Disparities in prostate cancer diagnosis, treatment, and survival among men with disabilities: Retrospective cohort study in South Korea

Intellectual disabilities and risk of cardiovascular diseases: A population-based cohort study

BACKGROUND

While intellectual disability is associated with higher mortality rates due to circulatory diseases, it is unclear whether intellectual disability is associated with higher risk of myocardial infarction (MI) and stroke than the general population.

OBJECTIVES

We aimed to analyze the risk of cardiovascular diseases (CVD), specifically myocardial infarction (MI) and ischemic stroke, and death due to circulatory diseases in individuals with disability.

METHODS

This retrospective cohort study used data from the National Disability Registration System linked to the Korean National Health Insurance Service database. Individuals who underwent national health examinations in 2009 were followed until 2020. Cox-proportional hazard analyses were performed to estimate the risk of CVD, MI, ischemic stroke, and circulatory disease deaths with adjustment for covariates.

RESULTS

A total of 3642 individuals with intellectual disability (mean [SD] age 39.1 [12.6], 28.8 % female) and 3,889,794 individuals without intellectual disability (mean [SD] age 47.1 [13.9], 45.6 % female) were included. Compared to those without intellectual disability, those with intellectual disability had higher risk of CVD (adjusted hazard ratio [aHR] 1.71, 95 % confidence interval [CI] 1.45-2.02), ischemic stroke (aHR 2.21, 95 % CI 1.81-2.69), and death due to circulatory diseases (aHR 4.20, 95 % CI 3.24-5.45), and a non-significant risk for MI (aHR 1.24, 95 % CI 0.95-1.63) after full adjustment for covariates.

CONCLUSIONS

Individuals with intellectual disability were at increased risk of CVD, in particular ischemic stroke, and death due to circulatory diseases. Healthcare professionals should be aware of increased CVD risk in individuals with intellectual disability.

Disparities in the diagnosis and treatment of colorectal cancer among patients with disabilities

BACKGROUND

Little is known about disparities in diagnosis and treatment among colorectal cancer (CRC) patients with and without disabilities.

AIM

To investigate the patterns of diagnosis, treatment, and survival for people with and without disabilities who had CRC.

METHODS

We performed a retrospective analysis using the Korean National Health Insurance Service database, disability registration data, and Korean Central Cancer Registry data. The analysis included 21449 patients with disabilities who were diagnosed with CRC and 86492 control patients diagnosed with CRC.

RESULTS

The overall distribution of CRC stage was not affected by disability status. Subjects with disabilities were less likely than those without disabilities to undergo surgery [adjusted odds ratio (aOR): 0.85; 95% confidence interval (95%CI): 0.82-0.88], chemotherapy (aOR: 0.84; 95%CI: 0.81-0.87), or radiotherapy (aOR: 0.90; 95%CI: 0.84-0.95). The rate of no treatment was higher in patients with disabilities than in those without disabilities (aOR: 1.48; 95%CI: 1.41-1.55). The overall mortality rate was higher in patients with disabilities [adjusted hazard ratio (aHR): 1.24; 95%CI: 1.22-1.28], particularly severe disabilities (aHR: 1.57; 95%CI: 1.51-1.63), than in those without disabilities.

CONCLUSION

Patients with severe disabilities tended to have a late or unknown diagnosis. Patients with CRC and disabilities had lower rates of treatment with almost all modalities compared with those without disabilities. During the follow-up period, the mortality rate was higher in patients with disabilities than in those without disabilities. The diagnosis and treatment of CRC need improvement in patients with disabilities.

The association between disability and mortality: a mixed-methods study

BACKGROUND

Globally, 1·3 billion people have a disability and are more likely to experience poor health than the general population. However, little is known about the mortality or life expectancy gaps experienced by people with disabilities. We aimed to undertake a systematic review and meta-analysis of the association between disability and mortality, compare these findings to the evidence on the association of impairment types and mortality, and model the estimated life expectancy gap experienced by people with disabilities.

METHODS

We did a mixed-methods study, which included a systematic review and meta-analysis, umbrella review, and life expectancy modelling. For the systematic review and meta-analysis, we searched MEDLINE, Global Health, PsycINFO, and Embase for studies published in English between Jan 1, 2007, and June 7, 2023, investigating the association of mortality and disability. We included prospective and retrospective cohort studies and randomised controlled trials with a baseline assessment of disability and a longitudinal assessment of all-cause mortality or cause-specific mortality. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. We did a random-effects meta-analysis to calculate a pooled estimate of the mortality rate ratio for people with disabilities compared with those without disabilities. We did an umbrella review of meta-analyses examining the association between different impairment types and mortality. We used life table modelling to translate the mortality rate ratio into an estimate of the life expectancy gap between people with disabilities and the general population. The systematic review and meta-analysis is registered with PROSPERO, CRD42023433374.

FINDINGS

Our search identified 3731 articles, of which 42 studies were included in the systematic review. The meta-analysis included 31 studies. Pooled estimates showed that all-cause mortality was 2·24 times (95% CI 1·84-2·72) higher in people with disabilities than among people without disabilities, although heterogeneity between the studies was high (τ2=0·28, I2=100%). Modelling indicated a median gap in life expectancy of 13·8 years (95% CI 13·1-14·5) by disability status. Cause-specific mortality was also higher for people with disabilities, including for cancer, COVID-19, cardiovascular disease, and suicide. The umbrella review identified nine meta-analyses, which showed consistently elevated mortality rates among people with different impairment types.

INTERPRETATION

Mortality inequities experienced by people with disabilities necessitate health system changes and efforts to address inclusion and the social determinants of health.

FUNDING

National Institute for Health and Care Research, Rhodes Scholarship, Indonesia Endowment Funds for Education, Foreign, Commonwealth and Development Office (Programme for Evidence to Inform Disability Action), and the Arts and Humanities Research Council.

Risk of Parkinson disease in stroke patients: A nationwide cohort study in South Korea

BACKGROUND AND PURPOSE

Previous studies have examined the risk of stroke in patients with Parkinson disease (PD), but the incidence of PD onset among stroke patients and its risk according to severity of poststroke disabilities have scarcely been investigated. This study aims to determine whether the risk of PD is increased among stroke patients using a retrospective cohort with a large population-based database.

METHODS

We used data collected by the Korean National Health Insurance Service from 2010 to 2018 and examined 307,361 stroke patients and 380,917 sex- and age-matched individuals without stroke to uncover the incidence of PD. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI), and the risk of PD was compared according to presence and severity of disability.

RESULTS

During 4.31 years of follow-up, stroke patients had a 1.67 times higher risk of PD compared to individuals without stroke (adjusted HR = 1.67, 95% CI = 1.57-1.78). The risk of PD was greater among stroke patients with disabilities than among those without disabilities, even after adjustment for multiple covariates (adjusted HR = 1.72, 95% CI = 1.55-1.91; and adjusted HR = 1.66, 95% CI = 1.56-1.77, respectively).

CONCLUSIONS

Our study demonstrated an increased risk of PD among stroke patients. Health professionals need to pay careful attention to detecting movement disorders as clues for diagnosing PD.

Disparities in Cancer Incidence across Income Levels in South Korea

BACKGROUND

Recent nationwide studies of disparities in cancer incidence by income are scarce in Korea. This study investigated such disparities in cancer incidence and the stage at cancer diagnosis across income groups in Korea.

METHODS

This study utilized data from a national cancer database, specifically focusing on cases recorded in the year 2018. Income levels were categorized into quintiles according to the insurance premium paid in addition to the Medicaid benefit. The slope index of inequality (SII) and relative index of inequality (RII) were used to measure absolute and relative differences in cancer incidence by income. A multivariable logistic regression was performed to estimate the risk of a distant stage at cancer diagnosis.

RESULTS

The total number of cases of incident cancer was 223,371 (men: 116,320, women: 107,051) with shares of the total of 29.5% (5Q), 20.4% (4Q), 16.0% (3Q), 13.5% (2Q), 15.6% (1Q), and 5% (Medicaid). The most common cancer type was thyroid cancer, followed by gastric and colorectal cancers. The age-standardized incidence rate for all cancers was lowest in the highest income group, but the SII was not statistically significant (SII: -35.7), and the RII was -0.07. Colorectal and cervical cancers had lower incidence rates for higher income groups, while thyroid and prostate cancers had higher incidence rates for higher income groups. The odds ratio for a distant stage at diagnosis for all cancers increased for lower income groups relative to 5Q.

CONCLUSIONS

Disparities in cancer incidence in a Korean population differed by cancer type, and lower income was a significant predictor of a distant stage at diagnosis for cancers overall. These results emphasize the need for further study of the underlying causes of disparities in cancer incidence and the stage at diagnosis, as well as the need for interventions to mitigate these disparities.

Growing disparity in the prevalence of chronic obstructive pulmonary disease between people with and without disabilities: a Korean nationwide serial cross-sectional study

Few studies have examined the association between disability and chronic obstructive pulmonary disease (COPD). We compared the trends in the annual COPD prevalence between people with and without disabilities, and examined the association between disability and COPD. We linked the National Health Information Database (2008-2017) with the National Disability Registration Database, which includes more than 2 million people with disabilities every year. In the 2017 dataset, people with disabilities had a higher prevalence of COPD than those without disabilities (30.6% vs. 12.5%, P < 0.001). The age-standardized prevalence rate of COPD among people without disabilities increased from 4.2 in 2008 to 10.9% in 2017 (change of 6.7%), whereas that among those with disabilities increased from 7.0 to 17.1% (change of 10.1%). In multivariate analysis, compared to people without disabilities, those with disabilities had a higher probability of having COPD (adjusted odds ratio, 1.42; 95% confidence interval 1.42-1.43). The results of subgroup analysis by disability characteristics suggested that disabilities due to failure of an organ, such as the kidney, lung, heart, or liver, and severe disabilities were particularly vulnerable to COPD. In conclusion, people with disabilities are more likely to have COPD compared to people without disabilities. Further longitudinal studies that examine cause-and-effect relationship between disability and COPD are needed to clarify this relationship and to further investigate any potential negative effects associated with the coexistence of these conditions.

The Korea National Disability Registration System

The Korea National Disability Registration System (KNDRS) was established in 1989 to provide social welfare benefits based on predefined criteria for disability registration and an objective medical assessment using a disability grading system. Disability registration requires (1) a medical examination by a qualified specialist physician and (2) a medical advisory meeting to review the degree of disability. Medical institutions and specialists for the diagnosis of disabilities are legally stipulated, and medical records for a specified period are required to support the diagnosis. The number of disability types has gradually expanded, and 15 disability types have been legally defined. As of 2021, 2.645 million people were registered as disabled, accounting for approximately 5.1% of the total population. Among the 15 disability types, disabilities of the extremities account for the largest proportion (45.1%). Previous studies have investigated the epidemiology of disabilities using data from the KNDRS, combined predominantly with data from the National Health Insurance Research Database (NHIRD). Korea has a mandatory public health insurance system that covers the entire Korean population, and the National Health Insurance Services manages all eligibility information, including disability types and severity ratings. In short, the KNDRS-NHIRD is a significant data resource for research on the epidemiology of disabilities.

Increased Risk of Developing Depression in Disability after Stroke: A Korean Nationwide Study

Stroke is a leading cause of mortality and a major cause of disability worldwide. A significant number of stroke survivors suffer from depression, impeding the activities of daily living and rehabilitation. Here, we examined the risk of depression among stroke survivors according to the severity of disabilities and compared its incidence with a matched control group. We included data from the Korean National Health Insurance Service of 207,678 stroke survivors. Cox proportional hazard models were used to calculate the risk of depression among stroke survivors. Stroke survivors had a greater risk of developing depression than the matched control group with an adjusted hazard ratio of 2.12 (95% confidence interval 2.09-2.15). Stroke survivors with more severe disabilities were associated with a higher risk of depression than those with mild disabilities. The risk of developing depression was prominently high within the first year after a stroke. Males and younger people (<65 years) were independent risk factors for depression in stroke survivors. This study demonstrated an increased risk of developing depression in stroke survivors compared to control subjects, and a higher risk of depression was associated with a more severe degree of disability. Clinicians should be aware of the risk of depression developing in stroke survivors, especially those with disabilities.

Disparities in the Diagnosis, Treatment, and Survival Rate of Cervical Cancer among Women with and without Disabilities

Introduction

Not much is known regarding the disparities in cancer care between women with and without disabilities.

Objectives

The aim of this study was to investigate the potential disparities in the diagnosis, treatment, and survival of women with cervical cancer with and without disabilities.

Methods

We performed a retrospective cohort study and linked the National Disability Database, Korean Central Cancer Registry, and Korean National Health Insurance claims database. Charlson comorbidity index was used for adjusting the comorbidity. The study population comprised 3 185 women with disabilities (physical/brain, communication, mental, cardiopulmonary, and other impairment) who were diagnosed with cervical cancer and 13 582 age- and sex-matched women without disability who were diagnosed with cervical cancer for comparison.

Results

Distant metastatic stage (7.7% vs 3.7%) and unknown stage (16.1% vs 7.0%) were more common in cervical cancer women with grade 1 disabilities, compared with women without disabilities. Women with cervical cancer with disabilities were less likely to undergo surgery (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.73–0.90) or chemotherapy (aOR 0.86, 95% CI 0.77–0.97). Lower rate of surgery was more evident in patients with physical/brain impairment (aOR 0.46, 95% CI 0.37–0.58) and severe mental impairment (aOR 0.57, 95% CI 0.41–0.81). The overall mortality risk was also higher in patients with disabilities (adjusted hazard ratio (aHR) 1.36, 95% CI 1.25–1.48).

Conclusion

Women with cervical cancer with disabilities, especially with severe disabilities, were diagnosed at later stages, received less treatment, and had higher mortality rates, compared with patients who lacked disabilities. Social support and policies, along with education for women with disabilities, their families, and healthcare professionals, are needed to improve these disparities.