Showing papers by "Gordon H. Guyatt published in 1996"
TL;DR: The Paediatric Asthma Quality of Life Questionnaire has good measurement properties and is valid both as an evaluative and a discriminative instrument and captures aspects of asthma most important to the patient and adds additional information to conventional clinical outcomes.
Abstract: The Paediatric Asthma Quality of Life Questionnaire contains 23 items that children with asthma have identified as troublesome in their daily lives. The aim was to evaluate the measurement properties of the questionnaire. The study design consisted of a 9 week single cohort study with assessments at 1, 5 and 9 weeks. Patients participating in the study were fifty-two children, 7-17 years of age, with a wide range of asthma severity. At each clinic visit, a trained interviewer administered the Paediatric Asthma Quality of Life Questionnaire, the Feeling Thermometer, a clinical asthma control questionnaire and measured spirometry. For 1 week before each clinic visit, patients recorded morning peak flow rates, medication use and symptoms in a diary. The Paediatric Asthma Quality of Life Questionnaire was able to detect quality of life changes in those patients who altered their health status either as a result of treatment or natural fluctuations in their asthma (p < 0.001) and to differentiate these patients from those who remained stable (p < 0.0001). It was reproducible in patients who were stable (ICC = 0.95), which also indicates the instrument's strength to discriminate between subjects of different impairment levels. The questionnaire showed good levels of both longitudinal and cross-sectional correlations with the conventional asthma indices and with general quality of life. The results were consistent across individual domains and different age strata. The Paediatric Asthma Quality of Life Questionnaire has good measurement properties and is valid both as an evaluative and a discriminative instrument. It captures aspects of asthma most important to the patient and adds additional information to conventional clinical outcomes.
1,097 citations
TL;DR: A meta-analysis of randomised controlled trials of respiratory rehabilitation in patients with COPD found that it relieves dyspnoea and improves the control over COPD, and the value of the improvement in exercise capacity is not clear.
794 citations
TL;DR: The MENQOL (Menopause-Specific Quality of Life) questionnaire is a self-administered instrument which functions well in differentiating between women according to their quality of life and in measuring changes in theirquality of life.
633 citations
TL;DR: The Paediatric Asthma Caregiver's Quality of Life Questionnaire functions well as both an evaluative and a discriminative instrument and showed acceptable levels of longitudinal and cross-sectional correlations with the child's asthma status and health-related quality of life and with other measures of caregiver health- relatedquality of life.
Abstract: Parents and primary caregivers of children with asthma are limited in normal daily activities and experience anxieties and fears due to the child's illness. We have developed the Paediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ) to measure these impairments. The objective of this study was to evaluate the measurement properties of the PACQLQ. A 9-week single cohort study was conducted with assessments at 1, 5 and 9 weeks. Participants in the study were primary caregivers of 52 children (age 7–17 years) with symptomatic asthma, recruited from notices in the local media and paediatric asthma clinics. Caregivers completed the PACQLQ, Impact-on-Family Scale and Global Rating of Change Questionnaires. Patients completed the Paediatric Asthma Quality of Life Questionnaire and an asthma control questionnaire. Spirornetry and β-agonist use were recorded. The PACQLQ was able to detect quality of life changes in those caregivers who changed (p<0.001) and to differentiate these from the caregivers whose quality of life remained stable (p<0.0001). The PACQLQ is reproducible in subjects who are stable (ICC=0.84), and showed acceptable levels of longitudinal and cross-sectional correlations with the child's asthma status and health-related quality of life and with other measures of caregiver health-related quality of life. The PACQLQ functions well as both an evaluative and a discriminative instrument.
589 citations
TL;DR: There is strong evidence of reduced clinically important gastrointestinal bleeding with histamine2-receptor antagonists and sucralfate may be as effective in reducing bleeding as gastric pH—altering drugs and is associated with lower rates of pneumonia and mortality.
Abstract: Purpose. —To resolve discrepancies in previous systematic overviews and provide estimates of the effect of stress ulcer prophylaxis on gastrointestinal bleeding, pneumonia, and mortality in critically ill patients. Data Identification. —Computerized search of published and unpublished research, bibliographies, pharmaceutical and personal files, and conference abstract reports. Study Selection. —Independent review of 269 articles identified 63 relevant randomized trials for inclusion. Data Abstraction. —We made independent, duplicate assessment of the methodologic quality, population, intervention, and outcomes of each trial. Results. —The source of discrepancies between prior meta-analyses included incomplete identification of relevant studies, differential inclusion of non—English language and nonrandomized trials, different definitions of bleeding, provision of additional information through direct correspondence with authors, and different statistical methods. The current overview demonstrates that prophylaxis with histamine2-receptor antagonists decreases the incidence of overt gastrointestinal bleeding (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.42 to 0.79) and clinically important bleeding (OR, 0.44; 95% CI, 0.22 to 0.88). There is a trend toward decreased overt bleeding when antacids are compared with no therapy (OR, 0.66; 95% CI, 0.37 to 1.17). Histamine2-receptor antagonists and antacids are associated with a trend toward lower clinically important bleeding rates than sucralfate is. There is a trend toward an increased risk of pneumonia associated with histamine2-receptor antagonists as compared with no prophylaxis (OR, 1.25; 95% CI, 0.78 to 2.00). Sucralfate is associated with a lower incidence of nosocomial pneumonia when compared with antacids (OR, 0.80; 95% CI, 0.56 to 1.15) and histamine2-receptor antagonists (OR, 0.77; 95% CI, 0.60 to 1.01). Sucralfate is also associated with a reduced mortality rate (OR, 0.73; 95% CI, 0.54 to 0.97) relative to antacids and to histamine2-receptor antagonists (OR, 0.83; 95% CI, 0.63 to 1.09). Conclusions. —Our results emphasize the need for registries to include all randomized trials and demonstrate the importance of explicit methodology for systematic reviews. There is strong evidence of reduced clinically important gastrointestinal bleeding with histamine2-receptor antagonists. Sucralfate may be as effective in reducing bleeding as gastric pH—altering drugs and is associated with lower rates of pneumonia and mortality. However, the data are insufficient to determine the net effect of sucralfate compared with no prophylaxis. (JAMA. 1996;275:308-314)
554 citations
TL;DR: Observations support the role of the Chronic Respiratory Questionnaire for measuring patient's symptoms, the validity of the approach for assessing the MID, and an estimate on the order of 0.5 as the threshold for this particular health status measure.
366 citations
TL;DR: Calcium supplementation may lead to a small reduction in systolic but not diastolic blood pressure, and further studies should address the hypothesis that inadequate calcium intake is associated with increased blood pressure that can be corrected with calcium supplementation.
Abstract: Objective. —To review the effect of supplemental calcium on blood pressure. Data Source. —We searched MEDLINE and EMBASE for 1966 to May 1994. We contacted authors of eligible trials to ensure accuracy and completeness of data and to identify unpublished trials. Study Selection. —We included any study in which investigators randomized people to calcium supplementation or placebo and measured blood pressure for at least 2 weeks. Fifty-six articles met the inclusion criteria, and 33 were eligible for analysis, involving a total of 2412 patients. Data Extraction. —Two pairs of independent reviewers abstracted data and assessed validity according to six quality criteria. Data Synthesis. —We calculated the differences in blood pressure change between the calcium supplementation group and the control group and pooled the estimates, with each trial weighted with the inverse of the variance using a random-effects model. Predictors of blood pressure reduction that we examined included method of supplementation, baseline blood pressure, and the methodological quality of the studies. The pooled analysis showed a reduction in systolic blood pressure of -1.27 mm Hg (95% confidence interval [CI], -2.25 to -0.29 mm Hg;P=.01) and in diastolic blood pressure of -0.24 mm Hg (95% CI, -0.92 to 0.44 mm Hg;P=.49). None of the possible mediators of blood pressure reduction explained differences in treatment effects. Conclusions. —Calcium supplementation may lead to a small reduction in systolic but not diastolic blood pressure. The results do not exclude a larger, important effect of calcium on blood pressure in subpopulations. In particular, further studies should address the hypothesis that inadequate calcium intake is associated with increased blood pressure that can be corrected with calcium supplementation. (JAMA. 1996;275:1016-1022)
296 citations
TL;DR: There is strong evidence of reduced clinically important gastrointestinal bleeding with histamine2-receptor antagonists and sucralfate is as effective in reducing bleeding as gastric pH-altering drugs and is associated with lower rates of pneumonia and mortality.
Abstract: Purpose. —To resolve discrepancies in previous systematic overviews and provide estimates of the effect of stress ulcer prophylaxis on gastrointestinal bleeding, pneumonia, and mortality in critically ill patients. Data Identification. —Computerized search of published and unpublished research, bibliographies, pharmaceutical and personal files, and conference abstract reports. Study Selection. —Independent review of 269 articles identified 63 relevant randomized trials for inclusion. Data Abstraction. —We made independent, duplicate assessment of the methodologic quality, population, intervention, and outcomes of each trial. Results. —The source of discrepancies between prior meta-analyses included incomplete identification of relevant studies, differential inclusion of non—English language and nonrandomized trials, different definitions of bleeding, provision of additional information through direct correspondence with authors, and different statistical methods. The current overview demonstrates that prophylaxis with histamine2-receptor antagonists decreases the incidence of overt gastrointestinal bleeding (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.42 to 0.79) and clinically important bleeding (OR, 0.44; 95% CI, 0.22 to 0.88). There is a trend toward decreased overt bleeding when antacids are compared with no therapy (OR, 0.66; 95% CI, 0.37 to 1.17). Histamine2-receptor antagonists and antacids are associated with a trend toward lower clinically important bleeding rates than sucralfate is. There is a trend toward an increased risk of pneumonia associated with histamine2-receptor antagonists as compared with no prophylaxis (OR, 1.25; 95% CI, 0.78 to 2.00). Sucralfate is associated with a lower incidence of nosocomial pneumonia when compared with antacids (OR, 0.80; 95% CI, 0.56 to 1.15) and histamine2-receptor antagonists (OR, 0.77; 95% CI, 0.60 to 1.01). Sucralfate is also associated with a reduced mortality rate (OR, 0.73; 95% CI, 0.54 to 0.97) relative to antacids and to histamine2-receptor antagonists (OR, 0.83; 95% CI, 0.63 to 1.09). Conclusions. —Our results emphasize the need for registries to include all randomized trials and demonstrate the importance of explicit methodology for systematic reviews. There is strong evidence of reduced clinically important gastrointestinal bleeding with histamine2-receptor antagonists. Sucralfate may be as effective in reducing bleeding as gastric pH—altering drugs and is associated with lower rates of pneumonia and mortality. However, the data are insufficient to determine the net effect of sucralfate compared with no prophylaxis. (JAMA. 1996;275:308-314)
228 citations
TL;DR: It may not be harmful to follow biochemical and clinical status even in the presence of nonspecific symptoms potentially associated with hypothyroidism, and no measure of symptoms or HRQL either showed clinically important trends in favor of treatment, or approached conventional levels of statistical significance.
Abstract: OBJECTIVE: To determine if health-related quality of life (HRQL) in patients of middle age and older with elevated thyroid-stimulating hormone (TSH) and normal total thyroid hormone levels—subclinical hypothyroidism—improves withl-thyroxine replacement therapy. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Outpatient clinic. PATIENTS: Thirty-seven patients with subclinical hypothyroidism, most with symptoms consistent with hypothyroidism, over 55 years of age. INTERVEJVTIOJVS: Placebo or L-thyroxine replacement therapy to achieve normal TSH level. MEASUREMENTS AND MAIN RESULTS: Disease-specific and general HRQL, cognitive function, bone mineral density, lipid levels. The mean daily dose of L-thyroxine replacement in the active group was 68±21 µg. TSH decreased by 8.6 mIU/L (95% confidence interval [CI] 4.1 to 13.1) and T4 increased by 27.9 nmol/L (95% CI 14.8 to 41.2). There was a statistically significant improvement in a composite psychometric memory score in treated versus control patients; all other outcomes showed similar findings in the two groups. Although confidence intervals for most measures did not exclude an important improvement in HRQL with thyroid replacement, no measure of symptoms or HRQL either showed clinically important trends in favor of treatment, or approached conventional levels of statistical significance. CONCLUSIONS: In middle-aged and older patients with elevated TSH and normal T4, it may not be harmful to follow biochemical and clinical status even in the presence of nonspecific symptoms potentially associated with hypothyroidism.
222 citations
TL;DR: It is concluded that guideline developers should gain the endorsement of major organizations and present key aspects in brief, easily assimilated formats.
Abstract: To determine features of the presentation of clinical practice guidelines that may enhance their use by internists, we conducted a cross-sectional survey to which 1,513 (60%) of 2,513 eligible internists responded. Endorsements by respected colleagues and by major organizations were identified as very important by 72% and 69% of respondents, respectively. Respondents preferred short pamphlets and manuals summarizing a number of guidelines and felt that concise recommendations (86%), synopsis of supporting evidence (85%), and quantification of benefit (77%) were important in guideline presentation. We conclude that guideline developers should gain the endorsement of major organizations and present key aspects in brief, easily assimilated formats.
220 citations
TL;DR: There is within medicine, somewhere beneath the pessimism and discouragement resulting from the disarray of the health care system and its stupendous cost, an undercurrent of almost outrageous optimism about what may lie ahead for the treatment of human disease if only the authors can keep learning.
Abstract: There is within medicine, somewhere beneath the pessimism and discouragement resulting from the disarray of the health care system and its stupendous cost, an undercurrent of almost outrageous optimism about what may lie ahead for the treatment of human disease if only we can keep learning.
TL;DR: The 4-hour desensitization protocol may not be suitable for all patients allergic to CP, whereas a modified prolonged protocol seems to be more tolerable, and the short protocol may be at tempted initially but should be replaced by the prolonged protocol if adverse effects appear.
Abstract: tion of both CP and cisplatin. Hypersensitivity to mannitol was reported as a cause of apparent hypersensitivity to cisplatin. 6 In case 2 the result of a skin test with mannitol was negative, whereas the result of a skin test with the commercial formulation containing CP and mannitol was positive, suggesting that CP was solely responsible for the hypersensitivity reaction. In addition to the clinical tolerance induced by the desensitization protocol, skin responses to intradermal CP diminished. As shown in Table I, the ratio between wheal sizes of CP and histamine decreased more than 3.5 times after the desensitization. The observation of wheal-and-flare responses becoming negative has already been described in penicillin desensitization. 7 This phenomenon supports an antigen-specific desensitization. The rate at which the drug concentration increases in the extracellular fluid seems to be the most important factor in a successful outcome of desensitization. As suggested by our two patients, this rate can differ in each individual case. We conclude that the 4-hour desensitization protocol may not be suitable for all patients allergic to CP, whereas a modified prolonged protocol seems to be more tolerable. Until further data have been accumulated, the short protocol may be at tempted initially but should be replaced by the prolonged protocol if adverse effects appear. The prolonged protocol seems to be both safe and efficacious with regard to anti tumor activity.
TL;DR: A 78-year-old retired internist who has been complaining of increasing symptoms of benign prostatic hyperplasia insists that transurethral prostate surgery is dangerous and that international studies of thousands of patients have proved that old-fashioned open prostatectomy is safer than that keyhole surgery.
Abstract: CASE SCENARIO Your patient, a 78-year-old retired internist, has been complaining of increasing symptoms of benign prostatic hyperplasia. He has long-standing hypertension and coronary artery disease, with remote anterolateral myocardial infarction and bypass surgery 10 years ago. His left ventricular ejection fraction was recently documented at 20%, and he has been started on an angiotensin-converting enzyme inhibitor. Rectal examination confirms a moderately enlarged prostate, without irregularities, nodularity, or tenderness. As you discuss management options, your patient insists that transurethral prostate surgery is dangerous and that international studies of thousands of patients have proved that, as he puts it, "old-fashioned open prostatectomy is safer than that keyhole surgery." You prescribe a trial of an α-blocker, terazosin, and arrange to see him again. However, the retired internist sounds so convinced that you also resolve to look into the evidence about the two forms of prostatectomy. THE SEARCH Later, you sit down in
Journal Article•
TL;DR: The use of CNS/NPs as an alternative to pediatric residents in delivering care to critically ill neonates is supported, and the performance on the indicator conditions was comparable in the two groups except for two instances, jaundice and charting, both of which favored the CNS/NP group.
Abstract: Objective. To compare a clinical nurse specialist/neonatal practitioner (CNS/NP) team with a pediatric resident team in the delivery of neonatal intensive care. Design. Randomized, controlled trial. Setting. A 33-bed tertiary-level neonatal intensive care unit. Patients. Of 821 infants admitted to the neonatal intensive care unit between September 1991 and September 1992, 414 were randomized to care by the CNS/NP team, and 407 were randomized to care by the pediatric resident team. Intervention. Infants assigned to the CNS/NP team were cared for by CNS/NPs during the day and by pediatric residents during the night. Infants assigned to the pediatric resident team were cared for by pediatric residents around the clock. Neonatologists supervised both teams. Measures. Outcome measures included mortality; number of neonatal complications; length of stay; quality of care, as assessed by a quantitative indicator condition approach; parent satisfaction with care, measured using the Neonatal Index of Parent Satisfaction; long-term outcomes, measured using the Minnesota Infant Development Inventory; and costs. Results. There were 19 (4.6%) deaths in the CNS/NP group and 24 (5.9%) in the resident group (relative risk [RR], 0.78; confidence interval [CI], 0.43 to 1.40). In the CNS/NP group, 230 (55.6%) neonates had complications, in comparison with 220 (54.1%) in the resident group (RR, 1.03; CI 0.91 to 1.16). Mean lengths of stay were 12.5 days in the CNS/NP group and 11.7 days in the resident group (difference in means, 0.8 days; CI, -1.1 to 2.7). The performance on the indicator conditions was comparable in the two groups except for two instances, jaundice and charting, both of which favored the CNS/NP group. Mean scores on the Neonatal Index of Parent Satisfaction were 140 in the CNS/NP group and 139 in the resident group (difference in means, 1.0; CI, -3.6 to 5.6). In the CNS/NP group, 6 (2.6%) infants performed 30% or more below their age level in the Minnesota Infant Development Inventory, in comparison with 2 (0.9%) in the resident group (RR, 2.87; CI, 0.59 to 14.06) The cost per infant in the CNS/NP group was $14 245 and in the resident group $13 267 (difference in means, $978; CI, -1303.18 to 3259.05). Conclusions. CNS/NP and resident teams are similar with respect to all tested measures of performance. These results support the use of CNS/NPs as an alternative to pediatric residents in delivering care to critically ill neonates.
TL;DR: Raw utilization data are insufficient to assess whether cardiologists at your hospital are using PTCA inappropriately, and you need to review their practice in light of criteria for deciding whether each application of PTCAs was likely, given a set of criteria.
Abstract: CLINICAL SCENARIO You are a general internist attending a medical advisory committee meeting as the newly appointed chief of staff in a large community hospital affiliated with a major health maintenance organization. A junior administrator presents data showing that the hospital's utilization of percutaneous transluminal coronary angioplasty (PTCA) is high relative to similar-sized centers with similar numbers of interventional cardiologists. He insinuates that unnecessary PTCAs are being done. The cardiologists present are infuriated, and the meeting degenerates into a shouting match. After the hospital chief executive officer brings the meeting back to order, you and the chief of cardiology agree to research the matter independently and report back in 1 week. THE SEARCH Raw utilization data are insufficient to assess whether cardiologists at your hospital are using PTCA inappropriately. You need to review their practice in light of criteria for deciding whether each application of PTCA was likely, given a
TL;DR: To validate reference standards for the assessment of capacity to complete an advance directive and to develop and test three simple screening instruments.
Abstract: OBJECTIVE: To validate reference standards for the assessment of capacity to complete an advance directive and to develop and test three simple screening instruments.
METHODS: We administered five measures of capacity to 96 older subjects from nursing homes, retirement homes, and homes for the aged. The measures included two reference standard evaluations: an assessment by a specially trained nurse in collaboration with a multidisciplinary team (Competency Clinic assessment) and geriatrician assessment using a decisional aid. Three screening instruments were also included: a Generic Instrument designed for any advance directive, a Specific Instrument designed for the “Let Me Decide” advance directive, and the Standardized Mini-Mental Status Examination (SMMSE). The screening instruments and the geriatrician's assessment were administered twice to half of the respondents to determine interrater agreement.
RESULTS: The chance-corrected agreement for the assessment by two geriatricians was 0.78, and for agreement between the geriatricians and Competency Clinic assessments it was 0.82. Agreement for the Generic and Specific screening instrument assessments by two observers was 0.77 and 0.90, respectively. The areas under the Receiver Operating Characteristic curve relating the results of the three screening instruments to the Competency Clinic assessment were 0.82 for the Generic Instrument, 0.90 for the Specific Instrument, and 0.94 for the SMMSE; chance is an unlikely explanation for the difference between these three values (P ≤ .01).
CONCLUSIONS: Using rigorous methods, health workers can make reproducible and valid assessments of capacity to complete an advance directive. The SMMSE accurately differentiates people who can learn about and ultimately complete advance directives from those who cannot.
TL;DR: It is concluded that cisapride enhances gastric emptying in critically ill patients and studies to examine the effect of cisap Ride on tolerance to enteral nutrition, infectious morbidity, and other clinically important outcomes are warranted.
Abstract: We conducted a randomized, double-blind, placebo-controlled trial in mechanically ventilated intensive care unit (ICU) patients to evaluate the effect of cisapride on gastric emptying using an acetaminophen absorption model. We enrolled 72 patients expected to remain in the ICU for more than 48 h; 39% were female; the average age was 54.0 +/- 19.1 yr; 47% were postoperative, 83% were receiving narcotics, and the mean simplified acute physiology score (SAPS) was 9.5 +/- 3.0. Within 72 h of admission to ICU, 1.6 g of acetaminophen suspension was administered via a nasogastric tube into the stomach (Day 1). Blood samples were drawn at baseline, 30, 60, 90, 120, and 180 min for measurement of plasma acetaminophen levels. The following morning (Day 2), patients were randomized to receive 20 mg of cisapride or placebo and gastric emptying was again assessed. The difference (Day 2-Day 1) in the maximal plasma concentration was 49.1 mumol/L in the cisapride groups compared with 12.3 mumol/L in the placebo group (p = 0.005) and the time to reach maximal concentration was significantly shorter in the cisapride group (-40.8 min versus -4.2 min, p = 0.02). The difference in area under the time-acetaminophen concentration curve was also greater in the patients receiving cisapride (5,534 versus 2,832, p = 0.09). We conclude that cisapride enhances gastric emptying in critically ill patients. Studies to examine the effect of cisapride on tolerance to enteral nutrition, infectious morbidity, and other clinically important outcomes are warranted.
TL;DR: The Neonatal Index of Parent Satisfaction (NIPS) is likely to be a useful measure for discriminating between parents who differ in terms of their satisfaction with the medical care of their infant in the NICU.
Journal Article•
TL;DR: Anemia is common among elderly patients in hospital, however, iron deficiency is underrecognized and underinvestigated.
Abstract: OBJECTIVE: To determine whether anemia is documented and appropriately investigated for iron deficiency in hospitalized elderly people. DESIGN: Retrospective chart review. SETTING: Medical clinical teaching unit (CTU) in secondary care hospital in Hamilton, Ont. PARTICIPANTS: Consecutive patients 65 years of age or older admitted between April 1992 and March 1993. OUTCOME MEASURES: Proportion of anemic patients for whom documentation was adequate (included in problem list in patient chart) and for whom adequate investigations were performed (measurement of serum ferritin level in anemic patients in whom iron deficiency was suspected, bone-marrow aspiration for those with intermediate probability of iron deficiency after determination of serum ferritin level, and endoscopy of upper or lower gastrointestinal tract, or both, in patients with iron deficiency). RESULTS: Of 183 eligible patients admitted to the CTU 66 (36%) had anemia, in 47 cases (71%) the anemia was documented by house staff or attending physicians. Of the 66 anemic patients 49 had a non-macrocytic anemia of unknown cause: 26 had their serum ferritin level measured, 5 underwent bone-marrow aspiration, and 21 were referred for gastrointestinal endoscopy. Six of eight patients with probable iron deficiency (i.e., a serum ferritin level that was diagnostic [less than 18 micrograms/L] or suggestive [18 to 45 micrograms/L]) underwent endoscopy, two were found to have cancer of the stomach or cecum. Only 26 of the 49 patients had adequate investigation. CONCLUSIONS: Anemia is common among elderly patients in hospital. However, iron deficiency is underrecognized and underinvestigated.