Long-Term Particulate Matter Exposure and Mortality in Hospitalized Patients with COVID-19 in South Korea

Rationale: Particulate matter (PM) exposure exacerbates health outcomes by causing lung damage. Objectives: To investigate whether prior exposure to particulate matter ⩽10 μm and ⩽2.5 μm in aerodynamic diameter (PM10 and PM2.5) was associated with clinical outcomes among patients with coronavirus disease (COVID-19). Methods: Data from the nationwide registration database of the National Health Insurance and Korea Disease Control and Prevention Agency in South Korea were used. The study included adult patients who were admitted to monitoring centers or hospitals between October 8, 2020 and December 31, 2021, after COVID-19 confirmation. AirKOREA database, which compiles air pollutant data from 642 stations in 162 cities and counties across South Korea, was used to extract data on PM levels. Average values of monthly exposure to PM10 and PM2.5 from the year previous to hospital admission because of COVID-19 to the date of confirmation of COVID-19 were calculated and used to define PM exposures of patients with COVID-19. Results: In total, 322,289 patients with COVID-19 were included, and 4,633 (1.4%) died during hospitalization. After adjusting for covariates, a 1-μg/m3 increase in PM10 and PM2.5 exposure was associated with 4% (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.03-1.05; P < 0.001) and 6% (OR, 1.06; 95% CI, 1.04-1.07; P < 0.001) increase in the risk of in-hospital mortality, respectively. In addition, a 1-μg/m3 increase in PM10 and PM2.5 was associated with 5% (OR, 1.05; 95% CI, 1.04-1.07; P < 0.001) and 8% (OR, 1.08; 95% CI, 1.06-1.10; P < 0.001) increase in the risks of requiring intensive care unit (ICU) admission and mechanical ventilation, respectively. Conclusions: PM10 and PM2.5 exposure was associated with increased in-hospital mortality and the need for ICU admission and mechanical ventilation among patients with COVID-19 in South Korea.

Regional versus general anesthesia for total hip and knee arthroplasty: a nationwide retrospective cohort study

INTRODUCTION

We aimed to determine whether regional anesthesia (RA) has any advantages over general anesthesia (GA) in total joint arthroplasty (TJA) in terms of mortality and postoperative complications.

METHODS

This population-based retrospective cohort study included data of adults who underwent total knee or hip arthroplasty under RA or GA between 2016 and 2021 from the National Health Insurance Service of South Korea. RA included spinal or epidural anesthesia or a combination of both. Endpoints were 30-day mortality, 90-day mortality, and postoperative complications. Propensity score (PS) matching was used for statistical analysis.

RESULTS

We included 517 960 patients (RA, n=380 698; GA, n=137 262) who underwent TJA. After PS matching, 186 590 patients (93 295 in each group) were included in the final analysis. In the logistic regression analyses using the PS-matched cohort, the RA group compared with the GA group showed 31% (OR: 0.69; 95% CI, 0.60 to 0.80; p<0.001) and 22% (OR: 0.78; 95% CI, 0.72 to 0.85; p<0.001) lower 30-day and 90-day mortality rates, respectively. However, the total postoperative complication rate did not differ significantly between the two groups (p=0.105).

CONCLUSION

RA compared with GA was associated with improved 30-day and 90-day survival outcomes in patients who underwent TJA. However, the postoperative complication rate did not differ significantly. Therefore, our results should be interpreted with caution, and more well-designed future studies are needed to clarify the most appropriate type of anesthesia for TJA.

New-onset mental illness and long-term survival in survivors of critical illness: population-based cohort study in South Korea

BACKGROUND

Critical care unit (CCU) survivors have a high risk of developing mental illness.

AIMS

We aimed to examine the incidence and associated factors of newly developed mental illness among CCU survivors of critical illness. Moreover, we examined the association between newly developed mental illness and 2-year all-cause mortality.

METHOD

All adult patients (≥20 years) who were admitted to the CCU during hospitalisation between 2010 and 2018 and survived for 1 year were defined as CCU survivors and were included in this nationwide population-based cohort study. CCU survivors with a history of mental illness before CCU admission were excluded from the study.

RESULTS

A total of 1 353 722 CCU survivors were included in the analysis; of these, 33 743 survivors (2.5%) had newly developed mental illness within 1 year of CCU admission. Old age, longer CCU stay, hospital admission through the emergency room, increased total cost of hospitalisation, mechanical ventilatory support, extracorporeal membrane oxygenation support and continuous renal replacement therapy were associated with an increased incidence of newly developed mental illness. Moreover, the newly developed mental illness group showed a 2.36-fold higher 2-year all-cause mortality rate than the no mental illness group (hazard ratio: 2.36; 95% CI: 2.30-2.42; P < 0.001).

CONCLUSIONS

In South Korea, 2.5% of CCU survivors had newly developed mental illness within 1 year of CCU admission. Moreover, newly developed mental illness was associated with an increased 2-year all-cause mortality.

Opioid Prescription and Long-Term Survival Outcomes in Adults: A Nationwide Cohort Study in Korea

BACKGROUND

We aimed to investigate the association between short- and long-term opioid use and long-term mortality in Korea.

METHODS

In this population-based retrospective cohort study, data were obtained from the National Health Insurance Service of South Korea. The study included all adult individuals who were prescribed opioids in 2016. The control group comprised adults not prescribed opioids in 2016 selected using a 1:1 stratified random sampling technique. Participants were categorized into three groups: non-user, opioid 1-89 days user (short-term), and opioid ≥ 90 days user (long-term) groups. The primary endpoint in this study was 5-year all-cause mortality, evaluated from January 1, 2017 to December 31, 2021.

RESULTS

In total, 4,556,606 adults were included in this study. Of these, 2,070,039 were prescribed opioids at least once. Specifically, 1,592,883 adult individuals were prescribed opioids for 1-89 days, while 477,156 adults were prescribed opioid for ≥ 90 days. In the multivariable Cox regression modelling, the opioid user group had a 28% (hazard ratio [HR], 1.28; 95% confidence interval [95% CI], 1.26-1.29; P < 0.001) higher risk of 5-year all-cause mortality than had the non-user group. Moreover, the opioid 1-89 days and opioid ≥ 90 days user groups had 15% (HR, 1.15; 95% CI, 1.14-1.17; P < 0.001) and 49% (HR, 1.49; 95% CI, 1.47-1.51; P < 0.001) higher risks of 5-year all-cause mortality than had the non-user group, respectively.

CONCLUSION

Both short and long-term opioid prescriptions were associated with increased long-term mortality among the Korean adult population.

Long-term benzodiazepine usage and mortality in patients with chronic non-cancer musculoskeletal pain: A Nationwide cohort study

OBJECTIVES

The impact of benzodiazepine use on mortality in patients with chronic non-cancer pain (CNCP) has not been identified. We aimed to examine the factors associated with benzodiazepine use among patients with CNCP and examine whether long-term benzodiazepine usage is associated with mortality in patients with CNCP.

METHODS

This study was conducted using data from the National Health Insurance Service database of South Korea. We selected 2.5% of all adult patients diagnosed with musculoskeletal diseases (MSD) in South Korea from 2010 to 2019 using a stratified random sampling technique and included them in the analysis as patients with CNCP. The risk of 10-year all-cause mortality in patients with CNCP was investigated using the 2010 cohort of patients with CNCP.

RESULTS

The proportion of the study population that used benzodiazepine during the 10-year study period was 2.1% (390,683/18,770,234). Multivariable logistic regression showed that old age; increased Charlson comorbidity index (CCI); opioid, gabapentin or pregabalin, paracetamol, non-steroidal anti-inflammatory drugs, and Z-drugs usage; and underlying psychiatric comorbidities were associated with increased benzodiazepine use. In addition, benzodiazepine use was associated with increased 10-year all-cause mortality (adjusted hazard ratio: 1.03, 95% confidence interval: 1.01, 1.06; p < 0.001).

CONCLUSIONS

Benzodiazepine was prescribed to 2.1% of the patients with CNCP in South Korea from 2010 to 2019. Old age, increased CCI, underlying psychiatric comorbidities, and use of certain drugs are associated with increased use of benzodiazepines. In addition, benzodiazepine use is associated with 10-year all-cause mortality in patients with CNCP.

Mortality Risk After a Major Cancer Surgery Is Associated With Preoperative Exposure to Air Pollution: A Nationwide Cohort Study in South Korea

OBJECTIVE

The aim of the study is to examine whether preoprerative exposure to air pollution is associated with mortality after a major cancer surgery.

METHODS

All patients who underwent major cancer surgeries after hospitalization between January 1, 2016, to December 31, 2020, were included.

RESULTS

In total, 244,766 patients who underwent major cancer surgeries were included. Both 0.001-ppm increase in sulfur dioxide and 0.1-ppm increase in carbon monoxide were associated with a 7% increase in 90-day mortality rate after a major cancer surgery. Furthermore, a 0.001-ppm increase in sulfur dioxide, 0.1 ppm increase in carbon monoxide, and 1 μg/m 3 increase in particulate matter 2.5 were associated with a 4%, 3%, and 1% increase in 1-year all-cause mortality rate after a major cancer surgery.

CONCLUSIONS

Preoperative exposure to air pollution was associated with an increased risk of mortality in patients after major cancer surgery.

Insomnia disorder and cancer mortality in South Korea: a secondary analysis of musculoskeletal disease cohort

PURPOSE

The association between insomnia disorder and cancer-related mortality risk remains controversial. Therefore, this study aimed to investigate the correlation between insomnia disorder and cancer-related mortality.

METHODS

Patients who were diagnosed with musculoskeletal disease (MSD) between 2010 and 2015 were included in this study as a secondary analysis of a patient cohort with MSD in South Korea. Cancer mortality was evaluated between January 1, 2016, and December 31, 2020, using multivariable Cox regression modeling. Patients with and without insomnia disorder constituted the ID and non-ID groups, respectively.

RESULTS

The final analysis incorporated a total of 1,298,314 patients diagnosed with MSDs, of whom 11,714 (0.9%) died due to cancer. In the multivariable Cox regression model, the risk of total cancer-related mortality was 14% (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.10-1.19; P < 0.001) higher in the ID group than in the non-ID group. Moreover, the ID group had a higher risk of mortality due to esophageal (HR, 1.46; 95% CI, 1.08-1.96; P = 0.015), colorectal (HR, 1.20; 95% CI, 1.05-1.36; P = 0.007), head and neck (HR, 1.39; 95% CI, 1.01-1.94; P = 0.049), lung (HR, 1.17; 95% CI, 1.08-1.27; P < 0.001), and female genital organ (HR: 1.39, 95% CI: 1.09, 1.77; P = 0.008) cancers; leukemia; and lymphoma (HR, 1.30; 95% CI, 1.12-1.49; P < 0.001).

CONCLUSION

Insomnia disorder was associated with elevated overall cancer mortality in patients with MSDs, which was more evident for cancer mortality due to esophageal, colorectal, head and neck, lung, and female genital organ cancers; leukemia; and lymphoma.

Impact of prescribed opioid use on development of dementia among patients with chronic non-cancer pain

We aimed to examine the association between opioid use and the development of dementia in patients with chronic non-cancer pain in South Korea. Data were extracted from the National Health Insurance Service database in South Korea. Adult patients diagnosed with musculoskeletal diseases with chronic non-cancer pain between 2010 and 2015 were included in the analysis. Patients who were prescribed opioids regularly and continuously for ≥ 90 days were classified as opioid users. In total, 1,261,682 patients with chronic non-cancer pain were included in the final analysis, of whom 21,800 (1.7%) were opioid users. From January 1, 2016 to December 31, 2020, 35,239 (2.8%) patients with chronic non-cancer pain were newly diagnosed with dementia. In the multivariable model, opioid users showed a 15% higher risk of developing dementia than the control group. Additionally, opioid users showed a 15% and 16% higher risk of developing Alzheimer's disease and unspecified dementia, respectively, than the control group, but did not show any significant differences for vascular dementia. Among adult patients with chronic non-cancer pain, opioid users were at a higher risk of developing dementia than the control group; the risk was significantly higher for Alzheimer's disease but not for vascular dementia in this study. Our results suggest that in patients with CNCP, public health strategies should target opioid users for early dementia detection and intervention.

Implementation of a multidisciplinary nutritional support team and clinical outcomes in critically ill patients with COVID-19

BACKGROUND & AIMS

The South Korean government established the multidisciplinary nutritional support teams (NST) system for enhancing the evaluation and adequate supply of nutritional support to patients at high risk of malnutrition. However, the impact of the NST on clinical outcomes in critically ill patients with coronavirus disease 2019 (COVID-19) remains unclear. We aimed to investigate whether NST implementation affects survival outcomes in patients with COVID-19 requiring intensive care unit (ICU) admission.

METHODS

Using data from the National Health Insurance Service and Korea Disease Control and Prevention Agency in South Korea, adult patients with COVID-19 admitted to the ICU between October 8, 2020, and December 31, 2021, were included. The NST comprised four professional personnel (physicians, full-time nurses, full-time pharmacists, and full-time clinical dietitians). Patients admitted to ICUs with and without the NST system were assigned to the NST and non-NST groups, respectively.

RESULTS

A total of 13,103 critically ill adult patients were included in the final analysis; among them, 10,103 (77.1 %) and 3,000 (22.9 %) patients were included in the NST and non-NST groups, respectively. In the NST group, 2,803 (27.7 %) critically ill patients with COVID-19 were prescribed enteral or parenteral nutrition by the NST. In a covariate-adjusted multivariable model, the NST group showed a 40 % lower in-hospital mortality rate than the non-NST group (odds ratio: 0.60, 95 % confidence interval: 0.51, 0.71; P < 0.001). In subgroup analyses, compared with the non-NST group, the NST group showed significantly lower in-hospital mortality rates at 2, 3, 4, and 5 points on the World Health Organization clinical progression scale among patients with acute respiratory distress and mechanical ventilatory support.

CONCLUSIONS

NST implementation was associated with improved survival outcomes in critically ill patients with COVID-19; accordingly, it may be recommended for improving adequate nutritional support and evaluation in critically ill patients.

The association of perioperative blood transfusion with survival outcomes after major cancer surgery: a population-based cohort study in South Korea

PURPOSE

The correlation between perioperative blood transfusions and the prognosis after major cancer surgery remains controversial. We investigated the association between perioperative blood transfusion and survival outcomes following major cancer surgeries and analyzed trends in perioperative blood transfusions.

METHODS

Data for this population-based cohort study were obtained from the National Health Insurance Service of South Korea. Adult patients who underwent major cancer surgery between January 1, 2016, and December 31, 2020, were included. The primary endpoint was 90-day mortality.

RESULTS

The final analysis included 253,016 patients, of which 55,094 (21.8%) received perioperative blood transfusions. In the multivariable logistic regression model, select factors, including neoadjuvant/adjuvant chemotherapy, an increased preoperative Charlson Comorbidity Index, moderate or severe liver disease, liver cancer surgery, and small bowel cancer surgery, were associated with an increased likelihood of blood transfusion. In the multivariable Cox regression model, patients who received blood transfusion had a significantly higher risk of 90-day mortality (hazard ratio: 5.68; 95% confidence interval: 5.37, 6.00; P < 0.001) than those who did not.

CONCLUSION

We identified potential risk factors for perioperative blood transfusions. Blood transfusion is associated with an increased 90-day mortality risk after major cancer surgery.

Risk factors for discontinuing intravenous patient-controlled analgesia after thoracic surgery

PURPOSE

This study examined the risk factors of experiencing side effects from using intravenous patient-controlled analgesia (IV PCA) following lung and esophageal surgery.

METHODS

Our study included adult patients who underwent lung or esophageal surgery and received IV PCA for postoperative acute pain control between 2020 and 2022. We collected information on side effects from IV PCA use, the decision to discontinue PCA, and the PCA regimen from the daily reports of the acute pain management team and verified the accuracy using electronic records from ward nurses. The primary outcome was the risk factor associated with discontinuing IV PCA due to its side effects.

RESULTS

Out of the 1796 patients in our study, 1795 used PCA containing opioids; 196 patients stopped IV PCA due to unbearable side effects. Being female (adjusted odds ratio [aOR]: 2.65, 95% confidence interval [CI]: 1.70, 4.13) was linked to a higher chance of stopping PCA use. Having hypertension (aOR: 0.46, 95% CI: 0.26, 0.81) and being classified as the American Society of Anesthesiologists class 3 or higher (aOR: 0.48, 95% CI: 0.23, 0.86) were associated with a lower chance of discontinuing PCA use.

CONCLUSION

Our study determined the risk factors to stop using IV PCA due to side effects following lung or esophageal surgery. These results emphasize the need for personalized pain management plans that take into account the patient's characteristics and the type of surgery performed.

Extracorporeal Membrane Oxygenation Support and Critically Ill COVID-19 Patient Outcomes: A Population-Based Cohort Study

We selected critically ill patients with coronavirus disease 2019 (COVID-19) who were receiving extracorporeal membrane oxygenation (ECMO) support and had been transferred to experienced centers. Thus, we aimed to evaluate factors that were associated with receiving ECMO support and factors that were associated with patient mortality. Using data from the National Health Insurance Service and Korea Disease Control and Prevention Agency in South Korea, adult patients admitted to an intensive care unit from October 8, 2020, to December 31, 2021, with a main diagnosis of COVID-19 were included. They were divided into two groups: ECMO group (n = 455) and non-ECMO group (n = 12,648). Receiving ECMO support was less associated with old age [odds ratio (OR), 0.95; 95% confidence interval (CI), 0.94-0.96; p  < 0.001], underlying severe disabilities (OR, 0.49; 95% CI, 0.29-0.83; p  = 0.008), and booster vaccination status (second: OR, 0.61; 95% CI, 0.39-0.94; p  = 0.024; third: OR, 0.40; 95% CI, 0.25-0.65; p  < 0.001). In addition, after adjusting for various variables, low mortality in patients with ECMO support was associated with having previously received a second booster vaccination (OR, 0.33; 95% CI, 0.14-0.77; p  = 0.010). Vaccination and booster therapy may lower the need for ECMO support and lower mortality among critically ill patients with COVID-19 with ECMO support.

Joblessness, decreased income, and disability in intensive care unit survivors of nontraumatic intracranial hemorrhage in South Korea

OBJECTIVES

To examine the proportions of unemployment, decreased household income, and newly acquired disability, and their impact on long-term mortality after intensive care unit (ICU) admission due to nontraumatic intracranial hemorrhage (IH).

MATERIALS AND METHODS

This nationwide population-based retrospective cohort study enrolled adult patients admitted to the ICU because of nontraumatic IH between 2010 and 2018 in South Korea. Patients who were alive ≥365 days after ICU admission were defined as nontraumatic IH survivors.

RESULTS

In total, 104,086 nontraumatic IH survivors were included in the final analysis. Among them, 7,225 (6.9 %) experienced job loss, 25,709 (24.7 %) experienced decreased household income, and 20,938 (20.1 %) had newly acquired disabilities, of whom 14,188 (13.6 %) had newly acquired brain disabilities. Male sex, increased duration of intensive care unit stay, comorbid status, hospital admission through the emergency room, nontraumatic intracerebral hemorrhage, receipt of surgery, mechanical ventilatory support, and increased total cost of hospitalization were associated with job loss, decreased household income, and newly acquired disabilities. However, these changes were not significantly associated with 2-year all-cause mortality (adjusted hazard ratio: 1.00, 95 % confidence interval: 0.95, 1.06; P = 0.997).

CONCLUSIONS

Many nontraumatic IH survivors experienced unemployment, decreased household income, and newly acquired disability one year after ICU admission in South Korea. Some factors were potential risk factors for these changes, but the changes were not associated with 2-year all-cause mortality.

Trend of Intensive Care Unit Admission in Neurology-Neurosurgery Adult Patients in South Korea : A Nationwide Population-Based Cohort Study

OBJECTIVE

We aimed to examine trends in critically ill neurology-neurosurgery (NNS) patients who were admitted to the intensive care unit (ICU) in South Korea and identify risk factors for in-hospital mortality after ICU admission in NNS patients.

METHODS

This nationwide population-based retrospective cohort study enrolled adult NNS adult patients admitted to the ICU from 2010 to 2019 extracted from the National Health Insurance Service in South Korea. The critically ill NNS patients were defined as those whose main admission departments were neurology or neurosurgery at ICU admission. The number of ICU admission, age, and total cost for hospitalization from 2010 to 2019 in critically ill NNS patients were examined as trend information. Moreover, multivariable logistic regression modeling was used to identify risk factors for in-hospital mortality among critically ill NNS patients.

RESULTS

We included 845474 ICU admission cases for 679376 critically ill NNS patients in South Korea between January 1, 2010 to December 31, 2019. The total number of ICU admissions among NNS patients was 79522 in 2010, which increased to 91502 in 2019. The mean age rose from 62.8 years (standard deviation [SD], 15.6) in 2010 to 66.6 years (SD, 15.2) in 2019, and the average total cost for hospitalization per each patient consistently increased from 6206.1 USD (SD, 5218.5) in 2010 to 10745.4 USD (SD, 10917.4) in 2019. In-hospital mortality occurred in 75455 patients (8.9%). Risk factors strongly associated with increased in-hospital mortality were the usage of mechanical ventilator (adjusted odds ratio [aOR], 19.83; 95% confidence interval [CI], 19.42-20.26; p<0.001), extracorporeal membrane oxygenation (aOR, 3.49; 95% CI, 2.42-5.02; p<0.001), and continuous renal replacement therapy (aOR, 6.47; 95% CI, 6.02-6.96; p<0.001). In addition, direct admission to ICU from the emergency room (aOR, 1.38; 95% CI, 1.36-1.41; p<0.001) and brain cancer as the main diagnosis (aOR, 1.30; 95% CI, 1.22-1.39; p<0.001) are also potential risk factors for increased in-hospital mortality.

CONCLUSION

In South Korea, the number of ICU admissions increased among critically ill NNS patients from 2010 to 2019. The average age and total costs for hospitalization also increased. Some potential risk factors are found to increase in-hospital mortality among critically ill NNS patients.

Prior Evaluation of Nutritional Status and Mortality in Patients with Sepsis in South Korea

Our objective was to determine whether nutritional status correlates with mortality in sepsis patients. Data from a nationwide registration database were utilized for this population-based cohort study. The study subjects comprised adults who received standard health examinations before being admitted to the hospital for sepsis and were diagnosed with sepsis between 2018 and 2020. Nutrition scores were evaluated using the Nutritional Lifestyle Assessment Tool in South Korea. Overall, 2482 patients with sepsis were included in this study. The 90-day and 1-year mortality rates in patients with sepsis were 26.8% (664/2482) and 34.2% (848/2482), respectively. In the covariate-adjusted multivariable logistic regression model, a 1-point increase in nutrition score was associated with a decrease in 90-day mortality in patients with sepsis (odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.97, 0.98; p = 0.025). In the covariate-adjusted multivariable Cox regression model, a 1-point increase in nutrition score was associated with a decrease in 1-year mortality in patients with sepsis (hazard ratio [H.R.]: 0.99, 95% CI: 0.98, 0.99; p = 0.035). Our results suggest that adequate dietary intake and healthy eating habits might protect against mortality among sepsis patients.

Association between socioeconomic status and treatment in patients with low back or neck pain: a population-based cross-sectional study in South Korea

INTRODUCTION

Socioeconomic status affects the treatment of patients with low back pain and/or neck pain. We examined the relationship between socioeconomic status (occupation and household income level) and treatments such as chronic opioid use and interventional procedures among these patients.

METHODS

Data from the National Health Insurance Service database in South Korea were used in this population-based cross-sectional study. Approximately 2.5% of adult patients diagnosed with low back pain and/or neck pain between 2010 and 2019 were selected using a stratified random sampling technique and included in the analysis.

RESULTS

We analyzed the data of 5,861,007 patients with low back pain and/or neck pain in total. Among them, 4.9% were chronic opioid users and 17.7% underwent interventional procedures. Healthcare workers and unemployed individuals had 18% lower and 6% higher likelihood of chronic opioid use compared with office workers, respectively. Those with a very low household income had 18% higher likelihood of chronic opioid use than those with a poor household income. Other workers and unemployed individuals had 4% and 8% higher likelihood of undergoing interventional procedures than office workers, respectively. Healthcare workers had 5% lower likelihood of undergoing interventional procedures than office workers. Patients with middle, high, and very poor household incomes had a higher likelihood of undergoing interventional procedures, while those in the very high household income group had a lower likelihood of undergoing interventional procedures than those with poor household incomes.

CONCLUSIONS

Socioeconomic status factors are associated with treatment in patients with low back pain and/or neck pain.

Risk factors for discontinuation of intravenous patient-controlled analgesia after general surgery: a retrospective cohort study

Identifying patients at risk for developing side effects secondary to intravenous patient-controlled analgesia (IV PCA) and making the necessary adjustments in pain management are crucial. We investigated the risk factors of discontinuing IV PCA due to side effects following general surgery; adult patients who received IV PCA after general surgery (2020-2022) were included. Data on postoperative pain intensity, PCA pain relief, side effects, continuity of PCA use, and PCA pump settings were collected from the records of the acute pain management team. The primary outcome was identifying the risk factors associated with PCA discontinuation due to side effects. Of the 8745 patients included, 94.95% used opioid-containing PCA, and 5.05% used non-steroidal anti-inflammatory drug (NSAID)-only PCA; 600 patients discontinued PCA due to side effects. Female sex (adjusted odds ratio [aOR] 3.31, 95% confidence interval [CI] 2.74-4.01), hepato-pancreatic-biliary surgery (aOR 1.43, 95% CI 1.06-1.94) and background infusion of PCA (aOR 1.42, 95% CI 1.04, 1.94) were associated with an increased likelihood of PCA discontinuation. Preoperative opioid use (aOR 0.49, 95% CI 0.28-0.85) was linked with a decreased likelihood of PCA discontinuation. These findings highlight the importance of individualized pain management, considering patient characteristics and surgical procedures.

Preoperative Body Mass Index, Waist Circumference, and Mortality After Major Cancer Surgery: A Nationwide Cohort Study in Korea

BACKGROUND

Body mass index (BMI) and waist circumference (WC) were used to evaluate nutritional status and obesity. We aimed to examine whether preoperative BMI or WC was associated with mortality after cancer surgery.

METHODS

This population-based cohort study used data extracted from the National Health Insurance Service database of South Korea. We included adult patients who underwent major cancer surgery with curative intent between January 1, 2016, and December 31, 2020.

RESULTS

A total of 87,220 patients were included in the final analysis, and 1,374 (1.6%) died within 90 days after cancer surgery. In the multiple logistic regression model, the BMI < 18.5/kg/m² and > 35 kg/m² groups showed 1.98-fold (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.58-2.49; P < 0.001) and 2.60-fold (OR, 2.60; 95% CI, 1.25-5.40; P < 0.001) higher 90-day mortality after cancer surgery than did the BMI 18.5-24.9 kg/m² group. The 25.0-29.9 kg/m² (P = 0.144) and 30.0-34.9 kg/m² (P = 0.105) BMI groups did not show significant differences compared to the BMI 18.5-24.9 kg/m² group. Compared with the normal WC group, the high (P = 0.052) and very high (P = 0.232) WC groups also did not show significant differences in terms of 90-day mortality.

CONCLUSIONS

Preoperative BMI < 18.5 kg/m² and > 35 kg/m² is associated with an elevated risk of 90-day mortality after major cancer surgery. However, preoperative WC was not significantly associated with 90-day mortality after cancer surgery.

Propofol-based intravenous anesthesia is associated with improved survival outcomes after major cancer surgery: a nationwide cohort study in South Korea

BACKGROUND

The optimal anesthetic technique for cancer surgery remains a controversial issue. This study aimed to examine whether propofol-based total intravenous anesthesia (TIVA) was associated with survival outcomes after major cancer surgery in South Korea and compare its effectiveness with that of inhalation anesthesia.

METHODS

This nationwide population-based cohort study included adult patients who were admitted to the hospital and underwent major cancer surgery between January 1, 2016, and December 31, 2020. The major cancers included lung, gastric, colorectal, esophageal, small bowel, liver, pancreatic, and bile duct or gallbladder cancers.

RESULTS

A total of 253,003 patients who underwent major cancer surgery were included in the analysis. After propensity score (PS) matching, 115,370 patients (57,685 in each group) were included in the final analysis. In the PS-matched cohort, the TIVA group showed 9% (hazard ratio [HR]: 0.91, 95% CI [0.85, 0.98], P = 0.018) and 7% (HR: 0.93, 95% CI [0.89, 0.96], P < 0.001) lower 90-day and one-year mortality rates, respectively, than the inhalation group. In subgroup analyses, the TIVA group showed lower 90-day mortality than the inhalation group in the gastric (HR: 0.86, 95% CI [0.72, 0.97], P = 0.033), colorectal (HR: 0.64, 95% CI [0.56, 0.73], P < 0.001), and pancreatic (HR: 0.76, 95% CI [0.57, 0.94], P = 0.038) cancer surgery groups.

CONCLUSIONS

Propofol-based TIVA is associated with better survival outcomes after major cancer surgeries. Moreover, propofol-based TIVA was beneficial in patients who underwent gastric, colorectal, and pancreatic cancer surgeries.

Association between preoperative modifiable lifestyle factors and mortality after cancer surgery: a population-based cohort study in South Korea

Purpose

We aimed to examine whether preoperative lifestyle factors are associated with mortality after cancer surgery.

Methods

This study used data from the National Health Insurance Service database in South Korea. We included all adult patients who underwent major cancer surgery between January 1, 2016, and December 31, 2018. Three lifestyle factors were evaluated preoperatively: smoking status, alcohol consumption, and physical activity.

Results

A total of 48,557 patients who underwent major cancer surgery were included in the final analysis. In the multivariable logistic regression modeling, current smokers showed 1.40-fold higher odds of 90-day mortality after cancer surgery (odds ratio, 1.40; 95% confidence interval, 1.14-1.71; P = 0.001) than never smokers. However, alcohol consumption and physical activity were not associated with 90-day mortality after cancer surgery. In the multivariable Cox regression modeling, current smokers showed 1.25-fold higher odds of 1-year mortality after cancer surgery (hazard ratio, 1.25; 95% confidence interval, 1.13-1.38; P < 0.001) than never smokers. However, alcohol consumption and physical activity were not associated with 1-year mortality after cancer surgery.

Conclusion

In conclusion, current smoking was associated with worse short- and long-term survival outcomes in South Korea, though preoperative alcohol consumption and physical activity levels were not associated with mortality after cancer surgery.

Suicidal Thinking Among Patients With Spinal Conditions in South Korea: A Population-Based Cross-Sectional Study

OBJECTIVE

Chronic pain increases the risk of suicide because it is often accompanied by depressive symptoms. However, the existing information regarding suicidal thinking in patients with chronic pain such as spinal conditions is insufficient. We aimed to examine the prevalence of suicidal thinking and the factors associated with it among patients with spinal conditions.

METHODS

Data from the National Health Insurance Service database in South Korea were used in this population-based, cross-sectional study, and 2.5% of adult patients diagnosed with spinal conditions (low back pain and/or neck pain) between 2018 and 2019 were selected using a stratified random sampling technique. Patient Health Questionnaire-9 was used to determine the presence of suicidal thoughts and depressive symptoms.

RESULTS

33,171 patients with spinal conditions were included in this study. Among them, 5.9% had suicidal thinking and 20.7% had depressive symptoms. In the multivariable logistic regression model, old age, male sex, and employment were associated with a decreased prevalence of suicidal thinking. Current smokers, previous smokers, medical aid program recipients, and patients with mild-to-moderate or severe disability showed increased suicidal thinking. Underlying depression, bipolar disorder, insomnia disorder, and substance abuse were also associated with increased suicidal thinking.

CONCLUSION

In South Korea, 5.9% and 20.7% of patients with spinal conditions had suicidal thoughts and depressive symptoms, respectively. Some factors were associated with an increased prevalence of suicidal thoughts among patients with spinal conditions. Our results suggest that screening for these factors can help prevent suicide in patients with spinal conditions.

Association between Depression and Mortality in Patients with Pain Conditions: A South Korean Nationwide Cohort Study

PURPOSE

Patients with pain conditions may experience depression that greatly complicates treatment. In this study, we examined risk factors for depression in patients with pain conditions and associations between depression and long-term mortality in such patients.

MATERIALS AND METHODS

Data from the National Health Insurance Service database in South Korea were used in this cohort study. A total of 2.5% of adult patients diagnosed with pain conditions in 2010 were selected using a stratified random sampling technique and included for analysis. We performed multivariate logistic regression modelling to identify risk factors associated with depression and multivariate Cox regression modelling to determine whether depression is associated with 10-year survival outcomes in patients with pain conditions.

RESULTS

In total, data from 1808043 patients with pain conditions in 2010 were analyzed. Among them, 70148 (3.9%) patients had depression. Multivariate logistic regression modelling identified older age, comorbidities, analgesics, female sex, living in an urban area, and other underlying psychiatric morbidities as potential risk factors for depression in patients with pain conditions. Multivariate Cox regression revealed that 10-year all-cause mortality in patients with depression was 1.13-fold (hazard ratio, 1.13; 95% confidence interval, 1.11-1.16; p<0.001) higher than that in patients without depression and pain conditions.

CONCLUSION

We identified a few potential risk factors for depression among South Korean patients with pain conditions. Depression was associated with elevated 10-year all-cause mortality in patients with pain conditions.

Oral Glucocorticoid Use and Long-Term Mortality in Patients with Chronic Musculoskeletal Non-Cancer Pain: A Cross-Sectional Cohort Study

This study aimed to examine the associated factors of oral glucocorticoid (GC) use in patients with chronic non-cancer pain (CNCP) associated with musculoskeletal diseases (MSDs) in South Korea. Moreover, we examined whether oral GC use was associated with long-term mortality in patients with CNCP. This population-based cohort study used data from the national registration database in South Korea. Using a stratified random sampling technique, we extracted the data from 2.5% of adult patients diagnosed with MSDs in 2010. Patients with CNCP-associated MSDs who were prescribed oral GC regularly for ≥30 days were defined as GC users, while the other patients were considered to be non-GC users. A total of 1,804,019 patients with CNCP were included in the final analysis, and 9038 (0.5%) patients were GC users, while 1,794,981 (95.5%) patients were non-GC users. Some factors (old age, comorbid status, pain medication use, and MSD) were associated with GC use among patients with CNCP. Moreover, in the multivariable time-dependent Cox regression model, GC users showed a 1.45-fold higher 10-year all-cause mortality (hazard ratio: 1.45, 95% confidence interval: 1.36-1.54; p < 0.001) than non-GC users. In South Korea, the 10-year all-cause mortality risk increased in the patients with CNCP using GC.

Trends in Cardiovascular Surgery in South Korea: A Nationwide Cohort Study from 2010 to 2019

OBJECTIVES

We aimed to investigate mortality and its associated factors in cardiovascular surgery-associated intensive care unit (ICU) admissions in South Korea from 2010 to 2019.

DESIGN

Population-based cohort study.

SETTING

Data from the National Health Insurance Service database in South Korea were used in this study.

PARTICIPANTS

All adult patients admitted to the ICU associated with cardiovascular surgery in South Korea between January 1, 2010 and December 31, 2019 were analyzed.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 62,794 ICU admissions associated with cardiovascular surgery were included in the analysis (median value of age: 65 years; 58.0% men). This included patients who underwent coronary artery bypass grafting (CABG) only (n = 10,704), valve-only surgery (n = 35,812), CABG + valve surgery (n = 3,230), aortic procedures (n = 7,968), and others (n = 5,080). The number of cardiovascular surgeries associated with ICU admissions was 4,409 in 2010, which gradually increased to 10,366 in 2019. The aortic procedure group had the highest 1-year mortality rate after cardiovascular surgery (15.7%), followed by the CABG + valve (13.2%), others (11.5%), CABG-only (9.5%), and valve-only (8.7%) groups. Invasive life support procedures during the ICU stay and hospital admission through the emergency room were potential risk factors for 1-year mortality after cardiovascular surgery.

CONCLUSIONS

Cardiovascular surgery-associated intensive care admissions gradually increased from 2010 to 2019 in South Korea. Among these patients, the highest 1-year mortality rate was observed in the aortic procedures group, followed by the CABG + valve, others, CABG-only, and valve-only groups.

Intensivist coverage and critically ill COVID-19 patient outcomes: a population-based cohort study

BACKGROUND

Trained intensivist staffing improves survival outcomes in critically ill patients at intensive care units. However, the impact on outcomes of critically ill patients with coronavirus disease 2019 has not yet been evaluated. We aimed to investigate whether trained intensivists affect outcomes among critically ill coronavirus disease 2019 patients in South Korean intensive care units.

METHODS

Using a nationwide registration database in South Korea, we included adult patients admitted to the intensive care unit from October 8, 2020, to December 31, 2021, with a main diagnosis of coronavirus disease 2019. Critically ill patients admitted to intensive care units that employed trained intensivists were included in the intensivist group, whereas all other critically ill patients were assigned to the non-intensivist group.

RESULTS

A total of 13,103 critically ill patients were included, with 2653 (20.2%) patients in the intensivist group and 10,450 (79.8%) patients in the non-intensivist group. In the covariate-adjusted multivariable logistic regression model, the intensivist group exhibited 28% lower in-hospital mortality than that of the non-intensivist group (odds ratio: 0.72; 95% confidence interval: 0.62, 0.83; P < 0.001).

CONCLUSIONS

Trained intensivist coverage was associated with lower in-hospital mortality among critically ill coronavirus disease 2019 patients who required intensive care unit admission in South Korea.

Lifestyle factors and long-term survival in patients with chronic non-cancer pain: a nationwide cohort study in South Korea

PURPOSE

This study aimed to investigate the association of modifiable lifestyle factors with long-term survival outcomes in patients with chronic non-cancer pain (CNCP) in South Korea.

METHODS

This population-based cohort study used data from the National Health Insurance Service database in South Korea. We considered three lifestyle factors from the standard health examination (smoking status, alcohol consumption, and physical activity).

RESULTS

A total of 1,298,314 patients with CNCP were analyzed; moreover, the 5-year all-cause mortality rate was 3.3% (42,875 patients). In the multivariable Cox regression model, in the previous-smoker and current-smoker groups, it was 5% (hazard ratio [HR]:1.05, 95% confidence interval [CI]:1.02-1.08; P = 0.003) and 65% (HR: 1.65, 95% CI: 1.60-1.69; P < 0.001) higher, respectively, than that in the never-smoker group. The 5-year all-cause mortality was 19% (HR: 1.19, 95% CI: 1.14-1.24; P < 0.001) higher in the heavy-alcohol-consumption group than in the non-alcohol-consumption group. Compared with those without mild physical activity, patients who engaged in mild physical activity for 1-3 (HR: 0.89, 95% CI: 0.87-0.92; P < 0.001), 4-5 (HR: 0.88, 95% CI: 0.86-0.91; P < 0.001), and 6-7 (HR: 0.90, 95% CI: 0.88-0.93; P < 0.001) days per week exhibited a significantly decreased 5-year all-cause mortality. The association between moderate/intensive physical activity and 5-year all-cause mortality yielded similar results.

CONCLUSION

Lifestyle factors, including previous/current smoking, heavy alcohol consumption, and physical activity, were associated with a higher 5-year all-cause mortality risk among patients with CNCP in South Korea.

Prior Lifestyle and Survival Outcomes After Intensive Care Unit Admission

BACKGROUND

Although lifestyle is an important and modifiable risk factor for health-related outcomes, no study has focused on the impact of prior lifestyle habits on mortality among critically ill patients after intensive care unit (ICU) admission. Therefore, we aimed to investigate whether prior lifestyle factors affected short- and long-term survival after ICU admission.

METHODS

In this population-based cohort study using a nationwide registration database in South Korea, we included all patients who were admitted to the ICU between January 1, 2010 and December 31, 2018 and who had undergone standardized health examinations in the year prior to ICU admission. Three lifestyle factors (smoking status, alcohol consumption, and physical activity) were evaluated prior to ICU admission.

RESULTS

In total, 585,383 patients admitted to the ICU between 2010 and 2018 were included in the analysis. Of them, 59,075 (10.1%) and 113,476 (19.4%) patients died within 30 days and 1 year after ICU admission, respectively. Current smoking, mild alcohol consumption, and heavy alcohol consumption were not associated with 30-day mortality after ICU admission. One to 3 days per week of intensive physical activity, 4-5 days and 6-7 days per week of moderate physical activity, and 1-3 days, 4-5 days, and 6-7 days per week of mild physical activity were associated with lower odds of 30-day mortality after ICU admission. Similar results were observed for the analyses of 1-year all-cause mortality after ICU admission.

CONCLUSION

Prior lifestyle factors, such as physical activity, were associated with the improvement of both short- and long-term survival outcomes in South Korea. This association was more evident for mild physical activities, such as walking, than for intensive physical activities.

Association between insomnia disorder and mortality among patients who underwent craniotomy for brain tumor resection: a South Korean nationwide cohort study

PURPOSE

To assess the prevalence and related factors of a newly developed insomnia disorder following craniotomy for brain tumor resection. Furthermore, we examined the association of pre- and postoperative insomnia with the 2-year mortality rate.

METHODS

The South Korean national registration cohort database was used as the data source. This study includes all adult patients who underwent craniotomy for brain tumor resection from January 1, 2011, to December 31, 2017. G47.0 and F51.0 (International Statistical Classification of Diseases and Related Health Problems 10th Revision codes) were used to identify insomnia disorders.

RESULTS

In total, 4,851 patients were included. Among them, 913 (18.8%) and 447 (9.2%) patients were assigned to the preoperative and postoperative insomnia groups, respectively. After modeling using multivariable logistic regression, older age (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.03; P < 0.001), reoperation within 1 year (OR 2.12, 95% CI 1.47-3.06; P < 0.001), and newly acquired brain disability (OR 1.32, 95% CI 1.01-1.71; P = 0.043) were associated with an increased prevalence of newly developed postoperative insomnia disorder. After modeling using multivariable Cox regression, the preoperative and postoperative insomnia disorder groups showed a 1.17-fold (hazard ratio (HR) 1.17, 95% CI 1.02-1.34; P = 0.021) and a 1.85-fold (HR 1.85, 95% CI 1.59-2.15, P < 0.001) increased 2-year all-cause mortality risk compared to the control group, respectively.

CONCLUSION

In South Korea, 9.2% of the patients with brain tumors were newly diagnosed with an insomnia disorder following craniotomy for brain tumor resection, which was associated with an increased risk of 2-year mortality.

National Trends in Transplantation-Associated Intensive Care Unit Admission in South Korea From 2010 to 2019

BACKGROUND

We aimed to investigate the mortality and associated factors among patients admitted to the intensive care unit (ICU) after transplantation in South Korea.

MATERIALS AND METHODS

The South Korean National Health Insurance Service database was used as the data source. All adult patients (age ≥18 years) who were admitted to the ICU for organ transplantation-related causes from January 1, 2010 to December 31, 2019 (10 years) were included. Transplantation-associated ICU admissions were defined as admissions to the ward and ICU after transplantation or to the ICU before transplantation.

RESULTS

A total of 23,994 ICU admissions after transplantation were included in the analysis (mean [SD] age: 52.7 [10.7] years; men: 67.0%; kidney transplantation: n = 9638; liver transplantation: n = 12,196; heart and/or lung transplantation: n = 1829; pancreas or small bowel transplantation: n = 331). Transplantation-associated ICU admissions gradually increased from 1666 in 2010 to 3014 in 2019. The 1-year mortality rates were 21.2%, 12.3%, 4.2%, and 3.0% after heart and/or lung, liver, pancreas or small bowel, and kidney transplantation, respectively. Invasive life support procedures during ICU stay, comorbidities, and older age were potential risk factors for 1-year mortality after transplantation.

CONCLUSION

Transplantation-associated ICU admissions gradually increased from 2010 to 2019 in South Korea. The 1-year mortality rate after transplantation was the highest in the heart and/or lung transplantation group, followed by those of the liver, pancreas or small bowel, and kidney transplantation groups.

Trained intensivist coverage and survival outcomes in critically ill patients: a nationwide cohort study in South Korea

BACKGROUND

The difference in survival outcomes between closed and open intensive care unit (ICU) designs with respect to trained intensivist coverage remains unknown. We aimed to investigate whether trained intensivist coverage is associated with mortality in critically ill patients admitted to the ICU in South Korea.

METHODS

This population-based cohort study used nationwide registration data from South Korea. This study enrolled all adult patients admitted to the ICU between January 1, 2016, and December 31, 2019. Patients, who were admitted ICU in a hospital that employed trained intensivists, were designated as the intensivist group.

RESULTS

This study included 1,147,493 critically ill patients admitted to the ICU. The intensivist and non-intensivist groups consisted of 484,004 (42.2%) and 663,489 (57.8%) patients, respectively. Mixed effect logistic regression revealed a 22% lower in-hospital mortality rate (odds ratio: 0.78. 95% confidence interval: 0.74, 0.81; P < 0.001) than that in the non-intensivist group. Mixed effect Cox regression revealed a 15% lower 1-year mortality rate (hazard ratio: 0.85. 95% confidence interval: 0.83, 0.89; P < 0.001) in the intensivist group than that in the non-intensivist group. Moreover, the in-hospital mortality was significantly lower in the intensivist group than that in the non-intensivist group, irrespective of age, Charlson comorbidity index, surgery or non-surgery associated admission, and invasive treatment during ICU stay.

CONCLUSIONS

A closed ICU design with trained intensivist coverage was associated with lower in-hospital and 1-year mortality rates. Our results suggest that hospitals should employ trained intensivists to improve both short-term and long-term survival outcomes of critically ill patients.

Risks and outcome of fatal respiratory events after lung cancer surgery: cohort study in South Korea

Background

Severe complications such as acute respiratory distress syndrome or respiratory failure can occur after lung cancer surgery. However, the prevalence and risk factors have not been well identified. The aim of this study was to investigate the prevalence of and risk factors for fatal respiratory events after lung cancer surgery in South Korea.

Methods

The National Health Insurance Service database in South Korea was used to extract data of all adult patients who were diagnosed with lung cancer and underwent lung cancer surgery from January 1, 2011, to December 31, 2018, for a population-based cohort study. Diagnosis of acute respiratory distress syndrome or respiratory failure after surgery was defined as postoperative fatal respiratory event.

Results

A total of 60,031 adult patients who received lung cancer surgery were included in the analysis. Among them, 0.5% (285/60,031) experienced fatal respiratory events after the lung cancer surgery. In multivariable logistic regression, some risk factors (older age, male sex, higher Charlson comorbidity index score, underlying severe disability, bilobectomy, pneumonectomy, redo-case, lower case volume, and open thoracotomy) for developing postoperative fatal respiratory events were identified. Moreover, the development of postoperative fatal respiratory events was associated with high in-hospital mortality, 1-year mortality, longer length of hospital stays, and higher total hospitalization costs.

Conclusions

Postoperative fatal respiratory events might worsen the clinical outcomes of lung cancer surgery. The knowledge of potential risk factors related to postoperative fatal respiratory events could enable earlier intervention to reduce the occurrence of these events and improve the postoperative clinical outcome.

The economic burden and long-term mortality in survivors of extracorporeal membrane oxygenation in South Korea

Background

The economic burden for extracorporeal membrane oxygenation (ECMO) survivors is a critical issue. We investigated the total healthcare costs for one year following ECMO support and its association with three-year all-cause mortality.

Methods

This population-based cohort study used data from the National Health Insurance Service (NHIS) in South Korea. Adult ECMO survivors (age ≥18 years who were alive ≥365 days following ECMO support) from January 1, 2005, to December 31, 2018, were included. The total healthcare costs for one year included all the expenses for hospital and outpatient clinic visits after discharge.

Results

In total, 6,044 patients were included in the final analysis comprising 3,566 (59.0%) in the cardiac indication group, 658 (10.9%) in the respiratory indication group, and 1,820 (30.1%) in the "other" group. The median total healthcare cost was United States Dollars (USD) 46,308.0 [interquartile range (IQR): 25,727.0-86,924.8]. The median ECMO support and hospital stay durations were three (IQR: 1-7) days and 25 (IQR: 15-31) days. In the multivariable Cox regression model, a USD 1,000 increase in the total healthcare cost was associated with an increase in the three-year all-cause mortality (hazard ratio, 1.01; 95% CI: 1.00-1.01; P=0.015).

Conclusions

After one year, ECMO survivors accrued USD 46,308 in healthcare costs in South Korea. An increase in the total healthcare cost was associated with a higher risk of three-year all-cause mortality among ECMO survivors.

Effect of preoperative psychiatric morbidity on postoperative outcomes of lung cancer surgery: A nationwide cohort study in South Korea

OBJECTIVE

Lung cancer is the leading cause of cancer-related mortality worldwide, and cancer is associated with severe psychological distress. We aimed to investigate whether preoperative psychiatric morbidities affect clinical outcomes of lung cancer surgery in South Korea.

METHODS

Using the National Health Insurance Service database, all adult patients who were diagnosed with lung cancer and underwent lung cancer surgery from January 1, 2011, to December 31, 2018, were included in this retrospective, population-based cohort study. Depression, anxiety disorder, schizophrenia, alcohol abuse, non-alcohol substance abuse, and post-traumatic stress disorder were considered as preoperative psychiatric morbidities.

RESULTS

Overall, 60,031 adult patients who underwent lung cancer surgery were included in the final analysis. Of these, 17,255 (28.7%) patients had preoperative psychiatric morbidity before lung cancer surgery. Multivariable logistic regression modeling revealed patients with preoperative alcohol abuse (odds ratio [OR]: 2.51, 95% confidence interval [CI]: 1.24, 5.08; P = 0.011) and those with bipolar disorder (OR: 2.91, 95% CI: 1.94, 4.53; P &lt; 0.001) to be associated with increased in-hospital mortality. Moreover, patients with preoperative psychiatric morbidities were associated with longer length of hospitalization (LOS), higher cost of hospitalization, and increased 1-year all-cause mortality.

CONCLUSION

In South Korea, patients with preoperative alcohol abuse and bipolar disorder were associated with increased in-hospital mortality after lung cancer surgery. Moreover, they were associated with increased 1-year all-cause mortality, longer LOS, and higher total costs for lung cancer surgery.

New, long-term opioid use after lung cancer surgery is associated with reduced 2-year survival: a retrospective population-based cohort study in South Korea

INTRODUCTION

We aimed to investigate the proportion and associated factors for new long-term opioid use and its long-term effects after lung cancer surgery.

METHODS

The South Korean National Health Insurance Database was used as a nationwide registration data source. All patients undergoing lung cancer surgery between 2011 and 2018 were included, and patients who were preoperative opioid users were excluded from the analysis. New long-term opioid use was defined as an active opioid prescription at 6 months postoperatively.

RESULTS

In total, 54 509 patients were included in the final analysis. At 6 months postoperatively, 3325 (6.1%) patients who were newly prescribed opioids comprised the new long-term opioid user group. Older age, male sex, wider surgical extent, open thoracotomy, increased Charlson Comorbidity Index score, neoadjuvant or adjuvant chemotherapy, preoperative anxiety disorder and insomnia disorder were associated with a higher rate of new long-term opioid use. The new long-term opioid user group showed a 40% (HR, 1.40; 95% CI 1.29 to 1.53; p<0.001) higher risk of 2-year all-cause mortality. Moreover, the new long-term potent opioid user and less potent opioid user groups showed a 92% (HR, 1.92; 95% CI 1.67 to 2.21; p<0.001) and 22% (HR, 1.22; 95% CI 1.10 to 1.36; p<0.001) higher risk of 2-year all-cause mortality, respectively.

CONCLUSIONS

Among preoperative opioid-naive patients in South Korea, 6.1% became new long-term opioid users after lung cancer surgery. Certain factors are potential risk factors for new long-term opioid use, which could be associated with poorer long-term survival outcomes.

Epidemiologic study of in-hospital cardiopulmonary resuscitation among pediatric patients: A retrospective, population-based cohort study in South Korea

We aimed to examine the clinical trends of in-hospital cardiopulmonary resuscitation (ICPR) and factors associated with live discharge following ICPR. As a national population-based cohort study, data were extracted from the South Korean National Inpatient Database. This study included 8992 pediatric patients under 18 years of age who underwent ICPR due to in-hospital cardiac arrest during hospitalization in South Korea between 2010 and 2019 (10 years). The annual prevalence, survival, duration of hospitalization, and total cost of hospitalization at ICPR were examined as clinical trends. In 2010, 7.94 per 100,000 pediatric patients received ICPR; the prevalence increased to 11.51 per 100,000 pediatric patients in 2019. The 10-year survival rates were similar, and the in-hospital, 6-month, and 1-year survival rates over 10 years were 44.0%, 34.0%, and 32.4%, respectively. The mean length of hospital stay at ICPR in 2010 was 20.7 (95% confidence interval [CI]: 19.3-22.2) days; this decreased to 16.6 (95% CI: 15.2-18.0) days in 2019. The mean total cost at ICPR was 11,081.1 (95% CI: 10,216.2-11,946.1) United States Dollars (USD) in 2010; this increased to 22,629.4 (95% CI: 20,588.3-24,670.5) USD in 2019. The prevalence of ICPR increased among pediatric patients in South Korea between 2010 and 2019; however, the survival rates were similar for the 10 years. The length of hospital stay at ICPR gradually decreased from 2010 through 2019, while the total cost of hospitalization at ICPR has gradually increased between 2010 and 2019.

Long-term opioid use and mortality in patients with chronic non-cancer pain: Ten-year follow-up study in South Korea from 2010 through 2019

BACKGROUND

We aimed to investigate the prevalence and factors associated with long-term opioid use among patients with chronic non-cancer pain (CNCP).

METHODS

We extracted data from the National Health Insurance Service (NHIS) database in South Korea. As a nationwide database, the NHIS database contains information regarding all disease diagnoses and prescriptions for any drug and/or procedures. A total of 2.5% of adult patients (≥20 years of age) who were diagnosed with musculoskeletal diseases and CNCP from 2010 to 2019 were selected using a stratified random sampling technique and included in the analysis. Patients who were prescribed opioids continuously for ≥90 days were classified as long-term opioid users.

FINDINGS

A total of 19,645,161 patients with CNCP were included in the final analysis. The prevalence of long-term opioid use was 0.47% (95% confidence interval [CI]: 0.46%, 0.48%; 8421/1,808,043) in 2010, which gradually increased to 2.63% (95% CI: 2.61%, 2.66%; 49,846/1,892,913) in 2019. Among the 2010 cohort (n = 1,804,019), in multivariable logistic regression: old age, underlying disability, increased Charlson comorbidity index, use of benzodiazepine or Z-drug, rheumatoid arthritis, osteoarthritis, and low back pain were associated with an increased prevalence of long-term opioid use among patients with CNCP. In a multivariable Cox regression, the 10-year all-cause mortality in long-term opioid users was found to be 1·21-fold (hazard ratio: 1.21, 95% CI: 1.13, 1.31; P<0·001) higher than that in opioid-naive patients with CNCP.

INTERPRETATION

Long-term opioid use increased in patients with CNCP in South Korea from 2010 to 2019. Certain factors were potential risk factors for long-term opioid use. Moreover, long-term opioid use was associated with increased 10-year all-cause mortality among patients with CNCP.

FUNDING

None.

Psychiatric morbidity among survivors of in-hospital cardiopulmonary resuscitation: A nationwide cohort study in South Korea

BACKGROUND

We aimed to examine the prevalence and associated factors of newly developed psychiatric morbidity among survivors of in-hospital cardiopulmonary resuscitation (ICPR). Additionally, we investigated whether pre-existing and newly developed psychiatric morbidities affect long-term mortality.

METHODS

We extracted data from the National Health Insurance Service database in South Korea. Adult ICPR survivors who underwent ICPR from January 1, 2010, to December 31, 2018, and who were alive for more than 1 year after ICPR were enrolled. Depression, anxiety, substance abuse, and post-traumatic stress disorder (PTSD) were evaluated as psychiatric morbidity.

RESULTS

A total of 22,611 survivors of ICPR from 615 hospitals in South Korea were included in the final analysis. Among them, 7825 (34.6%) had pre-existing psychiatric morbidity before ICPR, while 2524 (11.2%) had newly developed psychiatric morbidity after ICPR. In multivariable Cox regression analysis, compared to the no psychiatric morbidity group, the pre-existing psychiatric morbidity group (adjusted hazard ratio, 1.02; 95% confidence interval, 0.94, 1.11; P = 0.629) and the newly developed psychiatric morbidity group (adjusted hazard ratio, 1.02; 95% confidence interval, 0.90, 1.15; P = 0.798) were not associated with 1-year all-cause mortality among 1-year survivors of ICPR.

LIMITATION

Retrospective cohort design.

CONCLUSIONS

In South Korea, 11.2% of ICPR survivors had newly developed psychiatric morbidity such as depression, anxiety disorder, substance abuse, and PTSD within 1 year after ICPR. However, both pre-existing and newly developed psychiatric morbidities were not associated with 1-year all-cause mortality among 1-year survivors of ICPR.

Suicide Risk in Survivors of Acute Respiratory Distress Syndrome: A Nationwide Cohort Study in South Korea

OBJECTIVE

We aimed to examine the prevalence and risk factors of suicide among patients with acute respiratory distress syndrome (ARDS).

METHODS

Data were extracted from the National Health Insurance Service database in South Korea. This study included all adults admitted to intensive care units with a diagnosis of ARDS from January 1, 2010 to December 31, 2019, who survived ≥365. The primary endpoint in this study was suicide within 1 year of an ARDS diagnosis, which was determined as death by a suicide attempt or self-harm.

RESULTS

Analysis included 9,928 patients identified as ARDS survivors. One-year all-cause mortality occurred in 5,021 patients, 186 (1.9%) of which died by suicide. In multivariable Cox regression, older age, continuous renal replacement therapy, cardiopulmonary resuscitation incidence, history of self-harm or attempted suicide and concurrent substance abuse were associated with a higher risk of death by suicide among ARDS survivors.

CONCLUSION

During the 1-year follow-up period, 1.9% of ARDS survivors died by suicide in South Korea, and some factors were identified as potential risk factors for death by suicide. Knowledge of the factors associated with suicide might allow for earlier intervention to potentially reduce the death by suicide among ARDS survivors.

Impact of trained intensivist coverage on survival outcomes after in-hospital cardiopulmonary resuscitation: A nationwide cohort study in South Korea

AIM

We aimed to investigate whether trained intensivist coverage affects survival outcomes following in-hospital cardiopulmonary resuscitation (ICPR) for in-hospital cardiac arrest (IHCA).

METHODS

All adult patients who received ICPR for IHCA between January 1, 2016 and December 31, 2019 in South Korea were included. Patients who received ICPR in hospitals with trained intensivist coverage for ICU staffing were defined as the intensivist group, whereas other patients were considered the non-intensivist group.

RESULTS

In total 68,286 adult patients (36,025 [52.8%] in the intensivist group and 32,261 [47.2%] in the non-intensivist group) were included in the analysis. After propensity score (PS) matching 40,988 patients (20,494 in each group) were included. In logistic regression after PS matching, the intensivist group showed a 17% (odds ratio: 1.17; 95% confidence interval [CI]: 1.12-1.22; P < 0.001) higher live discharge rate after ICPR than the non-intensivist group. In Cox regression after PS matching, the 6-month and the 1-year mortality rates in the intensivist group after ICPR were 11% (hazard ratio [HR]: 0.89; 95% CI: 0.87-0.91; P < 0.001) and 10% (HR: 0.90; 95% CI: 0.88-0.92; P < 0.001) lower than those in the non-intensivist group, respectively. In Kaplan-Meir estimation the median survival time after ICPR in the intensivist group was 12.0 days (95% CI: 11.6-12.4) while that in the non-intensivist group was 8.0 days (95% CI: 7.7-8.3).

CONCLUSIONS

Trained intensivist coverage in the ICU was associated with improvements in both short and long-term survival outcomes after ICPR for IHCA.

Epidemiologic Study of Epidural Analgesia for Lung Cancer Surgery from 2011 to 2018 in South Korea: A National Health Insurance Database Cohort Study

Background

Epidural analgesia is commonly used for pain control during lung cancer surgery. However, the clinical trends in epidural analgesia, associated factors, and their association with clinical outcomes remain controversial. Therefore, we aimed to investigate the trends, associated factors, and their association with the clinical outcomes of epidural analgesia for lung cancer surgery.

Methods

The National Health Insurance Database was used as the data source in a nationwide cohort study. All adult patients who underwent lung cancer surgery between 2011 and 2018 were included.

Results

A total of 60,031 adult patients who underwent surgery for lung cancer were included. Of these, a total of 24,786 patients (41.3%) received epidural analgesia with a mean value of 1.5 days (standard deviation: 2.0 days). Male sex, increased Charlson comorbidity index (CCI), concurrent musculoskeletal disease, and a wider surgical extent were associated with higher odds of epidural analgesia for lung cancer surgery. Compared to open thoracotomy, video-assisted thoracoscopic surgery (VATS) was associated with lower odds of epidural analgesia for lung cancer surgery. Moreover, epidural analgesia was not associated with 30-day mortality, fatal respiratory events, or one-year mortality after lung cancer surgery.

Conclusions

From 2011 to 2018, 41.3% of patients with lung cancer in South Korea received epidural analgesia for lung cancer surgery. Some factors (male sex, increased CCI, concurrent musculoskeletal disease, wider surgical extent, and VATS) were associated with the use of epidural analgesia in lung cancer surgery. However, epidural analgesia was not associated with clinical outcomes after lung cancer surgery.

Risk factors and outcomes of fatal respiratory events after esophageal cancer surgery from 2011 through 2018: a nationwide cohort study in South Korea

BACKGROUND

Pulmonary complications are common after esophageal cancer surgery, but information regarding fatal respiratory events, such as postoperative acute respiratory distress syndrome (ARDS) and respiratory failure, is lacking. We aimed to investigate the prevalence, risk factors, and outcomes of fatal respiratory events after esophageal cancer surgery.

METHODS

We performed a retrospective population-based cohort study based on data from the National Health Insurance Service database in South Korea. All adult patients diagnosed with esophageal cancer who underwent esophageal surgery between January 2011 and December 2018 were included.

RESULTS

A total of 7039 patients were included in the final analysis. Among them, 100 patients (1.4%) experienced fatal respiratory adverse events (ARDS, 55 patients [0.8%]; respiratory failure, 45 patients [0.6%]). On multivariable logistic regression, residence in rural areas (vs. urban areas) at the time of surgery, open thoracotomy (vs. video-assisted thoracoscopic surgery), and lower annual case volume were associated with a higher prevalence of fatal respiratory adverse events. Moreover, postoperative fatal respiratory adverse events were related to increased in-hospital mortality, 1 year mortality, prolonged hospitalization, and increased total hospitalization costs.

CONCLUSION

In South Korea, 1.4% of patients experienced fatal respiratory events (ARDS or respiratory failure) after esophageal cancer surgery. Some factors were revealed as risk factors for fatal respiratory events, and fatal respiratory events worsened clinical outcomes after esophageal cancer surgery.

Trends in Mortality, Treatment, and Costs of Management of Acute Respiratory Distress Syndrome in South Korea: Analysis of Data between 2010 and 2019

PURPOSE

Despite recent advances in the understanding and management of acute respiratory distress syndrome (ARDS), trends in treatment, mortality, and healthcare costs following these advancements remain to be identified. In the present study, we aimed to investigate these trends using real-world data from a national cohort database in South Korea.

MATERIALS AND METHODS

Using the National Health Insurance Service database, we collected and analyzed data for critically ill adult patients with ARDS who were admitted to intensive care units in South Korea between 2010 and 2019.

RESULTS

The final analysis included 25431 patients with ARDS. The 30-, 90-, and 365-day mortality rates in 2010 were 43.8%, 56.5%, and 68.2%, respectively. These rates had gradually decreased to 36.6%, 50.2%, and 58.8%, respectively, by 2019. Extracorporeal membrane oxygenation support for patients with ARDS started in 2014 at a rate of 5.1% (118/2309), which gradually increased to 8.3% (213/2568) by 2019. The rate of neuromuscular blockade treatment gradually increased from 22.6% (626/2771) in 2010 to 30.9% (793/2568) in 2019. The renal replacement therapy rate gradually increased from 5.7% (157/2771) in 2010 to 12.0% (307/2568) in 2019. The mean total cost of hospitalization increased from 5986.7 USD in 2010 to 12336.4 USD in 2019.

CONCLUSION

Real-world data for 2010-2019 indicate that patients with ARDS in South Korea have experienced changes in mortality, treatment, and healthcare costs. Despite the increased financial burden, mortality among patients with ARDS has decreased due to advances in disease management.

Impacts of symptomatic HIV infection on In-Hospital Cardiopulmonary Resuscitation Outcomes: A Population-Based Cohort Study in South Korea

Background

The impacts of human immunodeficiency virus (HIV) infection on survival outcomes after in-hospital cardiopulmonary resuscitation (ICPR) remains controversial. This study aimed to investigate the impacts of HIV infection on both short-term and long-term outcomes after ICPR.

Methods

This nationwide, population-based cohort study used data taken from the South Korean National Health Insurance Service database. All adult (≥18 years old) patients who experienced ICPR between January 1, 2010, and December 31, 2019, were included.

Results

A total of 298,676 adult patients who underwent ICPR were initially included in the analysis. Among them, 586 (0.2%) patients were assigned to the PWH group (patients with symptomatic HIV infection), while 298,090 (99.8%) patients were assigned to the control group. After 1:10 propensity score (PS) matching, 586 patients in the PWH group and 5,845 patients in the control group were included in the analysis. Logistic regression analysis after PS matching showed that the PWH group had a 20% lower live discharge rate after ICPR compared to the control group (odds ratio: 0.80, 95% confidence interval [CI]: 0.65, 0.97; P=0.024). However, Cox regression analysis after PS matching showed that the risks of 6-month survival (hazard ratio [HR]: 1.01, 95% CI: 0.93, 1.11; P=0.768) and 1-year survival (HR: 1.02, 95% CI: 0.93, 1.11; P=0.702) were not significantly different between the PWH and control groups.

Conclusion

Although the PWH group showed lower live discharge rates compared to the control group after ICPR, long-term survival outcomes from 6 months and 1 year were not significantly different.

Prevalence and risk factors for suicide in patients with sepsis: nationwide cohort study in South Korea

BACKGROUND

Although a recent study reported that survivors of critical illness have an increased risk of suicide, the suicide rate and factors associated with suicide in patients with sepsis have not yet been investigated.

AIMS

We aimed to examine the prevalence and risk factors of suicide among patients with sepsis in South Korea.

METHOD

All adult patients who were admitted to all hospitals in South Korea with a main diagnosis of sepsis, from 1 January 2010 to 31 December 2018, were included in the study. The primary outcome was suicide within 1 year after sepsis diagnosis.

RESULTS

A total of 251 837 adult patients with sepsis were included, of which 132 691 patients (52.7%) died within 1 year after the diagnosis of sepsis, and death by suicide was the cause in 3903 patients (1.5%). Older age, male gender, living in a rural area, higher Charlson Comorbidity Index and Elixhauser Comorbidity Index scores, invasive treatment (continuous renal replacement therapy and mechanical ventilator support) and admission to a hospital with low annual case volumes were associated with a higher risk of suicide. In addition, concurrent substance misuse, post-traumatic stress disorder, bipolar disorder, dementia and previous attempt of suicide or self-harm were associated with a higher risk of suicide.

CONCLUSIONS

During the 1-year follow-up period, 1.5% of patients died by suicide after the diagnosis of sepsis in South Korea. Knowledge of the factors associated with suicide might allow for earlier intervention to potentially reduce the number of suicide attempts in patients with sepsis.

Trends in In-Hospital Cardiopulmonary Resuscitation from 2010 through 2019: A Nationwide Cohort Study in South Korea

We aimed to examine recent trends in in-hospital cardiopulmonary resuscitation in South Korea from 2010 to 2019. A population-based sample of all adult patients who experienced in-hospital cardiopulmonary resuscitation between 1 January 2010 and 31 December 2019, was included. In all, 298,676 patients who received in-hospital cardiopulmonary resuscitation were included in the survival analysis. In 2010, 60.7 per 100,000 adults experienced in-hospital cardiopulmonary resuscitation. A similar rate was observed until 2015. The rate increased to 83.5 per 100,000 adults in 2016 and gradually increased to 92.1 per 100,000 adults in 2019. Among all patients, 78,783 (26.2%) were discharged alive after in-hospital cardiopulmonary resuscitation. The 6-month and 1-year survival rates were 9.8% and 8.7%, respectively. In 2010, the mean total cost of hospitalization was USD 5822.80 (United States Dollar) (standard deviation; SD: USD 7493.4), which increased to USD 7886.20 (SD: USD 13,071.6) in 2019. The rate of in-hospital cardiopulmonary resuscitation and cost of care have significantly increased since 2010, while the 6-month and 1-year rates of survival post in-hospital resuscitation remain low.

Mortality Trends after Extracorporeal Membrane Oxygenation Support: A Korean Nationwide Cohort

BACKGROUND

This study aimed to investigate the prevalence of 7-, 30-, 60-, and 365-day overall and cause-specific mortality following extracorporeal membrane oxygenation (ECMO) support.

METHODS

The National Health Insurance claims database in South Korea was the data source for this population-based cohort study. We enrolled all adult patients aged ≥18 years receiving intensive care unit ECMO support from January 1, 2005 to December 31, 2018. The study population was divided into three groups based on the main diagnoses during ECMO support: 1) cardiovascular, 2) respiratory, and 3) other diagnoses group (all other main diagnoses rather than cardiovascular or respiratory diseases).

RESULTS

A total of 18,697 patients were included in the final analysis (64.5%, 10.9%, and 24.6% in the cardiovascular, respiratory, and other groups, respectively). The corresponding 7-, 30-, 60-, and 365-day mortality rates in these groups were 33.1%, 56.1%, 62.4%, and 67.7%. Kaplan-Meier curves demonstrated that the median survival time was shortest in the cardiovascular group (12.0 days, 95% confidence interval [CI]: 11.3-12.7), with 31.0 (95% CI: 28.5-33.6) and 49.0 (95% CI: 44.4-57.6) day survival in the respiratory and other diagnoses groups (p<0.001).

CONCLUSIONS

Approximately one-third of patients died within 7 days, half of the patients died within 30 days, and two-thirds died within 365 days of ECMO support. Overall survival time was shortest in the cardiovascular group, followed by that of the respiratory group.

Limb Amputation Following Extracorporeal Membrane Oxygenation Therapy Among Survivors: A Nationwide Cohort Study from South Korea

We aimed to investigate the incidence of limb amputation due to vascular complications related to extracorporeal membrane oxygenation (ECMO) therapy among survivors and examine its association with long-term mortality in these cases. Data from the National Health Insurance Service database in South Korea were extracted for this population-based cohort study. Adult people who underwent ECMO therapy between 2005 and 2018 were included. ECMO survivors were defined as those who survived for at least 365 days after the initiation of ECMO therapy. A total of 6,968 ECMO survivors were included in the study. Among them, 114 (1.6%) underwent limb amputation within 365 days of starting ECMO therapy. On multivariable Cox regression analysis, the risk of 3-year all-cause mortality was not significantly associated with limb amputation compared with those without limb amputation (hazard ratio: 1.53; 95% CI: 0.89-2.63; P = 0.072). In South Korea, 1.6% of ECMO survivors underwent limb amputation within 365 days after initiating ECMO therapy; however, it was not significantly associated with the 3-year all-cause mortality. Our findings warrant future studies on the impact on the quality of life and morbidity-related implications among patients who undergo limb amputation due to ECMO therapy.