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Biomedical subjects

D W Bates

Publications and source records attributed to D W Bates.

At least 91 records · Page 5Linked to original sources
PubMed1998

What proportion of common diagnostic tests appear redundant?

PURPOSE: To identify ancillary tests for which there are criteria defining the earliest interval at which a repeat test might be indicated, to determine how often each test is repeated earlier than these intervals and, if repeated, provides useful information. SUBJECTS AND METHODS: We performed a retrospective cohort study of 6,007 adults discharged from a large teaching hospital during a 3-month period in 1991. We measured the proportion of commonly performed diagnostic tests that were redundant, and their associated charges. RESULTS: Of the 6,007 patients discharged, 5,289 (88%) had at least one of 12 target tests performed. Overall, 78,798 of the target tests were performed during the study period, of which 22,237 (28%) were repeated earlier than test-specific predefined intervals. This percentage varied substantially by test (range, 2% to 62%). To assess how many early repeats were justified, we performed chart reviews in a random sample stratified by test. For two tests, nearly all the initial results in the sample were abnormal, and all repeats were considered justified. Of early repeats following a normal initial result for the remaining 10 tests, chart review found no clinical indication for 92%, and a weighted mean of 40% appeared redundant. Overall, 8.6% of these 10 tests appeared redundant; if these were not performed, the annual charge reductions would be $930,000 at our hospital, although the impact on costs would be much smaller. CONCLUSIONS: For some tests, an important proportion are repeated too early to provide useful clinical information. Most such tests might be eliminated using computerized reminder systems.

Adult↗
PubMed1998

Asking residents about adverse events in a computer dialogue: how accurate are they?

BACKGROUND: Although retrospective identification of adverse events is time-consuming, whether they are present and/or expected is often readily apparent to providers during the provision of care. METHODS: A computer program to flag admissions with possible adverse events was developed. Readmissions to the hospital within 31 days and admissions including more than one visit to the operating room (OR) were flagged. For surgical site infections, all admissions--including a visit to the OR--were flagged, but only a sample was evaluated in the reliability assessment. Residents in an urban, tertiary care hospital were questioned when inputting computerized discharge orders regarding adverse events among 391 cases sampled from 6,813 admissions for a two-month period. RESULTS: For the 228 readmissions (3.3% of all admissions) identified by the computer program, resident responses had a sensitivity of 57% and a specificity of 73% in detecting an unexpected readmission (nurse responses, 96% and 91%). For the 79 patients with a return to the OR, the residents' responses had a sensitivity of 86% and a specificity of 84% for detecting an unexpected return (versus 75% and 98% for the nurses' responses). For the 209 patients with an OR visit, the sensitivity and specificity for a surgical site infection were 85% and 98% for the residents and 54% and 99% for the nurses. DISCUSSION: Information systems can be used to screen for adverse events and to ask providers whether adverse events are unexpected, although the reliability of this approach is likely to vary by event type.

Boston↗
PubMed1998

Gender and utilization of ancillary services.

OBJECTIVE: To determine whether gender is associated with the use of ancillary services in hospitalized patients. DESIGN: A retrospective study of laboratory and radiology tests ordered for medical and surgical inpatients over 16-month and 20-month periods, respectively. Obstetric patients were excluded. MEASUREMENTS AND MAIN RESULTS: Number of clinical laboratory and radiology tests per admission, their associated charges, and total charges per admission were measured. In crude analyses, women had 16.5% fewer clinical laboratory tests (p < .0001) with 18.8% lower associated charges (p < .0001) and 24.4% fewer radiology tests (p < .0001) with 15.6% lower associated charges (p < .0001) than men. Total changes for the admission were lower for women in both the clinical laboratory study period ($16,178 vs $18,912, p < .0001) and the radiology study period ($14,621 vs $18,182, p < .0001). When adjusted for age, race, insurance status, service, diagnosis-related-group weight, and length of stay, these differences were smaller but persisted: women had 3.7% fewer laboratory tests performed (p < .001) with 4.8% lower associated charges (p < .001). In similarly adjusted analyses for radiology studies, women received 10.4% fewer radiology examinations (p < .001), with 4.1% lower associated charges (p < .01). There were no significant differences in the adjusted total charges in the laboratory group ($17,450 vs $17,655, p = .20) and only a marginally significant difference in the radiology group ($16,278 vs $16,498, p = .05). When we compared ancillary utilization within the five largest diagnosis-related groups, these differences persisted. CONCLUSIONS: Men receive more ancillary services than women, even after adjusting for potential confounders.

Ancillary Services, Hospital↗
PubMed1998

Limulus amebocyte lysate assay for detection of endotoxin in patients with sepsis syndrome. AMCC Sepsis Project Working Group.

Clinical predictions alone are insufficiently accurate to identify patients with specific types of bloodstream infection; laboratory assays might improve such predictions. Therefore, we performed a prospective cohort study of 356 episodes of sepsis syndrome and did Limulus amebocyte lysate (LAL) assays for endotoxin. The main outcome measures were bacteremia and infection due to gram-negative organisms; other types of infection were secondary outcomes. Assays were defined as positive if the result was > or = 0.4 enzyme-linked immunosorbent assay units per milliliter. There were positive assays in 119 (33%) of 356 episodes. Assay positivity correlated with the presence of fungal bloodstream infection (P < .003) but correlated negatively with the presence of gram-negative organisms in the bloodstream (P = .04). A trend toward higher rates of mortality in the LAL assay-positive episodes was no longer present after adjusting for severity. Thus, results of LAL assay did not correlate with the presence of bacteremia due to gram-negative organisms or with mortality after adjusting for severity but did correlate with the presence of fungal bloodstream infection.

Bacteremia↗
PubMed1998

Improving the use of therapeutic drug monitoring.

Many studies suggest that therapeutic drug monitoring (TDM) could be used better. For example, a high proportion of TDM assays either lack an inappropriate indication or are drawn with suboptimal timing, particularly for inpatients. From a perspective of quality, undermonitoring has more potential adverse consequences than overmonitoring. Because both overuse and underuse occur, it may be possible to improve the quality of TDM while reducing its costs and, more important, to have similar effects on the quality and costs associated with caring for patients administered drugs.

Drug Monitoring↗
PubMed1998

Trends in the use of radiology with inpatients: what has changed in a decade?

OBJECTIVE: Our goal was to evaluate trends in the use of radiology with inpatients in the 10-year period of 1984-1993. MATERIALS AND METHODS: We retrospectively reviewed administrative data from a 751-bed, tertiary care hospital between October 1, 1983, and September 30, 1993 (Fiscal years 1984-1993). We coded each study by imaging technique: CT, MR imaging, sonography, nuclear medicine, or conventional studies (plain films and fluoroscopy). Echocardiography, cardiac catheterization, and angioplasty procedures were omitted. The number of admissions per year was adjusted for severity of disease (case-mix-adjusted admission [CMA]). We used relative value units to evaluate workload changes during the study period. We assessed significance of trends using linear regression analysis. RESULTS: The total number of imaging studies per CMA decreased during the study period (p = .0001). This was due to a decrease in the number of conventional studies (p = .0001) and sonograms per CMA (p = .02), despite significant increases in the numbers of CT (p = .005) and MR imaging (p = .0001) studies per CMA. No significant change existed in the number of nuclear medicine studies per CMA (p = .11). The global, professional, and technical relative value units per CMA rose during the latter half of the study. CONCLUSION: The overall number of imaging studies per CMA decreased during the decade, despite a significant rise in the use of CT and MR imaging, suggesting that these new imaging techniques are replacing older ones. To control further increases in overall imaging costs, priority should be placed on understanding the patterns of use for CT and MR imaging techniques and curbing their inappropriate use.

Adult↗
PubMed1998

Design and development of a computer-based clinical referral system for use within a physician hospital organization.

The process of creating a clinical referral for a patient and the transfer of information from the primary care physician to the specialist and back again is a key component in the struggle to deliver less costly and more effective clinical care. We have created a computer-based clinical referral application which facilitates 1) identifying an appropriate specialist; 2) collecting the clinical, demographic, and financial data required to generate a referral; and 3) transferring the information between the specialist and the primary care physician. Preliminary results indicate that the new computer-based process is faster.

Ambulatory Care Information Systems↗
PubMed1998

Measuring and improving quality using information systems.

Information systems (IS) are increasingly important for measuring and improving quality. In this paper, we describe our integrated delivery system's plan for and experiences with measuring and improving quality using IS. Our approach is that for quality measurement to be practical, it must be integrated with the routine provision of care, and whenever possible should be done using IS. Thus, at one hospital, we now perform almost all quality measurement using IS. However, IS are not only useful for measuring care, but represent powerful tools for improving care using decision support. Specific areas in which IS has already been particularly effective include reducing the unnecessary use of laboratory testing, reporting important abnormalities to key providers rapidly, adverse drug event detection and prevention, initiatives to reduce the costs of drugs, and making critical pathways available to providers. The next wave of effort will be to promote widespread use of computerized guidelines, which is likely to prove more challenging. However, the advent of managed care in the U.S. has produced strong incentives to provide high quality care at low cost, and our perspective is that only with better IS than exist today will this be possible on a widespread basis. Such systems make feasible implementation of care improvement and cost reduction initiatives on a scale which could not previously be considered.

Decision Making, Computer-Assisted↗
PubMed1998

Strategies for physician education in therapeutic drug monitoring.

Although therapeutic drug monitoring (TDM) is probably very useful overall, studies suggest that it could be used better. Many drug concentrations appear to have inappropriate indications or suboptimal timing, particularly in the inpatient setting. Undermonitoring is also a concern. Thus, it may be possible to both improve the quality of TDM and reduce the overall costs of care. Here we review approaches for improving the use of TDM and present some illustrative experiences. Specific approaches discussed include use of traditional approaches such as lectures and newsletters, multidisciplinary quality improvement efforts, formal TDM services, and use of the computer as a tool for education and behavior change. Computerized methods appear to hold substantial potential, particularly as more organizations develop better information systems, but other approaches are also effective and are complementary. To be most successful, interventions should consider all stages of the process.

Canada↗
PubMed1998

Towards improving the accuracy of the clinical database: allowing outpatients to review their computerized data.

We developed an application that allowed patients coming to the clinic to review on a paper form their computerized health maintenance, medication, and allergy data. The patient could edit the paper form and the physician then could enter the new data into the database. We implemented the system in 4 clinics (17 MDs) To evaluate the system, we reviewed 80 forms from one physician's patients to determine how often patients provided new data. We also sent questionnaires to the physicians asking for their estimates of how often there was new data and for their impression of the system. We interviewed secretaries in the clinics about logistical issues. Of the 80 forms, 29 (36%) had new data; 28% had new health maintenance data and 19% had new medication data. The 7 physicians who responded to the questionnaire estimated that new health maintenance data were present on 22% of the forms. The physicians who responded to the questionnaire felt the system was useful. The secretaries said that managing the paper flow in the clinic was often unwieldy and in some clinics, the system has been abandoned or is used intermittently. Having patients review their data is one avenue to improving the accuracy of computerized records.

Adult↗
PubMed1997

Does the computerized display of charges affect inpatient ancillary test utilization?

BACKGROUND: The computerized display of charges for ancillary tests in outpatients has been found to affect physician-ordering behavior, but this issue has not been studied in inpatients. OBJECTIVE: To assess whether the computerized display of charges for clinical laboratory or radiological tests affected physician-ordering behavior. PATIENTS AND METHODS: Two prospective controlled trials, randomized by patient, were performed. Each trial included all medical and surgical inpatients at 1 large teaching hospital during 4 and 7 months: 3536 intervention and 3554 control inpatients in the group with clinical laboratory tests, and 8728 intervention and 8653 control inpatients in the group with radiological tests. The intervention consisted of the computerized display of charges for tests at the time of ordering. MAIN OUTCOME MEASURES: The number of clinical laboratory and radiological tests ordered per admission and the charges for these tests. RESULTS: For the clinical laboratory tests, during a 4-month study period, patients in the intervention group had 4.5% fewer tests ordered, and the total charges for these tests were 4.2% lower, although neither difference was statistically significant. Compared with historical controls from the same 4-month period a year before, the charges for the tests per admission had decreased 13.3%, but the decrease was temporally correlated with a restriction of future ordering of tests, and not with the introduction of the display of charges. For the radiological tests, during a 7-month period, the intervention group had almost identical numbers of tests ordered and charges for these tests. CONCLUSIONS: The computerized display of charges had no statistically significant effect on the number of clinical laboratory tests or radiological procedures ordered or performed, although small trends were present for clinical laboratory tests. More intensive interventions may be needed to affect physician test utilization.

Computer Systems↗
PubMed1997

Epidemiology of sepsis syndrome in 8 academic medical centers.

CONTEXT: Sepsis syndrome is a leading cause of mortality in hospitalized patients. However, few studies have described the epidemiology of sepsis syndrome in a hospitalwide population. OBJECTIVE: To describe the epidemiology of sepsis syndrome in the tertiary care hospital setting. DESIGN: Prospective, multi-institutional, observational study including 5-month follow-up. SETTING: Eight academic tertiary care centers. METHODS: Each center monitored a weighted random sample of intensive care unit (ICU) patients, non-ICU patients who had blood cultures drawn, and all patients who received a novel therapeutic agent or who died in an emergency department or ICU. Sepsis syndrome was defined as the presence of either a positive blood culture or the combination of fever, tachypnea, tachycardia, clinically suspected infection, and any 1 of 7 confirmatory criteria. Estimates of total cases expected annually were extrapolated from the number of cases, the period of observation, and the sampling fraction. RESULTS: From January 4, 1993, to April 2, 1994, 12759 patients were monitored and 1342 episodes of sepsis syndrome were documented. The extrapolated, weighted estimate of hospitalwide incidence (mean+/-95% confidence limit) of sepsis syndrome was 2.0+/-0.16 cases per 100 admissions, or 2.8+/-0.17 per 1000 patient-days. The unadjusted attack rate for sepsis syndrome between individual centers differed by as much as 3-fold, but after adjustment for institutional differences in organ transplant populations, variation from the expected number of cases was reduced to 2-fold and was not statistically significant overall. Patients in ICUs accounted for 59% of total extrapolated cases, non-ICU patients with positive blood cultures for 11%, and non-ICU patients with negative blood cultures for 30%. Septic shock was present at onset of sepsis syndrome in 25% of patients. Bloodstream infection was documented in 28%, with gram-positive organisms being the most frequent isolates. Mortality was 34% at 28 days and 45% at 5 months. CONCLUSIONS: Sepsis syndrome is common in academic hospitals, although the overall rates vary considerably with the patient population. A substantial fraction of cases occur outside ICUs. An understanding of the hospitalwide epidemiology of sepsis syndrome is vital for rational planning and treatment of hospitalized patients with sepsis syndrome, especially as new and expensive therapeutic agents become available.

Adult↗
PubMed1997

Costs, outcomes, and patient satisfaction by provider type for patients with rheumatic and musculoskeletal conditions: a critical review of the literature and proposed methodologic standards.

PURPOSE: To compare the outcomes of care provided by generalists with that provided by specialists for patients with musculoskeletal and rheumatic conditions. DATA SOURCES: English-language studies published between 1986 and April 1996 were identified through a MEDLINE search. STUDY SELECTION: Studies that compared generalists' and specialists' treatment preferences, appropriateness of care, or outcomes with regard to musculoskeletal and rheumatic conditions were examined. DATA EXTRACTION: Studies were reviewed for methodologic rigor and outcomes. DATA SYNTHESIS: Low back pain is treated by many types of providers, without consistent differences in outcomes across provider types. In one study, however, patients were more satisfied with chiropractic care than with care provided by primary care physicians, although the former cost twice as much as the latter. For osteoarthritis of the hip, rheumatologists and primary care providers reported using different therapeutic regimens. For acute mono- and oligoarthritis, rheumatologists performed arthrocentesis more appropriately than nonrheumatologists and produced shorter durations of hospitalization. In the management of gout, rheumatologists used colchicine during the introduction of urate-lowering therapy more appropriately than other providers. In two population-based cohorts of patients with rheumatoid arthritis, patients cared for by rheumatologists were prescribed significantly more disease-modifying agents and had less disability than patients cared for by generalists. CONCLUSIONS: Although empirical data are scant, there seem to be differences between generalists and specialists for a range of outcomes in various musculoskeletal and rheumatic conditions. Studies to data have important methodologic limitations that need to be addressed in future research.

Health Care Costs↗
PubMed1997

Coronary angiography and angioplasty after acute myocardial infarction.

PURPOSE: To assess the data that support the use of coronary angiography and angioplasty after acute myocardial infarction, that identify the risks of these procedures, and that analyze their use and costs. DATA SOURCES: English-language articles published between 1970 and June 1995 identified through a search of the MEDLINE database. STUDY SELECTION: Studies that contained information about benefits, risks, use, and costs of coronary angiography and angioplasty after acute myocardial infarction. DATA EXTRACTION: Descriptive and analytic data from each study were collected. DATA SYNTHESIS: The outcome for patients who have complications of myocardial infarction (such as shock) is poor. Such patients usually undergo angiography, although the evidence that supports this practice is weak. Preliminary data suggest that patients who immediately have angiography and angioplasty after acute myocardial infarction have better outcomes than do patients who receive thrombolytic therapy with angioplasty only for specific indications in experienced centers. After the acute phase of myocardial infarction, patients who have noninvasive evidence of persistent or recurrent ischemia are believed to benefit from angiography. In the remaining patients, however, angiography after myocardial infarction has not been shown to be beneficial. Coronary angiography is done in 30% to 81% of patients after acute myocardial infarction in different settings and regions; for many of these patients, the benefit is questionable. Better outcomes are not always associated with more frequent use of the procedure. In the United States, catheterizations after myocardial infarction cost approximately $1 billion per year. CONCLUSIONS: Although many patients benefit from angiography and angioplasty after myocardial infarction, others probably do not. Substantial resources are at stake.

Angioplasty↗
PubMed1997

Predicting Clostridium difficile stool cytotoxin results in hospitalized patients with diarrhea.

OBJECTIVE: To validate a model for the prediction of Clostridium difficile cytotoxin assay results, and to identify a subgroup of patients with a very low likelihood of C. difficile-associated disease in whom the yield of routine cytotoxin testing is low. DESIGN: Prospective cohort study. Relevant clinical symptoms, signs, and antibiotic exposure were recorded before reporting of assay results. Each predictor was assigned a score based on regression coefficients, and patients were stratified according to their total score. SETTING: Two urban, tertiary care, university hospitals. PATIENTS: A total of 609 consecutive adult inpatients who received testing for C. difficile cytotoxin during a 3-month period in 1994. MEASUREMENTS AND MAIN RESULTS: The prevalence of positive cytotoxin assays was 8% in the validation set, compared with 14% in the derivation set. Defining patients without both prior antibiotic use and at least one symptom predictor (significant diarrhea or abdominal pain) as a low-risk subgroup, the misclassification rate was 2.8% (5/177) for assay results; of the five misclassified cases patients, only one was judged to have C. difficile-associated disease. Use of this rule to identify low-risk patients could have potentially averted 29% of all cytotoxin assays. CONCLUSIONS: Patients without a history of antibiotic use and either significant diarrhea or abdominal pain are unlikely to have positive C. difficile cytotoxin assays and may not require cytotoxin testing.

Adult↗
PubMed1997

Predicting bacteremia in patients with sepsis syndrome. Academic Medical Center Consortium Sepsis Project Working Group.

The goal of this study was to develop and validate clinical prediction rules for bacteremia and subtypes of bacteremia in patients with sepsis syndrome. Thus, a prospective cohort study, including a stratified random sample of 1342 episodes of sepsis syndrome, was done in eight academic tertiary care hospitals. The derivation set included 881 episodes, and the validation set included 461. Main outcome measures were bacteremia caused by any organism, gram-negative rods, gram-positive cocci, and fungal bloodstream infection. The spread in probability between low- and high-risk groups in the derivation sets was from 14.5% to 60.6% for bacteremia of any type, from 9.8% to 32.8% for gram-positive bacteremia, from 5.3% to 41.9% for gram-negative bacteremia, and from 0.6% to 26.1% for fungemia. Because the model for gram-positive bacteremia performed poorly, a model predicting Staphylococcus aureus bacteremia was developed; it performed better, with a low- to high-risk spread of from 2.6% to 21.0%. The prediction models allow stratification of patients according to risk of bloodstream infections; their clinical utility remains to be demonstrated.

Adult↗
PubMed1997

Preventable adverse drug events in hospitalized patients: a comparative study of intensive care and general care units.

OBJECTIVES: To compare the frequency and preventability of adverse drug events and potential adverse drug events in intensive care units (ICUs) and non-ICUs. To evaluate systems factors involving the individual caregivers, care unit teams, and patients involved in each adverse drug event by comparing ICUs with non-ICUs and medical ICUs with surgical ICUs. DESIGN: Prospective cohort study. Participants included all 4,031 adult admissions to a stratified, random sample of 11 medical and surgical units in two tertiary care hospitals over a 6-month period. Units included two medical and three surgical ICUs and four medical and two surgical general care units. SETTING: Two tertiary care hospitals: Eleven medical and surgical units, including two medical and three surgical ICUs. PATIENTS: Adult admissions (n = 4,031). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Rate of preventable adverse drug events and potential adverse drug events, length of stay, charges, costs, and measures of the unit's environment. Incidents were detected by stimulated self-report by nurses and pharmacists and by daily review of all charts by nurse investigators. Incidents were subsequently classified by two independent reviewers as to whether they represented adverse drug events or potential adverse drug events and as to severity and preventability. Those individuals involved in the preventable adverse drug event and potential adverse drug event underwent detailed interviews by peer case-investigators. The rate of preventable adverse drug events and potential adverse drug events in ICUs was 19 events per 1000 patient days, nearly twice that rate of non-ICUs (p <.01). The medical ICU rate (25 events per 1000 patient days) was significantly (p <.05) higher than the surgical ICU rate (14 events per 1000 patient days). When adjusted for the number of drugs used in the previous 24 hrs or ordered since admission, there were no differences in rates between ICUs and non-ICUs. ICU acuity, length of stay, and severity of the adverse drug event were greater in ICUs than non-ICUs, but there were no differences between medical ICU and surgical ICU patients. Structured interviews indicated almost no differences between ICUs and non-ICUs for many characteristics of the patient, patient care team, systems, and individual caregivers. CONCLUSIONS: The rate of preventable and potential adverse drug events was twice as high in ICUs compared with non-ICUs. However, when adjusted for the number of drugs ordered, there was no greater likelihood for preventable adverse drug events and potential adverse drug events to occur in ICUs than in non-ICUs. Preventable adverse drug events and potential adverse drug events occurred in units that functioned normally and involved caregivers who were working under reasonably normal circumstances, not at the extremes of workload, stress, or a difficult environment.

Adult↗