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Biomedical subjects

D L Hunt

Publications and source records attributed to D L Hunt.

17 recordsLinked to original sources

Multisensory plasticity in congenitally deaf mice: how are cortical areas functionally specified?

The neocortex of congenitally deaf mice was examined using electrophysiological recording techniques combined with cortical myeloarchitecture. Our results indicate that relative activity patterns across sensory systems during development contribute to modality assignment of cortical fields as well as the size of cortical fields. In congenitally deaf mice, "auditory cortex" contained neurons that responded to somatosensory, visual, or both somatosensory and visual stimulation; the primary visual area contained a larger proportion of neurons that responded to somatosensory stimulation than in normal animals, and the primary visual area had significantly increased in size. Thus, cortical architecture and functional specification were de-correlated. When results are considered in the light of molecular studies and studies in which peripheral activity is altered in development, it becomes clear that similar types of changes to the neocortex, such as alterations in cortical field size, can be achieved in more than one way in the developing and evolving neocortex.

3,4-Dihydroxyphenylacetic Acid↗

Using old technology to implement modern computer-aided decision support for primary diabetes care.

BACKGROUND: Implementation rates of interventions known to be beneficial for people with diabetes mellitus are often suboptimal. Computer-aided decision support systems (CDSSs) can improve these rates. The complexity of establishing a fully integrated electronic medical record that provides decision support, however, often prevents their use. OBJECTIVE: To develop a CDSS for diabetes care that can be easily introduced into primary care settings and diabetes clinics. THE SYSTEM: The CDSS uses fax-machine-based optical character recognition software for acquiring patient information. Simple, 1-page paper forms, completed by patients or health practitioners, are faxed to a central location. The information is interpreted and recorded in a database. This initiates a routine that matches the information against a knowledge base so that patient-specific recommendations can be generated. These are formatted and faxed back within 4-5 minutes. IMPLEMENTATION: The system is being introduced into 2 diabetes clinics. We are collecting information on frequency of use of the system, as well as satisfaction with the information provided. CONCLUSION: Computer-aided decision support can be provided in any setting with a fax machine, without the need for integrated electronic medical records or computerized data-collection devices.

Decision Making, Computer-Assisted↗

How to read a systematic review.

A systematic review is a carefully planned and conducted study designed to answer a specific focused clinical question. A systematic review differs from the frequently encountered narrative review article. Systematic review must be completed using a prespecified methodology. The reader must ask eight important questions when reading a systematic review: (i) did the review address a focused clinical question (ii) is it likely that important, relevant studies are missed (iii) were the inclusion criteria used to select appropriate articles (iv) was the validity of the included studies assessed (v) were the assessments of studies reproducible (vi) were the results similar from study to study (vii) what were the overall results and how precise are they and (viii) will the results help in caring for patients. The article also provides sources for systematic reviews.

Evidence-Based Medicine↗

Clinical examination for the detection of protective sensation in the feet of diabetic patients. International Cooperative Group for Clinical Examination Research.

OBJECTIVE: We compared the reproducibility and accuracy of conventional clinical examination of the diabetic foot to monofilament examination. We also sought to simplify the monofilament examination by reducing it to fewer touch points. METHODS: In a cross-sectional study at 10 centers in the United States, Canada, and Switzerland, general internists and residents performed a structured history and physical examination for neuropathy on the feet of diabetic patients. Independent examination by two observers included monofilament sensation, pinprick, vibration, position sense, and ankle reflexes. MAIN RESULTS: A total of 304 patients were examined by at least one practitioner, and 200 received duplicate examinations. Monofilament examination and ankle reflexes had the best reproducibility, with moderate agreement (kappa = 0.59); pinprick, position, and vibration sense had fair agreement (kappa = 0.28-0.36). No component of the history or physical examination, singly or in aggregate, was both sensitive and specific for identifying a patient with an abnormal monofilament examination. A simplified monofilament examination using only 4 sites per foot (total 8 sites) detected 90% of patients with an abnormal 16-site monofilament evaluation. CONCLUSIONS: Conventional clinical examination had low reproducibility and correlated poorly with monofilament examination for the identification of the at-risk patient. The Semmes-Weinstein monofilament examination, a reproducible, valid, and generalizable test of foot sensation, is recommended as the screening procedure of choice for examining diabetic feet.

Adult↗

Effects of computer-based clinical decision support systems on physician performance and patient outcomes: a systematic review.

CONTEXT: Many computer software developers and vendors claim that their systems can directly improve clinical decisions. As for other health care interventions, such claims should be based on careful trials that assess their effects on clinical performance and, preferably, patient outcomes. OBJECTIVE: To systematically review controlled clinical trials assessing the effects of computer-based clinical decision support systems (CDSSs) on physician performance and patient outcomes. DATA SOURCES: We updated earlier reviews covering 1974 to 1992 by searching the MEDLINE, EMBASE, INSPEC, SCISEARCH, and the Cochrane Library bibliographic databases from 1992 to March 1998. Reference lists and conference proceedings were reviewed and evaluators of CDSSs were contacted. STUDY SELECTION: Studies were included if they involved the use of a CDSS in a clinical setting by a health care practitioner and assessed the effects of the system prospectively with a concurrent control. DATA EXTRACTION: The validity of each relevant study (scored from 0-10) was evaluated in duplicate. Data on setting, subjects, computer systems, and outcomes were abstracted and a power analysis was done on studies with negative findings. DATA SYNTHESIS: A total of 68 controlled trials met our criteria, 40 of which were published since 1992. Quality scores ranged from 2 to 10, with more recent trials rating higher (mean, 7.7) than earlier studies (mean, 6.4) (P<.001). Effects on physician performance were assessed in 65 studies and 43 found a benefit (66%). These included 9 of 15 studies on drug dosing systems, 1 of 5 studies on diagnostic aids, 14 of 19 preventive care systems, and 19 of 26 studies evaluating CDSSs for other medical care. Six of 14 studies assessing patient outcomes found a benefit. Of the remaining 8 studies, only 3 had a power of greater than 80% to detect a clinically important effect. CONCLUSIONS: Published studies of CDSSs are increasing rapidly, and their quality is improving. The CDSSs can enhance clinical performance for drug dosing, preventive care, and other aspects of medical care, but not convincingly for diagnosis. The effects of CDSSs on patient outcomes have been insufficiently studied.

Clinical Competence↗

Locating and appraising systematic reviews.

Several methods can be used to identify systematic reviews. These include bibliographic databases, such as MEDLINE, Best Evidence, and the Cochrane Library. In the future, the Cochrane Library could become the source of choice for systematic reviews because it provides the full text for Cochrane reviews and citations to many other systematic reviews. Moreover, the Library is growing rapidly and becoming more readily available, and its searching capabilities are being improved with each update. Although Best Evidence contains fewer systematic reviews than the Cochrane Library, it is specifically designed for practicing internists and primary care physicians and includes systematic reviews on diagnosis, cause, prognosis, and quality improvement. At present, however, MEDLINE and other bibliographic databases are probably the most up-to-date and readily available sources of systematic reviews. Systematic reviews are a powerful and useful way to assemble evidence; however, just because a review has been done using systematic review methods does not guarantee that its results are credible. Regardless of the source, all systematic reviews (like all types of research evidence) require critical appraisal to determine their validity and to establish whether and how they will be useful in practice.

Anti-Inflammatory Agents, Non-Steroidal↗

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↗

Recognizing and investigating iron-deficiency anemia in hospitalized elderly people.

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.

Aged↗

Effects of dietary calcium supplementation on blood pressure. A meta-analysis of randomized controlled trials.

OBJECTIVE: To review the effect of supplemental calcium on blood pressure. DATA SOURCE: We searched MEDLINE and EMBASE for 1996 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.

Blood Pressure↗

A case-control study of nosocomial ampicillin-resistant enterococcal infection and colonization at a university hospital.

OBJECTIVE: To assess risk factors for colonization and nosocomial infection with ampicillin-resistant enterococci (ARE). DESIGN: Patients with ampicillin-resistant enterococci were compared retrospectively by logistic regression analysis with controls harboring susceptible strains. ARE were characterized by whole plasmid DNA analysis and restriction enzyme analysis of plasmid (REAP) DNA with EcoRI. SETTING: The study was done at a 1,125 bed, tertiary-care teaching hospital in North Carolina with patients from whom enterococci were isolated from June 1, 1989, to March 30, 1991. PATIENTS: The final study group comprised 44 cases with nosocomially-acquired colonization or infection with ARE and 100 controls with ampicillin-susceptible strains. Clinical and epidemiological risk factors for ARE were abstracted by chart review. RESULTS: After controlling for age and site of infection, patients with ARE were more likely to have been admitted previously to our hospital and to have received third-generation cephalosporins and clindamycin. However, only advanced age and clindamycin therapy were independently associated with presence of ARE. REAP with EcoRI showed 20 groups of enterococci on 19 different wards. CONCLUSIONS: These results suggest that ARE are endemic and multifocal in origin in our hospital and that advanced age and use of clindamycin are important selective risk factors for ARE colonization and infection.

Age Factors↗

Patient-specific evidence-based care recommendations for diabetes mellitus: development and initial clinic experience with a computerized decision support system.

BACKGROUND: adherence with evidence-based recommendations for chronic disease management is often suboptimal. Providing patient-specific reminders at the time of clinical encounters has the potential to improve this situation. A necessary prerequisite for providing such reminders, however, is to have an efficient means of acquiring patient information that can be matched to an underlying knowledge base. The decision support system: we have developed a computer-based, self-administered questionnaire for diabetes care. The questionnaire assesses numerous diabetes-related topics. Patients complete the questionnaire using a touchscreen interface, and their responses are then matched to evidence-based guidelines so that patient-specific care suggestions can be provided for both the patients and their health care professionals. The guidelines are derived from a database of abstracts of studies of diabetes care that are screened for scientific merit and clinical relevance, supplemented by recommendations from diabetes organizations. EVALUATION: initial evaluation of the system included an assessment of the agreement of responses to the automated questionnaire with responses to similar questions administered during a structured, personal interview. Overall agreement was 92.5% and the majority of disagreements were minor. More recently, patients aged 18-69 years have been completing the automated questionnaire before appointments at a diabetes clinic. The average time required has been 10.9 min and a mean of 3.0 recommendations have been provided per patient. Patient and health care practitioner satisfaction with the questionnaire and the patient-specific feedback have been high. CONCLUSIONS: evidence-based patient-specific diabetes care recommendations can be provided using a self-administered computer-based questionnaire.

Decision Support Systems, Clinical↗

The use of amphotericin B in nosocomial fungal infection.

The use of potent broad-spectrum antibacterial agents, the increasing number of immunocompromised hosts, and the use of invasive treatment modalities have exacerbated the problems involved in the management of nosocomial fungal infection. The hospital records at a tertiary-care medical center were retrospectively reviewed in an effort to determine the magnitude of these problems. A plethora of fungal species were isolated from patients. Hospital infection surveillance revealed between 30 and 40 nosocomial yeast infections per month, with 20% of nosocomial urinary tract infections caused by yeasts rather than by bacterial pathogens and one or two cases of fungemia per week. Although these figures represent a large number of nosocomial fungal infections, a significant increase in the number of such infections over the last several years could not be documented. The use of amphotericin B was found to have increased each year. The patterns of use of amphotericin B changed little between 1983 and 1987, but the number of patients treated with this agent increased dramatically.

Administration, Intravesical↗