Search PubMed⌕ Search

Biomedical subjects

B Burnand

Publications and source records attributed to B Burnand.

At least 55 records · Page 3Linked to original sources

Can the decision to operate be judged retrospectively? A study of medical records.

OBJECTIVE: To examine the precision and completeness of information in medical records for evaluating the appropriateness of operative indications for lumbar disc surgery. DESIGN: Retrospective review of records. SETTING: University department of neurosurgery, Switzerland. SUBJECT: 100 patients. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Proportion of pre-defined, detailed appropriateness criteria present in the records. Proportion of cases that could unequivocally be classified as to the appropriateness of the indication for operation. RESULTS: The criteria were present and precise for 52 of the items (range 9-90); present but imprecise for 38 of the items, and absent for 10. Because of this imprecision, the appropriateness of only 7 of the operative indications could be unequivocally assessed retrospectively. CONCLUSION: Medical records are of limited use in assessing the appropriate management of care. The process of care should therefore be evaluated prospectively.

Female↗

Overuse and underuse of diagnostic upper gastrointestinal endoscopy in various clinical settings.

OBJECTIVES: To describe and compare both overuse and underuse of diagnostic upper gastrointestinal endoscopy in different settings. DESIGN: Merging of data from three prospective observational studies. The appropriateness and necessity of indications for gastroscopy were evaluated using explicit criteria developed by a standardized expert panel method (RAND-UCLA). Inappropriate endoscopies represent overuse. Necessary indications not referred for the procedure constitute underuse. SETTING: Three primary care outpatient clinics, 20 general practices, three gastroenterology practices, two district and one university hospitals. SUBJECTS: A third of the collective were consecutive ambulatory patients with upper abdominal complaints, whereas the other two thirds were ambulatory and hospitalized patients referred for the procedure. MAIN OUTCOME MEASURES: Proportions of overuse and underuse in the different settings. RESULTS: A total of 2885 patients were included (mean age, 49 years, 52% male, 2442 outpatients), 1858 patients underwent > or = 1 endoscopy. Among 2086 endoscopies, 805 (39%) were inappropriate, most of which were performed for dyspepsia (83%). Overuse was higher in young, foreign, female patients and lower in inpatient settings, the latter reflecting a different distribution of presenting symptoms. Among 1646 patient visits in primary care, overuse represented 148 endoscopies (9%). Underuse was identified in 104 of the same patient visits (6%) and was higher as patient age increased; there were no significant differences between men and women. CONCLUSIONS: Rates of overuse and underuse depend mainly on case presentation and patient characteristics. Both over- and underuse should be addressed to maintain and improve quality of care.

Adolescent↗

Statistical approaches in the development of clinical practice guidelines from expert panels: the case of laminectomy in sciatica patients.

BACKGROUND: Variation in expert opinion and lack of a systematic methodology hinder the development of reliable clinical practice guidelines. However standardized protocols have been defined to quantify, combine, and summarize expert judgments. In addition, statistical methods may help to outline guidelines based on simplified models of these judgments. METHODS: To test this hypothesis, stepwise logistic regression (SLR) and classification tree pruning (CTP) were used to predict the results of two expert panels (USA 1992 and Switzerland 1995) on laminectomy in sciatica conditions. Both panels, using the RAND-UCLA explicit method, assessed whether the procedure would be inappropriate or of potential use in 720 case scenarios combining 7 relevant factors. RESULTS: Laminectomy was rated as inappropriate in 60% and 70% of the scenarios by the US and Swiss panels, respectively. Either statistical method, in both panels, based its simplest model on the same 4 factors, as follows: imaging test results; disability; neurological findings; and conservative treatment trials (in decreasing order); the influence of 2 other factors, duration of pain and nerve root irritation, were only marginal. The correct classification rates of the models were 89% and 93% for SLR and 93% and 85% for CTP. Adopting the CTP US algorithm as a guideline would lead to consider performing laminectomy only in patients with imaging evidence of hernia, relatively severe disability, reflex abnormalities, and previous nonsurgical treatment. Adherence to the corresponding CTP Swiss algorithm would result in less restrictive conditions. CONCLUSION: The statistical techniques proved as useful instruments to structure and simplify appropriateness criteria developed by expert panels and to outline parsimonious decision models for clinical practice.

Algorithms↗

The direct antiglobulin test: still a place for the tube technique?

OBJECTIVES: Antibodies of different immunoglobulin isotypes, or complement, may coat red blood cells in vivo. They are detected by the direct antiglobulin test (DAT), usually performed by the conventional tube technique. The purpose of this study was to compare the latter technique with the gel test. METHODS: Three hundred and ninety-eight consecutive samples, sent to our laboratory for direct antiglobulin testing, were analyzed with the tube technique and the gel test, using reagents from different manufacturers. Eighty-seven samples had been collected from newborns and 23 from fetuses. Results were expressed as positive or negative. RESULTS: In 162 out of 398 cases, the DAT was negative with both methods, whereas in 178 out of 398 cases, the DAT was positive with both techniques using polyspecific antibodies (observed agreement: 84.5%; kappa = 0.71). Discrepancies between the two methods were observed in 58 cases: 51 samples appeared as DAT positive using the tube method and negative with the gel test, whereas only 7 were positive exclusively with the gel test. Among the 178 samples that were positive with both techniques, 93 samples showed discordant results when evaluated with monospecific antisera (11 with anti-IgG and 82 with anti-C3d, respectively). The sensitivity of the DAT performed by the gel test, in comparison with the conventional tube technique, was 75.4% (95% confidence interval (CI): 69.4-80.8). 96. 8% (95% CI: 92.8-99.0), and 16.3% (95% CI: 9.8-24.9) with polyspecific, anti-IgG and anti-Cd3 reagents, respectively. CONCLUSIONS: The gel test appeared to be less sensitive than the conventional tube technique when utilized for DAT, particularly when C3d was present on red blood cells. These results emphasize that before implementing a new technique in the laboratory, comparison with existing techniques, using different reagents, is mandatory.

ABO Blood-Group System↗

Dose-dependent inverse relationship between alcohol consumption and serum Lp(a) levels in black African males.

Serum or plasma levels of Lp(a) vary widely between individuals and are higher in Africans and their descendants compared with white persons. In whites, high serum levels of Lp(a) are associated with the premature development of atherosclerosis. In both ethnic groups, serum Lp(a) levels are highly genetically determined and only a few environmental or physiological factors, like testosterone or estrogen, have been shown to lower serum Lp(a) levels. In whites, alcohol consumption is associated with lower serum Lp(a) levels. However, the mechanism underlying this association and whether it holds true for blacks is not known. To address these questions, we analyzed serum Lp(a) levels in 333 middle-aged males of African descent from the Seychelles Islands (Indian Ocean). In addition, we analyzed the size of the apo(a) isoforms and the serum levels of albumin and sex hormones in a subset of 279 subjects. Serum Lp(a) levels were similar in teetotalers (median, 32.5 mg/dL; n=42) and occasional drinkers (median, 34.1 mg/dL; n=112). In contrast, individuals consuming 10 to 80 g of ethanol/d (n=83) and heavy drinkers (>80 g of ethanol/d, n=96) had a 9% and 32% lower median Lp(a) level than teetotalers, respectively (P=0.01). The size distribution of the apo(a) isoforms and the mean serum levels of albumin, estradiol, and luteinizing hormone were similar in teetotalers and occasional drinkers compared with moderate and heavy drinkers. These latter 2 groups had lower serum levels of testosterone and sex hormone-binding globulin. These data indicate that alcohol intake is associated in a dose-dependent manner with lower serum Lp(a) levels in males of African descent and that this association is not related to the size of the apo(a) isoforms, to the synthetic function of the liver, or to sex hormone biochemical status.

Adult↗

Electronic monitoring of compliance to lipid-lowering therapy in clinical practice.

Nonadherence to treatment is a common problem in the clinical management of hypercholesterolemic patients. This study was carried out with the aim of monitoring the daily compliance to a 6-month course of lipid-lowering therapy, using a microelectronic device, the Medication Event Monitoring System (MEMS), versus pill count. Forty men with primary hypercholesterolemia were prescribed fluvastatin 1 x 40 mg daily, provided in a MEMS package to record the date and time of each opening of the pillbox. Thirty-nine of 40 patients (98%) completed the study. Total cholesterol and LDL cholesterol levels decreased significantly (18% and 25%, p < 0.001) during the 6-month therapy period. A high mean rate of compliance was achieved by MEMS using the following three indexes--compliance to total prescribed dose (88.8% +/- 13.5%), compliance to prescribed days (82.4% +/- 19.5%), and compliance to prescribed time of day (81.86% +/- 19.5%)--and by pill count (93.4% +/- 9.5%). In addition, the MEMS provided some patterns of nonadherence to medication, undetectable by pill count alone, such as a drug holiday in 38% of cases, a drug omission for more than 7 consecutive days in 9% of cases, and, conversely, use of more than the one prescribed daily dose in 47% of cases. A significant correlation between the rate of compliance and the decrease in LDL cholesterol was observed only when the compliance was assessed by MEMS. The results indicate that MEMS is a useful tool for monitoring compliance in clinical practice and may possibly increase adherence to long-term lipid-lowering therapy.

Adult↗