Hannah Chung’s research while affiliated with Institute for Clinical Evaluative Sciences and other places

Background Emerging evidence shows the lasting impact of SARS-CoV-2 infection on health care use and needs. Policy-makers require data on population-level service use to understand patient needs and health system impacts following hospitalization for COVID-19. Objective To compare health service use within 12 months following hospitalization for COVID-19 among people with and without pre-existing disabilities, and to determine the extent to which such use is related to disability and other risk factors. Design Population-based cohort study, Ontario, Canada. Participants Adults with and without disabilities hospitalized for COVID-19, 01/25/2020–02/28/2022. Main Measures We used Poisson regression to model adjusted rate ratios (aRR) of ambulatory care visits, diagnostic testing, emergency department (ED) visits, hospital admissions, and palliative care visits within 1-year post-discharge, comparing patients with and without disabilities. Models were adjusted sequentially for sociodemographic factors, comorbidities, and prior health service use. The importance of each set of covariates in its ability to explain observed associations was determined by calculating relative changes in disability parameter coefficients after each sequential risk-adjustment. Key Results The cohort included 25,320 patients with disabilities and 15,953 without. In the year after hospitalization for COVID-19, people with disabilities had higher rates of ambulatory care visits, diagnostic tests, ED visits, hospital admissions, and palliative care visits. A significant proportion of these associations was explained by sociodemographic factors, comorbidities, and prior health service use. However, adjusted relative rates associated with disability remained elevated, even after adjustment, for ambulatory care visits (aRR 1.09, 95% CI 1.08, 1.10), diagnostic tests (aRR 1.14, 95% CI 1.12, 1.16), ED visits (aRR 1.25, 95% CI 1.21, 1.29), and hospital admissions (aRR 1.21, 95% CI 1.16, 1.29). Conclusions These findings support the need to develop and evaluate models of care for the post-COVID-19 condition that address the needs of people with disabilities.

Background and aims The expanded use of virtual care may worsen pre-existing disparities in use and delivery of end-of-life care among certain groups of people. We measured the use of virtual care in the last three months of life before and after the introduction of virtual care fee codes that funded care delivery at the start of COVID-19 on March 14, 2020, and identified changes in the characteristics of people using it. Methods We used linked clinical and administrative datasets to study use of virtual care in the last three months of life among 411,564 adults who died between January 25, 2018, and November 30, 2022. Modified Poisson regression was used to measure the association of the use of virtual care in the last three months of life with the pandemic study period and its association with each person- and physician-level factor. Results 14,261 people (8%) used virtual care in the last three months of life before the pandemic, and 161,000 people (69%) used it during the pandemic (relative risk [RR] 8.76; 95% CI 8.48–9.05). Several individual patient characteristics were associated with statistically significant increases in the use of virtual care after March 14, 2020 (following the introduction of virtual care fee codes), compared to before such as among older adults, ethnic minorities, multiple chronic comorbid health conditions and higher frailty groups. Conclusions The introduction of new fee codes broadening technology and funding for end-of-life care at the start of pandemic combined with pandemic-related effects was associated with a substantial increase in the use of virtual care near the end of life among certain groups and a general leveling of pre-existing disparities in its use. Virtual end-of-life care delivery may strengthen person-centredness for individuals with limited ability to attend in-person appointments and by providers who may not have previously engaged in such care.

Objective To measure the association between types of serious illness and the use of different physician-delivered care models near the EOL during the COVID-19 pandemic. Design, setting and participants Population-based cohort study using health administrative datasets in Ontario, Canada, for adults aged ≥18 years in their last 90 days of life who died of cancer or terminal noncancer illness and received physician-delivered care models near the end-of-life between March 14, 2020 and January 24, 2022. Exposure The type of serious illness (cancer or terminal noncancer illness). Main outcome Physician-delivered care models for adults in the last 90 days of life (exclusively virtual, exclusively home-based in-person, or mixed). Results The study included 75,930 adults (median age 78 years, 49% female, cancer n = 58,894 [78%], noncancer illness n = 17,036 [22%]). A higher proportion of people with cancer (39.3%) received mixed model of care compared to those with noncancer illnesses (chronic organ failure 24.4%, dementia 37.9%, multimorbidity 28%). Compared to people with cancer, people with chronic organ failure (adjusted odds ratio [aOR], 1.61, 95% CI: 1.54 to 1.68) and those with multimorbidity ([aOR], 1.49, 95% CI: 1.39 to 1.59) had a higher odds of receiving virtual care than a mixed model of care. People with dementia had a higher odds of home-based in-person care than a mixed model of care ([aOR], 1.47, 95% CI 1.27, 1.71) and virtual care ([aOR], 1.40, 95% CI 1.20–1.62) compared to people with cancer. Conclusion A person’s type of serious illness was associated with different care models near the end-of-life. This study demonstrates persistent disease-specific differences in care delivery or possibly the tailoring of models of care in the last 90 days of life based on a person’s specific care needs.

Recognizing higher rates of co-occurring health conditions in autistic adults and the frequent use of hospital-based health care services, this study compared rates of repeat emergency visits, repeat hospitalizations, and delayed discharges in autistic adults to other adults with and without developmental disabilities matched for age and sex, living in Ontario, Canada. Returning to the hospital emergency department within a month, being readmitted to hospital within a month and experiencing a delayed discharge from hospital were each more likely to occur in autistic males and females than their counterparts without developmental disabilities, with the risk ratios being the highest for delayed discharges. Males and females with other developmental disabilities were more likely to return to the emergency department within a month than their autistic counterparts, and males with other developmental disabilities were more likely than autistic males to be readmitted to hospital, but the likelihood of delayed discharge in the two groups was similar. These findings suggest that more needs to be done to both improve hospital-based experiences of autistic adults and adults with other developmental disabilities, and to strengthen community-based care to reduce the likelihood of repeat and extended stays in hospital. Lay abstract We know that autistic people have more health problems and are more likely to go to the emergency department and get hospitalized than other people, but we know less about the problems they have once they get to the hospital. In this study, we looked at all autistic adults in Ontario and compared them to adults who were not autistic and to adults who had other kinds of developmental disabilities to see who came back to the emergency department in the month after an emergency department visit, who got re-hospitalized in the month after being sent home from hospital, and who stayed in the hospital longer than they needed to because there was no place appropriate for them to go to. We found that both autistic males and females were more likely to have these things happen to them than the same age- and sex-matched adults who did not have developmental disabilities. We also found that adults with other kinds of developmental disabilities had similar problems to autistic people. This makes us think that we need to work harder to improve health care for autistic adults and adults with other developmental disabilities when they come to hospital. We also need to make community services work better, and work more closely with hospital services, so that people only come to hospital when they need to and that they can go home when they are ready.

Background People with disabilities are at elevated risk of adverse short-term outcomes following hospitalization for acute infectious illness. No prior studies have compared long-term healthcare use among this high-risk population. We compared the healthcare use of adults with disabilities in the one year following hospitalization for COVID-19 vs. sepsis vs. influenza. Methods We performed a population-based cohort study using linked clinical and health administrative databases in Ontario, Canada of all adults with pre-existing disability (physical, sensory, or intellectual) hospitalized for COVID-19 (n = 22,551, median age 69 [IQR 57–79], 47.9% female) or sepsis (n = 100,669, median age 77 [IQR 66–85], 54.8% female) between January 25, 2020, and February 28, 2022, and for influenza (n = 11,216, median age 78 [IQR 67–86], 54% female) or sepsis (n = 49,326, median age 72 [IQR 62–82], 45.8% female) between January 1, 2014 and March 25, 2019. The exposure was hospitalization for laboratory-confirmed SARS-CoV-2 or influenza, or sepsis (not secondary to COVID-19 or influenza). Outcomes were ambulatory care visits, diagnostic testing, emergency department visits, hospitalization, palliative care visits and death within 1 year. Rates of these outcomes were compared across exposure groups using propensity-based overlap weighted Poisson and Cox proportional hazards models. Findings Among older adults with pre-existing disability, hospitalization for COVID-19 was associated with lower rates of ambulatory care visits (adjusted rate ratio (aRR) 0.88, 95% confidence interval (CI), 0.87–0.90), diagnostic testing (aRR 0.86, 95% CI, 0.84–0.89), emergency department visits (aRR 0.91, 95% CI, 0.84–0.97), hospitalization (aRR 0.74, 95% CI, 0.71–0.77), palliative care visits (aRR 0.71, 95% CI, 0.62–0.81) and low hazards of death (adjusted hazard ratio (aHR) 0.71, 95% 0.68–0.75), compared to hospitalization for sepsis during the COVID-19 pandemic. Rates of healthcare use among those hospitalized for COVID-19 varied compared to those hospitalized for influenza or sepsis prior to the pandemic. Interpretation This study of older adults with pre-existing disabilities hospitalized for acute infectious illness found that COVID-19 was not associated with higher rates of healthcare use or mortality over the one year following hospital discharge compared to those hospitalized for sepsis. However, hospitalization for COVID-19 was associated with higher rates of ambulatory care use and mortality when compared to influenza. As COVID-19 enters an endemic phase, the associated long-term health resource use and risks in the contemporary era are reassuringly similar to sepsis and influenza, even among people with pre-existing disabilities. Funding This study was supported by 10.13039/100012665ICES, which is funded by an annual grant from the 10.13039/501100000226Ontario Ministry of Health and the Ministry of Long-Term Care. This study also received funding from the 10.13039/501100000024Canadian Institutes of Health Research (CIHR GA4-177772).

Background High-cost users (HCU) represent important targets for health policy interventions. Sepsis is a life-threatening syndrome that is associated with high morbidity, mortality, and economic costs to the healthcare system. We sought to estimate the effect of sepsis on being a subsequent HCU. Methods Using linked health-administrative databases, we conducted a population-based, propensity score-weighted cohort study of adults who survived a hospitalization in Ontario, Canada between January 2016 and December 2017. Sepsis was identified using a validated algorithm. The primary outcome was being a persistent HCU after hospital discharge (in the top 5% or 1% of total health care spending for 90 consecutive days), and the proportion of follow-up time since discharge as a HCU. Results We identified 927,057 hospitalized individuals, of whom 79,065 had sepsis. Individuals who had sepsis were more likely to be a top 5% HCU for 90 consecutive days at any time after discharge compared to those without sepsis (OR 2.24; 95% confidence interval [CI] 2.04–2.46) and spent on average 42.3% of their follow up time as a top 5% HCU compared to 28.9% of time among those without sepsis (RR 1.46; 95% CI 1.45–1.48). Individuals with sepsis were more likely to be a top 1% HCU for 90 consecutive days compared to those without sepsis (10% versus 5.1%, OR 2.05 [95% CI 1.99–2.11]), and spent more time as a top 1% HCU (18.5% of time versus 10.8% of time, RR 1.68 [95% CI 1.65–1.70]). Conclusions The sequelae of sepsis result in higher healthcare costs with important economic implications. After discharge, individuals who experienced sepsis are more likely to be a HCU and spend more time as a HCU compared to individuals who did not experience sepsis during hospitalization.

(Abstracted from JAMA Netw Open. 2024;7:e248676) Midwives work in conjunction with obstetrics professionals and collaborate with other specialists when clinically indicated. Women receiving obstetrics care are often discharged quickly after birth and have only 1 follow-up visit at 6 weeks postpartum.

Importance Emergency department (ED) use postpartum is a common and often-preventable event. Unlike traditional obstetrics models, the Ontario midwifery model offers early care postpartum. Objective To assess whether postpartum ED use differs between women who received perinatal care in midwifery-model care vs in traditional obstetrics-model care. Design, Setting, and Participants This retrospective population-based cohort study took place in Ontario, Canada, where public health care is universally funded. Participants included women who were low risk and primiparous and gave birth to a live baby in an Ontario hospital between 2012 and 2018. Data were collected from April 2012 to March 2018 and analyzed from June 2022 to April 2023. Exposures Perinatal care clinician, namely, a midwife or obstetrician. Main Outcome and Measures : Any unscheduled ED visit 42 days postpartum or less. Poisson regression models compared ED use between women with midwifery-model care vs obstetrics-model care, weighting by propensity score-based overlap weights. Results Among 104 995 primiparous women aged 11 to 50 years, those in midwifery-model care received a median (IQR) of 7 (6-8) postpartum visits, compared with 0 (0-1) visits among those receiving obstetrics-model care. Unscheduled ED visits 42 days or less postpartum occurred for 1549 of 23 124 women (6.7%) with midwifery-model care compared with 6902 of 81 871 women (8.4%) with traditional obstetrics-model care (adjusted relative risks [aRR], 0.78; 95% CI, 0.73-0.83). Similar aRRs were seen in women with a spontaneous vaginal birth (aRR, 0.71; 95% CI, 0.65-0.78) or assisted vaginal birth (aRR, 0.70; 95% CI, 0.59-0.82) but not those with a cesarean birth (aRR, 0.94; 95% CI, 0.86-1.03) or those with intrapartum transfer of care between a midwife and obstetrician (aRR, 0.94; 95% CI, 0.87-1.04). ED use 7 days or less postpartum was also lower among women receiving midwifery model care (aRR, 0.70; 95% CI, 0.65-0.77). Conclusions and Relevance In this cohort study, midwifery-model care was associated with less postpartum ED use than traditional obstetrics-model care among women who had low risk and were primiparous, which may be due to early access to postpartum care provided by Ontario midwives.

The use of virtual care for people at the end-of-life significantly increased during the COVID-19 pandemic, but its association with acute healthcare use and location of death is unknown. The objective of this study was to measure the association between the use of virtual end-of-life care with acute healthcare use and an out-of-hospital death before vs. after the introduction of specialized fee codes that enabled broader delivery of virtual care during the COVID-19 pandemic. This was a population-based cohort study of 323,995 adults in their last 90 days of life between January 25, 2018 and December 31, 2021 using health administrative data in Ontario, Canada. Primary outcomes were acute healthcare use (emergency department, hospitalization) and location of death (in or out-of-hospital). Prior to March 14, 2020, 13,974 (8%) people received at least 1 virtual end-of-life care visit, which was associated with a 16% higher rate of emergency department use (adjusted Rate Ratio [aRR] 1.16, 95%CI 1.12 to 1.20), a 17% higher rate of hospitalization (aRR 1.17, 95%CI 1.15 to 1.20), and a 34% higher risk of an out-of-hospital death (aRR 1.34, 95%CI 1.31 to 1.37) compared to people who did not receive virtual end-of-life care. After March 14, 2020, 104,165 (71%) people received at least 1 virtual end-of-life care visit, which was associated with a 58% higher rate of an emergency department visit (aRR 1.58, 95%CI 1.54 to 1.62), a 45% higher rate of hospitalization (aRR 1.45, 95%CI 1.42 to 1.47), and a 65% higher risk of an out-of-hospital death (aRR 1.65, 95%CI 1.61 to 1.69) compared to people who did not receive virtual end-of-life care. The use of virtual end-of-life care was associated with higher acute healthcare use in the last 90 days of life and a higher likelihood of dying out-of-hospital, and these rates increased during the pandemic.