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R Jaeschke

Publications and source records attributed to R Jaeschke.

47 records · Page 3Linked to original sources
PubMed1990

A comparison of seven-point and visual analogue scales. Data from a randomized trial.

Many controlled trials rely on subjective measures of symptoms or quality of life as primary outcomes. The relative merits of different response options for these instruments is an important issue. Therefore, we compared the responsiveness and validity of seven-point versus visual analogue scales (VAS) in a questionnaire measuring quality of life in chronic heart failure in a double-masked crossover trial of digoxin versus placebo. The VAS and seven-point scale versions of the questionnaire were administered to 20 patients during 7 weeks on digoxin and 7 weeks on placebo. The order of administration of the questionnaires was determined by random allocation. The ability of the two methods to distinguish digoxin and placebo, and their correlation with other measures, were comparable. We conclude that the two methods of presenting response options show comparable responsiveness and validity in a randomized trial setting. The ease of administration and interpretation of the seven-point scale recommend its use.

Humans↗
PubMed1990

Randomized trials in the study of antihypertensive drugs.

Heterogeneity in response to antihypertensive drugs can be addressed by randomized trials in individual subjects. In such a trial a patient receives pairs of treatment periods (one period of each pair active drug, one matched placebo, in random order); patient and clinician are blinded to allocation, and treatment targets are monitored. These trials can optimize antihypertensive therapy in clinical practice and facilitate the investigation of new drugs and the study of pathophysiology. Such trials also have potential in helping decide whether common, nonspecific symptoms reported by patients are really drug related.

Antihypertensive Agents↗
PubMed1989

Why different trials on digitalis give conflicting data.

Taking a careful look at each of the outcomes measured in randomized, controlled trials of digoxin suggest that discrepancies in results may be more apparent than real. Digoxin does work, but clinically important benefit is restricted to a relatively small proportion of congestive heart failure (CHF) patients. The play of chance, the dose of digoxin used, and the severity of heart failure in patients enrolled in the studies are other factors that may explain the variability in results that were observed. A systematic examination of the sort undertaken here is likely to help resolve apparent difference in outcomes of clinical trials of new (and old) therapies in CHF patients.

Digoxin↗
PubMed1989

Measurement of health status. Ascertaining the minimal clinically important difference.

In recent years quality of life instruments have been featured as primary outcomes in many randomized trials. One of the challenges facing the investigator using such measures is determining the significance of any differences observed, and communicating that significance to clinicians who will be applying the trial results. We have developed an approach to elucidating the significance of changes in score in quality of life instruments by comparing them to global ratings of change. Using this approach we have established a plausible range within which the minimal clinically important difference (MCID) falls. In three studies in which instruments measuring dyspnea, fatigue, and emotional function in patients with chronic heart and lung disease were applied the MCID was represented by mean change in score of approximately 0.5 per item, when responses were presented on a seven point Likert scale. Furthermore, we have established ranges for changes in questionnaire scores that correspond to moderate and large changes in the domains of interest. This information will be useful in interpreting questionnaire scores, both in individuals and in groups of patients participating in controlled trials, and in the planning of new trials.

Activities of Daily Living↗
PubMed1989

Research methods for obtaining primary evidence.

The use of new therapeutic and diagnostic technologies has become commonplace in modern medical practice. To avoid both clinical disappointment and the waste of money, health, and lives, the introduction of these technologies will have to be based on evidence that these technologies will do more good than harm. The evidence supporting their use should be derived using research methods designed to deal with placebo effects, confounders, and biases. Some of these methods, and the rationale for their use, are discussed in this article. Although the value of evidence derived from randomized controlled trials is stressed, the importance of reviewing critically the methodological details of such trials and interpreting their results with caution is emphasized. The benefits and risks of relying on case-control and cohort studies are reviewed.

Bias↗
PubMedDate not supplied

Critical appraisal of therapeutic interventions in the intensive care unit: human monoclonal antibody treatment in sepsis. Journal Club of the Hamilton Regional Critical Care Group.

Using the medical literature to solve patient problems is challenging and rewarding. For intensive care physicians, this evidence-based medicine approach is more compelling when basic critical appraisal skills are developed. We highlight the important methodological points for interpreting the literature on treatment, using a cogent example from the critical care literature--monoclonal antibody therapy in sepsis. It is likely that as we move into the 1990s, growth in the number of articles on immunotherapy in the sepsis syndrome will parallel the growth of the general biomedical literature.

Antibodies, Monoclonal↗