Biomedical subjects
L A Petersen
Publications and source records attributed to L A Petersen.
Incidence of adverse drug events and potential adverse drug events. Implications for prevention. ADE Prevention Study Group.
OBJECTIVES: To assess incidence and preventability of adverse drug events (ADEs) and potential ADEs. To analyze preventable events to develop prevention strategies. DESIGN: Prospective cohort study. PARTICIPANTS: All 4031 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 intensive care units and four medical and two surgical general care units. MAIN OUTCOME MEASURES: Adverse drug events and potential ADEs. METHODS: 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 ADEs or potential ADEs and as to severity and preventability. RESULTS: Over 6 months, 247 ADEs and 194 potential ADEs were identified. Extrapolated event rates were 6.5 ADEs and 5.5 potential ADEs per 100 nonobstetrical admissions, for mean numbers per hospital per year of approximately 1900 ADEs and 1600 potential ADEs. Of all ADEs, 1% were fatal (none preventable), 12% life-threatening, 30% serious, and 57% significant. Twenty-eight percent were judged preventable. Of the life-threatening and serious ADEs, 42% were preventable, compared with 18% of significant ADEs. Errors resulting in preventable ADEs occurred most often at the stages of ordering (56%) and administration (34%); transcription (6%) and dispensing errors (4%) were less common. Errors were much more likely to be intercepted if the error occurred earlier in the process: 48% at the ordering stage vs 0% at the administration stage. CONCLUSION: Adverse drug events were common and often preventable; serious ADEs were more likely to be preventable. Most resulted from errors at the ordering stage, but many also occurred at the administration stage. Prevention strategies should target both stages of the drug delivery process.
Evaluation of screening criteria for adverse events in medical patients.
The goals of this study were to evaluate the sensitivity and specificity of 15 screening criteria for adverse events, preventable adverse events, and severe adverse events in medical patients, and to evaluate combinations of these criteria, including those available through hospital billing data, to determine whether a small subset of generic screens might efficiently identify adverse events. The authors studied 3,137 consecutive admissions to a medical service over a 4-month period at an urban tertiary care hospital. Chart reviews were performed after discharge by reviewers blinded to the eventual determination of presence of an adverse event. Judgments regarding presence, severity, and preventability of adverse events were made using guided implicit reviews by physicians. Of all admissions, 341 (11%) were judged to include an adverse event, of which 274 were severe and 145 were preventable. Sensitivity and specificity of individual screens varied widely, with prior hospitalization the most sensitive (68%) but least specific (56%). Death was specific (97%) but not sensitive (9%); readmission was intermediate (sensitivity 28%, specificity 80%). In analyses using severe and preventable adverse events as the outcome, results were generally similar. Combinations of screens also were compared, including some using only screens available through billing data; the most sensitive billing strategy detected just 47% of adverse events, but cost only $3 per admission reviewed and $57 per adverse event, versus $13 per admission and $116 per adverse event for a strategy in which all records were reviewed. It is concluded that no small subset of screens identified a high percentage of adverse events. Using screens available through billing data, although insensitive, would be much less costly.
Does housestaff discontinuity of care increase the risk for preventable adverse events?
OBJECTIVE: To study the relation between housestaff coverage schedules and the occurrence of preventable adverse events. DESIGN: Case-control study. SETTING: Urban teaching hospital. PATIENTS: All 3146 patients admitted to the medical service during a 4-month period. MEASUREMENTS: A previously tested confidential self-report system to identify adverse events, which were defined as unexpected complications of medical therapy that resulted in increased length of stay or disability at discharge. A panel of three board-certified internists confirmed events and evaluated preventability based on case summaries. Housestaff coverage was coded according to the day in the usual intern's schedule and to cross-coverage status. Cross-coverage was defined as care by a house officer who was not the patient's usual intern and not a member of the usual intern's patient care team. Coverage for an adverse event was assigned according to who was covering during the proximate cause of that event. Clinical data were collected for each patient and two matched controls. RESULTS: Of the 124 adverse events reported and confirmed, 54 (44%) were judged potentially preventable. In the univariate analysis, patients with potentially preventable adverse events were more likely than their controls to be covered by a physician from another team at the time of the event (26% compared with 12% [odds ratio, 3.5; P = 0.01]). In the multivariate analysis, three factors were significant independent correlates of potentially preventable adverse events; cross-coverage (odds ratio, 6.1; 95% CI, 1.4 to 26.7), Acute Physiology and Chronic Health Evaluation II score (odds ratio per point, 1.2; CI, 1.1 to 1.4), and history of gastrointestinal bleeding (odds ratio, 4.7; CI, 1.2 to 19.0). CONCLUSION: Potentially preventable adverse events were strongly associated with coverage by a physician from another team, which may reflect management by housestaff unfamiliar with the patient. The results emphasize the need for careful attention to the outcome of work-hour reforms for housestaff.
Physician reporting compared with medical-record review to identify adverse medical events.
OBJECTIVE: To assess the effectiveness of housestaff physician reporting as a method for identifying adverse events on a medical service and to compare the physician reporting mechanism with a retrospective record review mechanism. SETTING: Medical service of an urban, university-affiliated teaching hospital. DESIGN: Concurrent physician reporting mechanism using the hospital electronic mail system compared with a retrospective record review using a screening mechanism followed by structured, implicit physician review of the record. PATIENTS: All 3146 admissions to the medical service from 13 November 1990 to 14 March 1991. RESULTS: The housestaff physician reporting method identified nearly the same number (89) of adverse events as did the record review (85). However, the two methods identified only 41 of the same patients (kappa = 0.52). No statistically significant clinical or socioeconomic differences occurred between the patients identified as having had an adverse event, using the two reporting methods (physician versus record review). The housestaff did report statistically more preventable adverse events (62.5% compared with 32%; P = 0.003). The physician reporting mechanism was also less costly (approximately $15,000 compared with $54,000). CONCLUSION: An adverse event identification strategy based on physician self-referral uncovers as many adverse events as does a record review and is less costly. In addition, physician-identified events are more likely to be preventable and, thus, are targets for quality improvement.
Integrating providers into quality improvement: a pilot project at one hospital.
Brigham and Women's Hospital initiated a study of the quality of care centering on self-reporting of potential medical injuries by providers. The goal of the study is to decrease the incidence of such injuries through a continuous quality methodology that integrates providers into the identification phase and incorporates all hospital employees in the development of new practices. This article provides an overview of the investigation methodology and discusses the conceptual relationships between clinical epidemiological analyses and industrial quality improvement.
Isolation and characterization of isoprene mutants of Escherichia coli.
Isoprenoid compounds are found in all organisms. In Escherichia coli the isoprene pathway has three distinct branches: the modification of tRNA; the respiratory quinones ubiquinone and menaquinone; and the dolichols, which are long-chain alcohols involved in cell wall biosynthesis. Very little is known about procaryotic isoprene biosynthesis compared with what is known about eucaryote isoprene biosynthesis. This study approached some of the questions about isoprenoid biosynthesis and regulation in procaryotes by isolating and characterizing mutants in E. coli. Mutants were selected by determining their resistance to low levels of aminoglycoside antibiotics, which require an electron transport chain for uptake into bacterial cells. The mutants were characterized with regard to their phenotypes, map positions, enzymatic activities, and total ubiquinone content. In particular, the enzymes studied were isopentenyldiphosphate delta-isomerase (EC 5.3.3.2), farnesyldiphosphate synthetase (EC 2.5.1.1), and higher prenyl transferases.
Fetal surveillance in multifetal pregnancy.
Multiple methods of tocolysis and fetal surveillance provide unprecedented ways to improve multifetal outcomes through meticulous antepartum care. Although few practitioners have much experience with these complicated pregnancies, knowledge is growing with the increasing incidence of multifetal pregnancy. A review of the current literature regarding antepartum surveillance provides the basis for a discussion of the techniques essential to quality nursing care during multifetal pregnancy. Guidelines are provided for nursing standards in documentation, terminology, and care during surveillance of multiple fetuses.
The costs of adverse drug events in hospitalized patients. Adverse Drug Events Prevention Study Group.
OBJECTIVE: To assess the additional resource utilization associated with an adverse drug event (ADE). DESIGN: Nested case-control study within a prospective cohort study. PARTICIPANTS: The cohort included 4108 admissions to a stratified random sample of 11 medical and surgical units in 2 tertiary-care hospitals over a 6-month period. Cases were patients with an ADE, and the control for each case was the patient on the same unit as the case with the most similar pre-event length of stay. MAIN OUTCOME MEASURES: Postevent length of stay and total costs. METHODS: Incidents were detected by self-report stimulated by nurses and pharmacists and by daily chart review, and were classified as to whether they represented ADEs. Information on length of stay and charges was obtained from billing data, and costs were estimated by multiplying components of charges times hospital-specific ratios of costs to charges. RESULTS: During the study period, there were 247 ADEs among 207 admissions. After outliers and multiple episodes were excluded, there were 190 ADEs, of which 60 were preventable. In paired regression analyses adjusting for multiple factors, including severity, comorbidity, and case mix, the additional length of stay associated with an ADE was 2.2 days (P=.04), and the increase in cost associated with an ADE was $3244 (P=.04). For preventable ADEs, the increases were 4.6 days in length of stay (P=.03) and $5857 in total cost (P=.07). After adjusting for our sampling strategy, the estimated postevent costs attributable to an ADE were $2595 for all ADEs and $4685 for preventable ADEs. Based on these costs and data about the incidence of ADEs, we estimate that the annual costs attributable to all ADEs and preventable ADEs for a 700-bed teaching hospital are $5.6 million and $2.8 million, respectively. CONCLUSIONS: The substantial costs of ADEs to hospitals justify investment in efforts to prevent these events. Moreover, these estimates are conservative because they do not include the costs of injuries to patients or malpractice costs.