The goal of the present study was to test the reliability and validity of the Japanese version of the Quality of Life after Brain Injury (QOLIBRI) scale. Correlations between the QOLIBRI and Glasgow Coma Scale scores, anxiety, depression, general quality of life (QOL), and demographic characteristics were examined to assess scale validity. The structure of the QOLIBRI was investigated with exploratory and confirmatory factor analyses, as well as the Partial Credit Model. Test–retest reliability was assessed over a 2-week interval. Participants were 129 patients with traumatic brain injury (TBI) recruited from rehabilitation centers in Japan. The QOLIBRI showed good-to-excellent internal consistency (Cronbach's α: 0.82–0.96), test–retest reliability, and validity (r = 0.77–0.90). Factor analyses revealed a 6-factor structure. Compared to an international sample (IS), Japanese patients had lower QOLIBRI scores and lower satisfaction in several domains. There were positive correlations between the QOLIBRI scales and the Short Form 36 Health Survey (r = 0.22–0.41). The Japanese version of the QOLIBRI showed good-to-excellent psychometric properties. Differences between JS and IS may reflect sampling bias and cultural norms regarding self-evaluation. The QOLIBRI could be a useful tool for assessing health-related QOL in individuals with TBI.
Anxiety ; Asian Continental Ancestry Group ; Brain Injuries ; Brain ; Depression ; Diagnostic Self Evaluation ; Glasgow Coma Scale ; Health Surveys ; Humans ; Japan ; Psychometrics ; Quality of Life ; Rehabilitation Centers ; Reproducibility of Results ; Selection Bias ; Weights and Measures

Randomized controlled trial is widely accepted as the best design for evaluating the efficacy of a new treatment because of the advantages of randomization (random allocation). Randomization eliminates accidental bias, including selection bias, and provides a base for allowing the use of probability theory. Despite its importance, randomization has not been properly understood. This article introduces the different randomization methods with examples: simple randomization; block randomization; adaptive randomization, including minimization; and response-adaptive randomization. Ethics related to randomization are also discussed. The study is helpful in understanding the basic concepts of randomization and how to use R software.
Bias (Epidemiology) ; Ethics ; Probability Theory ; Random Allocation ; Selection Bias

BACKGROUND: Maintenance of tracheal intubation is associated with use of sedatives, stress due to mechanical ventilation, or respiratory complications. The aim of this study is to compare the incidence of delirium between early and late extubation groups after liver transplantation (LT). METHODS: Medical records from 247 patients who received LT from January 2010 to July 2017 in a single university hospital were retrospectively reviewed. Patients were divided with 2 groups: Those who underwent early extubation after LT (E group, n = 52) and those who underwent extubation within few hours of intensive care unit (ICU) admission after surgery (C group, n = 195). The patients’ demographic data, perioperative managements and postoperative complications were collected. Early extubation was defined as performing extubation in the operating room after LT. A propensity score matching analysis was performed to reduce the effects of selection bias. RESULTS: Among them, 4/52 (7.69%) in E group and 30/195 (15.38%) in C group occurred postoperative delirium after LT, respectively (P = 0.180). After propensity score matching, there was no difference of the period of hospitalization in ICU (P = 0.961), time to discharge after surgery (P = 0.117) and incidence of delirium between groups (P = 1.000). CONCLUSIONS: Although this study is a retrospective study and limited by the small number of subjects, early extubation does not affect the incidence of delirium after LT. Therefore, further prospective studies on this were needed.
Airway Extubation ; Delirium ; Hospitalization ; Humans ; Hypnotics and Sedatives ; Incidence ; Intensive Care Units ; Intubation ; Liver Transplantation ; Liver ; Medical Records ; Operating Rooms ; Postoperative Complications ; Propensity Score ; Prospective Studies ; Respiration, Artificial ; Retrospective Studies ; Selection Bias

PURPOSE: The aim of this study was to assess oncological outcomes of postoperative radiotherapy plus chemotherapy (CRT) versus chemotherapy alone (CTx) in stage II or III upper rectal cancer patients who underwent curative surgery. METHODS: We retrospectively reviewed 263 consecutive patients with pathologic stage II or III upper rectal cancer who underwent primary curative resection with postoperative CRT or CTx from January 2008 to December 2014 at Chonnam National University Hwasun Hospital. Multivariate and propensity score matching analyses were used to reduce selection bias. RESULTS: Median follow-up was 48.1 months for the entire cohort and 53.5 months for the matched cohort. In subgroup analysis of the propensity score matched cohort, the 3-year local recurrence-free survival was 94.1% (95% confidence interval [CI], 87.8%–100%) in the CRT group and 90.1% (95% CI, 82.8%–97.9%) in the CTx group (P = 0.370). No significant difference in disease-free survival was observed according to treatment type. On multivariate analysis, circumferential resection margin involvement (hazard ratio [HR], 2.386; 95% CI, 1.190–7.599; P = 0.032), N stage (HR, 6.262; 95% CI, 1.843–21.278, P = 0.003), and T stage (HR, 5.896, 95% CI, 1.298–6.780, P = 0.021) were identified as independent risk factors for local recurrence of tumors of the upper rectum. CONCLUSION: Omission of radiotherapy in an adjuvant treatment setting may not jeopardize oncologic outcomes in stages II and III upper rectal cancer.
Chemoradiotherapy ; Cohort Studies ; Disease-Free Survival ; Drug Therapy ; Follow-Up Studies ; Humans ; Jeollanam-do ; Multivariate Analysis ; Propensity Score ; Radiotherapy ; Rectal Neoplasms ; Rectum ; Recurrence ; Retrospective Studies ; Risk Factors ; Selection Bias

PURPOSE: Although linear-shaped gastroduodenostomy (LSGD) was reported to be a feasible and reliable method of Billroth I anastomosis in patients undergoing totally laparoscopic distal gastrectomy (TLDG), the feasibility of LSGD for patients undergoing totally robotic distal gastrectomy (TRDG) has not been determined. This study compared the feasibility of LSGD in patients undergoing TRDG and TLDG.MATERIALS AND METHODS: ALL C: onsecutive patients who underwent LSGD after distal gastrectomy for gastric cancer between January 2009 and December 2017 were analyzed retrospectively. Propensity score matching (PSM) analysis was performed to reduce the selection bias between TRDG and TLDG. Short-term outcomes, functional outcomes, learning curve, and risk factors for postoperative complications were analyzed.RESULTS: This analysis included 414 patients, of whom 275 underwent laparoscopy and 139 underwent robotic surgery. PSM analysis showed that operation time was significantly longer (163.5 vs. 132.1 minutes, P<0.001) and postoperative hospital stay significantly shorter (6.2 vs. 7.5 days, P<0.003) in patients who underwent TRDG than in patients who underwent TLDG. Operation time was the independent risk factor for LSGD after intracorporeal gastroduodenostomy. Cumulative sum analysis showed no definitive turning point in the TRDG learning curve. Long-term endoscopic findings revealed similar results in the two groups, but bile reflux at 5 years showed significantly better improvement in the TLDG group than in the TRDG group (P=0.016).CONCLUSIONS: LSGD is feasible in TRDG, with short-term and long-term outcomes comparable to that in TLDG. LSGD may be a good option for intracorporeal Billroth I anastomosis in patients undergoing TRDG.
Bile Reflux ; Gastrectomy ; Gastroenterostomy ; Humans ; Laparoscopy ; Learning Curve ; Length of Stay ; Methods ; Postoperative Complications ; Propensity Score ; Retrospective Studies ; Risk Factors ; Robotic Surgical Procedures ; Selection Bias ; Stomach Neoplasms

PURPOSE: To identify the potential therapeutic role of postoperative radiotherapy (RT) in patients with locally advanced (stage II and stage III) gastric signet ring cell carcinoma (SRC).MATERIALS AND METHODS: Patients with locally advanced gastric SRC from the Surveillance, Epidemiology, and End Results program database between 2004 and 2012 were included in our study. Univariate and multivariate Cox proportional models were performed, and survival curves were generated to evaluate the prognostic effect of postoperative RT and surgery alone on SRC patients. Propensity score matching (PSM) was used to avoid selection bias among the study cohorts.RESULTS: We found that patients with postoperative RT had better probability of survival compared with those who did not receive RT (overall survival [OS], P<0.001; cancer-specific survival [CSS], P<0.001). After PSM, analysis of both overall and CSS showed that patients who underwent postoperative RT had better prognosis than those receiving surgery alone in the matched cohort (OS, P=0.00079; CSS, P=0.0036). Multivariate Cox proportional model indicated that postoperative RT had better effect on prognosis compared with surgery alone with respect to both overall (hazard ratio [HR], 0.716; 95% confidence interval [95% CI], 0.590–0.87; P=0.001) and CSS (HR, 0.713; 95% CI, 0.570–0.890; P=0.003).CONCLUSIONS: Postoperative RT had better prognosis compared with surgery alone for both overall and CSS for patients with locally advanced gastric SRC.
Carcinoma, Signet Ring Cell ; Cohort Studies ; Humans ; Nomograms ; Prognosis ; Propensity Score ; Radiotherapy ; SEER Program ; Selection Bias ; Stomach Neoplasms

OBJECTIVE: We aimed to investigate the long-term effects of atomoxetine on growth in Korean children and adolescents with attention-deficit/hyperactivity disorder (ADHD). METHODS: The medical records of 82 subjects (mean age, 9.0±2.0 years; 64 boys) with ADHD treated with atomoxetine for at least 1 year at the Department of Psychiatry at Asan Medical Center were retrospectively reviewed. Height and weight data were prospectively obtained and retrospectively gathered and converted to age- and gender-corrected z scores using norms from Korean youths. Growth changes were analyzed using random coefficients models with changes in height or weight z scores as the dependent variables. RESULTS: Height z scores significantly decreased during the treatment period (β=-0.054, p=0.024). Height z scores decreased during the 1st year of treatment (β=-0.086, p=0.003), but did not change after the 1st year. Weight z scores did not change significantly during treatment (β=0.004, p=0.925). CONCLUSION: Our results suggest that long-term atomoxetine treatment may be associated with deficits in height growth in Korean youths, although this effect was minor and tended to be attenuated over the first year. Because of the limitations of this study such as retrospective design and selection bias, further prospective studies are needed.
Adolescent* ; Atomoxetine Hydrochloride* ; Child* ; Chungcheongnam-do ; Humans ; Medical Records ; Prospective Studies ; Retrospective Studies* ; Selection Bias

PURPOSE: To investigate the current status of adjuvant chemotherapy (AC) regimens in Korea and the difference in efficacy of AC administered by surgical and medical oncologists in patients with stage II or III gastric cancers. MATERIALS AND METHODS: We performed a retrospective observational study among 1,049 patients who underwent curative resection and received AC for stage II and III gastric cancers between February 2012 and December 2013 at 29 tertiary referral university hospitals in Korea. To minimize the influence of potential confounders on selection bias, propensity score matching (PSM) was used based on binary logistic regression analysis. The 3-year disease-free survival (DFS) rates were compared between patients who received AC administered by medical oncologists or surgical oncologists. RESULTS: Between February 2012 and December 2013 in Korea, the most commonly prescribed AC by medical oncologists was tegafur/gimeracil/oteracil (S-1, 47.72%), followed by capecitabine with oxaliplatin (XELOX, 16.33%). After performing PSM, surgical oncologists (82.74%) completed AC as planned more often than medical oncologists (75.9%), with statistical significance (P=0.036). No difference in the 3-year DFS rates of stage II (P=0.567) or stage III (P=0.545) gastric cancer was found between the medical and surgical oncologist groups. CONCLUSIONS: S-1 monotherapy and XELOX are a main stay of AC, regardless of whether the prescribing physician is a medical or surgical oncologist. The better compliance with AC by surgical oncologists is a valid reason to advocate that surgical oncologists perform the treatment of AC for stage II or III gastric cancers.
Capecitabine ; Chemotherapy, Adjuvant* ; Compliance ; Disease-Free Survival ; Hospitals, University ; Humans ; Korea* ; Logistic Models ; Observational Study ; Propensity Score ; Referral and Consultation ; Retrospective Studies* ; Selection Bias ; Stomach Neoplasms*

BACKGROUND: Cervical foraminal stenosis (CFS) is one of the degenerative changes of the cervical spine; however, correlations between the severity of stenosis and that of symptoms are not consistent in the literature. Studies to date on the prevalence of stenosis are based on images obtained from the departments treating cervical lesions, and thus patient selection bias may have occurred. The purpose of this study was to investigate the prevalence of CFS according to the site, extent, and morphology of stenosis using cervical computed tomography (CT) images obtained from patients who were visiting not because of symptoms related to the cervical spine, cervical pain, or upper limb pain. METHODS: Among patients who underwent CT from January 2016 to March 2016 for reasons other than cervical spine symptoms, a total of 438 subjects were enrolled, and 2,628 cervical disc images (C4–5, C5–6, and C6–7; left and right sides) were examined. Three orthopedic surgeons performed two measurements each at 4-week intervals. Values were used for analysis if matched by more than two surgeons; if no match was found, the median values were used for analysis. The left and right sides on the same axial image were independently classified. RESULTS: Left C5–6 stenosis was most common (24.66%) among patients. At the left C6–7, there were 20 focal types and 33 diffuse types. At bilateral C4–5 and right C6–7, the focal type was more common, whereas at bilateral C5–6 and left C6–7, the diffuse type was more common. Age and the severity of stenosis showed statistically significant correlation at all cervical levels. CONCLUSIONS: The prevalence of CFS was highest at the C5–6 level (19.06%). Compared to other levels, focal stenosis was more frequent at C4–5 and diffuse stenosis was more common at C5–6. At C6–7, the incidence of focal stenosis was higher on the right side and that of diffuse stenosis was higher on the left side.
Bias (Epidemiology) ; Cervical Vertebrae ; Constriction, Pathologic* ; Female ; Humans ; Incidence ; Neck Pain ; Orthopedics ; Patient Selection ; Prevalence* ; Spinal Stenosis ; Spine ; Surgeons ; Upper Extremity

This paper summaries the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I), a tool for evaluating risk of bias about Non-randomized Studies-of Interventions (NRSI), and introduces the application of ROBINS-I in a published NRSI. According to the characteristics of NRSI, evaluation field and signaling question were designed in ROBINS-I to provide essential information about risk of bias for NRSI included in systematic reviews. ROBINS-I is the tool in assessment of risk of bias in observational studies and quasi-randomised studies. Although the tool has been used in practice to some extent, but it still needs further improvement. Attention should be paid to its update and progress.
Animals ; Bias ; Controlled Clinical Trials as Topic ; Humans ; Reproducibility of Results ; Risk Assessment/methods* ; Selection Bias