Epidemiology and Health最新文献

Objectives: Unequal access to cancer clinical trials is an important issue, given the potential benefits of participation for cancer patients. We evaluated regional disparities in access to cancer clinical trials in Korea.

Methods: From the Ministry of Food and Drug Safety database, we extracted 2,465 records of all cancer clinical trials approved between January 2012 and April 2023. To measure disparities in cancer clinical trial access, we calculated the ratio of clinical trials open to non-capital areas relative to those open to capital areas. We then analyzed temporal trends in this ratio, which we termed the trial geographical equity index (TGEI).

Results: Disparities in access to cancer clinical trials, as indicated by the TGEI, did not significantly improve during the study period (regression coefficient, 0.002; p=0.59). However, for phase II/III trials sponsored by global pharmaceutical companies, the TGEI improved significantly (regression coefficient, 0.021; p<0.01). In contrast, the TGEI deteriorated for trials initiated by investigators or those testing domestically developed therapeutics (regression coefficient, -0.015; p=0.05). Furthermore, the increasing trend of TGEI for phase II/III trials sponsored by global companies began to reverse after 2019, coinciding with the outbreak of coronavirus disease 2019 (COVID-19).

Conclusions: Over the past decade, access to cancer clinical trials has improved in Korea, particularly for phase II/III trials evaluating therapeutics from global companies. However, this increase in accessibility has not extended to trials initiated by investigators or those assessing domestically developed therapeutics. Additionally, the impact of COVID-19 on disparities in clinical trial access should be closely monitored.

Objectives: This study aimed to establish the validity-specifically, the sensitivity and specificity-of the screening questionnaire and diagnostic criteria for oral frailty proposed by the Korean Academy of Geriatric Dentistry (KAGD) among community-dwelling older adults.

Methods: This study enrolled 100 participants. Among various definitions of oral frailty, this study used the criteria proposed by Tanaka as the reference test. The screening questionnaire consisted of 11 items for screening physical frailty, chewing ability, swallowing difficulties, oral dryness, and tongue and lip motor function. Each question had a different scoring weight, and if the total score was 1 or higher, an oral frailty diagnostic examination proposed by the KAGD would be recommended. The diagnostic test was the oral frailty diagnostic criteria proposed by the KAGD including 6 measures: chewing ability, occlusal force, tongue pressure, oral dryness, swallowing difficulty, and oral hygiene. If a participant exhibited 2 or more positive measures, this participant was classified as "oral frail." The screening questionnaire was analyzed using a cut-off value of 1 or higher, while the diagnostic criteria utilized a cut-off of 2 or more positive measures. Sensitivity and specificity were calculated.

Results: The screening questionnaire showed significant power for screening oral frailty (area under the receiver operating characteristic curve, 0.783; sensitivity, 87.8%; specificity, 52.5%). The diagnostic accuracy of the newly proposed diagnostic criteria was acceptable (sensitivity, 95.1%; specificity, 42.4%).

Conclusions: The newly proposed screening questionnaire and diagnostic criteria in Korea appear to be a useful tool to identify oral frailty in community-dwelling older adults.

Objectives: Serum matrix metalloproteinase (MMP) levels are associated with cardiovascular diseases. However, the causal associations between serum levels of specific MMPs and venous thromboembolism (VTE) remain unclear. The present study sought to explore the causal relationship between serum MMP levels and VTE by using the Mendelian randomization (MR) method.

Methods: In this study 2-sample MR study, the exposure data on serum MMP levels were derived from genome-wide association studies involving 21,758 individuals from 13 cohorts of European descent. The outcome data on VTE, including deep vein thrombosis and pulmonary embolism, were derived from the FinnGen research project. The primary method used was the inverse-variance weighting method. The MR-Egger intercept test and the Cochran Q test were used to evaluate pleiotropy and heterogeneity.

Results: Using the inverse-variance weighting method, higher serum MMP-12 levels were found to be associated with an increased risk of VTE (odds ratio, 1.04; 95% confidence interval, 1.01 to 1.07; p=0.001). Moreover, there was a weak association between the levels of certain MMPs and VTE. Sensitivity analyses revealed no significant heterogeneity and pleiotropy in our study, and the Steiger directionality test did not reveal a significant reverse causation association.

Conclusions: There is a causal association between MMP-12 levels and VTE, which may have substantial implications for the diagnostic and therapeutic strategies used for VTE.

Objectives: This study investigated whether the lower extremity muscle mass index (LMI) mediates the relationship between general obesity, central obesity, and knee osteoarthritis in middle-aged and elderly women in Korea.

Methods: Data of 2,843 women aged ≥50 years were collected from the Korean National Health and Nutrition Examination Survey conducted between 2009 and 2011. General obesity and central obesity were evaluated based on body mass index (BMI) and waist circumference (WC), calculated through anthropometric measurements and body composition assessments. LMI was calculated by dividing the muscle mass in both legs-measured using the dual-energy X-ray absorptiometry-by body weight. Knee osteoarthritis was defined as a Kellgren-Lawrence scale (KL) grade of ≥2 as assessed through radiographic images.

Results: Knee osteoarthritis prevalence, indicated by KL grades, was significantly higher in the general obesity and central obesity groups compared to the normal group, and conversely, lower with varying LMI levels. Using mediation analysis with bootstrapping and adjusting for covariates, we found that LMI mediated the relationship between BMI and KL (β, 0.005; 95% confidence interval [CI], 0.000 to 0.010) and WC and KL grade (β, 0.002; 95% CI, 0.001 to 0.003), explaining 4.8% and 6.7% of the total effects of BMI and WC on KL grade, respectively.

Conclusions: The study suggested that LMI partially mediates the link between general obesity and/or central obesity and knee osteoarthritis, proposing that a higher proportion of lower limb muscle mass relative to body weight can alleviate the increased risk of knee osteoarthritis caused by obesity.

Objectives: The combination of protein supplementation and resistance exercise shows promise for improving and maintaining muscle mass, strength, and performance in older adults with sarcopenia. This systematic review aimed to evaluate the effects of this combination on muscle mass, muscle strength, and physical performance in community-dwelling older adults with sarcopenia.

Methods: We conducted a comprehensive search of 4 electronic databases: PubMed, Scopus, Embase, and the MEDLINE Library. The search covered literature from January 2013 to January 2023 and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent reviewers assessed the methodological quality of each study using the standard critical appraisal tool from the Joanna Briggs Institute (JBI). Meta-analysis was performed with the JBI Sumari program.

Results: The review included 7 randomized controlled trials and 1 quasi-experimental study, encompassing a total of 854 participants aged 60 years and above. The study durations ranged from 10 weeks to 24 weeks. An analysis of standardized mean differences (SMDs) showed that protein supplementation combined with resistance exercise significantly increased muscle mass (SMD, 0.95; 95% confidence interval [CI], 0.13 to 1.78; p<0.05) and muscle strength (SMD, 0.32; 95% CI, 0.08 to 0.56; p<0.05).

Conclusions: Although the limited number of randomized controlled trials restricts the robustness of our conclusions, the evidence suggests that protein supplementation combined with resistance exercise is effective in enhancing muscle mass and strength in community-dwelling older adults with sarcopenia.

Objectives: Although previous studies have demonstrated an association between periodontal disease (PD) and diabetes mellitus (DM), the influence of age and the mediating role of inflammation have seldom been explored. This study investigated this association while considering the modifying effects of age and inflammatory status.

Methods: This study included 29,491 participants from the 2012-2018 Korea National Health and Nutrition Examination Survey. The community periodontal index (CPI) was assessed by trained dentists using the World Health Organization CPI probe. PD was defined as a CPI score of 3 or 4. Pre-existing and incident DM were identified based on serum glucose levels, a history of DM diagnosis, medication use, and insulin injections. Serum high-sensitivity C-reactive protein (hs-CRP) levels were utilized as an indicator of chronic inflammation.

Results: PD and DM exhibited a significant association, which was more pronounced with incident DM than with pre-existing DM, particularly in individuals younger than 65 years. Among those aged 20-44 years, the odds ratio of incident DM for CPI=4 versus CPI=0 was 2.61 (95% confidence interval, 1.16 to 6.09). High hs-CRP levels (>3 mg/L) were also associated with DM, especially in individuals with PD. This association was stronger with incident DM than with pre-existing DM. A notable joint effect was observed in younger individuals and those with PD.

Conclusions: The association between PD and DM was more pronounced in younger age groups and those with higher levels of inflammation. Therefore, early interventions for PD in younger patients may be crucial for preventing DM.

Objectives: Previous research has predominantly focused on total bilirubin levels without clearly distinguishing between direct and indirect bilirubin. In this study, the differences between these forms were examined, and their potential causal relationships with ischemic stroke were investigated.

Methods: Two-sample multivariable Mendelian randomization (MVMR) analysis was employed, extracting summary data on bilirubin from the Korean Cancer Prevention Study-II (n=159,844) and the Korean Genome and Epidemiology Study (n=72,299). Data on ischemic stroke were obtained from BioBank Japan (n=201,800). Colocalization analysis was performed, focusing on the UGT1A1, SLCO1B1, and SLCO1B3 genes, which are the primary loci associated with serum bilirubin levels.

Results: Crude 2-sample Mendelian randomization analysis revealed a significant negative association between total bilirubin levels and ischemic stroke. However, in MVMR analyses, only indirect bilirubin demonstrated a significant negative association with ischemic stroke (odds ratio, 0.76; 95% confidence interval, 0.59 to 0.98). Colocalization analysis did not identify a shared causal variant between the 3 genetic loci related to indirect bilirubin and the risk of ischemic stroke.

Conclusions: Our study establishes a causal association between higher genetically determined levels of serum indirect bilirubin and reduced risk of ischemic stroke in an Asian population. Future research should include more in-depth analysis of shared genetic variants between indirect bilirubin and ischemic stroke.

Objectives: This study investigated the prevalence, incidence, and prognosis of cardiac amyloidosis (CA) in Korea.

Methods: This retrospective nationwide population-based study used the Health Insurance Review and Assessment Service databases between 2008 and 2020. All patients diagnosed with amyloidosis were included, and those with a diagnosis of heart failure or cardiomyopathy were classified as having CA. Both the special code for amyloidosis (V121), which enables coverage of medical expenses, and the corresponding International Classification of Diseases, 10th revision codes for amyloidosis (E850- E854, E858, E859) were used to improve the reliability of amyloidosis diagnosis.

Results: Among 2,239 patients with amyloidosis, 758 met the criteria for CA (mean age, 64.4±11.9 years; 59.1% male). The mean age of patients with CA increased from 59.5±14.7 years in 2009 to 68.1±13.9 years in 2020. The incidence and prevalence increased from 0.09 (95% confidence interval [CI], 0.06 to 0.12) to 0.22 (95% CI, 0.18 to 0.27) per 100,000 person-years and 0.20 (95% CI, 0.16 to 0.25) to 1.30 (95% CI, 0.12 to 0.42) per 100,000 persons, respectively (all p<0.001). Patients with light-chain CA showed similar trends. In-hospital mortality decreased from 17.3% (95% CI, 9.23 to 29.6) to 6.10% (95% CI, 4.21 to 8.48) between 2009 and 2020. While age-specific in-hospital mortality was significantly higher in patients aged ≥70 years (p=0.004), no significant age-specific difference in in-hospital mortality was observed in patients with CA aged <70 years (p=0.981).

Conclusions: The prevalence and incidence of CA have increased in Korea, predominantly affecting older individuals, particularly males. Notably, in-hospital mortality decreased significantly.

Objectives: The purpose of this study was to assess the effectiveness of human papillomavirus (HPV) vaccination administered to adolescent girls through Korea's National Immunization Program.

Methods: This retrospective cohort study included patients who were 12-13 years old, whether vaccinated or unvaccinated, between July 2016 and December 2017. The incidence of genital warts (GWs) was monitored through 2021. Time-stratified hazard ratios (HRs) were estimated, adjusting for birth year, socioeconomic status, and the level of urbanization of the region, and were presented with 95% confidence intervals (CIs). Data were sourced from the Immunization Registry Integration System, linked with the National Health Information Database.

Results: The study included 332,062 adolescent girls, with an average follow-up period of approximately 4.6 years. Except for the first year, the HRs for the vaccinated group were lower than those for the unvaccinated group. The HRs for specific cut-off years were as follows: year 2, 0.62 (95% CI, 0.31 to 1.13); year 3, 0.58 (95% CI, 0.35 to 0.96); and year 4 and beyond, 0.39 (95% CI, 0.28 to 0.52).

Conclusions: Our findings indicate that HPV vaccination was associated with a reduction in the risk of GWs among adolescent girls. Notably, this reduction became significant as the incidence of GWs increased with age.

Objectives: This study developed an algorithm for identifying pregnancy episodes and estimating the last menstrual period (LMP) in an administrative claims database and applied it to investigate the use of pregnancy-incompatible immunosuppressants among pregnant women with systemic lupus erythematosus (SLE).

Methods: An algorithm was developed and applied to a nationwide claims database in Korea. Pregnancy episodes were identified using a hierarchy of pregnancy outcomes and clinically plausible periods for subsequent episodes. The LMP was estimated using preterm delivery, sonography, and abortion procedure codes. Otherwise, outcome-specific estimates were applied, assigning a fixed gestational age to the corresponding pregnancy outcome. The algorithm was used to examine the prevalence of pregnancies and utilization of pregnancy-incompatible immunosuppressants (cyclophosphamide [CYC]/mycophenolate mofetil [MMF]/methotrexate [MTX]) and non-steroidal anti-inflammatory drugs (NSAIDs) during pregnancy in SLE patients.

Results: The pregnancy outcomes identified in SLE patients included live births (67%), stillbirths (2%), and abortions (31%). The LMP was mostly estimated with outcome-specific estimates for full-term births (92.3%) and using sonography procedure codes (54.7%) and preterm delivery diagnosis codes (37.9%) for preterm births. The use of CYC/MMF/MTX decreased from 7.6% during preconception to 0.2% at the end of pregnancy. CYC/MMF/MTX use was observed in 3.6% of women within 3 months preconception and 2.5% during 0-7 weeks of pregnancy.

Conclusions: This study presents the first pregnancy algorithm using a Korean administrative claims database. Although further validation is necessary, this study provides a foundation for evaluating the safety of medications during pregnancy using secondary databases in Korea, especially for rare diseases.