PubMed Health⌕ Search

Biomedical subjects

B J McNeil

Publications and source records attributed to B J McNeil.

At least 19 recordsLinked to original sources
PubMed1992

Acute myocardial infarction in the Medicare population. Process of care and clinical outcomes.

OBJECTIVE: To describe the process of care and clinical outcomes associated with acute myocardial infarction (AMI) in the Medicare population, and to examine differences in process of care and outcome of care as a function of patient age, gender, and race. DESIGN: Retrospective cohort study using a longitudinal database created from Medicare utilization and administrative files. PATIENT POPULATIONS: A cohort of AMI patients covered by Medicare in 1987 and a random sample of Medicare patients without AMI. MAIN PROCESS AND OUTCOME MEASUREMENTS: (1) The use of coronary angiography, coronary artery bypass graft surgery, and percutaneous transluminal coronary angioplasty during the first 90 days after a new AMI; (2) mortality at 30 days, 1 year, and 2 years; (3) reinfarction rates; and (4) reoperation rates for coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty. MAIN RESULTS: Mortality rates were high: 26% at 30 days, 40% at 1 year, and 47% at 2 years. They varied greatly by age, less so by gender and race, and were high even among patients who survived the first 30 days. Compared with mortality, reinfarction was uncommon, occurring in 7.3% of patients. During the first 90 days, 23% of all patients underwent angiography and 13% underwent coronary revascularization (coronary artery bypass graft surgery, 8%; percutaneous transluminal coronary angioplasty, 5%). The use of all three procedures decreased with age and was less common among women and blacks than among men and whites. Differential use by age and race was greater for angiography than for revascularization procedures. CONCLUSIONS: The prognosis following AMI in patients aged 65 years and above is much worse than is commonly realized. Procedure use in these patients varies as a function of gender and race, even though mortality does not. Further research is needed to reduce the mortality of elderly patients with AMI and to understand the significance of differences in procedure use on the basis of sociodemographic characteristics.

Aged↗
PubMed1992

Ga-67 scintigraphy and computed tomography in the diagnosis of pneumocystis carinii pneumonia in patients with AIDS. A prospective comparison.

A prospective evaluation of Ga-67 scintigraphy and transmission computed tomography was performed in 70 consecutive patients with AIDS who were suspected of having Pneumocystis carinii pneumonia. Studies were evaluated independently by two observers. Receiver operating characteristic curves were plotted. Although scintigraphy had a higher true-positive ratio at any false-positive ratio, statistically the areas under the two receiver operating characteristic curves were not significantly different. However, at an FP rate of 15% to 20% (one in the clinically reasonable range), the sensitivity for scintigraphy was 0.84 and for CT 0.80; corresponding specificities were 0.82 and 0.64, respectively, for the two modalities. It seems from these data that gallium imaging is probably superior to CT in detecting P. carinii pneumonia in this group of patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Reading and decision aids for improved accuracy and standardization of mammographic diagnosis.

Image-reading and decision aids were designed to improve the accuracy of mammogram interpretation. The reading aid was a list of diagnostic radiographic features and scales for quantification of each feature. The decision aid, a computer program, converted the reader's scaled values, weighted for predictive power, into an advisory estimate of the probability of malignancy. The features were identified and their importance was assigned in four steps: (a) interviews of five expert readers to establish an initial set of features, (b) perceptual tests to refine the feature set, (c) a consensus meeting to refine this set and establish nomenclature and scales, and (d) the expert's scaling of each feature in a set of 150 mammograms. Those scaled judgments were analyzed to provide the final list of features and their relative importance and to program the computer decision aid. To test the enhancement effect, six other radiologists interpreted a different set of mammograms without, and later with, the two aids. Receiver operating characteristic analysis showed a gain of approximately 0.05 in sensitivity or specificity when the other value remained at 0.85. In a subset of the more difficult cases, the enhancement effect was approximately 0.15 in either sensitivity or specificity.

Humans↗
PubMed1992

Current issues in profiling quality of care.

Profiling provider performance for the assessment of quality involves a number of issues related to selection of appropriate quality measures, subsequent data collection and analysis, and selection of standards of comparison. This article emphasizes the limitations of current data systems for this purpose and discusses hierarchical modeling as the optimal analytic approach for analyzing resulting data. Mention is made of the difficulties of achieving large enough sample sizes for statistical significance at the individual provider level. Finally, the article discusses feasible options for profiling quality.

Data Collection↗
PubMed1991

Variations in length of stay and outcomes for six medical and surgical conditions in Massachusetts and California.

OBJECTIVES: --To determine the extent to which interinstitutional variations in length of stay are explained by differences in patient characteristics and to determine whether patients in hospitals with shorter lengths of stay had worse outcomes. DESIGN: --We reviewed patients' medical records and surveyed patients between 3 and 12 months after hospital discharge using a questionnaire. SETTING: --Six teaching hospitals in California and Massachusetts. PATIENTS: --A cohort of 2484 selected patients who had been hospitalized for acute myocardial infarction or to rule out acute myocardial infarction, coronary artery bypass graft surgery, total hip replacement, cholecystectomy, or transurethral prostatectomy. Between 73% and 84% of the patients with each condition completed a follow-up questionnaire. OUTCOME MEASURES: --In-hospital complications, deaths, length of stay, functional status after hospital discharge, readmission, and patient satisfaction with hospital care were analyzed. RESULTS: --Significant interinstitutional differences in length of stay were noted for all conditions except rule-out acute myocardial infarction. Statistical adjustment for case-mix differences accounted for most of the interinstitutional differences in length of stay for total hip replacement but explained little of the differences in the other conditions. When we controlled statistically for other predictors, length of stay did not have a significant impact on deaths, functional status after hospital discharge, the probability of readmission, or patient satisfaction with hospital care. CONCLUSION: --More research is needed to determine the medical practices that are related to variations in lengths of stay. Routinely available outcome data may help preserve quality in the face of efforts to decrease costs by effecting more standardized practices of care.

Adult↗
PubMed1991

Assessing quality of life after surgery.

Researchers and clinicians increasingly are recognizing the importance of assessing a wide range of outcomes when evaluating the efficacy of medical therapies or procedures. We developed and evaluated a set of self-report scales that assessed both generic and condition-specific aspects of health-related quality of life before and after surgery. We report data from a study of patients having one of four types of surgery at six teaching hospitals in California and Massachusetts. The four surgical conditions studied were: total hip replacement, transurethral prostatectomy, cholecystectomy, and coronary artery bypass graft surgery. All the outcome scales, except for those assessing cognitive functioning and fatigue, had internal consistencies greater than 0.70. The pattern of correlations between the scales and other measures of health status are similar to those reported in other studies and provide evidence of their construct validity. The scales also appeared to be sensitive to differences between presurgical and postsurgical health-related quality of life. The results suggest that the scales used were easy to administer, reliable, valid, and offered important information about outcomes of surgery that is not provided by more traditional clinical indicators.

Activities of Daily Living↗
PubMed1991

CT and MR imaging in staging non-small cell bronchogenic carcinoma: report of the Radiologic Diagnostic Oncology Group.

The accuracies of magnetic resonance (MR) imaging and computed tomography (CT) in determining tumor classification and assessing mediastinal node metastases were compared in a prospective cooperative study of 170 patients with non-small cell bronchogenic carcinoma. The sensitivity of CT in distinguishing T3-T4 tumors from T0-T2 tumors was 63%; specificity was 84%. These values for MR imaging were not significantly different (56% and 80%). With receiver operating characteristic (ROC) analysis, no difference existed between the accuracies of CT and MR imaging in diagnosis of bronchial involvement or chest wall invasion, but MR imaging was significantly more accurate than CT (P = .047) in diagnosis of mediastinal invasion. Lymph node sampling was performed in 155 patients (642 node stations). Cancerous nodes were found in 14% of stations in 21% of patients. There was no significant difference between the accuracies of CT and MR imaging in detecting mediastinal node metastases (N2 or N3); the sensitivities were 52% and 48%, respectively, and specificities were 69% and 64%. ROC analysis also showed no difference between CT and MR imaging.

Carcinoma, Non-Small-Cell Lung↗
PubMed1990

Comparison of magnetic resonance imaging and ultrasonography in staging early prostate cancer. Results of a multi-institutional cooperative trial.

BACKGROUND: In 1987, a cooperative study group consisting of five institutions was formed to determine the relative benefits of magnetic resonance imaging (MRI) and endorectal (transrectal) ultrasonography in evaluating patients with clinically localized prostate cancer (stage Ta or Tb). METHODS: Over a period of 15 months, 230 patients were entered into the study and evaluated with identical imaging techniques. We compared imaging results with information obtained at the time of surgery and on pathological analysis. RESULTS: MRI correctly staged 77 percent of cases of advanced disease and 57 percent of cases of localized disease; the corresponding figures for ultrasonography were 66 and 46 percent (P not significant). These figures did not vary significantly between readers; moreover, simultaneous interpretation of MRI and ultrasound scans did not improve accuracy. In terms of detecting and localizing lesions, MRI identified only 60 percent of all malignant tumors measuring more than 5 mm on pathological analysis and ultrasonography identified only 59 percent. CONCLUSIONS: The MRI and ultrasonography equipment that is currently available is not highly accurate in staging early prostate cancer, mainly because neither technique has the ability to identify microscopic spread of disease. Further evaluation with improved equipment may improve the accuracy of these techniques.

Adult↗
PubMed1990

Statistical methods for comparing dental diagnostic procedures.

In dental diagnosis, there are typically two or more clinical diagnostic procedures which may be used either independently or jointly to reach a conclusion regarding the presence of a particular disease in a patient. To determine which of these diagnostic procedures are more accurate, statistical methods may be applied to research data in which the true health status as well as the diagnosis provided by each clinical procedure are available on each observation. Results arising from this type of analysis can be of great interest to clinicians when the diagnostic procedures themselves are costly, painful, or even potentially harmful to the patient. Considered here is the special situation encountered in dental research in which each patient can have multiple concurrent cases of a certain disease such as caries, for then the statistical evaluation of diagnostic procedures is even further complicated. This report describes several statistical approaches for comparing the efficacy of diagnostic tests and illustrates their application on data from a study of diagnostic radiographs for dental caries.

Adult↗
PubMed1990

Collaborative evaluations of diagnostic tests: experience of the Radiology Diagnostic Oncology Group.

Multicenter, collaborative studies offer an effective way to meet the growing need for timely and generalizable clinical evaluations of imaging technologies. This article discusses issues of study design, statistical analysis, organization, and day-to-day group operation for collaborative prospective clinical evaluations. It draws significantly on the authors' experience with the Radiology Diagnostic Oncology Group, a cooperative group funded by the National Cancer Institute, which conducts comparative studies of the ability of diagnostic imaging modalities to enable the staging of various types of cancer including that of the prostate gland, lung, pancreas, colon, and rectum. The results from 2 1/2 years of the experience of this group hold promise for the importance of this approach to the future growth of radiologic research.

Diagnostic Imaging↗
PubMed1989

Multidimensionality of health status in an elderly population. Construct validity of a measurement battery.

Although health is generally accepted to be a multidimensional construct, the relationship among various domains has not been well defined. To understand this issue better we used principal components analysis to examine the relations among a set of health status measures gathered on 590 elderly members of a health maintenance organization (HMO). These included functional health, emotional health, social activity within and outside of the family, and cognitive functioning (all based on patient interview), physicians' ratings of patients' health, and chart-derived data on physiologic health. Support was obtained for the umbrella concept of "health" as well as for six subcomponents: functional health, emotional health, physiologic health, both kinds of social activity, and cognitive functioning. Patients' ratings of their overall physical and mental health were related to functional, physiologic, and emotional health factors, whereas physicians' ratings of overall physical and mental health were never related to the emotional health factor. This suggests that patients may hold a broader frame of reference in gauging overall health than physicians do.

Activities of Daily Living↗
PubMed1989

Cemented total hip prosthesis: radiographic and scintigraphic evaluation.

Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection.

Acetabulum↗
PubMed1988

Clinical indicators of radiographically detectable dental diseases in the adult patient.

A comprehensive analysis of the relationship between clinical observations in dental patients without symptoms and oral disease as detected by full-mouth and panoramic dental radiographs in a large population of patients has never been reported. Knowledge of these relationships is necessary in the design of a diagnostic decision process (clinical algorithm) that can predict which patients require dental radiographs for the diagnosis of dental caries or periodontal disease to be confirmed or refined. An accurate clinical algorithm could reduce the number of radiographs that are taken of certain routinely seen dental patients without symptoms, thus reducing unnecessary exposure x-radiation as well as potentially reducing health care costs for these patients. A sample of 602 adult men on whom a complete series of panoramic, posterior bitewing, and periapical dental radiographs and an independent oral examination were performed provided the opportunity to evaluate the relationship between clinically observed oral disease indicators and independent radiographic evidence of dental caries and periodontal disease. The analysis suggests that combinations of several clinical indicators can predict with some success which patients without symptoms will benefit most from oral radiographs. The presence of several carious lesions on oral examination was the best predictor of radiographic detection of dental caries. Clinical indicators tht appear to predict radiographic evidence of periodontal disease are clinical measures of pocket depth, mobility, and the patient's denture status. An important finding is that because of the high prevalence of gingivitis and plaque, these indicators were not related to radiographic evidence of periodontal disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Changes in ambulatory testing for hypertensive patients 1971-1980.

To determine temporal changes in the outpatient use of diagnostic tests, the authors studied ambulatory testing for 208 patients diagnosed with uncomplicated hypertension, cared for by 15 private office internists in 1971 through 1980. Patients diagnosed and treated earlier in the decade tended to have significantly higher blood pressure. After adjustment for blood pressure, use of diagnostic tests in terms of total charges for testing per patient per year peaked between 1973-74 and thereafter remained fairly stable at a level slightly lower than that in 1973-74. Considering the decade as a whole, use of tests was generally greater for patients with higher blood pressure readings (P less than 0.05). These findings suggest that use of tests for hypertensive patients in outpatient settings is related to severity of disease. Although treatment of new patient groups may be one factor increasing medical costs, the use of tests per se may have stabilized for diseases in which the diagnostic technologies have remained stable.

Ambulatory Care↗
PubMed1988

Modified DRGs as evidence for variability in patient severity.

The authors were interested in exploring the extent to which differences in the complexity of patients could be determined by modifications in combinations of the ICD-9-CM codes used to define DRGs. The 150 most common medical and surgical DRGs in one teaching hospital were studied. With clinical experts they identified 41 DRGs that were believed to have subgroups reflecting quite different types of patients, one group sicker and costlier than the other. Using a national data set, the authors then showed that 24 of these DRGs showed significant differences in standardized charges. In 11 of these 24 DRGs the higher cost subgroups were seen proportionately more often in major teaching hospitals compared with other types of hospitals. Results suggest that clinical modifications of a few DRGs would lead to clinically more meaningful case-mix groupings. These same results can also serve as the basis for a discussion on the implication of DRG payments for those DRGs with distributional differences among the higher-cost subgroups.

Costs and Cost Analysis↗
PubMed1988

Radiology work-load measurements reflecting variables specific to hospital, patient, and examination: results of a collaborative study.

The authors coordinated the efforts of 44 hospitals in the United States to develop average times required for technologists to perform each of 19 radiologic examinations. When applicable, the overall average times were compared with extant Canadian work-load statistics. In six of the 14 examinations for which Canadian standards exist, the average times differed by 25% or more. The data were further analyzed to adjust time estimates for the effects of different hospital characteristics (e.g., number of beds, teaching status), patient characteristics (e.g., ambulation, outpatient status), and examination characteristics (e.g., number of views, resident involvement). The key factors and the magnitude of their effects varied from examination to examination, but the effects were generally large enough to have managerial significance. The factors can be evaluated by individual hospitals to produce customized estimates of average examination times. The data presented in this report can be used in management control systems by radiology departments in hospitals of varying sizes and teaching characteristics.

Allied Health Personnel↗
PubMed1988

Assessment of radiologic tests: control of bias and other design considerations.

The assessment of new radiologic tests can be seriously hampered by the presence of systematic bias. Biases can arise from incomplete verification of the sample population; omission of uninterpretable tests; absence of a definitive reference test; extraneous factors affecting interpretation; and extrapolation factors including variations in test efficacy among patients, hospitals, and the radiologists who interpret the tests. The authors review these biases that affect the results of efficacy studies and provide guidelines to avoid these problems.

Evaluation Studies as Topic↗