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Concept: F-test


BACKGROUND: Hypertension is a risk factor for cardiovascular disease, and the prevalence of hypertension tends to increase with age. Current treatments for hypertension have adverse side effects and poor adherence. The purpose of this study is to evaluate the effects of moxibustion on blood pressure in individuals with pre- or stage I hypertension.Methods/designForty-five subjects with pre- or stage I hypertension will be randomized into three groups: treatment group A (2 times/week), treatment group B (3 times/week), and the control group (non-treated group). The inclusion criteria will be as follows: (1) aged between 19 and 65 years; (2) prehypertension or stage I hypertension (JNC 7, Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure); (3) the participants are volunteers and written consent obtained.The participants in the treatment group A will undergo indirect moxibustion 2 times per week for 4 weeks, and the participants in the treatment group B will undergo indirect moxibustion 3 times per week for 4 weeks. The participants in the control group (non-treated group) will maintain their current lifestyle, including diet and exercise. The use of antihypertensive medication is not permitted. The primary endpoint will be a change in patient blood pressure. The secondary endpoints will be the body mass index, lipid profile, EuroQol and Heart Rate Variability. The data will be analyzed with the Student’s t-test and analysis of variance (ANOVA) (p < 0.05). DISCUSSION: The results of this study will help to establish the optimal approach for the care of adults with pre- or stage I hypertension.Trial registrationClinical Research Information Service KCT0000469.

Concepts: Myocardial infarction, F-test, Analysis of variance, Obesity, Randomized controlled trial, Normal distribution, Blood pressure, Hypertension


Abstract Background: Gait speed and sleep quality are the health indices related to longevity and mortality. In the present study, we measured sleep quality, quality of life, gait speed, and visual acuity before and after cataract surgery to evaluate the efficacy of the procedure on systemic health. Methods: The study was conducted on 155 patients (93 women; average age 74.8 years) undergoing cataract surgery with the implantation of a yellow soft acrylic lens. Patients were evaluated using the Pittsburgh sleep quality index (PSQI) and the National Eye Institute Visual Function Questionnaire (VFQ-25; vision-related quality of life) before and then 2 and 7 months after surgery. Four-meter gait speed was also determined. Results: Of the 155 patients, 68 (43.9%) were classified as poor sleepers (PSQI >5.5) prior to surgery. Significant improvements were noted in sleep 2 months after surgery (P < 0.05, paired t-test), but thereafter the improvements were not significant. Prior to surgery, 117 patients (77.0%) were classified as slow walkers (speed<1.0 m/s). Gait speed increased significantly in these patients 2 months after surgery (P < 0.001, paired t-test). Multiple regression analysis revealed significant correlations between the preoperative VFQ-25 score and both PSQI (P < 0.05) and gait speed (P < 0.001). Postoperative increases in the VFQ-25 score were positively correlated with decreases in the PSQI (P < 0.05). Improvements in visual acuity were correlated with improvements in the VFQ-25 score, but not with either PSQI or gait speed. Conclusion: Cataract surgery effectively improves sleep quality and slow gait speed.

Concepts: Phacoemulsification, Improve, Linear regression, F-test, Statistics, Visual acuity, Ophthalmology, Regression analysis


Abstract Objective: To test the null hypothesis that there is no difference between the effects of fan-type rapid (FRME) and rapid maxillary expansion (RME) used with an acrylic bonded expansion appliance on dentofacial structures in early occlusal stages. Materials and Methods: This was a prospective clinical trial. The FRME group had an anterior constricted maxillary width with a normal intermolar width, and the RME group had bilateral constricted maxillary width. The FRME group consisted of 20 patients (mean age, 8.96 ± 1.19 years), and the RME group consisted of 22 patients (mean age, 8.69 ± 0.66 years). Lateral and frontal cephalometric radiographs and dental casts were taken before and after expansion and 3 months after completing treatment for each patient. The data were compared using repeated-measures analysis of variance. The paired-samples t-test was used to evaluate treatment and retention effects, and the independent samples t-test was used to consider the differences between the two groups. Results: The maxilla moved downward and forward in both groups. The nasal cavity and maxillary width were expanded more in the RME group, and there were only a few relapses in this group during the retention period. There was significant labial tipping of the upper incisors in the FRME expansion group. The expansion of intercanine width was similar in both groups, but the expansion of intermolar width was significantly greater in the RME group. Conclusion: The null hypothesis was rejected. There was a difference between the effects of FRME and RME used with an acrylic bonded expansion appliance on dentofacial structures in the early occlusal stages.

Concepts: Nasal cavity, Snake scales, Levene's test, F-test, Null hypothesis, Statistics, Student's t-test, Normal distribution


STUDY DESIGN: Block counterbalanced repeated measures crossover study. OBJECTIVES: To assess scapular upward rotation positional adaptations to experimentally-induced subacromial pain. BACKGROUND: Existing subacromial pathology is often related to altered scapular kinematics during humeral elevation such as decreased upward rotation and posterior tilting. These changes have the potential to limit subacromial space and mechanically impinge subacromial structures. Yet, it is unknown if these changes are causative or resulting from injury. The acute effects of subacromial pain on scapular upward rotation are currently unknown. METHODS: Subacromial pain was induced via hypertonic saline injection in 20 participants, aged 18 to 31 years. Scapular upward rotation was measured with a digital inclinometer at rest and 30°, 60°, 90°, and 120° of humeral elevation during a painful and pain free condition. Repeated measures analysis of variance (ANOVA) were conducted for scapular upward rotation position based on condition (pain or control) and humeral position. Post-hoc testing was conducted with paired t-tests as appropriate. RESULTS: Scapular upward rotation during the pain condition was significantly increased (range of average increase 3.5-7.7°) at all angles of humeral elevation tested. CONCLUSION: Acute subacromial pain elicited an increase in scapular upward rotation at all angles of humeral elevation tested. This adaptation to acute experimental pain may provide protective compensation to subacromial structures during humeral elevation.J Orthop Sports Phys Ther. Epub 14 January 2013. doi:10.2519/jospt.2013.4276.

Concepts: Classical mechanics, F-test, Experimental design, Repeated measures design, Variance, Normal distribution, Crossover study, Analysis of variance


BACKGROUND AND PURPOSE: Epileptic seizures account for 24-40% of all clinical onsets in patients with brain arteriovenous malformations (AVMs). METHODS: We retrospectively reviewed the angioarchitectural features of AVMs associated with seizures in 168 patients admitted to our Department from 1997 to 2012. Patients were dichotomized according to demographic characteristics, type of treatment, bleeding occurrence, and morphological and topographic features. Clinical status at admission and discharge was also recorded. The association of each one of these variables with seizures occurrence was statistically tested. Continuous variables and outcome were compared with Student’s t-test, whereas categorical ones were compared using Fisher’s exact test. The independent contribution of some seizures predictors was assessed with a logistic regression model. Associations were considered significant for P < 0.05. RESULTS: About 29% patients showed seizures and 47% bleeding. No significant difference in age and sex was observed between patients with and without seizures. AVMs > 4 cm (P = 0.001) and those fed by dilated arterial feeders (P = 0.02) were associated with increased risk of seizures. A higher risk of seizures occurrence was also observed in cortical AVMs compared with deeper ones (75.5% vs. 55.4%; P = 0.01), and in AVMs fed by middle and posterior cerebral arteries branches compared with the other vessels (81.6% vs. 45.3%; P < 0.001 and 48.9% vs. 23.5%; P = 0.002, respectively). No lobar predisposition was observed. A nidus > 4 cm also appeared as an independent risk factor of seizures occurrence (OR 2.82; 95% CI, 1.26-6.31; P = 0.009) at logistic regression analysis. CONCLUSIONS: AVM morphology, especially nidus dimension, appeared to more significantly influence seizures occurrence than their topography.

Concepts: Statistical significance, Prediction interval, F-test, Fisher's exact test, Arteriovenous malformation, Regression analysis, Logistic regression, Statistics


Purpose To assess cerebral microbleed (CMB) prevalence in patients with multiple sclerosis (MS) and clinically isolated syndrome (CIS) and associations with clinical outcomes. Materials and Methods CMBs are associated with aging and neurodegenerative disorders. The prevalence of CMBs has not previously been well established. In this study, 445 patients with MS (266 with relapsing-remitting MS, 138 with secondary progressive MS, and 41 with primary progressive MS), 45 patients with CIS, 51 patients with other neurological diseases, and 177 healthy control subjects (HCs) underwent 3-T magnetic resonance (MR) imaging and clinical examinations. A subset of 168 patients with MS and 50 HCs underwent neuropsychological testing. Number of CMBs was assessed on susceptibility-weighted minimum intensity projections by using the Microbleed Anatomic Rating Scale; volume was calculated by using quantitative susceptibility maps. Differences between groups were analyzed with the χ(2) test, Fisher exact test, Student t test, and analysis of variance; associations of CMBs with clinical and other MR imaging outcomes were explored with correlation and regression analyses. Because CMB frequency increases with age, prevalence was investigated in participants at least 50 years of age and younger than 50 years. Results Significantly more patients with MS than HCs had CMBs (19.8% vs 7.4%, respectively; P = .01) in the group at least 50 years old. A trend toward greater presence of CMBs was found in patients with MS (P = .016) and patients with CIS who were younger than 50 years (P = .039) compared with HCs. In regression analysis adjusted for age, hypertension, and normalized brain volume, increased number of CMBs was significantly associated with increased physical disability in the MS population (R(2) = 0.23, P < .0001). In correlation analysis, increased number of CMBs was significantly associated with deteriorated auditory and verbal learning and memory (P = .006) and visual information processing speed trends (P = .049) in patients with MS. Conclusion Monitoring CMBs may be relevant in patients with MS and CIS at higher risk for developing cognitive and physical disability. (©) RSNA, 2016 Online supplemental material is available for this article.

Concepts: Analysis of variance, Statistical tests, Regression analysis, Magnetic resonance imaging, F-test, Statistics, Normal distribution, Multiple sclerosis


Recent national guidelines call for improved nutrition within early years settings. The aim of this cross-sectional study was to describe foods and beverages served in nurseries, assess provider behaviors related to feeding, and compare these practices to national guidelines. We administered a mailed survey to a random sample of nurseries across England, stratifying by tertile of deprivation. A total of 851 nurseries returned the survey (54.3% response rate). We fitted separate multivariate logistic regression models to estimate the association of deprivation with each of the 13 food and beverage guidelines and the seven provider behavior guidelines. We also conducted a joint F-test for any deprivation effect, to evaluate the effect of the guidelines combined. After adjusting for confounders, we observed differences in the frequency of nurseries that reported serving healthier foods across the tertiles of deprivation (p = 0.02 for joint F test). These adjusted results were driven mainly by nurseries in more deprived areas serving more whole grains (OR 1.57 (95% CI 1.00, 2.46)) and legumes, pulses, and lentils (1.40 (1.01, 2.14)). We also observed differences in the frequency of nurseries reporting more provider behaviors consistent with national guidelines across the tertiles of deprivation (p = 0.01 for joint F test). Nurseries in more deprived areas were more likely to dilute juice with water (2.35 (1.48, 3.73)), allow children to select their own portions (1.09 (1.06, 1.58)), and sit with children during meals (1.84 (1.07, 3.15)). While nurseries in the most deprived areas reported serving more healthy foods, a large percentage were still not meeting national guidelines. Policy and intervention efforts may increase compliance with national guidelines in nurseries in more deprived areas, and across England.

Concepts: Psychology, Analysis of variance, F-test, Health, Food, Logistic regression, Nutrition, Regression analysis


The aim of the present study was to investigate if bullied nurses have a more negative coping style when facing stressful events than do non-bullied nurses, and to determine if coping style moderates the well-established bullying-anxiety relationship. Cohort data were gathered in 2008/2009 and 2010 with a time lag of approximately one year for all respondents. At T1 2059 Norwegian nurses participated, whereof 1582 also responded at T2. A t-test and a hierarchical regression analysis were conducted to obtain results for the hypothesized relationships. The results show that bullied nurses use an active goal-oriented coping style less often compared to non-bullied nurses. Furthermore, active goal-oriented coping seems beneficial only when exposure to bullying behaviors is very low. This effect diminishes however as the bullying behavior intensifies. Hence, victims of bullying seem to cope more negatively with stressful events than others. On the other hand, high exposure to bullying behaviors has negative consequences for the subsequent level of anxiety for those affected, regardless of their general coping style.

Concepts: Behavior, Regression analysis, Bullying, F-test, Present, Statistics, Human behavior, Psychology


Uphill running has been touted as a key interval training tactic for distance runners despite few scientifically-derived recommendations for individualized training prescription. To date, a majority of uphill training research has focused on shorter, faster training bouts; however, longer, slower bouts based on an individual’s velocity at maximum oxygen consumption (VMax) may prove more effective. One potential longer bout length may be associated with the time VMax can be maintained (TMax), an approach proven effective in level-grade interval training. Therefore, the purpose of this investigation included examining the TMax, heart rate and test-retest reliability of incline treadmill running (INC) on a 10% grade at 65%, 70%, 75%, 80% and 85%VMax compared to level-grade running at VMax. Twelve moderately trained distance runners (age, 26.4 ± 4.8; body mass, 64.3 ± 12.9 kg; height, 171.2 ± 9.3 cm; and VO2max, 56.6 ± 7.6 mL·min·kg) completed two TMax INC trials at each submaximal VMax and a level-grade TMax at VMax. The dependent variables were TMax, heart rate plateau (HRPlateau) and half-time to heart rate plateau (½HRPlateau) of each condition. Statistical significance was set to p < 0.05. Student's t-test revealed no significant differences in: 1) TMax, HRPlateau and ½HRPlateau between trials 1 and 2 at any INC condition. One-way ANOVA revealed significant differences in: 1) TMax during INC at 75%, 80% and 85%VMax and level-grade at VMax; and 2) ½HRPlateau during INC at 80% and 85%VMax and all other conditions. In conclusion, TMax and heart rate dynamics during INC proved reliable, and simple regression analysis revealed ∼68%VMax during INC yields the same level-grade TMax at VMax.

Concepts: Simple linear regression, F-test, Statistical significance, VO2 max, Regression analysis, Running, Reliability, Statistics


The aim of this study was to compare the effect of different modes of toothbrushing education (lecture, video and pamphlet) on the dental plaque index (PI) of adolescents. The cluster randomized intervention was performed on 128 participants aged 12 years, who were allocated into four groups based on the type of intervention. Group 1: no intervention; and groups 2, 3, 4: education via lecture, video, and pamphlet, respectively (n = 32). Their plaque index was measured at the baseline, 24 h and two months later. Data were analyzed by repeated measures analysis of variance (ANOVA), one-way ANOVA, independent and paired t-test. The plaque indices of groups 2, 3, 4 at 24 h (p values < 0.001) and two months (p values < 0.001) showed a significant reduction when compared to the baseline. The lowest PI score was observed in the pamphlet, video and lecture groups at 24 h, respectively. After 2 months, the lowest score of PI was measured in lecture, video and pamphlet groups, respectively; however, these differences were non-significant. Therefore, toothbrushing education via lecture, video and pamphlet reduced the dental plaque index with the same effectiveness.

Concepts: Multiple comparisons, Statistical tests, Levene's test, F-test, Dental plaque, Statistics, Normal distribution, Analysis of variance