A descriptive feast but an evaluative famine: systematic review of published articles on primary care computing during 1980-97.
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OBJECTIVES: To appraise findings from studies examining the impact of computers on primary care consultations. DESIGN: Systematic review of world literature from 1980 to 1997. DATA SOURCES: 5475 references were identified from electronic databases (Medline, Science Citation Index, Social Sciences Citation Index, Index of Scientific and Technical Proceedings, Embase, OCLC FirstSearch Proceedings), bibliographies, books, identified articles, and by authors active in the field. 1892 eligible abstracts were independently rated, and 89 studies met the inclusion criteria. MAIN OUTCOME MEASURES: Effect on doctors' performance and patient outcomes; attitudes towards computerisation. RESULTS: 61 studies examined effects of computers on practitioners' performance, 17 evaluated their impact on patient outcome, and 20 studied practitioners' or patients' attitudes. Computer use during consultations lengthened the consultation. Reminder systems for preventive tasks and disease management improved process rates, although some returned to pre-intervention levels when reminders were stopped. Use of computers for issuing prescriptions increased prescribing of generic drugs, and use of computers for test ordering led to cost savings and fewer unnecessary tests. There were no negative effects on those patient outcomes evaluated. Doctors and patients were generally positive about use of computers, but issues of concern included their impact on privacy, the doctor-patient relationship, cost, time, and training needs. CONCLUSIONS: Primary care computing systems can improve practitioner performance, particularly for health promotion interventions. This may be at the expense of patient initiated activities, making many practitioners suspicious of the negative impact on relationships with patients. There remains a dearth of evidence evaluating effects on patient outcomes. (+info)
Computing diffusion rates in T2-dark hematomas and areas of low T2 signal.
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BACKGROUND AND PURPOSE: It has been suggested that restricted diffusion is present within hematomas with intact red cell membranes; however, computing apparent diffusion coefficient (ADC) values in areas of low T2 signal can be problematic. Our purpose was to show the pitfalls of measuring diffusion within hematomas with intracellular blood products and to present a framework based on the properties of expected values for computing ADC values from regions with signal intensities close to that of the background noise (ie, T2-dark hematomas). METHODS: Twelve patients with intracranial hematomas who had undergone diffusion imaging were retrospectively identified during a 2-year period (four intracellular oxyhemoglobin, seven intracellular deoxyhemoglobin, one intracellular methemoglobin). Regions of interest were drawn on the hematomas, the contralateral white matter, and over the background. ADC values were computed using a variety of methods: 1) using expected values incorporating the variance of the background, 2) computing the mean of the regions of interest before taking the natural log, 3) masking negative values, and 4) masking the background at 0.5% increments from 0.5 to 5.5% and including the masked voxels (an intrinsically flawed method). Two-tailed Student's t test was performed between the white matter and the hematoma ADC values. RESULTS: There was no statistically significant difference between the hematomas and the white matter for methods 1 through 3 (P = .14, P = .23, and P = .83, respectively). Only method 4 revealed a statistically significant difference, beginning at 0.5% masking (P = .04) and becoming progressively more significant with increased masking (P = 4.14 x 10(-7) at 5.5% masking). The effect of masking was limited to the T2-dark hematomas. CONCLUSION: There is no restriction of diffusion for in vivo hematomas with intracellular blood products. The T2 blackout effect for T2-dark hematomas on diffusion-weighted images should not be interpreted as fast diffusion. The method of expected values can be used to obtain measurements for regions with signal intensities near the background noise. Using literature values for RBC self-diffusion, we computed lower limits of diffusion for hematomas with intracellular blood products to be 0.3 x 10(-3) mm2/s. (+info)
Childhood asthma: can computers aid detection in general practice?
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BACKGROUND: Childhood asthma remains underdiagnosed in general practice. Computers with a patient interface have the potential to screen children for asthma in a time-efficient manner. AIM: To develop a concise, validated self-report measure that calculates an 'asthma score' that predicts likelihood of asthma and its severity in childhood. DESIGN OF STUDY: Computerised questionnaire survey in general practitioners' (GPs') waiting rooms, followed by a written questionnaire and either bronchial challenge or skin allergy testing at the regional teaching hospital. SETTING: Children between 18 months and 18 years old accompanied by a parent or guardian in five group practices in Newcastle in New South Wales, Australia. METHOD: The responses from both the computerised questionnaire and the written questionnaire were compared with physician assessment of asthma, based on an existing validated questionnaire and clinical tests. RESULTS: Six items were identified to be independently and significantly associated (at P < 0.05) with the presence of asthma and its severity: parent or self-reported asthma, previous diagnosis, wheeze in the past year, physical activity affected by symptoms, night cough in the past year, and visits to a GP in the past year. From the regression model a linear score was derived that indicates whether a child is likely to have asthma and its likely severity. CONCLUSIONS: The asthma score is a valid indicator of asthma and its severity in children in general practice. (+info)
Development of a prognostic model for grading chronic graft-versus-host disease.
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The disease-specific survival (DSS) of 151 patients with chronic graft-versus-host disease (cGVHD) was studied in an attempt to stratify patients into risk groups and to form a basis for a new grading of cGVHD. The data included the outcome and 23 variables at the diagnosis of cGVHD and at the primary treatment failure (PTF). Eighty-nine patients (58%) failed primary therapy for cGVHD. Nonrelapse mortality was 44% after a median follow-up of 7.8 years. The probability of DSS at 10 years after diagnosis of cGVHD (DSS1) and after PTF (DSS2) was 51% (95% confidence interval [CI] = 39%, 60%) and 38% (95% CI = 28%, 49%), respectively. According to multivariate analysis, extensive skin involvement (ESI) more than 50% of body surface area; hazard ratio (HR) of 7.0 (95% CI = 3.6-13.4), thrombocytopenia (TP) (< 100 000/microL; HR, 3.6; 95% CI = 1.9-6.8), and progressive-type onset (PTO) (HR, 1.7; 95% CI = 0.9-3.0) significantly influenced DSS1. These 3 factors and Karnofsky Performance Score of less than 50% at PTF were significant predictors for DSS2. The DSS1 at 10 years for patients with prognostic factor score (PFS) at diagnosis of 0 (none), 1.9 and below [corrected] (ESI only or TP and/or PTO), above 1.9 and not above 3.5 [corrected] (ESI plus either TP or PTO), and more than 3.5 (all 3 factors) was 82%, 68%, 34%, and 3% (P =.05, <.001, <.001), respectively. The DSS2 at 5 years for patients with PFS at PTF of 0, 2 or less, 2 to 3.5, and more than 3.5 were 91%, 71%, 22%, and 4% (P =.2,.005, and <.001), respectively. It was concluded that these prognostic models might be useful in grouping the patients with similar outcome. (+info)
Application of the Sherlock Mycobacteria Identification System using high-performance liquid chromatography in a clinical laboratory.
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There is a growing need for a more accurate, rapid, and cost-effective alternative to conventional tests for identification of clinical isolates of Mycobacterium species. Therefore, the ability of the Sherlock Mycobacteria Identification System (SMIS; MIDI, Inc.) using computerized software and a Hewlett-Packard series 1100 high-performance liquid chromatograph to identify mycobacteria was compared to identification using phenotypic characteristics, biochemical tests, probes (Gen-Probe, Inc.), gas-liquid chromatography, and, when necessary, PCR-restriction enzyme analysis of the 65-kDa heat shock protein gene and 16S rRNA gene sequencing. Culture, harvesting, saponification, extraction, derivatization, and chromatography were performed following MIDI's instructions. Of 370 isolates and stock cultures tested, 327 (88%) were given species names by the SMIS. SMIS software correctly identified 279 of the isolates (75% of the total number of isolates and 85% of the named isolates). The overall predictive value of accuracy (correct calls divided by total calls of a species) for SMIS species identification was 85%, ranging from only 27% (3 of 11) for M. asiaticum to 100% for species or groups including M. malmoense (8 of 8), M. nonchromogenicum (11 of 11), and the M. chelonae-abscessus complex (21 of 21). By determining relative peak height ratios (RPHRs) and relative retention times (RRTs) of selected mycolic acid peaks, as well as phenotypic properties, all 48 SMIS-misidentified isolates and 39 (91%) of the 43 unidentified isolates could be correctly identified. Material and labor costs per isolate were $10.94 for SMIS, $26.58 for probes, and $42.31 for biochemical identification. The SMIS, combined with knowledge of RPHRs, RRTs, and phenotypic characteristics, offers a rapid, reasonably accurate, cost-effective alternative to more traditional methods of mycobacterial species identification. (+info)
New normal limits for the paediatric electrocardiogram.
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AIMS: Previous studies that determined the normal limits for the paediatric ECG had their imperfections: ECGs were recorded at a relatively low sampling rate, ECG measurements were conducted manually, or normal limits were presented for only a limited set of parameters. The aim of this study was to establish an up-to-date and complete set of clinically relevant normal limits for the paediatric ECG. METHODS AND RESULTS: ECGs from 1912 healthy Dutch children (age 11 days to 16 years) were recorded at a sampling rate of 1200 Hz. The digitally stored ECGs were analysed using a well-validated ECG computer program. The normal limits of all clinically relevant ECG measurements were determined for nine age groups. Clinically significant differences were shown to exist, compared with previously established normal limits. Sex differences could be demonstrated for QRS duration and several amplitude measurements. CONCLUSIONS: These new normal limits differ substantially from those commonly used and suggest that diagnostic criteria for the paediatric ECG should be adjusted. (+info)
A brief computer-based assessment of reinforcer dimensions affecting choice.
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In an extension of Neef, Shade, and Miller (1994), we used a brief computer-based assessment of differential responsiveness to reinforcer rate, quality, delay, and response effort in affecting the choices of 11 participants. The assessment involved successive presentations of two concurrent sets of math problems, each set associated with competing reinforcer or response dimensions in a counterbalanced fashion. The results showed that the reinforcer and response dimensions differentially affected choice, with time-allocation patterns varying across students. (+info)
Improving the reliability of stroke subgroup classification using the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria.
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BACKGROUND AND PURPOSE: We sought to improve the reliability of the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification of stroke subtype for retrospective use in clinical, health services, and quality of care outcome studies. The TOAST investigators devised a series of 11 definitions to classify patients with ischemic stroke into 5 major etiologic/pathophysiological groupings. Interrater agreement was reported to be substantial in a series of patients who were independently assessed by pairs of physicians. However, the investigators cautioned that disagreements in subtype assignment remain despite the use of these explicit criteria and that trials should include measures to ensure the most uniform diagnosis possible. METHODS: In preparation for a study of outcomes and management practices for patients with ischemic stroke within Department of Veterans Affairs hospitals, 2 neurologists and 2 internists first retrospectively classified a series of 14 randomly selected stroke patients on the basis of the TOAST definitions to provide a baseline assessment of interrater agreement. A 2-phase process was then used to improve the reliability of subtype assignment. In the first phase, a computerized algorithm was developed to assign the TOAST diagnostic category. The reliability of the computerized algorithm was tested with a series of synthetic cases designed to provide data fitting each of the 11 definitions. In the second phase, critical disagreements in the data abstraction process were identified and remaining variability was reduced by the development of standardized procedures for retrieving relevant information from the medical record. RESULTS: The 4 physicians agreed in subtype diagnosis for only 2 of the 14 baseline cases (14%) using all 11 TOAST definitions and for 4 of the 14 cases (29%) when the classifications were collapsed into the 5 major etiologic/pathophysiological groupings (kappa=0.42; 95% CI, 0.32 to 0.53). There was 100% agreement between classifications generated by the computerized algorithm and the intended diagnostic groups for the 11 synthetic cases. The algorithm was then applied to the original 14 cases, and the diagnostic categorization was compared with each of the 4 physicians' baseline assignments. For the 5 collapsed subtypes, the algorithm-based and physician-assigned diagnoses disagreed for 29% to 50% of the cases, reflecting variation in the abstracted data and/or its interpretation. The use of an operations manual designed to guide data abstraction improved the reliability subtype assignment (kappa=0.54; 95% CI, 0.26 to 0.82). Critical disagreements in the abstracted data were identified, and the manual was revised accordingly. Reliability with the use of the 5 collapsed groupings then improved for both interrater (kappa=0.68; 95% CI, 0.44 to 0.91) and intrarater (kappa=0.74; 95% CI, 0.61 to 0.87) agreement. Examining each remaining disagreement revealed that half were due to ambiguities in the medical record and half were related to otherwise unexplained errors in data abstraction. CONCLUSIONS: Ischemic stroke subtype based on published TOAST classification criteria can be reliably assigned with the use of a computerized algorithm with data obtained through standardized medical record abstraction procedures. Some variability in stroke subtype classification will remain because of inconsistencies in the medical record and errors in data abstraction. This residual variability can be addressed by having 2 raters classify each case and then identifying and resolving the reason(s) for the disagreement. (+info)