Searching the medical literature for the best evidence to solve clinical questions.
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Canada↗
Biomedical subjects
R B Haynes
Publications and source records attributed to R B Haynes.
Using informatics principles and tools to harness research evidence for patient care: evidence-based informatics.
With the huge worldwide investment in biomedical research during the past 50 years, there are many important advances in health care knowledge each year. Unfortunately, it commonly takes over 20 years for even the most important of these advances to be widely integrated into clinical practice. Many potentially remediable factors are responsible for this dilemma in research transfer, including defective continuing education for health professionals and patients; increasingly complex medical regimens; diminishing resources for health care; and inadequate evidence management. The principles and procedures of health informatics can help overcome some of these barriers to research transfer, particularly such evidence management tasks as retrieving, processing, summarizing, disseminating and applying evidence for clinical care. Evidence retrieval has been improved by better indexing and electronic search engines, by improved access from clinical and other settings, and by integration of evidence into clinical decision support systems. Evidence processing has been greatly accelerated by streamlined methods of critical appraisal of research and by centralization of these procedures for the development of current awareness publications and cumulative "best evidence" databases. The Cochrane Collaboration has revolutionized the summarization (systematic review) of evidence. The internet has provided access to patients, practitioners, and policy makers, alike. Direct-from-patient automated data collection promises to move the connection between evidence and practice to a higher level. In all of these innovations, health care practice is most likely to be enhanced by intertwining best evidence with best informatics techniques.
Databases as Topic↗
What's up in medical informatics?
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Computer Communication Networks↗
Systematic reviews: synthesis of best evidence for clinical decisions.
Systematic reviews can help practitioners keep abreast of the medical literature by summarizing large bodies of evidence and helping to explain differences among studies on the same question. A systematic review involves the application of scientific strategies, in ways that limit bias, to the assembly, critical appraisal, and synthesis of all relevant studies that address a specific clinical question. A meta-analysis is a type of systematic review that uses statistical methods to combine and summarize the results of several primary studies. Because the review process itself (like any other type of research) is subject to bias, a useful review requires clear reporting of information obtained using rigorous methods. Used increasingly to inform medical decision making, plan future research agendas, and establish clinical policy, systematic reviews may strengthen the link between best research evidence and optimal health care.
Decision Making↗
Nutritional management of cardiovascular risk factors. A randomized clinical trial.
BACKGROUND: Adherence to dietary recommendations for disease management is often hindered by the complexity of incorporating them into the daily diet. Nutrition and cardiovascular scientists and food technologists collaborated to develop a prepared meal plan that meets national dietary guidelines for cardiovascular risk reduction. OBJECTIVE: To assess the clinical effects of this plan, which incorporates all National Academy of Sciences National Research Council recommended dietary allowances for vitamins, minerals, and macronutrients, compared with a patient-selected American Heart Association Step I and Step II diet plan. METHODS: This multicenter, randomized, parallel-intervention trial was conducted at 10 medical centers in the United States and Canada and involved 560 men and women with hypertension, dyslipidemia, or diabetes. Following calculation of prescriptions to meet individual nutritional requirements based on the Harris-Benedict equation, participants were randomized to the Campbell's Center for Nutrition and Wellness (CCNW) plan, which is composed of prepackaged breakfast, lunch, and dinner meals provided to participants, or a nutritionist-guided American Heart Association Step I and Step II diet, in which participants self-selected foods to meet their nutrition prescription for 10 weeks. MAIN OUTCOME MEASURES: Blood pressure (BP); lipid, glucose, glycosylated hemoglobin (HbA1c), and insulin levels; body weight; dietary intake; and quality of life. RESULTS: Patients' BP, lipid levels, carbohydrate metabolism, weight, and quality of life (P < or = .001 for all findings except low-density lipoprotein-high-density lipoprotein ratio, P = .25) all improved on both nutrition plans. Mean differences (+/-SD) between baseline and treatment clinical values for the CCNW and the self-selected diet groups (between-group P values), respectively, were as follows: systolic BP, -6.4 +/- 9.2 mm Hg and -4.6 +/- 9.0 mm Hg (P = .02); diastolic BP, -4.2 +/- 5.7 mm Hg and -3.0 +/- 5.1 mm Hg (P = .006); cholesterol, -0.32 +/- 0.58 mmol/L and -0.27 +/- 0.56 mmol/L (-12.4 +/- 22.5 mg/dL and -10.4 +/- 21.9 mg/dL) (P = .30); glucose, -0.65 +/- 1.88 mmol/L and -0.75 +/- 2.03 mmol/L (-11.7 +/- 34.0 mg/dL and -13.5 +/- 36.6 mg/dL) (P = .10); and HbA1c, -0.4% +/- 0.8% and -0.3% +/- 0.7% (P = .66). Weight loss with the CCNW and self-selected plans, respectively, was as follows: men, -4.5 +/- 3.6 kg and -3.5 +/- 3.3 kg; and women, -4.8 +/- 3.0 kg and -2.8 +/- 2.8 kg. Quality of life was significantly improved for daily and work activities (P < .05) and nutritional health perceptions (P < .05) with the CCNW plan relative to the self-selected group. Overall nutrient intake and compliance were both significantly (P < .001) better with the CCNW plan. CONCLUSIONS: Nutritionally balanced meals that meet the recommendations of national health organizations improved multiple risk factors for patients with cardiovascular disease. The CCNW plan resulted in greater clinical benefits, nutritional completeness, and compliance than the self-selected diet. The CCNW is a comprehensive nutrition plan, convenient for both prescription and practice, and appears viable for effecting favorable dietary changes in patients at high risk for cardiovascular disease.
Adult↗
Nature and role of observational studies in public health policy concerning the effects of dietary salt intake on blood pressure.
Does dietary sodium in excess of a specified daily consumption substantively elevate blood pressure in normotensive people? Does lowering the daily consumption of sodium reduce blood pressure in normotensive people? Sound observational and interventional studies can address these questions, but there are substantial differences in the ability of various research designs to provide clear, bias-free answers. I summarize established scientific principles for addressing issues of causation and the effects of interventions and compare observational and interventional designs. Observational studies are important in exploring the possible determinants of health problems but are subject to bias and cannot directly assess the effects of interventions. They are superseded by sound interventional studies, particularly randomized controlled trials, in answering the key questions concerning causes and benefits of intervention.
Blood Pressure↗
Dietary compliance and cardiovascular risk reduction with a prepared meal plan compared with a self-selected diet.
Noncompliance with therapeutic diets remains a major obstacle to achieving improvements in cardiovascular disease (CVD) morbidity and mortality. This study compared dietary compliance and CVD risk factor response to two dietary interventions designed to treat hypertension, dyslipidemia, and diabetes mellitus. In a multicenter trial, 560 adults were randomly assigned to either a self-selected, mixed-food plan (n = 277), or a nutrient-fortified prepared meal plan (n = 283); each was designed to provide 15-20% of energy from fat, 55-60% from carbohydrate, and 15-20% from protein. Nutrient intake was estimated from 3-d food records collected biweekly throughout the 10-wk intervention. Compliance was determined by evaluating the participants' ability to meet specific criteria for energy intake [+/-420 kJ (100 kcal) from the midpoint of the prescribed energy range], fat intake (< 20%, < 25%, or < 30% of energy from total fat), and the National Cholesterol Education Program/American Heart Association Step 1 and 2 diet recommendations. Compliance with energy, fat, and Step 1 and 2 criteria was better in participants who followed the prepared meal plan than in those who followed the self-selected diet (P < 0.0001). Compliant participants in both groups achieved greater reductions in body weight, systolic and diastolic blood pressure, and total and low-density-lipoprotein cholesterol than noncompliant participants (P < 0.05). In general, better endpoint responses were observed with lower fat intakes regardless of group assignment. The prepared meal plan is a simple and effective strategy for meeting the many nutrient recommendations for CVD risk reduction and improving dietary compliance and CVD endpoints.
Adult↗
Automated direct-from-patient information collection for evidence-based diabetes care.
BACKGROUND: Computer-based clinical decision support tools can improve physician performance in ambulatory care settings. Acquiring and entering the patient-specific information necessary to take advantage of this technology, however, can often be a major impediment. OBJECTIVE: To develop and evaluate a self-administered electronic questionnaire for acquiring patient-specific information to be used for generating diabetes-related evidence-based care recommendations. METHODS: An initial paper questionnaire was developed that evaluated current diabetes management, complications, and screening interventions. This was then coded for electronic presentation using software that can also analyze patient responses and produce personal feedback. To evaluate the electronic questionnaire, 47 patients completed it using a small laptop computer and also responded to a personal interview that assessed similar topics. RESULTS: Patients required between 7-29 minutes to complete the questionnaire (mean: 15 min.). For 21 of the 23 topic assessed, the agreement between the electronic questionnaire and the personal interview was 80% or higher. CONCLUSIONS: An electronic, self-administered questionnaire can be used to acquire information for generating patient-specific care recommendations.
Data Collection↗
Systematic review of randomised trials of interventions to assist patients to follow prescriptions for medications.
BACKGROUND: Low adherence of patients to prescribed, self-administered medical interventions is ubiquitous. Low adherence limits the benefits of current medical care. Efforts to assist patients to follow treatments might improve the efficiency of care and substantially enhance benefits. Our objective was to summarise the results of randomised controlled trials (RCTs) of interventions to help patients follow prescriptions for medications. METHODS: A previous systematic review was updated through computerised searches in Medline, International Pharmaceutical Abstracts, Psychinfo, and HSTAR online databases; bibliographies in articles on patient adherence; articles in the reviewers' personal collections; and contact with authors. Articles were judged of interest if they reported original data concerning an unconfounded RCT of an intervention to improve adherence with prescribed medications, with one or more measure of medication adherence, one or more measure of treatment outcome, at least 80% follow-up of each group studied, and, for long-term treatments, at least 6 months of follow-up for studies with positive initial findings. Information on study design features, interventions and controls, and findings were extracted by one reviewer (RK) and checked by the other two reviewers. FINDINGS: 1,553 relevant citations and abstracts were screened, 252 full text articles were reviewed in detail, and 13 RCTs met all criteria. The studies were too disparate in clinical problems, adherence interventions, measures and reporting of adherence, and the clinical outcomes studied to warrant meta-analysis. Seven of 15 interventions were associated with improvements in adherence and six interventions led to improvements in treatment outcomes. For short-term treatments, one study showed an effect on adherence and outcome of counselling and written information. The interventions that were effective for long-term care were complex, including various combinations of more convenient care, information, counselling, reminders, self-monitoring, reinforcement, family therapy, and other forms of additional supervision or attention. Even the most effective interventions did not lead to substantial improvements in adherence. INTERPRETATION: Although adherence and treatment outcomes can be improved by certain-usually complex-interventions, full benefits of medications cannot be realised at currently achievable levels of adherence. It is time that additional efforts be directed towards developing and testing innovative approaches to assist patients to follow treatment prescriptions.
Drug Therapy↗
Evidence based medicine: what it is and what it isn't.
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Clinical Competence↗
Improved quality of life in patients with generalized cardiovascular metabolic disease on a prepared diet.
Current dietary recommendation for cardiovascular disease risk reduction and recommended dietary allowances (RDAs) were used to develop a nutritionally complete prepackaged prepared meal plan specifically designed to reduce the risk of cardiovascular disease. In the current study we tested patient acceptance of the diet as defined by measures of quality of life. In a randomized, parallel-design, multicenter clinical trial, 77 persons with hypertension, diabetes mellitus, dyslipidemia, or a combination of two or more of these conditions were recruited and randomly assigned to either a prepared meal plan (n = 39) or a comparable self-selected diet (n = 38) for 10 wk. The prepared meal plan met both the RDAs for all essential micronutrients and the dietary recommendations of national health organizations for macronutrients, cholesterol, sodium, and fiber. The prescribed self-selected diet was matched for macronutrients. Quality of life, as measured by a battery of instruments, was the major endpoint. Individuals consuming the prepared meal plan had significant improvements in mental health (P < 0.01), general perceived health (P < 0.005), daily activities (P < 0.05), work performance (P < 0.005), affect (P < 0.01), and nutritional health perceptions (P < 0.001), and reductions in nutrition hassles based on a standardized questionnaire (P < 0.001). The self-selected-diet group had significant improvements in nutritional health perceptions (P < 0.001) and affect (P < 0.001). There were significant improvements in weight (P < 0.001), blood pressure (P < 0.001), cholesterol (P < 0.002), low-density lipoproteins (P < 0.001), glucose (P < 0.014), and glycated hemoglobin (Hb A(1c) (P < 0.004) that were comparable in both groups. In summary, this study shows that a nutritionally complete diet, whether prepackaged or self-selected, improves multiple risk factors for cardiovascular disease. The prepackaged prepared meal plan had the added benefit of a greater improvement in quality of life.
Blood Glucose↗
More informative abstracts revisited.
Following proposals in 1987 and 1988, several medical journals have provided more informative abstracts ("structured abstracts") for articles of clinical interest. Structured abstracts for original studies require authors to systematically disclose the objective, basic research design, clinical setting, participants, interventions (if any), main outcome measurements, results, and conclusions; and for literature reviews the objective, data sources, methods of study selection, data extraction and synthesis, and conclusions. More informative abstracts of this kind can facilitate peer review before publication, assist clinical readers to find articles that are both scientifically sound and applicable to their practices, and allow more precise computerized literature searches. We review the feasibility, acceptability, and dissemination of structured abstracts, reassess the underlying strategy, and describe modifications of the approach. This innovation can aid communication from scientists to clinicians, and other clinical journals are invited to join this effort.
Abstracting and Indexing↗
Proceedings of the 1994 Canadian Clinical Practice Guidelines Network Workshop.
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Canada↗
No magic bullets: a systematic review of 102 trials of interventions to improve professional practice.
OBJECTIVE: To determine the effectiveness of different types of interventions in improving health professional performance and health outcomes. DATA SOURCES: MEDLINE, SCISEARCH, CINAHL and the Research and Development Resource Base in CME were searched for trials of educational interventions in the health care professions published between 1970 and 1993 inclusive. STUDY SELECTION: Studies were selected if they provided objective measurements of health professional performance or health outcomes and employed random or quasi-random allocation methods in their study designs to assign individual subjects or groups. Interventions included such activities as conferences, outreach visits, the use of local opinion leaders, audit and feedback, and reminder systems. DATA EXTRACTION: Details extracted from the studies included the study design; the unit of allocation (e.g., patient, provider, practice, hospital); the characteristics of the targeted health care professionals, educational interventions and patients (when appropriate); and the main outcome measure. DATA SYNTHESIS: The inclusion criteria were met by 102 trials. Areas of behaviour change included general patient management, preventive services, prescribing practices, treatment of specific conditions such as hypertension or diabetes, and diagnostic service or hospital utilization. Dissemination-only strategies, such as conferences or the mailing of unsolicited materials, demonstrated little or no changes in health professional behaviour or health outcome when used alone. More complex interventions, such as the use of outreach visits or local opinion leaders, ranged from ineffective to highly effective but were most often moderately effective (resulting in reductions of 20% to 50% in the incidence of inappropriate performance). CONCLUSION: There are no "magic bullets" for improving the quality of health care, but there are a wide range of interventions available that, if used appropriately, could lead to important improvements in professional practice and patient outcomes.
Humans↗
Changing physician performance. A systematic review of the effect of continuing medical education strategies.
OBJECTIVE: To review the literature relating to the effectiveness of education strategies designed to change physician performance and health care outcomes. DATA SOURCES: We searched MEDLINE, ERIC, NTIS, the Research and Development Resource Base in Continuing Medical Education, and other relevant data sources from 1975 to 1994, using continuing medical education (CME) and related terms as keywords. We manually searched journals and the bibliographies of other review articles and called on the opinions of recognized experts. STUDY SELECTION: We reviewed studies that met the following criteria: randomized controlled trials of education strategies or interventions that objectively assessed physician performance and/or health care outcomes. These intervention strategies included (alone and in combination) educational materials, formal CME activities, outreach visits such as academic detailing, opinion leaders, patient-mediated strategies, audit with feedback, and reminders. Studies were selected only if more than 50% of the subjects were either practicing physicians or medical residents. DATA EXTRACTION: We extracted the specialty of the physicians targeted by the interventions and the clinical domain and setting of the trial. We also determined the details of the educational intervention, the extent to which needs or barriers to change had been ascertained prior to the intervention, and the main outcome measure(s). DATA SYNTHESIS: We found 99 trials, containing 160 interventions, that met our criteria. Almost two thirds of the interventions (101 of 160) displayed an improvement in at least one major outcome measure: 70% demonstrated a change in physician performance, and 48% of interventions aimed at health care outcomes produced a positive change. Effective change strategies included reminders, patient-mediated interventions, outreach visits, opinion leaders, and multifaceted activities. Audit with feedback and educational materials were less effective, and formal CME conferences or activities, without enabling or practice-reinforcing strategies, had relatively little impact. CONCLUSION: Widely used CME delivery methods such as conferences have little direct impact on improving professional practice. More effective methods such as systematic practice-based interventions and outreach visits are seldom used by CME providers.
Decision Making↗
Accuracy and prognostic consequences of ultrasonography in identifying severe carotid artery stenosis. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Group.
BACKGROUND AND PURPOSE: The accuracy of routine ultrasonography in detecting severe carotid artery stenosis was evaluated in comparison with cerebral angiography. The precision of ultrasonographic criteria in predicting the risk of stroke was also assessed. METHODS: A total of 1011 symptomatic carotid bifurcations were studied in patients from the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Given that all patients were considered for entry into the trial, the chance of a verification bias affecting the analyses was minimized. The ultrasonographic data consisted of peak systolic velocities and frequency changes from both the internal and common carotid arteries. Angiographic stenosis was calculated as in NASCET. Receiver operating characteristic (ROC) curves were constructed from the ultrasonographic data for the detection of 70% or greater stenosis on the basis of an angiographic assessment. Kaplan-Meier stroke-free survival curves were used to predict the risk of stroke. RESULTS: The areas under the ROC curves ranged from 0.74 to 0.75 (95% confidence interval [CI], 0.69 to 0.79). The sensitivities and specificities ranged from 0.65 to 0.71. The risk of stroke at 18 months declined sharply as the degree of angiographically defined stenosis declined from 99% to 70%. No pattern of decline was apparent on the basis of the ultrasonographic data. CONCLUSIONS: The results indicate that the accuracy of ultrasonography is moderate when flow parameters are used to assess the degree of stenosis. Ultrasonography should be used as a screening tool to exclude patients with no carotid artery disease from further testing. Conventional angiography remains an essential investigation before assigning the risk of stroke and deciding appropriate treatment for extracranial carotid artery disease.
Blood Flow Velocity↗
Reasons for the loss of sensitivity and specificity of methodologic MeSH terms and textwords in MEDLINE.
OBJECTIVE: To determine the reasons for the loss of sensitivity and specificity of methodologic MeSH terms and textwords in MEDLINE for identifying sound clinical studies of the etiology, prognosis, diagnosis, prevention, or treatment of disorders in adult general medicine. DESIGN: Analytic survey of the information retrieval properties of methodologic MeSH terms and textwords selected to detect studies meeting basic methodologic criteria for direct clinical use in general adult medicine. MEASURES: Frequency of non-use and misuse of relevant methodologic MeSH terms and textwords among studies meeting and not meeting the basic criteria for clinical practice as determined by the manual review (the gold standard) of all articles in 10 internal and general medicine journals for 1986 and 1991. RESULTS: Loss of sensitivity due to the non-use of relevant methodologic terms among articles meeting basic methodologic criteria was more pronounced in the areas of diagnosis, prognosis, and etiology than treatment in 1991 and 1986. The use of relevant methodologic terms has improved from 1986 to 1991 in all areas except prognosis. Loss of specificity due to the use of relevant methodologic terms among articles not meeting basic methodologic criteria occurred most frequently in the areas of treatment and etiology. CONCLUSIONS: Although the appropriate use of methodologic MeSH and textwords has improved from 1986 to 1991 among studies meeting basic methodologic criteria for direct clinical use in general adult medicine much improvement is still needed in the areas of diagnosis, prognosis, and etiology. Improvement is needed in assigning the relevant methodologic index terms to studies that meet the methods criteria and in having the authors use the relevant methodologic textwords in the title or abstract. Some improvement is also needed in not using methodologic terms when the study clearly does not meet the methods criteria.
Abstracting and Indexing↗
Preliminary assessment of the effect of more informative (structured) abstracts on citation retrieval from MEDLINE.
OBJECTIVE: To compare the recall and precision of citation retrieval from MEDLINE when searching in journals containing traditional abstracts with journals containing abstracts prepared according to the guidelines of more informative abstracts (MIAs) for clinical journal articles. DESIGN: Analytic survey of operating characteristics of MeSH terms and textwords selected to detect studies meeting basic methodological criteria for direct clinical use in general adult medicine in priority journals with and without MIAs. MEASURES: The sensitivity, specificity, and precision of search terms were determined by comparison with a manual review of all articles (the gold standard) in 10 internal and general medicine journals for 1986 and 1991. The performance of each search term was compared before and after the implementation of MIAs and in two journal sets with and without MIAs in 1991. RESULTS: The sensitivity of some terms increased with the use of MIAs and also increased by the same amount in journals with usual abstracts in 1991 compared to 1986. The use of MIAs had the greatest impact in the areas of etiology and prognosis. Many MeSH and textwords had comparable performance before and after the implementation of MIAs and between journals with and without MIAs in 1991. CONCLUSIONS: More informative abstracts improved the retrieval properties of some, but not all, textwords and medical subject headings. Further work may be needed to enhance the effects of MIAs on bibliographic retrieval.
Abstracting and Indexing↗