Showing papers by "Gordon H. Guyatt published in 1989"
TL;DR: An approach to elucidating the significance of changes in score in quality of life instruments by comparing them to global ratings of change is developed, and a plausible range within which the minimal clinically important difference (MCID) falls is established.
4,170 citations
TL;DR: The Inflammatory Bowel Disease Questionnaire shows promise as a measure of health status for clinical trials in IBD, and responsiveness appeared greater in patients with ulcerative colitis than in those with Crohn's disease.
1,111 citations
TL;DR: Data from two studies are presented which clarify the relationship between the responsiveness and validity of instruments designed to measure health status in clinical trials and support the reproducibility, validity, and responsiveness of the questionnaire.
462 citations
Journal Article•
TL;DR: Although accurate measurement of quality of life in randomized trials is now feasible it is still not widely done, and investigators can choose generic or specific instruments according to the purpose and the focus of their trial.
Abstract: Measurement of quality of life is becoming increasingly relevant to controlled clinical trials. Two basic types of instrument are available: generic instruments, which include health profiles and utility measurements based on the patient's preferences in regard to treatment and outcome; and specific instruments, which focus on problems associated with individual diseases, patient groups or areas of function. The two approaches are not mutually exclusive; each has its strengths and weaknesses and may be suitable under different circumstances. We surveyed 75 randomized trials published in three medical journals in 1986 and categorized them according to the importance of quality of life as a measure of outcome and the extent to which quality of life was actually measured. Although a number of the investigators used quality-of-life instruments in a sophisticated manner, in only 10 of 55 trials in which the measurement had been judged to be crucial or important were instruments with established validity and responsiveness used. We conclude that although accurate measurement of quality of life in randomized trials is now feasible it is still not widely done. Using the framework we have outlined, investigators can choose generic or specific instruments according to the purpose and the focus of their trial.
407 citations
TL;DR: The authors develop a new measure of subjective health status for patients with heart failure that shows moderate correlations with patient global ratings, walk test scores, and clinical assessments of heart failure, and conclude that it may be useful for measuring health status in clinical trials in heart failure.
Abstract: The authors developed a new measure of subjective health status for patients with heart failure. Eighty-eight patients with heart failure were asked about the impact of their condition on 123 items related to physical and emotional function. The most frequently chosen and important items were included in a 16-item Chronic Heart Failure Questionnaire (CHQ) that examines dyspnea during daily activities, fatigue, and emotional function. The CHQ was tested in a controlled trial of digoxin in heart failure patients in sinus rhythm. When administered serially to 25 patients in the run-in phase of the trial, the CHQ proved reproducible. Subsequently, CHQ results distinguished those who reported improvement or deterioration from those who did not. The CHQ showed moderate correlations with patient global ratings, walk test scores, and clinical assessments of heart failure. The authors conclude that the CHQ may be useful for measuring health status in clinical trials in heart failure.
329 citations
TL;DR: The Chronic Respiratory Questionnaire (CRQ) was more powerful than the other questionnaires, either the Oxygen Cost Diagram or the Medical Research Council Dyspnea Questionnaire as modified by the Rand Corporation, and showed a higher correlation with changes in spirometry, walk test score, dyspnea following the walk test, and global ratings of dysPnea than did the other two measures.
143 citations
TL;DR: By letting study subjects see their previous responses the validity of subjective measures of health status in clinical trials can be improved, and changes in all four CRQ dimensions showed stronger correlations with corresponding global ratings using the informed questionnaire.
80 citations
TL;DR: Excerpt Congestive heart failure remains a common final manifestation of ischemic, valvular, hypertensive, and myocardial disease.
Abstract: Excerpt Congestive heart failure remains a common final manifestation of ischemic, valvular, hypertensive, and myocardial disease. In the United States alone an estimated 400 000 persons develop co...
5 citations
TL;DR: Taking a careful look at each of the outcomes measured in randomized, controlied trials of digoxin suggest that discrepancies in results may be more apparent than real.
Abstract: Taking a careful look at each of the outcomes measured in randomized, controlied 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 digozin 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.
4 citations