Three-group Analysis Research Articles

Effect of disease duration on fecal biomarkers in ulcerative colitis: a prospective cohort study

BackgroundBiomarkers such as fecal calprotectin (FC) and fecal immunochemical occult blood tests (FIT) for ulcerative colitis (UC) are used in clinical practice. In this study, the effect of UC disease duration on FC was investigated and compared to that on FIT.MethodsOne hundred twenty-eight colonoscopic examinations and two fecal biomarkers measurements were performed. The cases of UC were divided into short- and long-term disease-duration groups or categorized into three groups with disease durations of 0–5, 6–13, and 14–38 years. We analyzed correlations between biomarker levels and endoscopic scores, including the Mayo endoscopic subscore (MES), ulcerative colitis endoscopic index of severity, and the sum of MES.ResultsIn the analysis of short- and long-term disease durations, the three endoscopic scores and biomarker levels showed significant correlations in both long-term and short-term groups. Most of the correlation coefficients for the individual long-term group were lower than the corresponding values for all cases, while most of the correlation coefficients for the individual short-term groups were higher than the corresponding values for all cases. In the three-group analysis (disease durations of 0–5, 6–13, and 14–38 years), the two biomarkers and three endoscopic scores showed significant correlations, and most of the correlation coefficients between biomarkers and endoscopic scores tended to be lower in the long-term follow-up group. In the receiver operating characteristic analysis for predicting mucosal healing in the three groups, the area under the curve for FC and FIT concentrations in the 0–5 year disease-duration group showed particularly higher values than those for the other two groups.ConclusionsSimilar to FIT, FC is affected by the duration of UC, indicating that FC may be a highly useful biomarker, especially in short-term disease.

Complication Rates after Endoscopic Transsphenoidal Surgery for ACTH-Secreting Pituitary Adenomas: A Comparative Analysis with GH and Nonfunctioning Adenomas.

Objectives Some complications have been more frequently reported after surgery for adrenocorticotropin hormone (ACTH)-secreting pituitary adenomas. We compared complication rates in patients with ACTH-secreting pituitary adenomas with those in patients with growth hormone secreting pituitary adenomas (growth hormone [GH] group) and nonfunctioning adenomas (nonfunctioning group). Design A comparative three-group analysis was performed for all patients who had endoscopic transsphenoidal surgery for pituitary adenomas at our center between January 2011 and May 2019. Variables included demographics, preoperative clinical and radiological characteristics, and postoperative radiological and endocrinological outcomes. Complications were divided into four categories: endocrinological, neurosurgical, medical, and ENT (ear-nose-throat)-related complications. Univariate and multivariate statistical analysis were performed. Results A total of 111 patients with pituitary adenomas and a mean age of 53.7 years were included (25 ACTH, 35 GH, and 51 nonfunctioning adenomas). Overall, 28 patients had microadenomas (25.2%) and 83 had macroadenomas (74.8%). Univariate statistical analysis for complications between groups showed no differences in neurosurgical and medical complications. Transient diabetes insipidus and postsurgical bacterial sinusitis were the only variables more frequently seen in the ACTH group ( p = 0.01 and 0.04, respectively). Multivariate analysis for transient diabetes insipidus showed no differences between groups ( p = 0.58). Conclusion Complication rates were similar in all three adenoma groups, particularly concerning major infections, thrombotic events, postoperative cerebrospinal fluid (CSF) leak, and transient diabetes insipidus. Transient diabetes insipidus was related with adenoma size and intraoperative CSF leak. Despite postoperative bacterial sinusitis was statistically higher in the ACTH group, this data should be interpreted with caution given the low number of patients with this complication.

Lipid Fraction Derived From MRI In- and Opposed-Phase Sequence as a Novel Biomarker for Predicting Survival Outcome of Glioma

Our study evaluated the capability of magnetic resonance imaging in- and opposed-phase (IOP) derived lipid fraction as a novel prognostic biomarker of survival outcome in glioma. We analyzed 46 histologically proven glioma (WHO grades II-IV) patients using standard 3T magnetic resonance imaging brain tumor protocol and IOP sequence. Lipid fraction was derived from the IOP sequence signal-loss ratio. The lipid fraction of solid nonenhancing region of glioma was analyzed, using a three-group analysis approach based on volume under surface of receiver-operating characteristics to stratify the prognostic factors into three groups of low, medium, and high lipid fraction. The survival outcome was evaluated, using Kaplan-Meier survival analysis and Cox regression model. Significant differences were seen between the three groups (low, medium, and high lipid fraction groups) stratified by the optimal cut-off point for overall survival (OS) (p ≤ 0.01) and time to progression (p ≤ 0.01) for solid nonenhancing region. The group with high lipid fraction had five times higher risk of poor survival and earlier time to progression compared to the low lipid fraction group. The OS plot stratified by lipid fraction also had a strong correlation with OS plot stratified by WHO grade (R = 0.61, p < 0.01), implying association to underlying histopathological changes. The lipid fraction of solid nonenhancing region showed potential for prognostication of glioma. This method will be a useful adjunct in imaging protocol for treatment stratification and as a prognostic tool in glioma patients.

Texture analysis of sonographic muscle images can distinguish myopathic conditions.

Given the recent technological advent of muscle ultrasound (US), classification of various myopathic conditions could be possible, especially by mathematical analysis of muscular fine structure called texture analysis. We prospectively enrolled patients with three neuromuscular conditions and their lower leg US images were quantitatively analyzed by texture analysis and machine learning methodology in the following subjects : Inclusion body myositis (IBM) [N=11] ; myotonic dystrophy type 1 (DM1) [N=19] ; polymyositis/dermatomyositis (PM-DM) [N=21]. Although three-group analysis achieved up to 58.8% accuracy, two-group analysis of IBM plus PM-DM versus DM1 showed 78.4% accuracy. Despite the small number of subjects, texture analysis of muscle US followed by machine learning might be expected to be useful in identifying myopathic conditions. J. Med. Invest. 66 : 237-240, August, 2019.

Middle Cerebellar Peduncle Width-A Novel MRI Biomarker for FXTAS?

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a severe neurodegenerative movement disorder affecting over 40% of male and 16% of female FMR1 premutation carriers over the age of 50. However, there is a lack of prognostic biomarkers to aid early diagnosis and treatment planning. Therefore, this study aimed to assess the utility of the Magnetic Resonance Parkinson Index (MRPI) as a potential MRI biomarker for FXTAS. The four measurements required for the MRPI were assessed in 45 male premutation carriers at risk of developing FXTAS (Mean age = 59.54 years), 53 male patients with FXTAS (Mean age = 66.16 years) and 61 male controls (Mean age = 60.75 years), of which 73 participants had follow-up visits on average 1.96 years later. Middle cerebellar peduncle (MCP) width as well as midbrain and pons cross-sectional area were reduced in patients with FXTAS compared to both premutation carriers without FXTAS and controls. While these measurements were not found to change over time in the three-group analysis, age was an important predictor of midbrain cross-sectional area and pons/midbrain ratio. MCP width was initially reduced in a subset of premutation carriers who developed FXTAS symptoms between their initial and follow-up visits, which also decreased between visits, compared to age-matched premutation carriers who did not show any FXTAS symptom development over time. Therefore, while the MPRI may not be a useful biomarker for FXTAS, decreased MCP width may be one of the first notable signs of FXTAS, and therefore the first biomarker with the potential to identify those most at risk for the disorder.

Clinical implications of serum galactomannan measurement in patients with acute invasive fungal rhinosinusitis.

Acute invasive fungal rhinosinusitis (AIFR) is an aggressive opportunistic infection with a high mortality rate. Recently, non-invasive techniques have been introduced for diagnosis of invasive fungal disease. The purpose of this study is to evaluate the diagnostic significance of serum galactomannan measurement in patients with AIFR. We conducted a retrospective case-control study of 28 patients with AIFR and 36 fungus ball (FB) patients. We evaluated clinical, laboratory, and pathologic findings along with disease course. In 28 patients with AIFR, there were 21 cases of invasive aspergillosis (IA) and 7 cases of invasive mucormycosis (IM). The control group was comprised of 36 patients with FB. The three-group analysis showed a statistically significant difference among the groups. At the cut-off value of 0.48, the sensitivity and specificity were 71.4% and 93.0%, respectively. Comparison of mean serum galactomannan levels in 5 non-survivors and 9 survivors at initial measurement showed no significant difference, but that became significantly different 1 week later. Statistical analysis showed that the levels of serum galactomannan decreased significantly according to the measurement-point in within survivor-group analysis. The difference in between survivor-groups analysis was also significant. Serum galactomannan measurement seems useful for early diagnosis and discrimination of fungal species in patients with AIFR. In addition, clinical outcomes may be related to the levels and patterns of serum galactomannan, especially in IA. The appropriate measurement of galactomannan might be helpful in treating the patients at high risk for AIFR.

Clinical implications of serum galactomannan measurement in patients with acute invasive fungal rhinosinusitis

Acute invasive fungal rhinosinusitis (AIFR) is an aggressive opportunistic infection with a high mortality rate. Recently, non-invasive techniques have been introduced for diagnosis of invasive fungal disease. The purpose of this study is to evaluate the diagnostic significance of serum galactomannan measurement in patients with AIFR. We conducted a retrospective case-control study of 28 patients with AIFR and 36 fungus ball (FB) patients. We evaluated clinical, laboratory, and pathologic findings along with disease course. In 28 patients with AIFR, there were 21 cases of invasive aspergillosis (IA) and 7 cases of invasive mucormycosis (IM). The control group was comprised of 36 patients with FB. The three-group analysis showed a statistically significant difference among the groups. At the cut-off value of 0.48, the sensitivity and specificity were 71.4% and 93.0%, respectively. Comparison of mean serum galactomannan levels in 5 non-survivors and 9 survivors at initial measurement showed no significant difference, but that became significantly different 1 week later. Statistical analysis showed that the levels of serum galactomannan decreased significantly according to the measurement-point in within survivor-group analysis. The difference in between survivor-groups analysis was also significant. Serum galactomannan measurement seems useful for early diagnosis and discrimination of fungal species in patients with AIFR. In addition, clinical outcomes may be related to the levels and patterns of serum galactomannan, especially in IA. The appropriate measurement of galactomannan might be helpful in treating the patients at high risk for AIFR.

Corrected QT interval anomalies are associated with worse prognosis among patients suffering from sepsis.

Patients suffering from sepsis experience organ failure and metabolic derangements, with a negative impact on their prognosis and survival. Objective markers for dismal prognosis in this group of patients are sought. To assess the potential role of corrected QT interval anomalies as surrogates for metabolic derangements leading to increased short and medium-term mortality in patients suffering from sepsis. This study utilised a historic-cohort analysis of 257 septic patients admitted to internal medicine departments. Personal data, vital signs, laboratory results and electrocardiograms were collected. Patients were grouped according to QTc duration, weather mid-range (395-490 ms) or non-mid-range, and further defined as shorter (<395 ms) or longer (>490 ms). Mortality rates differed significantly between the mid-range QTc group and the non-mid-range groups at 14 days (23.7 vs 38.2%, respectively; P = 0.014) and at 3 months (38.5 vs 59.6%, respectively; P = 0.001). In a three-group analysis, the 14-day mortality was the highest in the longer QTc group and the lowest in the mid-range group compared with the shorter QTc group (44.4, 23.7 and 35.5%, respectively; P = 0.034), and this difference also remained at 3 months (74.1, 38.5 and 53.2%, respectively; P = 0.001). All differences remained statistically significant in a multivariate Cox regression analysis. QTc duration anomalies are associated with worse short- and medium-term prognosis and may act as a marker for more severe clinical sequelae.

Proximal Resection Margin in Ivor-Lewis Oesophagectomy for Cancer.

The purpose of this study was to investigate whether a long proximal oesophageal resection margin (PRM) is associated with improved survival after oesophagectomy for cancer and to identify the optimal margin to aim for in this patient group. A prospectively maintained database identified 174 patients who underwent Ivor-Lewis oesophagectomy for cancer. Demographic, clinical, and pathological data were collected. X-tile software was used to identify the optimal resection point. Two models were analysed: single point resection with comparison of two groups (short and long), and two resection points with three groups (short, medium, and long) to provide a range. The median PRM was 4.0cm (interquartile range: 2.5-6.0cm). After adjustment for significant confounders, multivariable Cox PH analysis demonstrated that the optimal resection margin was 1.7cm, and in the three-group analysis the optimum PRM was between 1.7 and 3cm. In the two-group analysis, the long margin had no effect on DFS (p=0.37), but carried a significantly improved overall survival (hazard ratio [HR]=0.46, 95% confidence interval [CI] 0.25-0.87, p=0.02). In the three-group analysis, the medium and long groups had improved OS compared with the short group (on average 54%, HR≥0.45, p≤0.04). The 5-year disease-free and overall survival rates were highest in the medium PRM group (48 and 57% respectively). Optimal survival following oesophagectomy for cancer is achieved with a PRM>1.7cm, but a PRM>3cm does not yield a further survival advantage. Thus, the optimal PRM is likely to be between 1.7 and 3cm.

Effectiveness of a school-community linked program on physical activity levels and health-related quality of life for adolescent girls

BackgroundThis study evaluated the effectiveness of a school-community program on Health-Related Quality of Life (HRQoL; the primary outcome), physical activity (PA), and potential mediators of PA among adolescent girls living in low-socioeconomic rural/regional settings.MethodThe study was a cluster-randomized controlled trial. Twelve communities with the requisite sports clubs and facilities were paired according to relevant criteria; one of each pair was randomly assigned to the intervention or control condition. Eight schools per condition were randomly selected from these communities and the intervention was conducted over one school year (2011). Female students in grades 7–9 in intervention schools participated in two 6-session PA units – a sport unit (football or tennis) and a recreational unit (leisure centre-based). These were incorporated into physical education (PE) curriculum and linked to PA opportunities for participation outside school. Students were surveyed at baseline and endpoint, self-reporting impact on primary and secondary outcome measures (HRQoL, PA) and PA mediators (e.g. self-efficacy). Linear mixed models for two-group (intervention, control) and three-group (completers, non-completers, control) analyses were conducted with baseline value, age and BMI as covariates, group as a fixed effect and school as random cluster effect.ResultsParticipants completing baseline and endpoint measures included: 358 intervention (baseline response rate 33.7%, retention rate 61.3%) and 256 control (14.1% and 84.0%). Adjustment for age and BMI made no substantive difference to outcomes, and there were no cluster effects. For HRQoL, after adjustment for baseline scores, the intervention group showed significantly higher scores on all three PedsQL scores (physical functioning: M ± SE = 83.9 ± 0.7, p = .005; psychosocial: 79.9 ± 0.8, p = .001; total score: 81.3 ± 0.7, p = .001) than the control group (80.9 ± 0.8; 76.1 ± 0.9 and 77.8 ± 0.8). The three-group analysis found intervention non-completers had significantly higher PedsQL scores (84.0 ± 0.8, p = .021; 80.4 ± 0.9, p = .003; 81.7 ± 0.8, p = .002;) than controls (80.9 ± 0.8, 76.1 ± 0.9 and 77.8 ± 0.8). There were no significant differences for any PA measure. Intervention completers had significantly higher scores than non-completers and controls for some mediator variables (e.g. self-efficacy, behavioural control).ConclusionPositive outcomes were achieved from a modest school-community linked intervention. The school component contributed to maintaining HRQoL; students who completed the community component derived a range of intra-personal and inter-personal benefits.Trial registrationACTRN12614000446662. April 30th 2014.

Aberrant Brain Activation During a Response Inhibition Task in Adolescent Eating Disorder Subtypes

Behavioral and personality characteristics associated with excessive inhibition and disinhibition are observed in patients with eating disorders, but neural correlates of inhibitory control have not been examined in adolescents with these disorders. Thirteen female adolescents with binge eating and purging behaviors (i.e., bulimia nervosa or anorexia nervosa, binge eating/purging type);14 with anorexia nervosa, restricting type; and 13 healthy comparison subjects performed a rapid, jittered event-related go/no-go task. Functional magnetic resonance images were collected using a 3 Tesla GE scanner and a spiral pulse sequence. A whole-brain three-group analysis of variance in SPM5 was used to identify significant activation associated with the main effect of group for the comparison of correct no-go versus go trials. The mean activation in these clusters was extracted for further comparisons in SPSS. The binge eating/purging group showed significantly greater activation than the healthy comparison group in the bilateral precentral gyri, anterior cingulate cortex, and middle and superior temporal gyri as well as greater activation relative to both comparison and restricting type anorexia subjects in the hypothalamus and right dorsolateral prefrontal cortex. Within-group analysis found that only the restricting type anorexia group showed a positive correlation between the percent correct on no-go trials and activation in posterior visual and inferior parietal cortex regions. The present study provides preliminary evidence that during adolescence, eating disorder subtypes may be distinguishable in terms of neural correlates of inhibitory control. This distinction is consistent with differences in behavioral impulsivity in these patient groups.

Early development, temperament, and functional impairment in autism and fragile X syndrome.

We compared the developmental status, functional abilities, and temperament of 31 young boys with fragile X syndrome (FXS) who did not have autism, matched on chronological age, gender, and race, with 31 boys with autism but no FXS. Children with autism exhibited a more variable profile of development in comparison with a relatively flat profile for children with FXS. Children with autism were significantly more delayed in social skills and were rated by observers as exhibiting a greater degree of impairment in cognitive, communication, and social skills. On temperament ratings, both groups were slower to adapt, less persistent, and more withdrawing than the reference group. Boys with FXS were rated as more active than the referent group, whereas boys with autism were rated as less intense, more distractible, having a higher threshold for response, and less rhythmic than the reference group. A smaller three-group analysis compared boys with FXS, boys with autism, and boys with both FXS and autism. Children with both autism and FXS were substantially more delayed than children with autism or FXS alone.

Exact test size and power of a Gaussian error linear model for an internal pilot study.

Wittes and Brittain recommended using an 'internal pilot study' to adjust sample size. The approach involves five steps in testing a general linear hypothesis for a general linear univariate model, with Gaussian errors. First, specify the design, hypothesis, desired test size, power, a smallest 'clinically meaningful' effect, and a speculated error variance. Second, conduct a power analysis to choose provisionally a planned sample size. Third, collect a specified proportion of the planned sample as the internal pilot sample, and estimate the variance (but do not test the hypothesis). Fourth, update the power analysis with the variance estimate to adjust the total sample size. Fifth, finish the study and test the hypothesis with all data. We describe methods for computing exact test size and power under this scenario. Our analytic results agree with simulations of Wittes and Brittain. Furthermore, our exact results apply to any general linear univariate model with fixed predictors, which is much more general than the two-sample t-test considered by Wittes and Brittain. In addition, our results allow for examination of the impact on test size of internal pilot studies for more complicated designs in the framework of the general linear model. We examine the impact of (i) small samples, (ii) allowing the planned sample size to decrease, (iii) the choice of internal pilot sample size, and (iv) the maximum allowable size of the second sample. All affect test size, power and expected total sample size. We present a number of examples including one that uses an internal pilot study in a three-group analysis of variance.

Response of incore γ-detectors to parametric fluctuations in a reactor core

Adjoint transport theory is applied to coupled neutron- and γ-transport in order to analyse the detection properties of γ-detectors with respect to fluctuating reactor core parameters. In a three-group analysis with two neutron-groups and one γ-group it is shown that a small incore γ-detector acts like a spatially smeared-out neutron-detector, concentrated mainly in the surrounding fuel rods and with a relatively high epithermal sensitivity.