Univariate Repeated Measures Analysis Of Variance Research Articles

Effects of Tongue Strength Training on Mealtime Function in Long-Term Care.

The primary aim of this study was to determine the feasibility and effectiveness of an 8-week tongue-strengthening intervention protocol for seniors with mild to moderately severe cognitive impairment in the long-term care setting. Outcome measures of interest included tongue strength, mealtime duration, and food intake. In this pre-post group study of treatment outcomes, data were collected from 7 adults (aged 84-99 years). Participants were observed across a series of mealtimes to determine mealtime duration and intake before and after 16 treatment sessions. During therapy, participants performed isometric strength exercises and tongue pressure accuracy tasks using the Iowa Oral Performance Instrument (model number 2.1, IOPI Medical). Differences in tongue strength as a function of treatment were explored between the first 3 and final 3 sessions using univariate repeated-measures analysis of variance. Single-subject methods were used to explore baseline and posttreatment data for measures of mealtime function. Anterior and posterior tongue strength increased significantly with therapy. There were no changes in mealtime function. This study shows proof of concept that some older adults with cognitive impairment are able to participate in a tongue-strengthening intervention and achieve improvements in tongue strength. Failure to find evidence of associated changes of mealtime function suggests that mealtime measures may not be directly sensitive to changes in tongue strength.

Effectiveness of the Dynamic Movement Orthosis Glove for a Child with Cerebral Palsy Hemiplegia and Obstetric Brachial Plexus Palsy

The purpose of this case series was to 1) describe the use of a custom-fitted Dynamic Movement Orthosis® (DMO) glove and 2) to provide data on the effect of wearing the DMO over time. Two subjects, one child with cerebral palsy (CP) hemiplegia and the other child with obstetric brachial plexus palsy (OBPP), using the DMO glove were followed. Assessments were conducted at baseline (T0), 1 month of wearing the DMO (T1), 3 months (T2), and 6 months (T3). The Melbourne Assessment of Unilateral Upper Limb Function (Melbourne Assessment) was used to measure outcomes for unimanual capacity. The overall affected upper-limb control improved after the use of the DMO. Improvements were observed in unimanual capacity, and the gains were maintained after 6 months of use. Using univariate repeated-measures analysis of variance (ANOVA), DMO was associated with functional improvement over time (p = 0.007). The use of the DMO glove is another alternative for providing alignment to the affected upper limb and may assist a child’s ability to use his/her hand, thus enhancing the acquisition of goal-directed functional skills.

Comparison of Lipid and Calorie Loss From Donor Human Milk Among 3 Methods of Simulated Gavage Feeding

The objective of this study was to compare the differences in lipid loss from 24 samples of banked donor human milk (DHM) among 3 feeding methods: DHM given by syringe pump over 1 hour, 2 hours, and by bolus/gravity gavage. Comparative, descriptive. There were no human subjects. Twenty-four samples of 8 oz of DHM were divided into four 60-mL aliquots. Timed feedings were given by Medfusion 2001 syringe pumps with syringes connected to narrow-lumened extension sets designed for enteral feedings and connected to standard silastic enteral feeding tubes. Gravity feedings were given using the identical syringes connected to the same silastic feeding tubes. All aliquots were analyzed with the York Dairy Analyzer. Univariate repeated-measures analyses of variance were used for the omnibus testing for overall differences between the feeding methods. Lipid content expressed as grams per deciliter at the end of each feeding method was compared with the prefed control samples using the Dunnett's test. The Tukey correction was used for other pairwise multiple comparisons. The univariate repeated-measures analysis of variance conducted to test for overall differences between feeding methods showed a significant difference between the methods (F = 58.57, df = 3, 69, P < .0001). Post hoc analysis using the Dunnett's approach revealed that there was a significant difference in fat content between the control sample and the 1-hour and 2-hours feeding methods (P < .0001), but we did not find any significant difference in fat content between the control and the gravity feeding methods (P = .3296). Pairwise comparison using the Tukey correction revealed a significant difference between both gravity and 1-hour feeding methods (P < .0001), and gravity and 2-hour feeding method (P < .0001). There was no significant difference in lipid content between the 1-hour and 2-hour feeding methods (P = .2729). Unlike gravity feedings, the timed feedings resulted in a statistically significant loss of fat as compared with their controls. These findings should raise questions about how those infants in the neonatal intensive care unit are routinely gavage fed.

Health-Related Quality of Life 2 Years After Treatment With Radical Prostatectomy, Prostate Brachytherapy, or External Beam Radiotherapy in Patients With Clinically Localized Prostate Cancer

To compare treatment impact on health-related quality of life (HRQL) in patients with localized prostate cancer, from before treatment to 2 years after the intervention. This was a longitudinal, prospective study of 614 patients with localized prostate cancer treated with radical prostatectomy (134), three-dimensional external conformal radiotherapy (205), and brachytherapy (275). The HRQL questionnaires administered before and after treatment (months 1, 3, 6, 12, and 24) were the Medical Outcomes Study 36-Item Short Form, the Functional Assessment of Cancer Therapy (General and Prostate Specific), the Expanded Prostate Cancer Index Composite (EPIC), and the American Urological Association Symptom Index. Differences between groups were tested by analysis of variance and within-group changes by univariate repeated-measures analysis of variance. Generalized estimating equations (GEE) models were constructed to assess between-group differences in HRQL at 2 years of follow-up after adjusting for clinical variables. In each treatment group, HRQL initially deteriorated after treatment with subsequent partial recovery. However, some dimension scores were still significantly lower after 2 years of treatment. The GEE models showed that, compared with the brachytherapy group, radical prostatectomy patients had worse EPIC sexual summary and urinary incontinence scores (-20.4 and -14.1; p < 0.001), and external radiotherapy patients had worse EPIC bowel, sexual, and hormonal summary scores (-3.55, -5.24, and -1.94; p < 0.05). Prostatectomy patients had significantly better EPIC urinary irritation scores than brachytherapy patients (+4.16; p < 0.001). Relevant differences between treatment groups persisted after 2 years of follow-up. Radical prostatectomy had a considerable negative effect on sexual functioning and urinary continence. Three-dimensional conformal radiotherapy had a moderate negative impact on bowel functioning, and brachytherapy caused moderate urinary irritation. These results provide relevant information for clinical decision making.

HYPOTHESIS TESTING IN COMPARATIVE AND EXPERIMENTAL STUDIES OF FUNCTION-VALUED TRAITS

Many traits of evolutionary interest, when placed in their developmental, physiological, or environmental contexts, are function-valued. For instance, gene expression during development is typically a function of the age of an organism and physiological processes are often a function of environment. In comparative and experimental studies, a fundamental question is whether the function-valued trait of one group is different from another. To address this question, evolutionary biologists have several statistical methods available. These methods can be classified into one of two types: multivariate and functional. Multivariate methods, including univariate repeated-measures analysis of variance (ANOVA), treat each trait as a finite list of data. Functional methods, such as repeated-measures regression, view the data as a sample of points drawn from an underlying function. A key difference between multivariate and functional methods is that functional methods retain information about the ordering and spacing of a set of data values, information that is discarded by multivariate methods. In this study, we evaluated the importance of that discarded information in statistical analyses of function-valued traits. Our results indicate that functional methods tend to have substantially greater statistical power than multivariate approaches to detect differences in a function-valued trait between groups.

Comparison of quantitative cartilage measurements acquired on two 3.0T MRI systems from different manufacturers

To investigate the comparability of two osteoarthritis (OA) surrogate endpoints--average cartilage thickness and cartilage volume--acquired from healthy volunteers on two 3.0T magnetic resonance imaging (MRI) systems from different manufacturers. Ten knees of five healthy volunteers were scanned on a 3.0T General Electric (GE) and a 3.0T Philips scanner using a fast three-dimensional fat-suppressed spoiled gradient (SPGR) imaging sequence. The acquisition parameters were optimized beforehand and were kept as comparable as possible on both scanners. For quantitative analysis, the average cartilage thickness and volume of the load-bearing regions of the femoral condyles were compared. Data were analyzed using a univariate repeated-measures analysis of variance (ANOVA) to examine the effects of position, condyle, and imaging system on the measurements. The average cartilage thickness and volume of the load-bearing regions of the femoral condyles did not differ between the two different 3.0T MRI systems (P > 0.05). There was no significant effect of position or condyle on the average cartilage thickness measurements (P > 0.05; range = 0.41-0.93) or cartilage volume (P > 0.05; range = 0.14-0.87). Two OA surrogate endpoints--average cartilage thickness and cartilage volume--acquired on two 3.0T MRI systems from different manufacturers are comparable.

Incremental exercise, plasma concentrations of catecholamines, reaction time, and motor time during performance of a noncompatible choice response time task.

The primary purpose was to examine the effect of incremental exercise on a noncompatible response time task. Participants (N=9) undertook a 4-choice noncompatible response time task under 3 conditions, following rest and during exercise at 70% and 100% of their maximum power output. Reaction and movement times were the dependent variables. Maximum power output had been previously established on an incremental test to exhaustion. A repeated-measures multivariate analysis of variance yielded a significant effect of exercise intensity on the task, observation of the separate univariate repeated-measures analyses of variance showed that only movement time was significantly affected. Post hoc Tukey tests indicated movement time during maximal intensity exercise was significantly faster than in the other two conditions. The secondary purpose of the study was to assess whether increases in plasma concentrations of adrenaline and nor-adrenaline during exercise and power output would act as predictor variables of reaction and movement times during exercise. Catecholamine concentrations were based on venous blood samples taken during the maximum power output test. None of the variables were significant predictors of reaction time. Only power output was a significant predictor of movement time (R2 = .24). There was little support for the notion that peripheral concentrations of catecholamines directly induce a central nervous system response.

Functional and morphologic changes after combined maxillary intrusion and mandibular advancement surgery

Purpose: The purposes of this investigation were 1) to compare the morphology and function of patients with combined vertical maxillary excess (VME) and mandibular retrognathia with that of controls, and 2) to examine how these parameters change after combined maxillary intrusion and mandibular advancement surgery. Patients and Methods: Fifteen female VME/retrognathic patients were compared with 26 female controls before and for up to 3 years after orthognathic surgery. Facial skeletal morphology, mandibular range of motion, maximum isometric bite force, and levels of electromyographic activity (EMG) in selected muscles of mastication were measured on all subjects. Where appropriate, one-way analysis of variance (ANOVA) or t-tests were used to compare the patients with controls. Univariate repeated-measures ANOVA was used to study longitudinal changes. Results: Preoperatively, patients' morphologic measurements were characteristic of VME compounded by mandibular retrognathia. At surgery, the maxilla was elevated an average of 2.8 mm, and the mandible was lengthened by an average of 7.1 mm. All of the postoperative morphologic measurements were closer to normal values. The patients' masseter mechanical advantage was significantly lower than that of controls both before and after surgery. Surgically induced changes in mechanical advantage were very small. The patients' maximum range of motion and excursion during mastication were all lower than those of controls before surgery. All measurements of mobility decreased immediately after surgery, with a gradual return to preoperative values. However, even 3 years after surgery, all of the motion measurements remained smaller than those of the controls. Before surgery, the patients had maximum isometric bite forces significantly lower than those of controls. Bite forces increased significantly after surgery, approaching normal values within 2 years. The activity levels in the muscles of mastication during isometric bites were not significantlyaltered by surgery. Conclusions: This study confirms that VME/retrognathia patients suffer from substantial deficiencies in their oromotor function. Surgical correction of this particular type of dentofacial deformity improves both the morphologic and functional deficits. Although some changes were not statistically significant, all were toward normalization of the presurgical values.

Functional and morphologic alterations secondary to superior repositioning of the maxilla

Purpose: The purpose of this investigation was to 1) compare morphological characteristics and functional performance of a sample of patients with vertical maxillary excess (VME) with controls, and to 2) examine how the patients' oral motor function adapts to surgery. Materials and Methods: Fifteen female VME patients were compared with 26 female controls before and up to 3 years after maxillary intrusion surgery. Measures of skeletal morphology, mandibular range of motion, maximum isometric bite force, and levels of electromyogram (EMG) activity in some of the muscles of mastication were made on all subjects over time. One-way analysis of variance (ANOVA) was used to compare the controls with the patients before and after surgery. Univariate repeated measures ANOVA was used to study longitudinal changes in the patients. Results: Preoperatively, the patients possessed morphological measurements characteristic of vertical maxillary excess. Superior repositioning of the maxilla averaged 3.3 mm. Concurrently, most skeletal measures were brought closer to normal values. Masseter muscle mechanical advantage was significantly lower in the patients than in controls both before and after surgery ( P < .05). There was no significant difference between patients and controls for other biomechanical measurements. Mandibular hypomobility was apparent at 6 weeks after surgery, but returned to control values within 6 to 12 months. Before surgery, the patients had maximum isometric bite forces significantly less than those of controls. Bite forces steadily increased after surgery, approaching normal values within 2 years. Before surgery the patients' muscle activity levels per unit of bite forces were equivalent to those of controls or somewhat lower. After surgery some of the patients' muscles had significantly lower levels of muscle activity per unit of bite force than did controls. Conclusions: The results of this study suggest that correction of vertical maxillary excess with maxillary intrusion surgery improves some characteristic functional deficits.

Approximate Power for Repeated-Measures ANOVA Lacking Sphericity

Abstract Violation of sphericity of covariance across repeated measures inflates Type I error rates in univariate repeated-measures analysis of variance. Hence the use of Geisser—Greenhouse or Huynh—Feldt is now common (to provide improved Type I error rate). With nonsphericity, no method has been available to compute power. A convenient method is suggested for approximating power and test size under nonsphericity. New approximations are suggested for (a) a weighted sum of independent noncentral χ2,s, (b) the trace of a noncentral Wishart (or pseudo-Wishart) matrix, (c) the expected values of and , and (d) the noncentral test statistic, whether corrected or uncorrected. The new approximations are extensions of the work of Box (1954a,b) and Satterthwaite (1941). The method performed well when evaluated against published and new simulations.

A method of testing for serial correlation in univariate repeated-measures analyses of variance

Many behavioral experiments utilize a two-factor split-plot design having one between-subjects grouping factor and one within-subjects repeated-measures factor. Subjects are assigned at random to the various levels of the grouping factor, but all subjects are exposed to all levels of the repeated-measures factor. Very often, the repeated-measures factor represents levels of a temporal variable (e.g., laboratory sessions or experimental trials). There are two assumptions concerning the variance-covariance matrices that must be met for a valid univariate test of the trials effect or the Trials by Groups interaction effect. First, the variance-covariance matrices for a set of orthonormal variables corresponding to the effect of the repeated factor must be equal across groups. The Box M test may be used to test this assumption (Huynh & Mandeville, 1979). Second, the common covariance matrix must be spherical. An approximate test for this assumption appears in Huynh and Feldt (1970).1 When these assumptions are not met, the use of a multivariate test or reducing the degrees of freedom on repeated-measures factors (Geisser & Greenhouse, 1958) to yield a conservative but more robust univariate F test are recommended. The purpose of this discussion is to comment briefly on a particular covariance matrix structure that is not spherical and to introduce a method with which to further explore the covariance matrix structure when violations of the sphericity assumption occur. When the repeated-measures factor is time, observations made closer together tend to be more highly correlated than those made further apart. One such pattern is the serial correlation pattern, and it can be a common cause of sphericity assumption violations in behavioral research. We recently examined the effects of the serial correlation pattern on conventional alpha levels (Hearne, Clark, & Hatch, in press) and found that in extreme cases of the pattern (correlation of trial levels one step apart =.8) actual alpha levels were more than three times the nominal level. Thus, certain types of covariance matrix structure that violate the sphericity