nationwide inpatient hospital data that was linked with Swiss census data. The sample included n = 62,109 patients aged 25 and older, hospitalized between 2012 and 2016 for one of 12 selected chronic conditions. Multivariate logistic regressions analysis was performed. Our results point to a significant association between social factors and readmission rates for patients with chronic conditions. Patients with upper secondary education (OR = 1.26, 95% CI: 1.11, 1.44) and compulsory education (OR = 1.51, 95% CI: 1.31, 1.74) had higher readmission rates than those with tertiary education when taking into account demographic, social and health status factors. Having private or semi-private hospital insurance was associated with a lower risk for 30-day readmission compared to patients with mandatory insurance (OR = 0.81, 95% CI: 0.73, 0.90). We did not find a general effect of social resources, measured by living with others in a household, on readmission rates. The risk of readmission for patients with chronic conditions was also strongly predicted by type of chronic condition and by factors related to health status, such as previous hospitalizations before the index hospitalization (+77%), number of comorbidities (+15% higher probability per additional comorbidity) as well as particularly long hospitalizations (+64%). Stratified analysis by type of chronic condition revealed differential effects of social factors on readmissions risks. Compulsory education was most strongly associated with higher odds for readmission among patients with lung cancer (+142%), congestive heart failure (+63%) and back problems (+53%). We assume that low socioeconomic status among patients with chronic conditions increases the risk of unplanned 30-day readmission after hospitalisation due to factors related to their social situation (e.g., low health literacy, material deprivation, high social burden), which may negatively affect cooperation with care providers and adherence to recommended therapies as well as hamper active participation in the medical process and the development of a shared understanding of the disease and its cure. Higher levels of comorbidity in socially disadvantaged patients can also make appropriate self-management and use of outpatient care more difficult. Our findings suggest a need for increased preventive measures for disadvantaged populations groups to promote early detection of diseases and to remove financial or knowledge-based barriers to medical care. Socially disadvantaged patients should also be strengthened more in their individual and social resources for coping with illness.

Social inequalities, length of hospital stay for chronic conditions and the mediating role of comorbidity and discharge destination: A multilevel analysis of hospital administrative data linked to the population census in Switzerland

Social factors are recognized determinants of morbidity and mortality and also have an impact on use of medical services. The objective of this study was to assess the associations of educational attainment, social and financial resources, and migration factors with length of hospital stays for chronic conditions. In addition, the study investigated the role of comorbidity and discharge destination in mediating these associations. The study made use of nationwide inpatient data that was linked with Swiss census data. The study sample included n = 141,307 records of n = 92,623 inpatients aged 25 to 84 years, hospitalized between 2010 and 2016 for a chronic condition. Cross-classified multilevel models and mediation analysis were performed. Patients with upper secondary and compulsory education stayed longer in hospital compared to those with tertiary education (β 0.24 days, 95% CI 0.14-0.33; β 0.37, 95% CI 0.27-0.47, respectively) when taking into account demographic factors, main diagnosis and clustering on patient and hospital level. However, these effects were almost fully mediated by burden of comorbidity. The effect of living alone on length of stay (β 0.60 days, 95% CI 0.50-0.70) was partially mediated by both burden of comorbidities (33%) and discharge destination (30.4%). (Semi-) private insurance was associated with prolonged stays, but an inverse effect was observed for colon and breast cancer. Allophone patients had also prolonged hospital stays (β 0.34, 95% CI 0.13-0.55). Hospital stays could be a window of opportunity to discern patients who need additional time and support to better cope with everyday life after discharge, reducing the risks of future hospital stays. However, inpatient care in Switzerland seems to take into account rather obvious individual needs due to lack of immediate support at home, but not necessarily more hidden needs of patients with low health literacy and less resources to assert their interests within the health system.

Social and Regional Factors Predict the Likelihood of Admission to a Nursing Home After Acute Hospital Stay in Older People With Chronic Health Conditions: A Multilevel Analysis Using Routinely Collected Hospital and Census Data in Switzerland

If hospitalization becomes inevitable in the course of a chronic disease, discharge from acute hospital care in older persons is often associated with temporary or persistent frailty, functional limitations and the need for help with daily activities. Thus, acute hospitalization represents a particularly vulnerable phase of transient dependency on social support and health care. This study examines how social and regional inequality affect the decision for an institutionalization after acute hospital discharge in Switzerland. The current analysis uses routinely collected inpatient data from all Swiss acute hospitals that was linked on the individual level with Swiss census data. The study sample included 60,209 patients 75 years old and older living still at a private home and being hospitalized due to a chronic health condition in 199 hospitals between 2010 and 2016. Random intercept multilevel logistic regression was used to assess the impact of social and regional factors on the odds of a nursing home admission after hospital discharge. Results show that 7.8% of all patients were admitted directly to a nursing home after hospital discharge. We found significant effects of education level (compulsory vs. tertiary education OR = 1.16 (95% CI: 1.03-1.30), insurance class (compulsory vs. private insurance OR = 1.24 (95% CI: 1.09-1.41), living alone vs. living with others (OR = 1.64; 95% CI: 1.53-1.76) and language regions (French vs. German speaking part: OR = 0.54; 95% CI: 0.37-0.80) on the odds of nursing home admission in a model adjusted for age, gender, nationality, health status, year of hospitalization and hospital-level variance. The language regions moderated the effect of education and insurance class but not of living alone. This study shows that acute hospital discharge in older age is a critical moment of transient dependency especially for socially disadvantaged patients. Social and health care should work coordinated together to avoid unnecessary institutionalizations.

Association between accuracy of weight perception and life satisfaction among adults with and without anxiety and mood disorders: a cross-sectional study of the 2015-2018 Canadian Community Health Survey

BACKGROUND

Weight status and weight perception have a significant impact on life satisfaction. As overweight prevalence increases in Canada, it is important to understand how accuracy of weight perception (AWP) is associated with life satisfaction. This study explored the association between AWP and life satisfaction among Canadian adults with and without anxiety and/or mood disorders.

METHODS

Using data from the 2015-2018 cycles of the Canadian Community Health Survey, an indicator of AWP was created to capture concordance between perceived weight and actual weight status. Univariate and multivariate Gaussian generalized linear models were assessed while stratifying by sex and presence of anxiety and/or mood disorders.

RESULTS

Our sample included 88 814 males and 106 717 females. For both sexes, perceiving oneself as overweight or underweight, regardless of actual weight status, was associated with lower life satisfaction (β = -0.93 to -0.30), compared to those who accurately perceived their weight as 'just about right'. Perceiving oneself as overweight or underweight was associated with more pronounced differences in life satisfaction scores in those with anxiety and/or mood disorders (β = -1.49 to -0.26) than in those without these disorders (β = -0.76 to -0.25).

CONCLUSION

Weight perception is more indicative of life satisfaction than actual weight status, especially in those with anxiety and/or mood disorders.

Avoidable hospitalizations and access to primary care: comparisons among Italians, resident immigrants and undocumented immigrants in administrative hospital discharge records

BACKGROUND

Immigrants face multiple barriers in accessing healthcare; however, empirical assessment of access presents serious methodological issues, and evidence on undocumented immigrants is scant and based mainly on non-representative samples. We examine avoidable hospitalization (AH) as an indicator of poor access to primary care (PC) in Italy, where a universal healthcare system guarantees access but fails to assign general practitioners to undocumented immigrants.

METHODS

Using anonymized national hospital discharge records in 2019, undocumented immigrants were identified through an administrative financing code. Potential effects of poor access to PC were measured by focusing on the incidence of AH, differentiated among chronic, acute and vaccine-preventable conditions, comparing Italian citizens, documented (foreign nationals with residence permits) and undocumented immigrants. We estimated odd ratios (ORs) through logistic regression models, controlling for individual and contextual confounders.

FINDINGS

Compared with Italians, undocumented and documented immigrants adjusted odd ratios (OR) for the risk of AH were 1·422 (95% CI 1·322-1·528) and 1·243 (95% CI 1·201-1·287), respectively. Documented immigrants showed ORs not significantly greater than 1 for AH due to chronic diseases compared with Italians, while undocumented immigrants registered higher adjusted OR for all AH categories - chronic (OR 1·187; 95% CI 1·064-1·325), acute (OR 1·645; 95% CI 1·500-1·803) and vaccine-preventable (OR 2·170; 95% CI 1·285-3·664).

INTERPRETATION

Documented and undocumented immigrants face considerably higher risk of AH compared to Italians. Considering the burden of AHs, access to PC (including preventive and ambulatory care) should be provided to undocumented immigrants, and additional barriers to care for all immigrants should be further explored.

FUNDING

None.

Cumulative social disadvantage and hospitalisations due to ambulatory care-sensitive conditions in Finland in 2011─2013: a register study

OBJECTIVES

To study the interplay between several indicators of social disadvantage and hospitalisations due to ambulatory care-sensitive conditions (ACSC) in 2011─2013. To evaluate whether the accumulation of preceding social disadvantage in one point of time or prolongation of social disadvantage had an effect on hospitalisations due to ACSCs. Four common indicators of disadvantage are examined: living alone, low level of education, poverty and unemployment.

DESIGN

A population-based register study.

SETTING

Nationwide individual-level register data on hospitalisations due to ACSCs for the years 2011-2013 and preceding data on social and socioeconomic factors for the years 2006─2010.

PARTICIPANTS

Finnish residents aged 45 or older on 1 January 2011.

OUTCOME MEASURE

Hospitalisations due to ACSCs in 2011-2013. The effect of accumulation of preceding disadvantage in one point of time and its prolongation on ACSCs was studied using modified Poisson regression.

RESULTS

People with preceding cumulative social disadvantage were more likely to be hospitalised due to ACSCs. The most hazardous combination was simultaneously living alone, low level of education and poverty among the middle-aged individuals (aged 45-64 years) and the elderly (over 64 years). Risk ratio (RR) of being hospitalised due to ACSC was 3.16 (95% CI 3.03-3.29) among middle-aged men and 3.54 (3.36-3.73) among middle-aged women compared with individuals without any of these risk factors when controlling for age and residential area. For the elderly, the RR was 1.61 (1.57-1.66) among men and 1.69 (1.64-1.74) among women.

CONCLUSIONS

To improve social equity in healthcare, it is important to recognise not only patients with cumulative disadvantage but also-as this study shows-patients with particular combinations of disadvantage who may be more susceptible. The identification of these vulnerable patient groups is also necessary to reduce the use of more expensive treatment in specialised healthcare.