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Biomedical subjects

R B Haynes

Publications and source records attributed to R B Haynes.

At least 91 records · Page 5Linked to original sources
PubMed1992

Performance appraisal of online MEDLINE access routes.

OBJECTIVE: To compare the performance and cost of 11 online MEDLINE systems with MEDLINE at Elhill. DESIGN: Comparative study. SYSTEMS: Eleven online daytime systems commercially available in North America offering the MEDLINE database. MEASURES: Number of relevant citations, number of irrelevant citations, proportion of searches producing no relevant citations and cost per relevant citation were analyzed for each system. Relevance and cost for each system were compared with direct searching of MEDLINE through NLM for librarian and clinician search strategies for 18 clinical questions. The citations retrieved by both strategies were pooled and rated for relevance on a 7-point scale. RESULTS: Numbers of relevant and irrelevant citations and cost per relevant citation were higher for clinician searches than librarian searches, reflecting the higher total number of citations retrieved by the clinician approaches. A lower proportion of clinician searches produced no relevant citations than librarian searches. CONCLUSIONS: Eleven daytime MEDLINE systems performed similarly in terms of retrieval and cost within similar searching groups. Clinicians, however, tended to capture larger overall retrievals resulting in higher numbers of relevant and irrelevant citations than librarians.

CD-ROM↗
PubMed1992

Increases in knowledge and use of information technology by entering medical students at McMaster University in successive annual surveys.

OBJECTIVE: To determine self-reported microcomputer and information technology competency, access, and usage by entering medical students and their perceptions of the need for training in additional applications. DESIGN: Cross-sectional surveys of successive classes. SETTING: McMaster University Faculty of Health Sciences Medical Undergraduate Program, which has a 33-month, problem-based, self-directed learning curriculum and a high applicant-to-student ratio. PARTICIPANTS: Medical school classes entering in 1987, 1988, and 1989. Response rates were 80%, 90%, and 86% respectively. MEASURES: A self-report questionnaire was sent to each student, with up to two follow-up letters to prompt a response. RESULTS: There was a progressive rise in reported information technology access and use for the three years. For the classes starting in 1987, '88, and '89 respectively, computer access was 29%, 49%, and 49% (P < 0.002 for linear trend), and, among those with computer access, modem access was 17%, 29% and 50% (P = 0.012). Self-service MEDLINE use on CD-ROM at the Health Sciences Library was 65%, 75%, and 89% respectively (P < 0.001) for all respondents within the first few months of starting medical school. Over 50% of each class stated they would take courses, if available, on clinical applications software, office management, online searching, filing, and CD-ROM searching. CONCLUSIONS: Half of the most recent entering students already had access to a personal computer and most wished to learn computer applications that would assist them with patient management, and with information access and organization. Medical schools need to address which applications they will teach or make available and how to bring all students to acceptable competency in their use.

Computer Literacy↗
PubMed1992

A critical appraisal of the literature on the effects of computer-based clinical decision support systems on clinician performance and patient outcomes.

OBJECTIVE: To review the evaluations of computer-based clinical decision support systems (CDSS's). DATA SOURCES: The literature collected in the MEDLARS, EMBASE, SCISEARCH and INSPEC databases was searched from 1974 to the present. The reference lists of relevant articles were reviewed as were conference proceedings. STUDY SELECTION: Prospective, controlled studies were included. Studies were rated for methodological quality. DATA EXTRACTION: Study quality was assessed and data on study setting, subjects, method of allocation, and computer system were collected and verified using a structured form. CONCLUSIONS: There is considerable heterogeneity in both systems evaluated and design features of those systems. Future evaluations of CDSS's should focus on methodological issues in order to enhance overall quality of evaluations.

Clinical Medicine↗
PubMed1992

A critical appraisal of ticlopidine, a new antiplatelet agent. Effectiveness and clinical indications for prophylaxis of atherosclerotic events.

BACKGROUND: Recommendations are broadening for the prophylaxis of atherosclerotic disorders, but aspirin is the only widely used agent. Ticlopidine hydrochloride, a new antiplatelet medication, has recently been approved for prescription in North America. We reviewed the major clinical trials of ticlopidine and derived guidelines for its use. METHODS: Studies of ticlopidine were sought through MEDLINE for 1980 to 1990 and through bibliographies of retrieved articles. All published, randomized trials of ticlopidine were appraised if they reported major morbidity and mortality as primary end points. All eligible studies were formally reviewed by an expert panel according to published principles for critical appraisal of the medical literature. Both benefits and risks were quantified. RESULTS: Four randomized trials reported major clinical end points. In these, ticlopidine was more effective than placebo for preventing recurrences after completed stroke; was more effective than aspirin for patients with transient ischemic attacks and partial strokes; and reduced vascular death and nonfatal myocardial infarction in an open trial among patients with unstable angina. For patients with intermittent claudication ticlopidine, was not significantly better than placebo for preventing myocardial infarction or stroke. Side effects were more common with ticlopidine than with aspirin or placebo. CONCLUSIONS: Ticlopidine should be prescribed in place of aspirin for stroke prophylaxis or unstable angina if the patient is unable to tolerate aspirin. Ticlopidine may also benefit patients who experience new ischemic events while taking aspirin or, probably, patients with peripheral vascular disease. A complete blood cell count should be performed every 2 weeks during the first 3 months of therapy to check for leukopenia.

Arteriosclerosis↗
PubMed1991

Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis.

BACKGROUND: Without strong evidence of benefit, the use of carotid endarterectomy for prophylaxis against stroke rose dramatically until the mid-1980s, then declined. Our investigation sought to determine whether carotid endarterectomy reduces the risk of stroke among patients with a recent adverse cerebrovascular event and ipsilateral carotid stenosis. METHODS: We conducted a randomized trial at 50 clinical centers throughout the United States and Canada, in patients in two predetermined strata based on the severity of carotid stenosis--30 to 69 percent and 70 to 99 percent. We report here the results in the 659 patients in the latter stratum, who had had a hemispheric or retinal transient ischemic attack or a nondisabling stroke within the 120 days before entry and had stenosis of 70 to 99 percent in the symptomatic carotid artery. All patients received optimal medical care, including antiplatelet therapy. Those assigned to surgical treatment underwent carotid endarterectomy performed by neurosurgeons or vascular surgeons. All patients were examined by neurologists 1, 3, 6, 9, and 12 months after entry and then every 4 months. End points were assessed by blinded, independent case review. No patient was lost to follow-up. RESULTS: Life-table estimates of the cumulative risk of any ipsilateral stroke at two years were 26 percent in the 331 medical patients and 9 percent in the 328 surgical patients--an absolute risk reduction (+/- SE) 17 +/- 3.5 percent (P less than 0.001). For a major or fatal ipsilateral stroke, the corresponding estimates were 13.1 percent and 2.5 percent--an absolute risk reduction of 10.6 +/- 2.6 percent (P less than 0.001). Carotid endarterectomy was still found to be beneficial when all strokes and deaths were included in the analysis (P less than 0.001). CONCLUSIONS: Carotid endarterectomy is highly beneficial to patients with recent hemispheric and retinal transient ischemic attacks or nondisabling strokes and ipsilateral high-grade stenosis (70 to 99 percent) of the internal carotid artery.

Aged↗
PubMed1991

Rapid evolution of microcomputer use in a faculty of health sciences.

OBJECTIVE: To assist with educational planning we surveyed health sciences faculty members in 1989 to determine their use of microcomputers, desire for further instruction and perceptions on what microcomputer services should be provided for students. The 1989 results were compared with those of a similar survey performed in 1986. DESIGN: A self-completed, mailed questionnaire, with up to three reminders. SETTING: Faculty of Health Sciences, McMaster University, Hamilton, Ont. PARTICIPANTS: All full-time (FT) and part-time (PT) faculty members were sent the questionnaire; over 80% of the FT and 65% of the PT faculty members responded in 1986 and in 1989. RESULTS: The proportions of faculty members who used microcomputers increased significantly over the 3 years, from 71% to 87% among FT members (p = 2.2 x 10(-8)) and from 48% to 69% among PT members (p = 4.9 x 10(-8)). There were significant increases in the use of many of the applications, especially database and filing uses (from 10% to 41% among FT members [p less than 1 x 10(-9)] and from 6% to 34% among PT members [p less than 1 x 10(-9)]) and on-line access to bibliographic databases (from 7% to 37% among FT members [p less than 1 x 10(-9)] and from 3% to 18% among PT members [p less than 1 x 10(-9)]. These changes occurred mainly through individual initiative and voluntary continuing education. CONCLUSIONS: The extraordinary rate of adoption of microcomputers attests to their perceived usefulness. Curriculum planners need to consider how the success of microcomputer applications can be evaluated objectively and how successful applications can be integrated into educational programs.

Attitude of Health Personnel↗
PubMed1991

PREOP: development of an evidence-based expert system to assist with preoperative assessments.

PREOP is a prototype expert system that is designed to provide physicians with evidence-based recommendations concerning the assessment and care of patients with comorbid medical problems who are about to undergo surgery. The knowledgebase for this system is currently undergoing transition from the conventional advice of medical experts, which is variably related to evidence published in the medical literature, to a more formal approach in which the best available evidence is used for each recommendation and the quality of the evidence made apparent to the user. This work seeks to address important questions concerning improvement of the information contained in expert knowledgebases, namely, how to find and recognize new evidence when it is published, how to assess the quality of evidence in a uniform and efficient fashion, how to replace evidence in the knowledgebase efficiently when it has been superseded by higher quality evidence, and how to represent evidence in a manner that is most valuable for the user.

Decision Making, Computer-Assisted↗
PubMed1991

A study to enhance clinical end-user MEDLINE search skills: design and baseline findings.

OBJECTIVE: To determine if a preceptor and timely, individualized feedback improves the performance of physicians in searching MEDLINE using GRATEFUL MED in clinical settings. DESIGN: Randomized controlled trial. SETTING: A 300 bed primary to tertiary care teaching hospital. Computers were installed in wards and clinics of 6 major clinical services, and the emergency room, intensive care and neonatal intensive care units. SUBJECTS: All physicians and physicians-in-training from the departments of Medicine, Family Medicine, Surgery, Psychiatry, Pediatrics, and Obstetrics and Gynecology were included if they made patient care decisions for at least 8 weeks during the study period. INTERVENTION: All participants were given a 1-hour training class and 1 hour of individualized searching with 1 of the 2 study librarians. After training, participants were randomized to a control group who received no further intervention or to an intervention group in which each person chose a clinical preceptor experienced in MEDLINE searching and received individualized feedback by a study librarian on their first 10 searches, indicating search quality and providing suggestions for improvement. Feedback was mailed the first week day after the search was done. MAIN MEASURES: Baseline characteristics by study group, department and level of training, study participation rates, and searching rates. MAIN RESULTS: 308 of 392 eligible physicians joined the study. Participation was almost 80% with some variation by department and level of training. Excellent balance in the baseline characteristics was achieved for the 2 groups, as well as for the number who did first searches. Intervention group participants searched MEDLINE more often than did controls (3.5 searches per month vs 2.5 per month for controls, P = 0.046). The recall and precision for first searches for both groups was significantly less than that of librarians. The analysis of study data will be completed by September 1991. CONCLUSIONS: Clinicians are willing to do self-service searching of MEDLINE in clinical settings but their precision and recall are less than a trained librarian at baseline. Search skills enhancements are needed and the effect of feedback and preceptors is being tested. SOURCE OF FUNDING: U.S. National Library of Medicine and Ontario Ministry of Health.

Computer User Training↗
PubMed1991

Evaluation of SAPHIRE: an automated approach to indexing and retrieving medical literature.

An analysis of SAPHIRE, an experimental information retrieval system featuring automated indexing and natural language retrieval, was performed on MEDLINE references using data previously generated for a MEDLINE evaluation. Compared with searches performed by novice and expert physicians using MEDLINE, SAPHIRE achieved comparable recall and precision. While its combined recall and precision performance did not equal the level of librarians, SAPHIRE did achieve a significantly higher level of absolute recall. SAPHIRE has other potential advantages over existing MEDLINE systems. Its natural language interface does not require knowledge of MeSH, and it provides relevance ranking of retrieved references.

Abstracting and Indexing↗
PubMed1991

Online access to MEDLINE in clinical settings: impact of user fees.

The effect of introducing user fees on the frequency and quality of MEDLINE searching with GRATEFUL MED by physicians in clinical settings was tested. After training and free use (prior study), consenting participants were randomly allocated to pay searching costs (pay group) or continue without fees (no pay group). Fifty-nine physicians participated. Among the prior study's frequent searchers, the pay group searched at less than one third of the rate of those assigned to no pay. For less frequent searchers in the prior study, only 48% of those assigned to pay did any searches, compared with 85% for the no pay group (P = 0.006), and for those who did search, their frequency was almost half. However, there was no significant difference in the quality of searches; both groups demonstrated about equivalent recall (P = 0.77), but significantly lower precision (P = 0.03) than for the librarian's independent searches. Similarly, there was no difference in the proportion of searches affecting clinical decisions for the two groups. Thus, imposing user charges for online searching in clinical settings after a period of free use adversely affects searching quantity, but not quality. MEDLINE providers should consider whether user fees will undermine its benefits.

Fees and Charges↗
PubMed1990

Loose connections between peer-reviewed clinical journals and clinical practice.

Many important advances in medical care are first reported in the biomedical literature, but physicians find the literature overwhelming and, therefore, are often unaware of advances. This article examines the ways in which peer-reviewed clinical journals contribute to this problem and proposes some solutions for both their editors and clinical readers. Peer-reviewed clinical journals impede the dissemination of validated advances to practitioners by mixing a few rigorous studies (communications from scientists to practitioners) with many preliminary investigations (communications from scientists to scientists). Journals wishing to improve communication with practitioners should feature rigorous studies of the nature, cause, prognosis, diagnosis, prevention, and treatment of disease and should feature sound clinical review articles (communications from practitioners to practitioners). Additional strategies for improving communication between medical scientists and practitioners include improving publication standards for clinical journals, proving more informative abstracts for clinical articles, fostering the development of derivative literature services, and enhancing practitioners' skills in critically appraising the medical literature.

Abstracting and Indexing↗
PubMed1990

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↗
PubMed1990

Online access to MEDLINE in clinical settings. A study of use and usefulness.

STUDY OBJECTIVE: We introduced self-service access to the medical literature database, MEDLINE, into clinical settings to assess the frequency, patterns, purposes, and success of use. DESIGN: Longitudinal descriptive study. SETTING: Inpatient and outpatient services of a university medical center. PARTICIPANTS: All trainees and attending staff working at the service sites were invited to participate; 158 (84%) did so. INTERVENTIONS: Free online access was provided to MEDLINE through GRATEFUL MED software. Participants were offered a 2-hour introduction to online searching and 2 hours of free search time. MEASUREMENTS AND MAIN RESULTS: For each search, a computer program requested identification of the user and the question to be addressed. Search transactions were recorded automatically. Interviews were conducted after a random sample of searches, and search questions were given to more expert searchers to run for comparison with the original. Eighty-one percent of participants did searches on study computers, at a mean rate of 2.7 searches per month. On comparison searches, participants retrieved 55% of the number of relevant articles retrieved by reference librarians (P = 0.024) and 50% more irrelevant articles (P less than 0.001). Forty-seven percent of searches on patient problems affected clinical decisions, but often on scanty information. CONCLUSIONS: MEDLINE searching from clinical settings is feasible with brief training and affects clinical decisions. However, inexperienced searchers miss many relevant citations and search inefficiently. Further studies are needed to assess the impact of searching on physician performance and patient care.

Academic Medical Centers↗
PubMed1990

How good are clinical MEDLINE searches? A comparative study of clinical end-user and librarian searches.

The objective of this study was to determine the quality of MEDLINE searches done by physicians, physician trainees, and expert searchers (clinicians and librarians). Its design was an analytic survey with independent replication in a setting of self-service online searching from medical wards, an intensive care unit, a coronary care unit, an emergency room, and an ambulatory clinic in a 300-bed teaching hospital. Participating were all M.D. clinical clerks, house, and attending staff responsible for patients in the above settings. Intervention for all participants consisted of a 2-h small group class and 1-h practice session on MEDLINE searching (GRATEFUL MED) before free access to MEDLINE. Search questions from 104 randomly selected novice searches were given to 1 of 13 clinicians with prior search experience and 1 of 3 librarians to run independent searches (triplicated searches). Measurements and main results from these unique citations of the triplicated searches were sent to expert clinicians to rate for relevance (7-point scale). Recall (number of relevant citations retrieved from an individual search divided by the total number of relevant citations from all searches on the same topic) and precision (proportion of relevant citations retrieved in each search) were calculated. Librarians were significantly better than novices for both. Librarians had equivalent recall to, and better precision than, experienced end-users. Unexpectedly, only 20% of relevant citations were retrieved by more than one search of the set of three, with the conclusion that novice searchers on MEDLINE via GRATEFUL MED after brief training have relatively low recall and precision. Recall improves with experience but precision remains suboptimal. Further research is needed to determine the "learning curve," evaluate training interventions, and explore the non-overlapping retrieval of relevant citations by different searchers.

Evaluation Studies as Topic↗
PubMed1989

Comparison of daily and twice-weekly regimens to treat pulmonary tuberculosis.

A randomised controlled trial compared the effectiveness and toxicity in pulmonary tuberculosis of two drug regimens containing rifampicin and isoniazid given daily or twice-weekly for 4 months after a 2-month period of intensive treatment with daily isoniazid, rifampicin, and pyrazinamide. 667 patients with newly diagnosed pulmonary tuberculosis were randomly allocated to continue daily treatment with isoniazid (400 mg) and rifampicin (600 mg) or to twice-weekly treatment with isoniazid (900 mg) and rifampicin (600 mg). 544 of the 667 patients (81%) completed the 6-month course (287 of 337 [85%] treated daily and 257 of 330 [79%] treated twice-weekly). Drug toxicity was not a great problem; the treatment was permanently discontinued in only 2% of patients. There was no significant difference at the end of months 5 and/or 6 of chemotherapy between the groups treated daily and twice-weekly in the proportions with bacteriological failure (at least one positive sputum culture with more than 20 colonies) or who had died from tuberculosis (17 [6%] vs 10 [3%]). Nor was there a significant difference in the relapse rate (17 [7%] treated daily vs 10 [4%] treated twice-weekly) during follow-up of 12 months. Thus, the twice-weekly regimen was at least as effective as the daily regimen for treatment of pulmonary tuberculosis.

Administration, Oral↗
PubMed1989

A review of medical education and medical informatics.

Physicians have considerable difficulty collecting and interpreting information from patients, dealing with the uncertainties associated with diagnosing and treating their patients, communicating precisely with one another, keeping up to date, and applying recommended procedures when indicated. Some of the advances in information technology may help physicians to manage information more effectively through more accessible, validated clinical indexes, data bases of diagnostic test characteristics, computerized audits of clinical activities with feedback, expert systems, on-line access to the medical literature, and other tools of medical informatics. Medical educators can catalyze this process by facilitating the introduction of information technology into academic clinical settings so that students can learn its use first-hand and by promoting the evolution of this and other aspects of medical informatics, a new discipline dedicated to the solution of information problems in health care. The potential roles for computer-aided instruction and centralized computer laboratories in medical schools are much less clear.

Canada↗