Biomedical subjects

C van Walraven

Publications and source records attributed to C van Walraven.

28 records · Page 2Linked to original sources

PubMed1998

Effect of population-based interventions on laboratory utilization: a time-series analysis.

CONTEXT: Previous studies have identified methods of decreasing laboratory utilization. However, most were hospital-based, relatively small, single-centered, or of limited duration. OBJECTIVE: To determine the effect of 3 population-based interventions (physician guidelines, laboratory requisition form modification, and changes to funding policy) on laboratory utilization in Ontario. DESIGN: Interventional time-series analysis in which data analysis was based on all claims made to the Ontario Health Insurance Program between July 1, 1991, and April 1997 for laboratory tests affected by the interventions. SETTING: All clinical laboratories (not based in hospitals) in Ontario. INTERVENTIONS: Physician guidelines, modification of laboratory requisition form, and changes in funding policy for the use of the erythrocyte sedimentation rate test (ESR), microscopic urinalysis, tests for renal function, iron stores, serum urea, and serum iron determinations, and tests for thyroid dysfunction (total thyroxine and thyroid-stimulating hormone [TSH]). MAIN OUTCOME MEASURES: Change from 1991 to 1997 in utilization rates of ESR, microscopic urinalysis, serum urea and iron determinations, and tests for total thyroxine and TSH. RESULTS: Age- and sex-standardized rates for laboratory tests unaffected by the interventions were stable during the study period. Utilization of ESR and urea determination decreased by 58% (P<.001) and 57% (P<.001), respectively, after they were removed from the requisition form and guidelines discouraging their use were disseminated. Rates for urinalyses without microscopy increased by 1700% (P<.001), while microscopic urinalysis decreased by 14% (P<.001), after a policy change eliminated microscopic urinalysis from routine urinalysis. Rates of iron determination declined by 80% (P<.001) and ferritin rates increased by 34% (P= .05) when policy changes eliminated iron testing when ordered with ferritin and guidelines advocating ferritin alone for investigating iron deficiency were disseminated. Utilization of total thyroxine testing declined by 96% (P = .02) when the provincial health plan stopped its funding. When TSH was removed from the laboratory requisition form, a 12% decline (P= .03) in its use was observed. Through April 1997, these interventions saved more than 625000 tests or $210400. CONCLUSIONS: The combination of guideline dissemination, laboratory requisition form modification, and changes to funding policy was associated with significant reductions in laboratory utilization.

Clinical Laboratory Techniques↗

PubMed1998

Do we know what inappropriate laboratory utilization is? A systematic review of laboratory clinical audits.

OBJECTIVE: Laboratory utilization has steadily increased, and some studies suggest inappropriate utilization. Therefore, we wished to assess studies that measure inappropriate laboratory use in light of methodological criteria. DESIGN: Systematic review of published studies. DATA SOURCES: MEDLINE, HEALTHSTAR, and EMBASE databases were searched from 1966 to September 1997 using a broad and inclusive strategy with no language restriction. In addition, the references of all retrieved studies and 3 textbooks on diagnostic testing were hand-searched. STUDY SELECTION: All studies that provided and applied criteria for inappropriate laboratory use. DATA EXTRACTION: Studies were categorized based on whether the criteria were implicit (objective criteria for inappropriate utilization not provided or very broad) or explicit. Guidelines for evaluation were applied to each study by a single reviewer. DATA SYNTHESIS: Forty-four eligible studies were identified. Eleven studies used implicit criteria for inappropriate laboratory utilization and contained small numbers of patients or physicians. Most did not adequately assess the reliability of the implicit criteria. Thirty-three studies used explicit criteria based on the appropriateness of test choice, frequency, and timing, as well as the probability of a positive result. There were large variations in the estimates of inappropriate laboratory use (4.5%-95%). Evidence supporting the explicit criteria was frequently weak by the standards suggested for therapeutic maneuvers, but was nonetheless compelling based on principles of physiology, pharmacology, and probability. CONCLUSIONS: Many studies identify inappropriate laboratory use based on implicit or explicit criteria that do not meet methodological standards suggested for audits of therapeutic maneuvers. Researchers should develop alternative evidentiary standards for measuring inappropriateness of laboratory test use.

Clinical Laboratory Techniques↗

PubMed1998

Do advanced cardiac life support drugs increase resuscitation rates from in-hospital cardiac arrest? The OTAC Study Group.

STUDY OBJECTIVE: The benefit of Advanced Cardiac Life Support (ACLS) medications during cardiac resuscitation is uncertain. The objective of this study was to determine whether the use of these medications increased resuscitation from in-hospital cardiac arrest. METHODS: A prospective cohort of patients undergoing cardiac arrest in 1 of 5 academic hospitals was studied. Patient and arrest factors related to resuscitation outcome were recorded. We determined the association of the administration of ACLS drugs (epinephrine, atropine, bicarbonate, calcium, lidocaine, and bretylium) with survival at 1 hour after resuscitation. RESULTS: Seven hundred seventy-three patients underwent cardiac resuscitation, with 269 (34. 8%) surviving for 1 hour. Use of epinephrine, atropine, bicarbonate, calcium, and lidocaine was associated with a decreased chance of successful resuscitation (P <.001 for all except lidocaine, P <.01). While controlling for significant patient factors (age, gender, and previous cardiac or respiratory disease) and arrest factors (initial cardiac rhythm, and cause of arrest), multivariate logistic regression demonstrated a significant association between unsuccessful resuscitation and the use of epinephrine (odds ratio . 08 [95% confidence interval .04-.14]), atropine (.24 [.17-.35]), bicarbonate (.31 [.21-.44]), calcium (.32 [.18-.55]), and lidocaine (.48 [.33-.71]). Drug effects did not improve when patients were grouped by their initial cardiac rhythm. Cox proportional hazards models that controlled for significant confounders demonstrated that survivors were significantly less likely to receive epinephrine (P <. 001) or atropine (P <.001) throughout the arrest. CONCLUSION: We found no association between standard ACLS medications and improved resuscitation from in-hospital cardiac arrest. Randomized clinical trials are needed to determine whether other therapies can improve resuscitation from cardiac arrest when compared with the presently used ACLS drugs.

Aged↗

PubMed1998

Standardized or narrative discharge summaries. Which do family physicians prefer?

OBJECTIVES: To determine whether family physicians prefer discharge summaries in narrative or standardized format and to determine factors affecting this preference. DESIGN: Mailed survey. SETTING: Internal medicine ward at a teaching hospital. PARTICIPANTS: Random sample of 180 family physicians practising in the Ottawa-Carleton area. Of the original sample, 20 were not family physicians and were excluded. Of the 160 physicians remaining, 126 responded for a response rate of 78.8%. INTERVENTION: For a stratified random sample of patients, medical records and narrative discharge summaries were abstracted using a data acquisition form to capture essential information. Information on completed forms was transformed into standardized summaries. Physicians were sent both narrative and standardized summaries. MAIN OUTCOME MEASURE: Physicians' format preference as indicated on an ordinal 7-point scale. RESULTS: The standardized format was preferred with a score of 4.28 versus 3.84 for the narrative (P < .05). Responses indicated the standardized format provided information most relevant to ongoing care, with a mean score of 4.82 (95% confidence interval [CI] 4.48 to 5.15), and easier access to summary information (5.60, CI 5.30 to 5.89). The narrative summary better described patients' admission (3.54, CI 3.18 to 3.90). Preference for standardized summaries correlated with lengthier narrative summary (P < .05), shorter length of stay (P < .05), and physicians' dissatisfaction with previous summaries (P < .001). Standardized discharge summaries were significantly shorter (302 versus 619 words, P = .004) than narrative summaries. CONCLUSIONS: Physicians preferred a standardized format for discharge summaries. Format preference is influenced by physician, patient, and discharge summary characteristics.

Attitude of Health Personnel↗

PubMed1996

A reader's guide to the evaluation of prognostic studies.

In this article, we review guidelines which may be used to evaluate studies documenting prognosis. We describe a clinical problem involving the prognosis of a patient in an intensive care unit. An approach to the literature search is then outlined. The results of the literature search are described and criteria for the appraisal of articles describing prognosis and prognostic factors are discussed using one article as an example.

Guidelines as Topic↗

PubMed1995

Quality assessment of a discharge summary system.

OBJECTIVE: To assess the completeness of hospital discharge summaries and the efficiency of the discharge summary system in two urban teaching hospitals. DESIGN: Descriptive study, with follow-up telephone survey. SETTING: General internal medicine services at two urban tertiary care hospitals affiliated with the University of Ottawa. PATIENTS: A total of 135 patient charts, representing 10% of the patients discharged from the services between Aug. 1 and Dec. 31, 1993. Three charts were unavailable for review, and 26 were excluded because of patient death, early patient discharge (within 48 hours after admission) or lack of discharge summary; this left 106 summaries for analysis of completeness and 114 (including the charts without a summary) for analysis of efficiency. OUTCOME MEASURES: Completeness: proportion of summaries in which the following information was reported: admission diagnosis, drug allergies, physical examination, significant laboratory tests and results, discharge diagnosis, discharge medications and medical follow-up. Efficiency: time taken to generate the discharge summary and whether the patient's family physician received it. RESULTS: Of the 106 charts with a discharge summary, information was available from the dictation system database for all but one (99.1% complete). Information was missing on the admission diagnosis in 34.0% (36/106) of the summaries, the discharge diagnosis in 25.5% (27/106) and the discharge medications in 22.8% (23/101). Of the 268 significant laboratory tests and results noted in the charts 115 (42.9%) were not reported in the discharge summary. Of the 94 discharge summaries in charts with the patient's family physician listed on the facesheet, 38 (40.4%) were not received by the family physician. CONCLUSIONS: Considerable deficiencies in the completeness of the discharge summaries and the efficiency of the discharge summary system were found in the participating hospitals. Replication of this study in other settings is indicated, and strategies to improve the process should be pursued.

Data Interpretation, Statistical↗

PubMed1990

False-positive coding for acute myocardial infarction on hospital discharge records: chart audit results from a tertiary centre.

Hospital medical records staff enter diagnostic codes on charts using the International Classification of Diseases (Clinically Modified), Ninth Revision (ICD-9-CM). In a downtown Toronto tertiary hospital, 209 consecutive charts coded for acute myocardial infarction as the primary diagnosis in 1987-88 were reviewed. Criteria for documentation of acute myocardial infarction included symptomatic, electrocardiographic and enzymatic elements. Forty-three (21%) false-positives, ie, charts coded acute myocardial infarction where criteria were not fulfilled, were found (95% confidence interval 15 to 26%). Physician diagnosis of acute myocardial infarction appeared on the face sheet of 30 of the false-positive cases. Common reasons for false-positive face sheet entries and chart coding were acute myocardial infarction within the previous eight weeks with transfer or readmission for coronary angiography and other procedures; and presumed acute myocardial infarction on admission subsequently unproven or disproved. The false-positive proportion was similar to a Canadian study drawing on charts from hospitals of various sizes in 1977, lower than in recent reports from various American tertiary teaching hospitals (P less than 0.0001), and higher than in five Boston area community hospitals (P = 0.0005) where procedure-related transfers or readmissions of previous acute myocardial infarction patients were less likely. This audit lends credence to arguments that changes are needed in ICD-9-CM codes for acute myocardial infarction and in the assignation of reasons for hospitalization.

Canada↗

PubMedDate not supplied

An hypothesis paper on practice environment and the provision of health care: could hospital occupancy rates effect quality?

This paper will explore whether hospital occupancy influences quality of care. It discusses the 'systems' theory of error causation in the context of adverse medical outcomes. It then relates how high occupancy rates may cause problems in hospital systems. The evidence relating to quality of care and occupancy is reviewed. Finally, a new method of studying this relationship using time series analysis is proposed. We conclude that the relationship requires further exploration since revealing 'system' problems may compel clinicians to expose problems medical errors.

Bed Occupancy↗

PubMedDate not supplied

What is necessary for high-quality discharge summaries?

The objective of this study was to determine what physicians perceive to be necessary for high-quality discharge summaries. One-on-one surveys of 100 hospital-based physicians-in-training and community family physicians were conducted. Participants indicated the amount that 56 items contributed to discharge summary quality on a 15-category ordinal scale. Results were transformed to a continuous scale, extending from -6.6 ("item makes summary useless") through 0 ("item has no effect on discharge summary quality") to 10 ("item is so essential that summary is useless without it"). Quality decreased significantly when summary length exceeded 2 pages and when the delay from patient discharge to summary delivery increased. Summary content that increased quality most included admission diagnosis (mean 8.2; 95% confidence interval [7.7, 8.6]), pertinent physical examination findings (6.6 [6.0, 7.2]) and laboratory results (6.8 [6.3, 7.4]), procedures (7.1 [6.7, 7.6]) and complications in hospital (7.1 [6.6, 7.5]), discharge diagnosis (8.8 [8.4, 9.1]), discharge medications (7.9 [7.4, 8.4]), active medical problems at discharge (7.8 [7.4, 8.2]), and follow up (6.6 [6.0, 7.1]). With minor exceptions, hospital and family physicians agreed on contributors to summary quality. For this sample of physicians, summaries were of high quality when they were short, delivered quickly, and contained pertinent data that concentrated upon discharge information.

Analysis of Variance↗

PubMedDate not supplied

An introduction to multilevel regression models.

Data in health research are frequently structured hierarchically. For example, data may consist of patients nested within physicians, who in turn may be nested in hospitals or geographic regions. Fitting regression models that ignore the hierarchical structure of the data can lead to false inferences being drawn from the data. Implementing a statistical analysis that takes into account the hierarchical structure of the data requires special methodologies. In this paper, we introduce the concept of hierarchically structured data, and present an introduction to hierarchical regression models. We then compare the performance of a traditional regression model with that of a hierarchical regression model on a dataset relating test utilization at the annual health exam with patient and physician characteristics. In comparing the resultant models, we see that false inferences can be drawn by ignoring the structure of the data.

Bias↗