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G Stucki

Publications and source records attributed to G Stucki.

At least 73 records · Page 4Linked to original sources
PubMed1999

Superior responsiveness of the pain and function sections of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) as compared to the Lequesne-Algofunctional Index in patients with osteoarthritis of the lower extremities.

OBJECTIVE: To compare the responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and a questionnaire format of the Lequesne-Algofunctional Index in patients with OA of the lower extremities. METHODS: Longitudinal analysis of the instruments' responsiveness [standardized response mean (SRM), effect size (ES)] in ambulatory patients undergoing hip or knee arthroplasty. RESULTS: At six months 36, and at one year 40 out of 43 patients undergoing hip (N=30) or knee arthroplasty (N=13) could be examined. Both responsiveness statistics revealed the same order of responsiveness. For both indices and for both locations, the pain sections were more responsive than the function sections. However, the WOMAC scales and the WOMAC global index (hip at 12 months: SRM=2.4; knee at 12 months: SRM=2.0 ) were more responsive than the comparable Lequesne sections and Lequesne index (hip at 12 months: SRM=2.1; knee at 12 months: SRM=1.5). CONCLUSIONS: Although our results are based on a German version using a self-report format, the WOMAC scales appear to be more responsive than the Lequesne index in patients with OA of the lower extremities.

Adult↗
PubMed1999

A patient-derived disease activity score can substitute for a physician-derived disease activity score in clinical research.

OBJECTIVE: Joint counts have a central role in assessing disease activity in rheumatoid arthritis (RA). They are usually undertaken by physicians or nurses. We investigated whether joint counts can be devolved to patients and evaluated the use of a patient-derived Disease Activity Score (DAS). METHODS: One hundred RA patients attending a specialist unit were evaluated, comparing joint counts by a physician with patient-assessed joint counts and DAS derived from both methods. They were related to other measures of disease activity in the European League Against Rheumatism (EULAR) core data set and with the Rheumatoid Arthritis Disease Activity Index (RADAI; a validated patient self-assessment index). RESULTS: Regression analysis showed no significant differences between a physician's and patient's joint counts and DAS. There were middle to high correlations between patient and physician assessments of tender joints and swollen joints; using R2, this explained 70% of the variance for tender joints and 40% for swollen joints. Kappa analysis showed good agreement between physician and patient assessments of individual joint tenderness (kappa values 0.49-0.84). There was lower agreement for individual swollen joints (kappa values 0.02-0.61). Physician DAS and patient DAS had a similar correlation with the Health Assessment Questionnaire (HAQ) (r = 0.50 and r = 0.48, respectively). CONCLUSION: The agreements between physician and patient assessments are sufficient to allow patients' assessments to be used for clinical research. This is especially the case with a patient-derived DAS. However, the results are not directly interchangeable and further studies are needed before patients' assessments are used to guide clinical practice.

Arthritis, Rheumatoid↗
PubMed1999

Development and validation of a self-administered systemic sclerosis questionnaire (SySQ).

OBJECTIVE: To develop a self-administered systemic sclerosis questionnaire (SySQ) covering condition-specific functional limitation and symptoms. METHODS An initial item pool was generated by open patient interviews. A preliminary questionnaire was devised using 62 systemic sclerosis (SSc; scleroderma) patients. Factor analysis was used for further selection and grouping of items into distinct scales. The retrieved scales were tested for internal consistency and test-retest reliability. Spearman's rank correlation and Wilcoxon's rank sum test were used to examine hypothesized associations of the SySQ with various clinical and laboratory features. RESULTS: Altogether 32 SySQ items were selected and aggregated into 12 scales addressing 'pain', 'stiffness', 'coldness', 'complex functions', 'strength of hands', 'rising', 'walking', shortness of breath', 'upper airway symptoms', 'eating', 'swallowing' and 'heartburn/regurgitation'. Internal consistency ranged from 0.93 ('complex functions') to 0.73 ('heartburn/regurgitation'); Spearman's correlation coefficient for test retest reliability ranged from 0.93 to 0.73 (P < 0.001). While the scales were associated with corresponding functional impairments, there was generally less association with morphological impairments. CONCLUSION: The SySQ is a valid and reliable condition-specific measure in patients with SSc. Individually applicable scales cover a wide spectrum of general and organ-specific SSc symptoms and functional limitation. After further validation with respect to its ability to measure change, it may be used in clinical, health services and epidemiological research.

Adult↗
PubMed1999

Evaluation of costs in rheumatic diseases: a literature review.

The aim of our review was to examine recently published cost-evaluations presenting originally developed data in rheumatic conditions. We identified 21 articles: 9 presenting original data on rheumatoid arthritis and/or osteoarthritis; 7 focusing on other musculoskeletal conditions such as back pain, scleroderma, Lyme disease, and fibromyalgia; and 5 assessing costs in total knee and hip arthroplasty. Most of the studies originated in the United States. In contrast to earlier reviews in this journal, fewer studies focused on only pharmacoeconomic aspects. In reviewing these studies, we found a lack of standardization in cost-assessment leading to a limited comparability of study results. As main tasks to improve the evidence achieved by performing cost-evaluations in clinical settings, we identified a standardization of main cost-components that should be covered by each clinical trial and the assessment of validity, reliability, and comparability of different data sources used to collect cost-data.

Arthritis, Rheumatoid↗
PubMed1999

Responsiveness and sensitivity to change of SLE disease activity measures.

The ability of outcome measures to detect change over time is critical for their usefulness in clinical trials. Two concepts are applied in the assessment of evaluative instruments: We endorse the recommendation that a distinction be made between sensitivity and responsiveness. Sensitivity to change refers to the capacity of instruments to measure change statistically. Sensitivity statistics relate the magnitude of observed change to some measure of variablity and are essentially signal-to-noise ratios. Responsiveness addresses the detection of clinically relevant change. The methodology is still evolving but a common approach has been to correlate the observed change in scores with external standards that are believed to indicate clinical relevance (e.g., physician- or patient-based transition scales). Sensitivity to change and responsiveness of SLE activity indices have been addressed in a small number of studies. These indicate that the most widely used systems (SLEDAI. SLAM, BILAG) are sensitive to change although the available evidence does not allow preference for one instrument over the others. Little research has been done on the responsiveness of these measures. This article reviews the methodological concepts in measuring clinical change and summarizes reports on sensitivity and responsiveness of lupus activity scores.

Analysis of Variance↗
PubMed1999

Changes in cross-sectional measurements of the spinal canal and intervertebral foramina as a function of body position: in vivo studies on an open-configuration MR system.

OBJECTIVE: The purpose of this study was to evaluate physiologic changes of the cross-sectional area of the spinal canal and neural foramina in young asymptomatic volunteers. SUBJECTS AND METHODS: Twelve asymptomatic volunteers were examined in a 0.5-T open-configuration MR system. T2-weighted fast spin-echo sequences were obtained in upright neutral, upright flexed, upright extended, and supine extended positions. The cross-sectional area of the spinal canal and the thickness of the ligamentum flavum were measured on angled axial images at the L4-L5 level. The anteroposterior diameter of the spinal canal and cross-sectional areas of the neural foramina were measured on sagittal images from L1 to S1. RESULTS: At disk level, the cross-sectional area of the spinal canal varied significantly between body positions, most notably between the upright flexed (mean, 268 mm2) and the upright extended (mean, 224 mm2) positions (p < .0001). The maximum thickness of the ligamenta flava increased in the extended positions (p < .0001). The cross-sectional area of the neural foramina underwent position-dependent variations of as much as 44.4%. The smallest cross-sectional areas were found in the extended positions. CONCLUSION: In asymptomatic volunteers, MR imaging is able to show position-dependent changes in the cross-sectional areas of the spinal canal and the intervertebral foramina. The extended positions best reveal important findings.

Adult↗
PubMed1999

Comparison of the Dougados Functional Index and the Bath Ankylosing Spondylitis Functional Index. A literature review.

The preliminary core set for endpoints in ankylosing spondylitis (AS) clinical trials includes physical function. The objective of this review was to compare properties and performance of the 2 most widely used measures of functional capacity in AS: the Dougados Functional Index (DFI) and the Bath Ankylosing Spondylitis Functional Index (BASFI). A MEDLINE search was performed covering the years 1988 through April 1998. AS studies were identified and selected if they included the DFI and/or the BASFI. Additional studies were identified by scrutinizing the references cited in the retrieved articles and by correspondence with the authors of the 2 questionnaires. The instruments were examined with respect to development, truth, discrimination, and feasibility. We identified 27 articles dealing with the instruments. Both are valid and reliable measures of functional capacity in AS. While the DFI was sensitive to change in one disease controlling (DC-ART) and in 4 symptom modifying antirheumatic drug (SMARD) clinical trials, the BASFI is not sufficiently tested in these settings. The only direct comparison of both indices in a physical therapy setting confirmed 4 other studies that suggested a better discriminative capacity of the BASFI in physical therapy clinical trials. Two likely reasons for the lack of responsiveness of the DFI in these settings are the distribution of baseline scores showing a tendency towards normal values and the less sensitive scoring system. Discriminative capacity of the BASFI was found to be superior in patients with mild functional disability. It remains to be seen whether the BASFI performs as well as or better than the DFI in SMARD and DC-ART clinical trials.

Activities of Daily Living↗
PubMed1999

Validity aspects of erythrocyte sedimentation rate and C-reactive protein in ankylosing spondylitis: a literature review.

The preliminary core set for endpoints in disease controlling antirheumatic therapy includes acute phase reactants. The objective of this clinically oriented literature review was to examine and compare the validity of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in ankylosing spondylitis (AS) clinical trials. A MEDLINE search was performed covering the years 1967 through April 1998. AS studies were identified and selected if they included ESR and/or CRP and either presented data about their relation with disease activity or were designed as longitudinal clinical trials. Additional studies were identified by scrutinizing references cited in the retrieved studies. The selected studies were examined for truth (association with disease activity), discriminative power (sensitivity to change and discrimination between active and inactive treatment in longitudinal clinical trials), and feasibility (e.g., applicability and costs) of ESR and CRP in AS. We identified 12 articles on the association of ESR and/or CRP with disease activity and 13 longitudinal clinical trials reporting ESR and/or CRP data. Although the applied definitions or disease activity proved very inhomogenous, there was some evidence that both acute phase reactants are correlated with disease activity. In terms of discriminative capacity the available data are inconclusive. Relevant feasibility aspects are general availability, technically simple measurement, and an advantage in the cost of ESR and central laboratory facilities for CRP. Acute phase reactants do not comprehensively represent the disease process in AS. Their worth in AS clinical trials is limited. Based on the currently existing data neither measure is clearly superior in terms of validity. When selecting an acute phase reactant, feasibility aspects may be most relevant in choice of measure.

Antirheumatic Agents↗
PubMed1999

Comparative responsiveness of 3 functional indices in ankylosing spondylitis.

OBJECTIVE: To compare the responsiveness of the Bath Ankylosing Spondylitis Functional Index (BASFI), the Dougados Functional Index (DFI), and the ankylosing spondylitis-specific version of the Health Assessment Questionnaire (HAQ-S). METHODS: Using data from a placebo controlled, randomized clinical trial we designed a responsiveness model including both hypothesized improvement (n = 39; continuous diclofenac treatment) and hypothesized deterioration (n = 40; patients who withdrew from the clinical trial because of a flare) of functional performance. Instrument responsiveness was examined using 4 statistics including standardized response mean (SRM), effect size (ES), the Guyatt method, and the variance method. Ceiling and floor effects were visualized using histograms for cross sectional and time-path diagrams for longitudinal analysis. RESULTS: The BASFI ranked superior compared to the DFI and HAQ-S in detecting both improvement and deterioration of functional performance. All 4 responsiveness statistics consistently confirmed this superiority of the BASFI. However, the median baseline scores of all 3 questionnaires were close to the lower end of the instrument and the score distribution showed skewed patterns. CONCLUSION: The BASFI appears to be more responsive than the DFI and the HAQ-S in situations of both improvement and deterioration of functional performance. However, addition of particular difficult items may improve the performance of the BASFI as well as of the other 2 instruments.

Adult↗
PubMed1999

Preliminary core set of domains and reporting requirements for longitudinal observational studies in rheumatology.

Observational and longitudinal observational studies (LOS) provide essential information about the course and outcome of rheumatic disorders that cannot be provided by randomized controlled trials, and they constitute the major clinical scientific communication in rheumatology. There has been no consensus as to the full and appropriate content of LOS. This report defines a core set of domains and reporting requirements for LOS. At the 1998 OMERACT IV Conference a consensus process evaluated the literature of rheumatology in light of the constructs, variables, and outcomes of rheumatology by using introductory lectures, nominal groups, and plenary sessions. The result of this process was to identify 5 "core" domains that should be included in every LOS: Health Status, Disease Process, Damage, Mortality, and Toxicity/Adverse Reactions. Two additional domains, Work Disability and Costs, were recognized as important, but need not be used in all LOS. Eleven subdomains were identified that divided the domains into convenient clinical and conceptual units. A set of reporting requirements was also determined. The core recommendations, which follow on the WHO ICIDH-2 outline, are not disease-specific; the substitution of different "disease process" and "damage" measures make them suitable for many rheumatic disorders. The core set is intended to serve as a core for LOS in almost all rheumatic conditions.

Decision Making↗
PubMed1998

Rapid atrazine mineralisation in soil slurry and moist soil by inoculation of an atrazine-degrading Pseudomonas sp. strain.

The evaluation of pesticide-mineralising microorganisms to clean-up contaminated soils was studied with the widely applied and easily detectable compound atrazine, which is rapidly mineralised by several microorganisms including the Pseudomonas sp. strain Yaya 6. The rate of atrazine removal was proportional to the water content of the soil and the amount of bacteria added to the soil. In soil slurry, 6 mg atrazine kg soil-1 was eliminated within 1 day after application of 0.3 g dry weight inoculant biomass kg soil-1 and within 5 days when 0.003 g kg soil-1 was used. In partially saturated soil (60% of the maximal water-holding capacity) 15 mg atrazine kg soil-1 was used. In unsaturated soil, about 60% [U-ring-14C] atrazine was converted to 14CO2 within 14 days. Atrazine was very efficiently removed by the inoculant biomass, not only in soil that was freshly contaminated but also in soil aged with atrazine for up to 260 days. The bacteria exposed to atrazine in unsaturated sterile soil were still active after starvation period of 240 days: 15 mg newly added atrazine kg soil-1 was eliminated within 5 days.

Atrazine↗
PubMed1998

[Vitamin E in therapy of rheumatic diseases].

Over the past years, antioxidants, and particularly vitamin E, have received considerable attention in the treatment of human diseases. In rheumatology, interest has been given to the treatment and prevention of rheumatoid arthritis and osteoarthritis. However, the concept of using antioxidant nutrients as potential remedies is not new. As early as the sixties, first case reports have described beneficial effects of vitamin E in the therapy of osteoarthritis. Nonetheless, most of the following studies were not conducted properly, thus, not allowing valid inferences about the efficacy of vitamin E. Newer studies with sound methodology have shown a beneficial effect in rheumatic diseases, mainly in the reduction of pain. This paper reviews current and past studies about vitamin E in the treatment of rheumatic diseases.

Antioxidants↗
PubMed1998

Comparison of the WOMAC (Western Ontario and McMaster Universities) osteoarthritis index and a self-report format of the self-administered Lequesne-Algofunctional index in patients with knee and hip osteoarthritis.

OBJECTIVE: To compare the metric properties and validity of German versions of the WOMAC (Western Ontario and McMaster Universities) and a self-administered questionnaire-format of the Lequesne-Algofunctional-Index in patients with osteoarthritis (OA) of the lower extremities. DESIGN: Cross-sectional analysis of the instruments' internal consistency (Cronbach's coefficient alpha) and construct validity (correlation with radiological OA-severity and limitation in range-of-motion) in ambulatory patients and patients before hip arthroplasty. Test-retest reliability was assessed on a subsample after 10 days. RESULTS: Data from 51 patients out of 91 contacted could be analyzed. Twenty-nine patients had knee and 22 patients had hip OA. Both the WOMAC and Lequesne OA-indices and their scales or sections had a satisfactory test-retest reliability (Intraclass correlation coefficient 0.43-0.96). All scales of the WOMAC were internally consistent (Cronbach's coefficient alpha 0.81-0.96) and associated with radiological OA-severity and joint range of motion. However, only the function but not the symptom sections (Cronbach's coefficient alpha knee: 0.55; hip: 0.63) of the self-administered Lequesne OA index were internally consistent for both, patients with knee and hip OA. Also, the symptom components were not or only weakly associated with radiological OA-severity and joint range of motion. CONCLUSIONS: Although our results are based on a German version using a self-report format we may caution using the self-administered Lequesne OA index without prior testing of its metric properties and validity.

Aged↗
PubMed1998

Weighting for joint surface area improves the information provided by a reduced 28-joint articular index of swollen joints.

The objective of our study was to examine whether weighting for joint surface area or recording of simultaneously tender and swollen joints increases the association of a reduced 28-joint articular index with clinical and outcome parameters. In a cross-sectional study we examined 61 consecutive outpatients with RA fulfilling the American Rheumatism Association 1987 revised criteria. Tender, swollen, and simultaneously tender and swollen joints were recorded. The association of 28- and 68-joint articular indices with clinical and outcome parameters were estimated with nonparametric correlation analyses. Weighting for joint surface yielded consistently increased correlation of clinical and outcome parameters with swollen and tender and swollen but not with tender joint counts. The correlation of the 28-joint articular and 68-articular indices with these parameters were similar. In conclusion, weighting for joint surface notably improves the information provided by swollen joint counts, whereas it does not appear to improve the information provided by tender joint counts.

Adult↗
PubMed1998

Isometric muscle strength is an indicator of self-reported physical functional disability in patients with rheumatoid arthritis.

The objective of our study was to examine (1) whether isometric muscle strength contributes to the explanation of the physical functional disability of a rheumatoid arthritis (RA) patient population after accounting for other disease parameters and demographic variables and (2) whether change in isometric muscle strength is an indicator of change in physical functional disability. Sixty-five consecutive patients fulfilling the American Rheumatism Association 1987 revised criteria for RA were included in the study. Isometric muscle strength was measured with a validated Muscle Strength Index (MSI) calculated as the mean score of standardized isometric extension and flexion strength of the knee and elbow joints. Physical functional disability was measured with the physical dimension of the Health Assessment Questionnaire (HAQ). For 56 patients, we could obtain 1 yr follow-up data. Cross-sectionally, there was a significant correlation (r = -0.51, P < 0.01) between the MSI and the HAQ. Muscle strength remained a significant determinant of the HAQ in multivariate analysis accounting for disease and demographic variables. Longitudinally, change in MSI explained additional variance of change in HAQ after accounting for change in pain, the most important correlate of change in HAQ.

Adult↗
PubMed1998

Aerobic mineralization of 2,6-dichlorophenol by Ralstonia sp. strain RK1.

A new aerobic bacterium was isolated from the sediment of a freshwater pond close to a contaminated site at Amponville (France). It was enriched in a fixed-bed reactor fed with 2,6-dichlorophenol (2,6-DCP)as the sole carbon and energy source at pH 7.5 and room temperature. The degradation of 2,6-DCP followed Monod kinetics at low initial concentrations. At concentrations above 300 microM (50 mg.liter-1), 2,6-DCP increasingly inhibited its own degradation. The base sequence of the 16S ribosomal DNA allowed us to assign the bacterium to the genus Ralstonia (formerly Alcaligenes). The substrate spectrum of the bacterium includes toluene, benzene, chlorobenzene, phenol, and all four ortho- and para-substituted mono- and dichlorophenol isomers. Substituents other than chlorine prevented degradation. The capacity to degrade 2,6-DCP was examined in two fixed-bed reactors. The microbial population grew on and completely mineralized 2,6-DCP at 2,6-DCP concentrations up to 740 microM in continuous reactor culture supplied with H2O2 as an oxygen source. Lack of peroxide completely stopped further degradation of 2,6-DCP. Lowering the acid-neutralizing capacity of the medium to 1/10th the original capacity led to a decrease in the pH of the effluent from 7 to 6 and to a significant reduction in the degradation activity. A second fixed-bed reactor successfully removed low chlorophenol concentrations (20 to 26 microM) with hydraulic residence times of 8 to 30 min.

Chlorophenols↗