Health Insurance and Disparities in Mortality among Older Survivors of Critical Illness: A Population Study

Three-year mortality, readmission, and medical expenses in critical care survivors: A population-based cohort study

BACKGROUND

Due to the increasing number of critical care survivors, population-based studies on the long-term outcomes after discharge are necessary to inform local decision-making.

OBJECTIVES

This study aimed to investigate mortality and its risk factors, readmissions, and medical expenses of intensive care unit survivors for 3 years after hospital discharge.

METHODS

This retrospective study analysed data from the National Health Insurance Service-National Sample Cohort in Korea. Of the 195,702 patients who survived and were discharged from hospital in 2012, 2693 intensive care unit patients were assigned to the case group for the study, and the remaining 193,009 were assigned to the comparison group. The primary outcome was all-cause mortality for 3 years after discharge. Secondary outcomes were all-cause hospital readmission and medical expenses in 3 years. We analysed risk factors for mortality using the Cox proportional hazard regression. The differences in hospital readmission and medical expenses between the case and comparison groups were analysed by multivariate logistic regression and independent t-tests.

RESULTS

The 1-year, 2-year, and 3-year cumulative mortality rates in the case group were 15.9%, 20.5%, and 24.4%, respectively, and older age, disability, medical admission, and longer hospital stay increased mortality. Almost 40% of intensive care unit survivors were readmitted to hospital within 6 months of discharge, and their odds of being readmitted were significantly higher than those of the comparison group. Medical expenses were also significantly higher in the case group, with the highest paid within 6 months.

CONCLUSIONS

Mortality, hospital readmission, and medical expenses for intensive care unit survivors were the worst within 6 months of discharge. In light of the long-term recovery trajectory of critical illness, it is necessary to investigate what factors may have contributed to the negative outcome during this period. Further research is needed to determine which services primarily contributed to the increase in medical expenses.

Association Between Socioeconomic Disadvantage and Decline in Function, Cognition, and Mental Health After Critical Illness Among Older Adults : A Cohort Study

BACKGROUND

Older adults admitted to an intensive care unit (ICU) are at risk for developing impairments in function, cognition, and mental health. It is not known whether socioeconomically disadvantaged older persons are at greater risk for these impairments than their less vulnerable counterparts.

OBJECTIVE

To evaluate the association between socioeconomic disadvantage and decline in function, cognition, and mental health among older survivors of an ICU hospitalization.

DESIGN

Retrospective analysis of a longitudinal cohort study.

SETTING

Community-dwelling older adults in the National Health and Aging Trends Study (NHATS).

PARTICIPANTS

Participants with ICU hospitalizations between 2011 and 2017.

MEASUREMENTS

Socioeconomic disadvantage was assessed as dual-eligible Medicare-Medicaid status. The outcome of function was defined as the count of disabilities in 7 activities of daily living and mobility tasks, the cognitive outcome as the transition from no or possible to probable dementia, and the mental health outcome as the Patient Health Questionnaire-4 score in the NHATS interview after ICU hospitalization. The analytic sample included 641 ICU hospitalizations for function, 458 for cognition, and 519 for mental health.

RESULTS

After accounting for sociodemographic and clinical characteristics, dual eligibility was associated with a 28% increase in disability after ICU hospitalization (incidence rate ratio, 1.28; 95% CI, 1.00 to 1.64); and nearly 10-fold greater odds of transitioning to probable dementia (odds ratio, 9.79; 95% CI, 3.46 to 27.65). Dual eligibility was not associated with symptoms of depression and anxiety after ICU hospitalization (incidence rate ratio, 1.33; 95% CI, 0.99 to 1.79).

LIMITATION

Administrative data, variability in timing of baseline and outcome assessments, proxy selection.

CONCLUSION

Dual-eligible older persons are at greater risk for decline in function and cognition after an ICU hospitalization than their more advantaged counterparts. This finding highlights the need to prioritize low-income seniors in rehabilitation and recovery efforts after critical illness and warrants investigation into factors leading to this disparity.

PRIMARY FUNDING SOURCE

National Institute on Aging.

A systematic review of quantitative bias analysis applied to epidemiological research

BACKGROUND

Quantitative bias analysis (QBA) measures study errors in terms of direction, magnitude and uncertainty. This systematic review aimed to describe how QBA has been applied in epidemiological research in 2006-19.

METHODS

We searched PubMed for English peer-reviewed studies applying QBA to real-data applications. We also included studies citing selected sources or which were identified in a previous QBA review in pharmacoepidemiology. For each study, we extracted the rationale, methodology, bias-adjusted results and interpretation and assessed factors associated with reproducibility.

RESULTS

Of the 238 studies, the majority were embedded within papers whose main inferences were drawn from conventional approaches as secondary (sensitivity) analyses to quantity-specific biases (52%) or to assess the extent of bias required to shift the point estimate to the null (25%); 10% were standalone papers. The most common approach was probabilistic (57%). Misclassification was modelled in 57%, uncontrolled confounder(s) in 40% and selection bias in 17%. Most did not consider multiple biases or correlations between errors. When specified, bias parameters came from the literature (48%) more often than internal validation studies (29%). The majority (60%) of analyses resulted in >10% change from the conventional point estimate; however, most investigators (63%) did not alter their original interpretation. Degree of reproducibility related to inclusion of code, formulas, sensitivity analyses and supplementary materials, as well as the QBA rationale.

CONCLUSIONS

QBA applications were rare though increased over time. Future investigators should reference good practices and include details to promote transparency and to serve as a reference for other researchers.