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Biomedical subjects

Gordon Guyatt

Publications and source records attributed to Gordon Guyatt.

At least 37 records · Page 2Linked to original sources
PubMed2006

Levels of care in the intensive care unit: a research program.

A multidisciplinary research program on levels of care was conducted in 15 adult intensive care units in North America, Europe, and Australia. The program addressed advance directives for cardiopulmonary resuscitation, provision of advanced life support, and clinicians' discomfort with evolving treatment plans. The results indicated that the factors that determined the establishment of directives for advance life support differed from the factors that informed a decision to limit or withdraw support after admission to an intensive care unit. In addition, clinicians' prognoses were imprecise and often an underestimation of the probability of short-term survival. Finally, some degree of discomfort was common in care providers in the intensive care unit, most often because they thought interventions were excessive and not compatible with an acceptable future quality of life. The provision of advanced life support mandates explicit decision making about how life-support measures should be used.

Adult↗
PubMed2005

Quality of life in multiple sclerosis patients with urinary disorders: discriminative validation of the English version of Qualiveen.

UNLABELLED: The Qualiveen questionnaire is a urinary disorder (UD)-specific health related quality of life (HRQL) instrument. Recent data suggests Qualiveen has excellent validity in French-speaking multiple sclerosis (MS) patients. AIM: To assess discriminative measurement properties of the English version of Qualiveen. METHODS: Fifty-five Canadian MS out-patients completed a set of questionnaires, including Qualiveen, MSQOL-54, a MS-specific HRQL questionnaire, urinary function assessments and the Expanded Disability Status Scale (EDSS) twice at an interval of two to four weeks. RESULTS: Qualiveen proved internally consistent (Cronbach's alpha coefficients 0.73 to 0.90 for the four Qualiveen domains) and test-retest reliable (intraclass correlation coefficients 0.88 to 0.94). Consistent with a priori predictions, we found a strong association between overall Qualiveen score and the degree of incontinence (0.63), a moderate correlation with the type of urinary symptoms (0.49), a weak association with manner of voiding (0.28) and weak or absent correlations with MSQOL-54 domains, EDSS bladder/bowel and global EDSS. Predictions proved generally accurate (weighted kappa = 0.65). CONCLUSION: The internal consistency, test-retest reliability and cross-sectional construct validity of the English version of Qualiveen are excellent, and similar to the original French version. Further studies should explore Qualiveen's longitudinal validity and responsiveness.

Cross-Sectional Studies↗
PubMed2005

Pilot study to determine the impact of a multidisciplinary educational intervention in patients hospitalized with heart failure.

BACKGROUND: Patients with heart failure (HF) face challenges complying with multidrug regimens. OBJECTIVES: To examine the impact of a compliance enhancing intervention on medication compliance and morbidity in HF. DESIGN: Patients were randomized to either usual care or an inhospital educational intervention delivered by a multidisciplinary team (Intervention). SETTING: Acute medical and surgical units at a teaching hospital. PATIENTS: One hundred thirty four patients with a clinical diagnosis of HF and a left ventricular ejection fraction of < 40% requiring long-term medical treatment. MAIN OUTCOME MEASURES: A validated HF-specific instrument provided a measure of knowledge. We characterized patients as noncompliant if pharmacy refill data suggested they had taken < or = 0.80 of their medication. We measured quality of life using the Minnesota Living with Heart Failure Questionnaire and the Short Form 36 and conducted a time to first event analysis of a composite end point including mortality, readmissions, and emergency department visits. RESULTS: The Intervention group showed higher knowledge scores at discharge and 1 year (P = .05). The risk of noncompliance in Intervention patients varied from 0.78 (95% CI 0.33-1.89) for ACE-I (13% Intervention, 17% Control) to 1.02 (0.49-2.12) for diuretics (23% Intervention, 23% Control). Quality of life improved in both groups over time; the only difference between groups favored the Intervention (Minnesota Living with Heart Failure Questionnaire, P = .04). The composite end point occurred in 67% of control and 60% of Intervention patients (hazard ratio 0.85, 95% CI 0.55-1.30). CONCLUSIONS: An inhospital educational intervention improved knowledge and, possibly, quality of life and may be useful as part of a comprehensive compliance enhancing strategy in patients with HF.

Aged↗
PubMed2005

Prophylaxis of Thromboembolism in Critical Care (PROTECT) Trial: a pilot study.

PURPOSE: There is no randomized trial comparing low-molecular weight heparin (LMWH) and unfractionated heparin (UFH) for thromboprophylaxis in medical-surgical ICU patients. The primary objective of this randomized pilot study on LMWH vs UFH was to assess the feasibility of conducting a large randomized trial with respect to timely enrollment and blinded study drug administration, practicality of twice-weekly lower limb ultrasounds to screen for deep venous thrombosis, LMWH bioaccumulation and dose adjustment in renal insufficiency, and recruitment rates for a future trial in medical-surgical intensive care unit (ICU) patients. Its additional goals were to evaluate the suitability of the exclusion criteria and to document the range of research activities that precede accrual of patients into a trial to plan multisite management. MATERIALS AND METHODS: By computerized telephone randomization, we allocated 129 medical-surgical ICU patients to treatment with dalteparin 5,000 IU QD SC or that with UFH 5,000 IU BID SC. Within each clinical center, only the study pharmacist was not blinded. We performed bilateral lower limb compression ultrasounds within 48 hours of ICU admission, twice weekly, on suspicion of deep venous thrombosis, and 7 days after ICU discharge. Research coordinators and investigators at 7 centers reported the time they engaged in all research activities before the first patient was randomized. RESULTS: Timely complete study drug administration occurred after enrollment. More than 99% of scheduled doses were administered in a blinded fashion. Scheduled ultrasounds were performed without exception. No bioaccumulation of dalteparin was observed when creatinine clearance decreased to lower than 30 mL/min. Average recruitment was 2 patients/center per month before the study exclusion criteria were modified. Study startup activities required, on average, 65.5 hours of combined investigator and research coordinator time at each center. Careful examination of the accrual in the pilot study led to a reexamination of the Prophylaxis of Thromboembolism in Critical Care Trial (PROTECT) study exclusion criteria. CONCLUSIONS: This pilot study suggests that a multicenter randomized clinical trial comparing LMWH with UFH in critically ill medical-surgical patients is feasible. Pilot studies can improve the design of larger trials and may enhance successful timely completion.

Anticoagulants↗
PubMed2005

Deep venous thrombosis in medical-surgical critically ill patients: prevalence, incidence, and risk factors.

OBJECTIVE: Critically ill patients may be at high risk of venous thromboembolism. The objective was to determine the prevalence, incidence, and risk factors for proximal lower extremity deep venous thrombosis among critically ill medical-surgical patients. DESIGN: Prospective cohort. SETTING: Closed university-affiliated intensive care unit. PATIENTS: We enrolled consecutive patients > or =18 yrs of age expected to be in intensive care unit for > or =72 hrs. Exclusion criteria were an admitting diagnosis of trauma, orthopedic surgery, pregnancy, and life support withdrawal. INTERVENTIONS: Interventions included bilateral lower extremity compression ultrasound within 48 hrs of intensive care unit admission, twice weekly, and if venous thromboembolism was clinically suspected. Thromboprophylaxis was protocol directed and universal. We recorded deep venous thrombosis risk factors at baseline and daily, using multivariate regression analysis to determine independent predictors. Patients were followed to hospital discharge. RESULTS: Among 261 patients with a mean Acute Physiology and Chronic Health Evaluation II score of 25.5 (+/-8.4), the prevalence of deep venous thrombosis was 2.7% (95% confidence interval 1.1-5.5) on intensive care unit admission, and the incidence was 9.6% (95% confidence interval 6.3-13.8) over the intensive care unit stay. We identified four independent risk factors for intensive care unit-acquired deep venous thrombosis: personal or family history of venous thromboembolism (hazard ratio 4.0, 95% confidence interval 1.5-10.3), end-stage renal failure (hazard ratio 3.7, 95% confidence interval 1.2-11.1), platelet transfusion (hazard ratio 3.2, 95% confidence interval 1.2-8.4), and vasopressor use (hazard ratio 2.8, 95% confidence interval 1.1-7.2). Patients with deep venous thrombosis had a longer duration of mechanical ventilation (p = .03), intensive care unit stay (p = .005), and hospitalization (p < .001) than patients without deep venous thrombosis. CONCLUSIONS: Despite universal thromboprophylaxis, medical-surgical critically ill patients remain at risk for lower extremity deep venous thrombosis. Further research is needed to evaluate the risks and benefits of more intense venous thromboembolism prophylaxis.

APACHE↗
PubMed2005

Outcome measures for clinical research in sepsis: a report of the 2nd Cambridge Colloquium of the International Sepsis Forum.

BACKGROUND AND OBJECTIVES: Sepsis is the leading cause of morbidity and mortality for patients admitted to an intensive care unit. The evaluation of new therapies has been hampered by the underdevelopment of outcome measures used to detect biological activity and patient-centered benefit in a complex and highly heterogeneous patient population. We sought to evaluate existing approaches and to draw on insights from other disciplines to propose a comprehensive approach to outcome evaluation in sepsis clinical trials. METHODS: An expert colloquium organized by the International Sepsis Forum brought together sepsis researchers, clinical epidemiologists, and experts in the development and implementation of outcome measures in rheumatology, neurology, and oncology. RESULTS: The translation of an evolving understanding of the biology of sepsis into effective new therapies for critically ill patients requires a reevaluation of the end points used to determine response to intervention. These represent a continuum that measures biological activity against the target at one end and sustained improvement in survival or quality of life at the other. Early phase research should determine whether an intervention works in vivo, using measures that are responsive and informative to provide proof of principle, to aid in selecting optimal patient populations for study, and to gain insights into optimal dose and duration of therapy. After in vivo biology has been demonstrated and the possibility of efficacy inferred by plausible improvements in surrogate physiologic measures, definitive studies should seek robust evidence of benefit using end points that measure important, patient-centered benefit, including intermediate and longer term survival and health-related quality of life. Nonmortal measures of benefit assume particular importance for populations, such as children, whose mortality risk is low, or who have significant rates of comorbidities that independently limit survival. Composite measures that integrate morbidity and mortality effects may provide the most meaningful information about therapeutic efficacy. CONCLUSIONS: The development of explicit, hypothesis-driven, and iterative approaches to outcome measure development, patterned on approaches used in the fields of rheumatology and oncology, may improve the conduct of clinical studies in the critically ill.

Clinical Trials as Topic↗
PubMed2005

Natural health product-drug interactions: a systematic review of clinical trials.

Interactions between natural health products (NHP) and prescription medications are of increasing concern. This paper aims to identify all clinical trials of NHP-drug interactions. To determine the prevalence and outcomes of clinical investigations of NHP-drug pharmacokinetic interactions, electronic databases were searched from inception through March 2004, as well as reference lists from published reports and experts in the field for unpublished studies. Eligible studies were clinical investigations of the interaction between a NHP and the metabolism of a regulated medication in humans. Studies were excluded that only investigated the metabolism of an NHP or examined food-drug or NHP-NHP interactions. Two reviewers selected studies for inclusion and independently extracted data. Forty-seven trials were identified, studying an average of 14 participants/study (95% confidence interval [CI] 11-18), examined drug interactions with 19 different herbal preparations. All trials were pharmacokinetic studies, 41 of healthy volunteers and 6 of patients. Ten different herbal medicines as well as 5 different traditional herbal concoctions were studied. Potentially clinically significant drug interactions were observed with St. John wort (16/24 studies), garlic (2/5 studies), and American ginseng (1 study). Research on NHP-drug interactions is limited in number and scope. With the exception of St. John wort, clinicians and the public do not have information that permits strong inferences about interactions between NHPs and conventional medications.

Clinical Trials as Topic↗
PubMed2005

What do children's global ratings of oral health and well-being measure?

OBJECTIVES: To explore the constructs children incorporate in the responses to global ratings of their oral health (OH) and OH-related overall well-being (OWB). METHODS: Data were collected as part of a project to validate the Child Perceptions Questionnaire for ages 11-14 (CPQ11-14), a self-report measure of OH-related quality of life. Its 37 questions are organized in the symptoms, functional limitations, emotional and social well-being domains. Children were recruited from paediatric dentistry, orthodontic and orofacial dental clinics. To identify the CPQ11-14 domain scores and questions predicting the global ratings, correlation and multiple regression analyses were used. RESULTS: Of the 123 children, 22.8% rated their OH as 'Fair/Poor' and 30.1% reported that their OWB was affected by their oral/orofacial condition. Positive significant correlations were observed between the OH ratings and the CPQ11-14 oral symptoms and emotional well-being domains, and between the OWB ratings and all four CPQ11-14 domains. The number of the CPQ11-14 questions significantly correlated with the OH and OWB ratings were 8 and 19, respectively. Only the symptoms domain entered the model for the OH (R2=0.05), while age, functional limitations and emotional well-being domains predicted the OWB (R2=0.18). The OH model included three questions (R2=0.13) and the OWB model included age and six questions (R2=0.25). In both models all but one of the questions came from the emotional and social well-being domains. CONCLUSIONS: These findings suggest that children view OH and its impact on well-being as multidimensional concepts. Further research, including qualitative studies, is needed to better understand the referents children use when responding to global ratings and the factors that determine their responses.

Adolescent↗
PubMed2005

Melatonin in the treatment of cancer: a systematic review of randomized controlled trials and meta-analysis.

Most observational studies show an association between melatonin and cancer in humans. We conducted a systematic review of randomized controlled trials (RCTs) of melatonin in solid tumor cancer patients and its effect on survival at 1 yr. With the aid of an information specialist, we searched 10 electronic databases from inception to October 2004. We included trials using melatonin as either sole treatment or as adjunct treatment. Prespecified criteria guided our assessment of trial quality. We conducted a meta-analysis using a random effects model. We included 10 RCTs published between 1992 and 2003 and included 643 patients. All trials included solid tumor cancers. All trials were conducted at the same hospital network, and were unblinded. Melatonin reduced the risk of death at 1 yr (relative risk: 0.66, 95% confidence interval: 0.59-0.73, I2=0%, heterogeneity P<or=0.56). Effects were consistent across melatonin dose, and type of cancer. No severe adverse events were reported. The substantial reduction in risk of death, low adverse events reported and low costs related to this intervention suggest great potential for melatonin in treating cancer. Confirming the efficacy and safety of melatonin in cancer treatment will require completion of blinded, independently conducted RCTs.

Humans↗
PubMed2005

Device selection and outcomes of aerosol therapy: Evidence-based guidelines: American College of Chest Physicians/American College of Asthma, Allergy, and Immunology.

BACKGROUND: The proliferation of inhaler devices has resulted in a confusing number of choices for clinicians who are selecting a delivery device for aerosol therapy. There are advantages and disadvantages associated with each device category. Evidence-based guidelines for the selection of the appropriate aerosol delivery device in specific clinical settings are needed. AIM: (1) To compare the efficacy and adverse effects of treatment using nebulizers vs pressurized metered-dose inhalers (MDIs) with or without a spacer/holding chamber vs dry powder inhalers (DPIs) as delivery systems for beta-agonists, anticholinergic agents, and corticosteroids for several commonly encountered clinical settings and patient populations, and (2) to provide recommendations to clinicians to aid them in selecting a particular aerosol delivery device for their patients. METHODS: A systematic review of pertinent randomized, controlled clinical trials (RCTs) was undertaken using MEDLINE, EmBase, and the Cochrane Library databases. A broad search strategy was chosen, combining terms related to aerosol devices or drugs with the diseases of interest in various patient groups and clinical settings. Only RCTs in which the same drug was administered with different devices were included. RCTs (394 trials) assessing inhaled corticosteroid, beta2-agonist, and anticholinergic agents delivered by an MDI, an MDI with a spacer/holding chamber, a nebulizer, or a DPI were identified for the years 1982 to 2001. A total of 254 outcomes were tabulated. Of the 131 studies that met the eligibility criteria, only 59 (primarily those that tested beta2-agonists) proved to have useable data. RESULTS: None of the pooled metaanalyses showed a significant difference between devices in any efficacy outcome in any patient group for each of the clinical settings that was investigated. The adverse effects that were reported were minimal and were related to the increased drug dose that was delivered. Each of the delivery devices provided similar outcomes in patients using the correct technique for inhalation. CONCLUSIONS: Devices used for the delivery of bronchodilators and steroids can be equally efficacious. When selecting an aerosol delivery device for patients with asthma and COPD, the following should be considered: device/drug availability; clinical setting; patient age and the ability to use the selected device correctly; device use with multiple medications; cost and reimbursement; drug administration time; convenience in both outpatient and inpatient settings; and physician and patient preference.

Adrenergic beta-Agonists↗
PubMed2005

A comparison of pain, strength, range of motion, and functional outcomes after hemiarthroplasty and total shoulder arthroplasty in patients with osteoarthritis of the shoulder. A systematic review and meta-analysis.

BACKGROUND: A systematic review of the literature was performed to estimate the impact of hemiarthroplasty compared with total shoulder arthroplasty on function and range of motion in patients suffering from osteoarthritis of the shoulder. METHODS: We conducted an electronic search for relevant studies published in any language from 1966 to 2004, a manual search of the proceedings from five major orthopaedic meetings from 1995 to 2003, and a review of the reference lists from potentially relevant studies. Four randomized clinical trials, with similar eligibility criteria and surgical techniques, that compared hemiarthroplasty and total shoulder arthroplasty for the treatment of primary osteoarthritis of the shoulder were found to be eligible. Authors from three of the four studies provided original patient data. Analysis of covariance focused on the two-year outcome and included a comparison of the aggregate University of California at Los Angeles shoulder score, four University of California at Los Angeles domain scores, and range of motion. RESULTS: A total of 112 patients (fifty managed with hemiarthroplasty and sixty-two managed with total shoulder arthroplasty), who had a mean age of sixty-eight years, were included in this analysis. A significant moderate effect was detected in the function domain of the University of California at Los Angeles shoulder score (p < 0.001) in favor of total shoulder arthroplasty (mean [and standard deviation], 8.1 +/- 0.3) compared with hemiarthroplasty (mean, 6.6 +/- 0.3). A significant difference in the pain score was found in favor of the total shoulder arthroplasty group (p < 0.0001). However, the large degree of heterogeneity (p = 0.006, I(2) = 80.2%) among the studies decreased our confidence that total shoulder arthroplasty provides a true, consistent benefit with regard to pain. There was a significant difference in the overall change in forward elevation of 13 degrees (95% confidence interval, 0.5 degrees to 26 degrees ) in favor of the total shoulder arthroplasty group (p = 0.008). CONCLUSIONS: At a minimum of two years of follow-up, total shoulder arthroplasty provided better functional outcome than hemiarthroplasty for patients with osteoarthritis of the shoulder. Since continuous degeneration of the glenoid after hemiarthroplasty or glenoid loosening after total shoulder arthroplasty may affect the eventual outcome, longer-term (five to ten-year) results are necessary to determine whether these findings remain consistent over time.

Activities of Daily Living↗