Search PubMed⌕ Search

Biomedical subjects

W W Buchanan

Publications and source records attributed to W W Buchanan.

At least 73 records · Page 4Linked to original sources
PubMed1991

Ankylosing spondylitis antirheumatic drug trials. III. Setting the delta for clinical trials of antirheumatic drugs--results of a consensus development (Delphi) exercise.

Defining the minimum clinically important difference or delta to be detected in a clinical trial depends on a number of factors including the research hypothesis, patient characteristics, the nature of the intervention and the trial design. In 2 previous studies, we have developed standardized procedures for conducting outcome measurement based on current Food and Drug Administration and European League Against Rheumatism guidelines for clinical trials in ankylosing spondylitis, and thereafter, determined the standard deviation for these outcome measures. In the final component of this series of studies, we have employed a Delphi technique to establish estimates for delta, and calculated the sample size requirements under 2 different conditions of Type I and Type II error probabilities.

Anti-Inflammatory Agents↗
PubMed1991

Rheumatoid arthritis antirheumatic drug trials. I. Effects of standardization procedures on observer dependent outcome measures.

A study was designed to assess the effects of standardization procedures on reducing interobserver variability for outcome measures given in the current Food and Drug Administration and European League Against Rheumatism guidelines and others selected from the rheumatology literature. Over 2 days, 6 rheumatologists independently examined 6 patients with rheumatoid arthritis (RA) in predetermined order before and after standardizing their examination techniques. An important and beneficial effect of the standardization procedure was observed on the majority of outcome variables. Such reductions in observer variability have the potential to diminish sample size requirements for antirheumatic drug studies.

Adult↗
PubMed1991

Rheumatoid arthritis antirheumatic drug trials. III. Setting the delta for clinical trials of antirheumatic drugs--results of a consensus development (Delphi) exercise.

Defining the minimum clinically important difference or delta to be detected in a clinical trial depends on a number of factors including the research hypothesis, patient characteristics, the nature of the intervention and the trial design. In 2 previous studies, we have developed standardized procedures for conducting outcome measurement based on current Food and Drug Administration and European League Against Rheumatism guidelines for RA clinical trials, and thereafter, determined the standard deviation for these outcome measures. In the final component of this series of studies, we employed a Delphi technique to establish estimates for delta and calculated the sample size requirements under different conditions of Type I and Type II error probabilities.

Arthritis, Rheumatoid↗
PubMed1991

Rheumatoid arthritis antirheumatic drug trials. II. Tables for calculating sample size for clinical trials of antirheumatic drugs.

The calculation of sample size requires knowledge of the standard deviation (SD) of index variables. Unfortunately, there are no published lists of SD and it is exceedingly difficult to locate variance estimates based on relevant populations. We used standardized procedures to determine in 60 patients with rheumatoid arthritis (RA) the SD of key outcome measures recommended in current Food and Drug Administration and European League Against Rheumatism guidelines for RA clinical trials. We anticipate that these tables will be useful to clinical researchers in selecting outcome measures as well as for calculating sample size requirements for future clinical studies in RA.

Anti-Inflammatory Agents↗
PubMed1990

[Rheumatic diseases and alternative medicine].

Besides the scientific- rational medicine alternative medicine keeps spreading in our days. The authors give a review of the possibilities of the alternative therapy of locomotor diseases. Patients suffering from locomotor diseases ask increasingly often for these therapeutical procedures. Literary review is given on acupuncture, manual therapy, homeopathy and certain physiotherapeutical techniques as well as on other less often applied alternative therapeutical procedures. It is stressed that alternative treatment may also involve potential danger. It is stated finally that as shown by the review of the literature well controllable clinical examinations required indispensably for the estimation of the efficacy of a therapeutical procedure are only in limited number at disposal.

Acupuncture Therapy↗
PubMed1990

Methotrexate in rheumatoid arthritis. Impact on quality of life assessed by traditional standard-item and individualized patient preference health status questionnaires.

In a double-blind, randomized trial of methotrexate vs placebo in rheumatoid arthritis, the effect of treatment on physical, social, and emotional function was measured in two different ways: the same, standard measurements in all patients, and individualized measurements selected by the patients at the start of the trial as representing the functions they most wanted to have improved by treatment. On the standard measurements, methotrexate-treated patients fared better than placebo-treated patients in their physical, social, and emotional function by 11%, 5%, and 6%, respectively, results that, although statistically significant, were small. However, methotrexate-treated patients were 29% better in the individualized measures, a result that was both highly statistically significant and greater than the differences in the standard measurements or in joint counts, grip strength, proximal interphalangeal joint circumference, morning stiffness, or walking time. Because the individualized measurements were as efficient as the best direct joint examination measures, yet reflected functional outcomes of greatest importance to individual patients, they constitute useful measures for such trials.

Adult↗
PubMed1990

Signal measurement strategies: are they feasible and do they offer any advantage in outcome measurement in osteoarthritis?

The applicability of a signal measurement strategy was compared with a traditional method of measuring outcome in osteoarthritis. The signal method detected statistically significant alterations in health status with small sample sizes and with a relative efficiency close to or at unity. The prevalence of deterioration in nonsignal items was low. Signal methods of measurement may provide an alternative approach to outcome measurement in osteoarthritis clinical trials.

Feasibility Studies↗
PubMed1990

Correlation between tests of muscle involvement and clinical muscle weakness in polymyositis and dermatomyositis.

A correlation study was performed on the degree of muscle weakness in 36 patients with dermatomyositis and 69 with polymyositis in relation to muscle biopsy findings, electromyography (EMG) abnormalities, and serum concentrations of creatine kinase (CK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes. Statistically significant correlations were found between muscle weakness and EMG results in patients with polymyositis, and between muscle weakness and serum CK and AST levels in dermatomyositis. As expected, correlations were found between the results of the three enzyme determinations in both groups of patients.

Alanine Transaminase↗
PubMed1990

A controlled comparison of piroxicam and diclofenac in patients with osteoarthritis.

Eighty patients with osteoarthritis were randomly assigned to either piroxicam (20 mg daily) or diclofenac (75-150 mg daily) in a 12-week double-blind, parallel groups study. In the 70 patients who completed the study, both medications were effective; statistically significant improvement was observed on all assessments of efficacy. However, no statistically significant differences between the two drugs were seen on any of the efficacy parameters measured. There was a trend towards better tolerance in the piroxicam treated patients, although this was not statistically significant; 3 of the 40 piroxicam treated patients versus 6 of the 40 patients on diclofenac were discontinued from the trial due to intolerable adverse events.

Activities of Daily Living↗
PubMed1990

Pregnancy and rheumatoid disease.

The onset of pregnancy appears to result in the amelioration of rheumatoid disease activity. This is most likely to be related to the change in hormonal, and thus immunological, status of the mother. Spontaneous abortion appears to be increased in mothers with rheumatoid disease. Whether this is due to disease status or to drug therapy is not entirely clear for all cases, but there is a suggestion that it could be the disease state. If at all possible, drugs should be avoided during pregnancy but simple anti-inflammatory drugs in low dosage probably do not produce any major problems. Immunosuppressant drugs should be avoided at all times except when the mother's health is at serious risk. The continued use of disease remitting agents throughout pregnancy is probably not necessary and there is still sufficient question as to whether these drugs could be potentially toxic to the infant. Primum non nocere.

Arthritis↗
PubMed1990

Polymorphism of major histocompatibility complex extended haplotypes bearing HLA-DR3 in patients with rheumatoid arthritis with gold induced thrombocytopenia or proteinuria.

The distribution of DR3 and of extended haplotypes bearing DR3 was studied in three groups of subjects: 35 patients with rheumatoid arthritis (RA) with gold induced thrombocytopenia or proteinuria, 185 patients with RA without these side effects, and 300 normal healthy controls. The extended haplotypes bearing DR3 were analysed with cDNA probes for DR alpha, DR beta, DQ alpha, and DQ beta genes. The data showed that the prevalence of DR3 was significantly higher in patients who developed gold induced thrombocytopenia or proteinuria than in normal controls or patients with RA without these side effects. Distribution of three extended haplotypes bearing DR3 (B8, DR3; B18,DR3; non-B8,non-B18,DR3) in patients with RA with thrombocytopenia or proteinuria was significantly different from that in normal controls, but not from that in patients with RA without these toxic reactions. Southern blot analysis of DR, DQ genes with cDNA probes showed that the extended haplotype bearing B8,DR3, which carries DQA2.1 and DQB2.1 genes, was present in a significantly higher proportion of patients with RA with gold induced thrombocytopenia or proteinuria (22/24, 92%) than in patients with RA without these side effects (32/45, 71%) or normal subjects (40/61, 66%). The data suggest that the genomic region on chromosome 6 involved in susceptibility to gold induced thrombocytopenia or proteinuria should be extended to the DQA2, DQB2 gene loci.

Arthritis, Rheumatoid↗