Georg Gittler

Combined exercise and motivation program: Effect on the compliance and level of disability of patients with chronic low back pain: A randomized controlled trial

OBJECTIVE To assess the effect of a combined exercise and motivation program on the compliance and level of disability of patients with chronic and recurrent low back pain. DESIGN A double-blind prospective randomized controlled trial. SETTING Physical therapy outpatient department, tertiary care. PATIENTS Ninety-three low back pain patients were randomly assigned to either a standard exercise program (n = 49) or a combined exercise and motivation program (n = 44). INTERVENTIONS Patients were prescribed 10 physical therapy sessions and were advised to continue exercising after treatment termination. The motivation program consisted of five compliance-enhancing interventions. Follow-up assessments were performed at 3 1/2 weeks, 4 months, and 12 months. MAIN OUTCOME MEASURES Disability (low back outcome score), pain intensity, physical impairment (modified Waddell score, fingertip-to-floor distance, abdominal muscle strength), working ability, motivation, and compliance. RESULTS The patients in the motivation group were significantly more likely to attend their exercise therapy appointments (p = .0005). Four and 12 months after study entry there was a significant difference in favor of the motivation group with regard to the disability score (p = .004) and pain intensity (p < or = .026). At 4 months, there was a significant advantage for the motivation group in the fingertip-to-floor distance (p = .01) and in abdominal muscle strength (p = .018). No significant differences were found in motivation scores, self-reported compliance with long-term exercise, and modified Waddell score. In terms of working ability, there was a trend favoring the combined exercise and motivation program. CONCLUSION The combined exercise and motivation program increased the rate of attendance at scheduled physical therapy sessions, ie, short-term compliance, and reduced disability and pain levels by the 12-month follow-up. However, there was no difference between the motivation and control groups with regard to long-term exercise compliance.

Long-term effect of a combined exercise and motivational program on the level of disability of patients with chronic low back pain.

Study Design. A prospective clinical randomized controlled trial. Objectives. To determine the long-term effect of a combined exercise and motivational program on the level of disability of patients with chronic and recurrent low back pain (LBP). Summary of Background Data. There is agreement on the importance of exercise during the course of chronic LBP. However, it is well known that long-term adherence with exercises is particularly low. Methods. A total of 93 patients with LBP were randomly assigned to the control group (standard exercise program) or the motivational group (combined exercise and motivational program). Follow-up assessments were performed at 3.5 weeks, 4 months, 12 months, and 5 years. Main outcome measures were disability scores, pain intensity, and working ability. In addition to classic statistics, the sophisticated linear partial credit model was used to test the effects of treatment on disability scores. Results. In both groups, significant improvements in the disability scores were found at all points of follow-up assessment, however, the cumulative effect of the treatment in the motivational group was more than twice as much as in the control group. This result is in accordance with the increasing divergence in pain intensity between groups between 12 months and 5 years after intervention. A significant, positive long-term effect at the 5-year reassessment in working ability was only seen in the motivational group. All statistically significant results were confirmed by intention-to-treat analyses. Conclusions. Regarding long-term efficacy, the combined exercise and motivation program was superior to the standard exercise program. Five years after the supervised combined exercise and motivational program, patients had significant improvements in disability, pain intensity, and working ability.

Cortical activity of good and poor spatial test performers during spatial and verbal processing studied with Slow Potential Topography

Whether essential processing of spatial information is lateralized asymmetrically in the human cortex is still a matter of debate. In this study, items of an Item Response Theory calibrated test for spatial ability were used to ensure stimulus homogeneity and validity. Subjects were preselected as extreme groups of good and poor spatializers. Mapping of true DC-recorded slow potential shifts (SPSs) resulted in distinctly discriminable topographies with spatial and verbal-analytic material as well as with spatial performance groups within the spatial block. Left fronto-central negativity maxima in the verbal condition clearly contrasted with occipito-parietal peak activity in the spatial condition. Poor spatializers showed higher amplitudes as well as a tendency to asymmetric activity in right parietal (parieto-temporal) areas, whereas in good spatializers the activity was localized symmetrically in occipital and occipito-parietal regions. The findings emphasize the importance of the right posterior cortex for spatial processing (negativity maxima at occipital and right parietal sites) and suggest a task-specific lower cortical efficiency or, seen from a processing perspective, a higher Investment of Cortical Effort (ICE) on the part of poor spatializers.

Cross-Cultural Validation of Item Complexity in a LLTM-Calibrated Spatial Ability Test

In the “Linear Logistic Test Model” (LLTM; Fischer, 1983), item difficulties of intelligence/ability test items can be modeled in terms of hypothesized facets of complexity. This feature of the LLTM makes it possible to classify cross-cultural bias on a conceptual level that is beyond simple detection of DIF items. In the present study, a spatial ability test, the “Three-Dimensional Cube Comparison Test” (3DC; Gittler, 1990), was administered to university students, 384 from the United States and 307 from Austria. Compared to subjects from Austria, US students worked faster but scored considerably lower overall. It is suggested that these differences in test-taking behavior were probably caused by motivational factors. After differences in motivation were accounted for, responses were analyzed using the LLTM and no cross-cultural differences were found in the hypothesized complexity facets of the 3DC items. However, a sufficient number of warm-up items is crucial to ensure the cross-cultural equivalence o...

Chew on this: No support for facilitating effects of gum on spatial task performance.

OBJECTIVE To determine whether chewing of gum facilitates spatial task performance in healthy participants, two behavioral experiments were performed. DESIGN In the first experiment, spatial task performance of 349 men and women preceding and after treatment administration (saccharated chewing gum, sugar-free chewing gum, no chewing gum) was assessed using effect modeling by means of Item Response Theory. In the second experiment, another 100 participants were either administered sugar-free chewing gum or no chewing gum during spatial task performance. Effects of gum in the second study were assessed by standard means of data analysis. RESULTS Results indicated no significant effects of either chewing gum or sugar on spatial task performance in either experiment. CONCLUSIONS Our findings are consistent with recent studies investigating the influences of chewing gum on various memory functions, extending them by another measure of cognitive ability. Thus, further doubt is cast on enhancing effects of chewing gum on cognitive task performance.

Automatic Generation of Quantitative Reasoning Items

This paper deals with three studies on the computer-based, automatic generation of algebra word problems. The cognitive psychology based generative/quality control frameworks of the item generator are presented. In Study I the quality control framework is empirically tested using a first set of automatically generated items. Study II replicates the findings of Study I using a larger set of automatically generated algebra word problems. Study III deals with the generative framework of the item generator by testing construct validity aspects of the item generator produced items. Using nine Rasch-homogeneous subscales of the new intelligence structure battery (INSBAT, Hornke et al., 2004), a hierarchical confirmatory factor analysis is reported, which provides first evidence of convergent as well as divergent validity of the automatically generated items. The end of the paper discusses possible advantages of automatic item generation in general ranging from test security issues and the possibility of a more ...

Endlosschleifen: Psychometrische Grundlagen des Aufgabentyps EP

Zusammenfassung. Fur den Raumvorstellungs-Aufgabentyp EP (photographische Endlosschleifen) wird die “theoriegeleitete“ Skalenkonstruktion auf Basis des Rasch-Modells beschrieben. In drei empirischen Studien, die ein konsekutives, aufeinander abgestimmtes Entwicklungsprogramm umfassen, wird der - oft muhsame - Weg zur Modellgeltung (Rasch-Homogenitat) dargestellt. In Studie 1 (n = 324) wird uber den Ausgangspunkt und die Konstruktionsgrundlagen der EP sowie uber erste Ergebnisse berichtet. Als wesentlicher Entwicklungsfortschritt gelingt es in Studie 2 (n = 378), die Rasch-Homogenitat des Itemtyps zu realisieren; zudem lassen sich neue Erkenntnisse bezuglich der Itemgenerierung ableiten. Studie 3 (n = 254) fungiert als Validierungsstudie, welche die Eindimensionalitat des Itemsets aus Studie 2 bestatigt. Vor dem Hintergrund, dass in empirischen Daten Rasch-Homogenitat erreicht werden konnte, wird die theoriegeleitete Vorgangsweise als prototypisch fur einen Erfolg versprechenden Einsatz des Rasch-Modells z...

IRT-basierter Vergleich zweier Varianten automatisiert erstellter Matrizentestaufgaben

Zusammenfassung: In der vorliegenden Arbeit wird uber 2 Pilotstudien im Vorfeld der Entwicklung eines Itemgenerators zur vollautomatisierten Herstellung von Matrizentestaufgaben berichtet. Besonderes Augenmerk wurde auf den Vergleich zweier theoriegeleitet erstellter Varianten von Items gelegt und ob sich diese als geeignet erweisen, bei automatisierter Itemgenerierung mit erwunscht hoher psychometrischer Qualitat (Geltung des Modells von Rasch, 1960/1980) erstellt werden zu konnen. Die durchgefuhrten Studien weisen aus Sicht der IRT auf prinzipielle Gleichwertigkeit der beiden Itemvarianten bei unterschiedlicher Robustheit der erzielbaren psychometrischen Qualitat hin. Dieses Ergebnis wird im Lichte von “affordances” und “constraints” im Hinblick auf Konstruktreprasentativitat der beiden Itemvarianten diskutiert (Greeno, Moore & Smith, 1993). Zusatzlich konnten wertvolle Erkenntnisse fur die Erweiterung des generativen Regelwerks zur Einbindung in den Itemgenerator gewonnen werden. Abschliesend werden mo...

EMPIRICAL CONTRIBUTION TO THE QUESTION OF SEX-DEPENDENT INHERITANCE OF SPATIAL ABILITY '""

The X-linked recessive gene hypothesis, a theory to predict the mode of genetic inheritance of spatial ability, was tested using a new Rasch-calibrated space test, the Three-dimensional Cube Test (Gittler, 1990). This allowed solving the homogeneity problem (insufficient unidimensionality of test material) by which earlier research in this field was affected. The empirical correlations from our sample of 134 families were compared with the theoretically predicted values. Present data do not corroborate the model; however, the problems of its general falsification are discussed. The fact that differences in performance in favour of males exist in the parental generation but not in the filial generation accentuates the importance of environmental factors.

IRT-Based Measurement of Short-Term Changes of Ability, With an Application to Assessing the “Mozart Effect”

The article extends and applies previous approaches by Klauer and Fischer to the statistical evaluation of ability changes in tests conforming to the Rasch model (RM). Exact uniformly most powerful unbiased (UMPU) hypothesis tests and uniformly most accurate (UMA) confidence intervals (CIs) for the amount of change can be constructed for each testee separately. Under the H 0 of no change, the individual p values of testees can be aggregated also within groups. The current results extend this method by an estimator for a group effect, an exact UMPU test of its significance, a corresponding UMA CI, and a likelihood ratio test for group comparisons. All these methods are applied to two sets of data concerning a highly controversial issue in literature: the so-called Mozart Effect (ME). As test material, a unidimensional test of spatial ability by Gittler and Arendasy was presented to two samples of testees (Studies I and II). On the basis of these data, the occurrence of a short-term effect of the experimental condition can be demonstrated which, however, seems to be related to the relaxation between pretest and posttest rather than to the musical priming.