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Biomedical subjects

N Bellamy

Publications and source records attributed to N Bellamy.

At least 109 records · Page 6Linked to original sources
PubMed1991

Ankylosing spondylitis antirheumatic drug trials. I. Effects of standardization procedures on observer dependent outcome measures.

We designed a study to assess the effects of standardization procedures on reducing interobserver variability for outcome measures given in the current Food Drug Administration and European League Against Rheumatism guidelines and others selected from the rheumatology literature. Over 2 days, 6 rheumatologists independently examined 7 patients with ankylosing spondylitis (AS) 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 AS antirheumatic drug studies.

Adult↗
PubMed1991

Ankylosing spondylitis antirheumatic drug trials. II. Tables for calculating sample size for clinical trials.

The calculation of sample size requires knowledge of the standard deviation (SD) of index variables. Unfortunately, there are no published lists of standard deviations and it is exceedingly difficult to locate variance estimates based on relevant populations. We used standardized procedures to determine in 60 patients with ankylosing spondylitis (AS) the SD of key outcome measures recommended in current Food Drug Administration and European League Against Rheumatism guidelines for AS 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 AS.

Analysis of Variance↗
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

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

Relapsing polychondritis in pregnancy.

A 25-year-old patient presented at 14 weeks of her 3rd pregnancy with chondritis affecting the cartilaginous portion of her right ear. The clinical syndrome of recurrent chondritis, scleritis, iritis and arthritis supported a diagnosis of relapsing polychondritis. Fetal and maternal outcomes were favorable despite steroid dependent active disease during the period of fetal organogenesis. Chondritis was limited to the 3rd pregnancy, ocular inflammation occurring in the 2nd and 3rd pregnancies. A 4th pregnancy was uneventful. This may represent the first case of relapsing polychondritis in pregnancy.

Adult↗
PubMed1990

Rhythmic variations in pain perception in osteoarthritis of the knee.

Twenty patients with primary osteoarthritis (OA) of the knee completed self-administered questionnaires probing pain severity on 10 occasions every day for 7 consecutive days. Rhythmometric analyses detected a significant circadian rhythm in pain in the majority of patients. Our data suggest that perceived pain severity varies substantially with time of day. These observations have important implications for the administration of pain questionnaires as outcome measures for clinical trials of nonsteroidal antiinflammatory drugs in OA of the knee.

Aged↗
PubMed1989

A survey of current prescribing practices of anti-inflammatory and urate-lowering drugs in gouty arthritis in New South Wales and Queensland.

We recently have conducted a cross-sectional survey to determine the prescribing practices of rheumatologists and a random sample of general practitioners in New South Wales and Queensland. While in general there was agreement as to the preferred management of gout, several important differences were noted between the two groups of doctors. In particular, general practitioners were more liberal than were rheumatologists in their use of allopurinol. However, they were less likely to cover the introduction of allopurinol with anti-inflammatory agents, to titrate the dose against the serum uric acid level or to adjust the dose according to the serum creatinine level. A small number of doctors continued to use urate-lowering drugs as a routine in the treatment of entirely asymptomatic hyperuricaemia. The data indicate a continuing need to disseminate information regarding the preferred management of hyperuricaemic states.

Allopurinol↗
PubMed1989

Critical review of clinical assessment techniques for rheumatoid arthritis trials: new developments.

Since the early work of Taylor (1937) and Steinbrocker (1949), clinical methods of assessing the response of patients to anti-rheumatic drugs have undergone considerable revision. The evolution of clinical metrology has seen simplicity yield to complexity, and in some instances resulted in controversy. Clinical assessment techniques (indices) for rheumatoid arthritis (RA) trials should fulfil ten fundamental criteria: the index should be designed for a specific purpose (clinical versus radiographic, short versus long-term, unidimensional versus multidimensional outcomes); the index should have been validated on individuals or populations of patients having similar characteristics to future study populations; reliability (test-retest, intra-class correlation, observer agreement) should be adequate for achieving measurement objectives; validity (face, content, criterion, construct) should be adequate for achieving measurement objectives; the index must be sufficiently responsive, i.e. able to detect significant change in the underlying variable; index performance should have been maintained in subsequent applications under similar study conditions; the method of deriving scores, particularly in composite indices, should be both credible and comprehensive; the feasibility of data collection and instrument application should not be constrained by time or cost; the measurement process must be ethical; and finally, utilisation of the index should have been adopted by other clinical investigators. Despite progress in clinical assessment techniques in RA trials, there is still insufficient standardisation. This situation could be improved with further outcome conferences and consensus development exercises.

Anti-Inflammatory Agents↗
PubMed1988

Treatment considerations in the elderly rheumatic patient.

The elderly represent a large subset of the rheumatic population, some of whom have experienced musculoskeletal disease since early life or middle age, whereas others are affected for the first time in their later years. They may be afflicted with a variety of musculoskeletal disorders, some of which occur almost exclusively in elderly individuals. Advancing age may be accompanied by failure of the musculoskeletal system and other major organs. As a result, elderly patients frequently receive concurrent treatment with several pharmacologically active compounds, which increases the potential for significant adverse drug-drug interactions. In addition, the elderly may be less tolerant of certain classes of compounds, including some antirheumatic drugs, necessitating careful drug selection and patient monitoring. Diagnostic and therapeutic decision making may be impeded by the patient's inability to recall completely and accurately important historical details, particularly those relating to drug therapy. Treatment objectives may be compromised further by poor compliance, and adequate follow-up made more difficult by the patient's lack of mobility and declining independence. Successful management of the elderly rheumatic patient, therefore, requires an accurate clinical assessment, comprehensive evaluation of major organ functioning, identification of potential drug-drug interactions, appropriate selection of anti-rheumatic drugs and other treatment modalities, effective doctor-patient communication, and careful monitoring for both beneficial and adverse responses to therapy.

Aged↗
PubMed1988

A comparative analysis of two dosing strategies of flurbiprofen in rheumatoid arthritis: an application of sequential trial design.

Forty patients with classic or definite rheumatoid arthritis were entered into a double-blind, randomized, multiple crossover, sequential trial comparing two doses (300 mg vs 150 mg per day) and two dosing schedules (b.i.d. vs t.i.d.) of flurbiprofen. Clinical assessments (Ritchie Index, grip strength, walking time, physician and patient global assessments) were made at baseline and at biweekly intervals during the next six weeks of active treatment. Overall there were no statistically significant differences either between the two dosage levels or the dosing schedules. This study demonstrates the utility of the sequential trial design in assessing drug efficacy. The data confirm a lack of difference between the two doses of flurbiprofen selected and suggest that twice-daily dosing with flurbiprofen is similar in efficacy to thrice-daily dosing.

Adolescent↗