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BACKGROUND: Age-related changes in left ventricular (LV) structure and function lower the threshold for the onset of heart failure with preserved ejection fraction (HFpEF). LV parameters change also with race; however, the racial differences in age-related changes in LV parameters with and without adjustment for body mass index (BMI), heart rate (HR), and blood pressure (BP) remain unclear. METHODS AND RESULTS: We performed a subanalysis of the World Alliance Society of Echocardiography Normal Values Study, an international cross-sectional study that examined normal echocardiographic values in 15 countries. The age-related changes in 2-dimensional echocardiographic derived parameters including LV size, systolic function, and mass, were compared between healthy Japanese (n=227) and healthy White (n=98) and Black (n=69) American participants. In men, age-related changes in all parameters did not differ significantly among races. However, compared with Japanese women, White American women had a smaller body surface area (BSA)-indexed LV volume, BSA-indexed LV internal dimension at end-systole, BSA-indexed LV stroke volume, and LV mass index to BSA, and a larger LV ejection fraction with age, even after adjusting for BMI, HR, and BP. CONCLUSIONS: Age-related changes in LV structure and function, which are important for the pathophysiology of HFpEF, may differ by race. Therefore, future studies examining echocardiographic reference values for each age group in each race are needed.
Subject(s)
Echocardiography , Heart Ventricles , Ventricular Function, Left , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Age Factors , Aging/physiology , Aging/ethnology , Black or African American , Body Mass Index , Cross-Sectional Studies , East Asian People , Heart Ventricles/diagnostic imaging , Heart Ventricles/physiopathology , Japan , Reference Values , Stroke Volume , United States , WhiteABSTRACT
Objective: A Mediterranean dietary pattern, sleeping habits, physical activity, and lifestyle appear to affect reproductive health. There are few reports about whether fertility-specific quality of life (QOL) is linked to infertility treatment outcomes. The aim of this study is to investigate when lifestyle factors and fertility-specific QOL are comprehensively considered, which factors influence assisted reproductive technology (ART) outcomes. Methods: This prospective cohort includes 291 women undergoing a first ART treatment at multiple centers in Japan and was designed to evaluate the influence of diet, physical activity, sleeping pattern, computer use duration, and fertility-specific quality of life tool (FertiQoL) score on ART treatment outcomes using a questionnaire. The primary endpoint was the good-quality blastocyst rate per oocyte retrieval and the secondary endpoints were a positive pregnancy test and gestational sac (GS) detection. Results: The good-quality blastocyst rate per oocyte retrieval tended to be negatively associated with frequent fish consumption. After all embryo transfer (ET) cycles, a positive pregnancy test tended to be positively associated with longer sleep and longer computer use (OR = 1.6, 95% CI = 0.9-2.7 and OR = 1.7, CI = 1.0-2.8, respectively) and negatively associated with a smoking partner (OR = 0.6, CI = 0.3-1.0). GS detection was positively and significantly associated with frequent olive oil intake and longer computer use (OR = 1.7, CI = 1.0-3.0 and OR = 1.7, CI = 1.0-3.0, respectively). After ET cycles with a single blastocyst, a positive pregnancy test was positively and significantly associated with longer computer use (OR = 2.0, CI = 1.1-3.7), while GS detection was significantly more likely in women with longer computer use (OR = 2.1, CI = 1.1-3.8) and tended to be more likely in women with a higher FertiQoL Total scaled treatment score (OR = 1.8, CI = 1.0-3.3). p < 0.05 was considered statistically significant and 0.05 ≤ p <0.01 as tendency. Conclusions: Olive oil may be an important factor in dietary habits. Fertility-specific QOL and smoking cessation guidance for partners are important for infertile couples.
Subject(s)
Infertility , Quality of Life , Humans , Pregnancy , Female , Prospective Studies , Olive Oil , Fertility , Fertilization in Vitro , Infertility/therapy , Life StyleABSTRACT
Background: Clinical data management (CDM) collects, integrates, and makes data available. It plays a vital role in clinical research. However, there are few opportunities for Japanese clinical data managers to learn about its systematic framework, particularly in academic research organizations. While Japanese-language CDM training exists, its effectiveness in a Japanese context requires clarification. Objectives: We aimed to develop an advanced program of instruction for professionals to understand CDM and to determine the effectiveness of the training program. Methods and results: We developed an advanced program including risk-based monitoring and the Clinical Data Interchange Standards Consortium on a trial basis for clinical data managers to provide them with a comprehensive understanding of CDM. Fifty-two people attended the program and reported that they were highly satisfied with it. Conclusions: To provide comprehensive CDM training in Japan, it is imperative to continue improving the content and develop an advanced program. Due to the recent tightening of clinical research regulations and the development and dissemination of various systems for conducting clinical research, the competency-based educational program requires further development.
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OBJECTIVE: To assess the annual incidence of vestibular neuritis (VN) in the Japanese population. METHODS: We conducted a mail-based survey targeting otolaryngologic clinics and hospitals across Japan to estimate the annual number of patients who were newly-diagnosed with VN during the one-year period of 2021. Using a stratified sampling method, we selected 1,107 departments and asked them to report the number of new patients with VN and their demographics. The total number of VN patients was estimated by multiplying the reported numbers by the reciprocal of the sampling rate and response rate. RESULTS: The overall survey response rate was 40.5 % (448 departments). The estimated number of newly-diagnosed VN patients in 2021 was 8,861 (95 % confidential interval [CI], 2,290-15,432) The annual incidence of VN was 7.05 per 100,000 population in Japan. The male-to-female ratio of VN patients was 0.96, and the mean age was 60.3 ± 16.1 years (range 11-94 years). CONCLUSIONS: The annual incidence of VN in Japan in 2021 had almost doubled and the mean age had become older compared to the previous study in 1993 (annual incidence; 3.5 per 100,000 per year; mean age: 45 years).
Subject(s)
Vestibular Neuronitis , Humans , Male , Female , Child , Adolescent , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , Vestibular Neuronitis/epidemiology , Vestibular Neuronitis/diagnosis , Japan/epidemiology , Incidence , Caloric Tests , Surveys and QuestionnairesABSTRACT
PURPOSE: Surgical procedures are often evaluated subjectively, and an objective evaluation has been considered difficult to make and rarely reported, especially in open surgery, where the range of motion is wide. This study evaluated the effectiveness of surgical suturing training as an educational tool using the Leap Motion Controller (LMC), which can capture hand movements and reproduce them as data comprising parametric elements. METHODS: We developed an off-the-job training system (Off-JT) in our department, mainly using prosthetic grafts and various anastomotic methodologies with graded difficulty levels. We recruited 50 medical students (novice group) and 6 vascular surgeons (expert group) for the study. We evaluated four parameters for intraoperative skills: suturing time, slope of the roll, smoothness, and rate of excess motion. RESULTS: All 4 parameters distinguished the skill of the novice group at 1 and 10 h off-JT. After 10 h of off-JT, all 4 parameters of the novices were comparable to those of the expert group. CONCLUSION: Our education system using the LMC is relatively inexpensive and easy to set up, with a free application for analyses, serving as an effective and ubiquitous educational tool for young surgeons.
Subject(s)
Laparoscopy , Learning Curve , Humans , Motion Capture , Laparoscopy/education , Movement , Anastomosis, Surgical , Clinical Competence , MotionABSTRACT
BACKGROUND/OBJECTIVE: Persistent postural-perceptual dizziness (PPPD) is worsened in a standing posture, or by body movement, or visual stimulation. We aimed to evaluate postural stability in PPPD patients using foam posturography and to investigate the dependence on visual and somatosensory input in the standing posture. METHODS: Foam posturography was performed on 53 PPPD patients, and data from the PPPD patients were compared with the data from an age- and sex-matched healthy controls. The PPPD patients were divided into four groups based on the findings of vestibular function tests and the effect of vestibular function on posturographic data was examined. RESULTS: Romberg's ratios were significantly higher in PPPD patients than in controls. The median Romberg's ratios in PPPD patients with normal vestibular function were also higher than those in controls. However, foam ratio was significantly lower in PPPD patients than in controls. The median foam ratios in PPPD patients with vestibular dysfunction were also lower than those in controls. CONCLUSIONS: In a standing posture, PPPD patients may be more dependent on visual input and less dependent on somatosensory input than healthy subjects. Higher dependence on visual and lower dependence on somatosensory input in PPPD may be a feature unaffected by vestibular function.
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We investigated the tumor immune response in gastric cancer patients receiving third-line nivolumab monotherapy to identify immune-related biomarkers for better patient selection. Nineteen patients (10 males, median age 67 years) who received nivolumab as a third- or later-line therapy were enrolled. We analyzed the tumor immune response in durable clinical benefit (DCB) and non-DCB patients. Pre-treatment and early-on-treatment tumor transcriptomes were examined, and gene expression profiles, immunograms, and T cell receptor (TCR) repertoire were analyzed. DCB was observed in 15.8% of patients, with comparable secondary endpoints (ORR; objective response rate, OS; overall survival, PFS; progression-free survival) to previous trials. The immunograms of individual subjects displayed no significant changes before or early in the treatment, except for the regulatory T cell (Treg) score. Moreover, there were no consistent alterations observed among cases experiencing DCB. The intratumoral immune response was suppressed by previous treatments in most third- or later-line nivolumab recipients. TCR repertoire analysis revealed newly emerged clonotypes in early-on-treatment tumors, but clonal replacement did not impact efficacy. High T cell/Treg ratios and a low UV-radiation-response gene signature were linked to DCB and treatment response. This study emphasizes the tumor immune response's importance in nivolumab efficacy for gastric cancer. High T cell/Treg ratios and specific gene expression signatures show promise as potential biomarkers for treatment response. The tumor-infiltrating immune response was compromised by prior treatments in third-line therapy, implying that, to enhance immunotherapeutic outcomes, commencing treatment at an earlier stage might be preferable. Larger cohort validation is crucial to optimize immune-checkpoint inhibitors in gastric cancer treatment.
Subject(s)
Antineoplastic Agents, Immunological , Stomach Neoplasms , Male , Humans , Aged , Nivolumab , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics , Stomach Neoplasms/chemically induced , Antineoplastic Agents, Immunological/pharmacology , Neoplasm Recurrence, Local/drug therapy , Receptors, Antigen, T-Cell/genetics , BiomarkersABSTRACT
INTRODUCTION: Patients undergoing hemodialysis exhibit a high incidence of subclavian steal syndrome. Many cases of endovascular treatment for subclavian artery stenosis were only reported recently; however, the long-term results of surgical treatment are also important. Herein, we report a case of subclavian steal syndrome treated with common carotid-axillary bypass surgery in a patient undergoing hemodialysis. PRESENTATION OF CASE: An 83-year-old woman experienced dizziness and pain in her left hand during hemodialysis. Computed tomography and angiography revealed severe stenosis and calcified lesions in the left subclavian artery. Ultrasonography revealed a retrograde blood flow waveform in the left vertebral artery. The patient was diagnosed with subclavian steal syndrome. We performed common carotid-axillary bypass for lesions that were difficult to revascularize via endovascular therapy. The post-operative course was uneventful, and the dizziness and numbness in the patient's left hand during dialysis disappeared. Post-operative ultrasonography revealed an antegrade blood flow waveform in the left vertebral artery. DISCUSSION: Subclavian steal syndrome is an indication for revascularization in symptomatic patients. Endovascular treatment should be considered the first choice; however, surgery should be considered for patients in whom endovascular treatment is difficult, such as those with severe calcification. We chose common carotid-axillary artery bypass because the subclavian approach is a more familiar technique. Until 1 year post-operatively, the patient had not experienced any symptom recurrence, and the shunt flow was well maintained. CONCLUSION: Common carotid-axillary bypass can be useful for revascularization of lesions for which endovascular therapy is considered difficult in patients with subclavian steal syndrome.
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Although cardiac rehabilitation (CR) has been shown to improve exercise tolerance and prognosis in patients with cardiovascular diseases, there remains low participation in outpatient CR. This may be attributed to the patients' busy schedules and difficulty in visiting the hospital due to distance, cost, avoidance of exercise, and severity of coronary disease. To overcome these challenges, many countries are exploring the possibility of remote CR. Specifically, there is increasing attention on the development of remote CR devices, which allow transmission of vital information to the hospital via a remote CR application linked to a wearable device for telemonitoring by dedicated hospital staff. In addition, remote CR programs can support return to work after hospitalization. Previous studies have demonstrated the effects of remote CR on exercise tolerance. However, the preventive effects of remote CR on cardiac events and mortality remain controversial. Thus, safe and effective remote CR requires exercise risk stratification for each patient, telenursing by skilled staff, and multidisciplinary interventions. Therefore, quality assurance of telenursing and multi-disciplinary interventions will be essential for remote CR. Remote CR may become an important part of cardiac management in the future. However, issues such as cost-effectiveness and insurance coverage still persist.
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BACKGROUND: The reproducibility of the effective intensity of noisy galvanic vestibular stimulation (nGVS) to improve postural stability is not well known. OBJECTIVE: We aimed to investigate inter-day and intra-day variations in effective intensity in patients with bilateral vestibulopathy (BVP). METHODS: Thirteen BVP patients were measured for center-of-pressure movements in the standing posture at five time points: morning of the first test day, morning and evening of the second test day, and morning and evening of the third test day. The mean velocity, the envelopment area, and the root mean square were measured in the eyes-closed condition for 30âs during nGVS application ranging from 0 to 1000µA. The effective intensity was defined as the intensity at which all the three parameters measured during the stimulation were simultaneously smaller than the values at baseline (0µA). RESULTS: Seven of the 13 patients had a common effective intensity throughout the three test days. Six patients on the second test day and five patients on the third test day had no common effective intensity between morning and evening. CONCLUSIONS: The effective intensity of nGVS changes depending on the time during the day as well as between the days.
Subject(s)
Bilateral Vestibulopathy , Vestibule, Labyrinth , Humans , Bilateral Vestibulopathy/diagnosis , Bilateral Vestibulopathy/therapy , Reproducibility of Results , Postural Balance/physiology , Vestibule, Labyrinth/physiology , Posture/physiology , Electric StimulationABSTRACT
Objective: To investigate the effects of self-management vestibular rehabilitation (VR) on the subjective symptoms of dizziness and postural stability in persistent postural-perceptual dizziness (PPPD). Study design: Retrospective case review. Methods: The medical records of 30 patients newly diagnosed with PPPD based on the Bárány Society's diagnostic criteria were reviewed. Nineteen patients (4 males and 15 females; age range 27-84 years, mean age ± standard deviation 57.4 ± 14.2 years) who was newly instructed to self-management VR were included and instructed to perform self-management VR for 2 months. Results: One patient did not visit the outpatient clinic again, and in the remaining 18 patients, 4 (22%) discontinued VR at their own discretion. In the 12 patients who completed 2 months of VR (67%), there was a significant improvement in Niigata PPPD Questionnaire (NPQ) and Dizziness Handicap Inventory (DHI) scores after VR compared to those before VR (p < .05). However, the mean velocity of center of pressure (COP) movement (velocity) and the envelopment area traced by COP movement (area), as well as the Romberg ratio and foam ratio of velocity and area, did not differ significantly after VR when compared to those before VR (p > .05). Conclusions: For PPPD, self-management VR improved subjective symptoms of dizziness, but not stability of standing posture. It is necessary to improve patients' adherence to the treatment. Level of evidence: 4.
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Background: Functionally impaired variants of COQ2, encoding an enzyme in biosynthesis of coenzyme Q10 (CoQ10), were found in familial multiple system atrophy (MSA) and V393A in COQ2 is associated with sporadic MSA. Furthermore, reduced levels of CoQ10 have been demonstrated in MSA patients. Methods: This study was a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial. Patients with MSA were randomly assigned (1:1) to either ubiquinol (1500 mg/day) or placebo. The primary efficacy outcome was the change in the unified multiple system atrophy rating scale (UMSARS) part 2 at 48 weeks. Efficacy was assessed in all patients who completed at least one efficacy assessment (full analysis set). Safety analyses included patients who completed at least one dose of investigational drug. This trial is registered with UMIN-CTR (UMIN000031771), where the drug name of MSA-01 was used to designate ubiquinol. Findings: Between June 26, 2018, and May 27, 2019, 139 patients were enrolled and randomly assigned to the ubiquinol group (n = 69) or the placebo group (n = 70). A total of 131 patients were included in the full analysis set (63 in the ubiquinol group; 68 in the placebo group). This study met the primary efficacy outcome (least square mean difference in UMSARS part 2 score (-1.7 [95% CI, -3.2 to -0.2]; P = 0.023)). The ubiquinol group also showed better secondary efficacy outcomes (Barthel index, Scale for the Assessment and Rating of Ataxia, and time required to walk 10 m). Rates of adverse events potentially related to the investigational drug were comparable between ubiquinol (n = 15 [23.8%]) and placebo (n = 21 [30.9%]). Interpretation: High-dose ubiquinol was well-tolerated and led to a significantly smaller decline of UMSARS part 2 score compared with placebo. Funding: Japan Agency for Medical Research and Development.
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Persistent postural-perceptual dizziness (PPPD) is induced by preceding conditions that cause balance disorders. To investigate the association between vestibular function and preceding balance disorders in PPPD patients, a retrospective chart review was performed. Vestibular function in 55 PPPD patients was measured using the caloric test, cervical vestibular evoked myogenic potential testing to air-conducted sound (ACS cVEMP), ocular vestibular evoked myogenic potential testing to bone-conducted vibration (BCV oVEMP), and video head impulse testing (vHIT). Patients were classified according to the type of preceding balance disorder. The age-stratified Cochran-Mantel-Haenszel (CMH) test and the exact test for the common odds ratio were conducted to evaluate the association between preceding n ≥ 4 balance disorders and present peripheral vestibular dysfunction. PPPD patients with preceding vestibular neuritis presented a significant positive association with abnormal caloric responses (p = 0.013), while those with preceding benign paroxysmal positional vertigo (BPPV) had significantly lower rates of abnormal BCV oVEMP (p = 0.003). Furthermore, patients with preceding vestibular neuritis showed lateral semicircular canal dysfunction, while those with preceding BPPV presented normal utricular functions. These results present the influence of preceding balance disorders on the vestibular function in PPPD.
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Benefit-risk balance is gaining interest in clinical trials. For the comprehensive assessment of benefits and risks, generalized pairwise comparisons are increasingly used to estimate the net benefit based on multiple prioritized outcomes. Although previous research has demonstrated that the correlations between the outcomes impact the net benefit and its estimate, the direction and magnitude of this impact remain unclear. In this study, we investigated the impact of correlations between two binary or Gaussian variables on the true net benefit values via theoretical and numerical analyses. We also explored the impact of correlations between survival and categorical variables on the net benefit estimates based on four existing methods (Gehan, Péron, Gehan with correction, and Péron with correction) in the presence of right censoring via simulation and application to actual oncology clinical trial data. Our theoretical and numerical analyses revealed that the true net benefit values were impacted by the correlations in various directions depending on the outcome distributions. With binary endpoints, this direction was governed by a simple rule with a threshold of 50% for a favorable outcome. Our simulation showed that the net benefit estimates based on Gehan's or Péron's scoring rule could be substantially biased in the presence of right censoring, and that the direction and magnitude of this bias were associated with the outcome correlations. The recently proposed correction method greatly reduced this bias, even in the presence of strong outcome correlations. The impact of correlations should be carefully considered when interpreting the net benefit and its estimate.
Subject(s)
Clinical Trials as Topic , Risk Assessment , HumansABSTRACT
BACKGROUND: In clinical studies, the EQ-5D-5L is often employed with disease-specific health-related quality of life instruments. The questions in the former are more general than the latter; however, it is known that responses to general questions can be influenced by preceding specific questions. Thus, the responses to the EQ-5D-5L have the possibility of being influenced by the preceding disease-specific health-related quality of life instruments. This may lead to bias in the cost-effectiveness analysis results. Therefore, this study aimed to evaluate the impact of the preceding cancer-specific health-related quality of life instruments on the EQ-5D-5L responses. METHODS: We prepared questionnaire booklets containing the EQ-5D-5L, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and the Functional Assessment of Cancer Therapy General with different orders. Using a quasi-randomized design, they were distributed to the patients undergoing drug therapy for advanced cancer, who were classified into three groups: Groups 1, 2, and 3 (the EQ-5D-5L placed first, second, and last, respectively). We compared the EQ-5D-5L index and the missingness of EQ-5D-5L among the groups. RESULTS: The mean EQ-5D-5L index was 0.796, 0.760, and 0.789 for groups 1 (n = 300), 2 (n = 306), and 3 (n = 331), respectively. The difference between Groups 2 and 1 was - 0.036 (95% CI - 0.065 to - 0.007; p = 0.015). The proportion of patients with an incomplete EQ-5D-5L was 0.11, 0.11, and 0.05 for Groups 1, 2, and 3, respectively. The difference of the proportions between group 3 and 1 and between 3 and 2 was - 0.06 (95% CI - 0.10 to - 0.02; p = 0.003) and - 0.06 (95% CI - 0.10 to - 0.02; p = 0.003), respectively. CONCLUSIONS: Although the EQ-5D-5L index differed according to the instrument orders, the difference size would not be considerably larger than the minimally important difference. The patients tended to complete the EQ-5D-5L when they were placed at the end of the questionnaire.
Subject(s)
Neoplasms , Quality of Life , Surveys and Questionnaires , Humans , Reproducibility of ResultsABSTRACT
BACKGROUND: Facial information acquired via three-dimensional reconstruction of head computed tomography (CT) data may be considered personal information, which can be problematic for neuroimaging studies. However, no study has verified the relationship between slice thickness and face reproducibility. This study determined the relationship and match rate between image slice thickness and face detection accuracy of face-recognition software in facial reconstructed models. METHODS: Head CT data of 60 cases comprising entire faces obtained under conditions of non-contrast and 1-mm slice thickness were resampled to obtain 2-10-mm slice-thickness data. Facial models, reconstructed by image thresholding, were acquired from the data. We performed face detection tests per slice thickness on the models and calculated the face detection rate. The reconstructed facial models created from 1-mm slice-thickness data and other slice thicknesses were used as training and test data, respectively. Match confidence scores were obtained via three programs, match rates were calculated per slice thickness, and generalized estimating equations were used to evaluate the match rate trend. RESULTS: In general, the face detection rates for the 1-10-mm slice thicknesses were 100, 100, 98.3, 98.3, 95.0, 91.7, 86.7, 78.3, 68.3, and 61.7 %, respectively. The match rates for the 2-10-mm slice thicknesses were 100, 98.3, 98.3, 95.0, 85.0, 71.7, 53.3, 28.3, and 16.7 %, respectively. CONCLUSION: The reconstructed models tended to have higher match rates as the slice thickness decreased. Thus, thin-slice head CT imaging data may increase the possibility of the information becoming personally identifiable health information.
Subject(s)
Imaging, Three-Dimensional , Tomography, X-Ray Computed , Humans , Reproducibility of Results , Tomography, X-Ray Computed/methodsABSTRACT
This review aimed to summarise the effectiveness of preparation programs for magnetic resonance imaging (MRI) in children using mock scanners and the success rates by systematically reviewing the current literature. We initially identified 67 articles using the search terms "MRI," "mock" and "child" on online databases. All studies involving a preparation programme for MRI on children ages 18 years or younger, healthy children and those with medical diagnoses were included. The authors extracted data on study design, participant data, details of the MRI protocol and the total numbers of patients who underwent preparation programs and were scanned while awake, without sedation or general anesthesia. Twenty-three studies were included in this review. Preparation programs included in-home and hospital/research facility components; these consisted of a mock scanner, explanatory booklets, recorded MRI scan sounds and other educational materials. The success rate of MRI after the preparation programme reported in each study ranged from 40% to 100%. When all participants from studies that specifically assessed the efficacy of preparation programs were combined, participants who underwent a preparation programme (n = 196) were more likely to complete a successful MRI than those who did not undergo a preparation programme (n = 263) (odds ratio [OR] = 1.98). Our results suggest that preparation programs may help reduce the risk of children failing MRI scans.
Subject(s)
Anesthesia, General , Magnetic Resonance Imaging , Humans , Adolescent , Magnetic Resonance Imaging/methods , Teaching Materials , Magnetic Resonance SpectroscopyABSTRACT
OBJECTIVES: This study aimed to develop direct and response mapping algorithms from the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 onto the 5-level version of EQ-5D index based on the gradient boosted tree (GBT), a promising modern machine learning method. METHODS: We used the Quality of Life Mapping Algorithm for Cancer study data (903 observations from 903 patients) for training GBTs and testing their predictive performance. In the Quality of Life Mapping Algorithm for Cancer study, patients with advanced solid tumor were enrolled, and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and 5-level version of EQ-5D were simultaneously evaluated. The Japanese value set was used for direct mapping, whereas the Japanese and US value sets were used for response mapping. We trained the GBTs in the training data set (80%) with cross-validation and tested the predictive performance measured by the root mean squared error (RMSE), mean absolute error (MAE), and mean error in the test data set (20%). RESULTS: The RMSE and MAE in the test data set were larger in the GBT approaches than in the previously developed regression-based approaches. The mean error in the test data set tended to be smaller in the GBT approaches than in the previously developed regression-based approaches. CONCLUSIONS: The predictive performances in the RMSE and MAE did not improve by the GBT approaches compared with regression approaches. The flexibility of the GBT approaches had the potential to reduce overprediction and underprediction in poor and good health, respectively. Further research is needed to establish the role of machine learning methods in mapping a nonpreference-based measure onto health utility.