Accuracy of Practitioner Estimates of Probability of Diagnosis Before and After Testing.

Importance: Accurate diagnosis is essential to proper patient care. Objective: To explore practitioner understanding of diagnostic reasoning. Design, Setting, and Participants: In this survey study, 723 practitioners at outpatient clinics in 8 US states were asked to estimate the probability of disease for 4 scenarios common in primary care (pneumonia, cardiac ischemia, breast cancer screening, and urinary tract infection) and the association of positive and negative test results with disease probability from June 1, 2018, to November 26, 2019. Of these practitioners, 585 responded to the survey, and 553 answered all of the questions. An expert panel developed the survey and determined correct responses based on literature review. Results: A total of 553 (290 resident physicians, 202 attending physicians, and 61 nurse practitioners and physician assistants) of 723 practitioners (76.5%) fully completed the survey (median age, 32 years; interquartile range, 29-44 years; 293 female [53.0%]; 296 [53.5%] White). Pretest probability was overestimated in all scenarios. Probabilities of disease after positive results were overestimated as follows: pneumonia after positive radiology results, 95% (evidence range, 46%-65%; comparison P < .001); breast cancer after positive mammography results, 50% (evidence range, 3%-9%; P < .001); cardiac ischemia after positive stress test result, 70% (evidence range, 2%-11%; P < .001); and urinary tract infection after positive urine culture result, 80% (evidence range, 0%-8.3%; P < .001). Overestimates of probability of disease with negative results were also observed as follows: pneumonia after negative radiography results, 50% (evidence range, 10%-19%; P < .001); breast cancer after negative mammography results, 5% (evidence range, <0.05%; P < .001); cardiac ischemia after negative stress test result, 5% (evidence range, 0.43%-2.5%; P < .001); and urinary tract infection after negative urine culture result, 5% (evidence range, 0%-0.11%; P < .001). Probability adjustments in response to test results varied from accurate to overestimates of risk by type of test (imputed median positive and negative likelihood ratios [LRs] for practitioners for chest radiography for pneumonia: positive LR, 4.8; evidence, 2.6; negative LR, 0.3; evidence, 0.3; mammography for breast cancer: positive LR, 44.3; evidence range, 13.0-33.0; negative LR, 1.0; evidence range, 0.05-0.24; exercise stress test for cardiac ischemia: positive LR, 21.0; evidence range, 2.0-2.7; negative LR, 0.6; evidence range, 0.5-0.6; urine culture for urinary tract infection: positive LR, 9.0; evidence, 9.0; negative LR, 0.1; evidence, 0.1). Conclusions and Relevance: This survey study suggests that for common diseases and tests, practitioners overestimate the probability of disease before and after testing. Pretest probability was overestimated in all scenarios, whereas adjustment in probability after a positive or negative result varied by test. Widespread overestimates of the probability of disease likely contribute to overdiagnosis and overuse.

Six years of clinical follow-up with endothelial cell-seeded small-diameter vascular grafts during coronary bypass surgery.

This clinical study was performed to investigate the patency rate of endothelial cell-seeded small-diameter expanded polytetrafluoroethylene grafts during coronary artery bypass surgery. Between September 1995 and December 1998, 14 patients (median age: 71 years, range: 61-79 years) received 21 endothelial cell-seeded small-diameter grafts. In all, 43% of the performed implantations were reoperations. Endothelial cells were harvested from a forearm vein, cultured and characterized in the laboratory until a sufficient number was available. After in vitro seeding, the grafts were allowed to mature for another 10 days, prior to implantation. Graft patency was investigated with angiography, angioscopy, and intravascular ultrasonography during follow-up. Cumulative data represented 58 patients' years and was 100% complete. The seeded autologous vascular endothelial cell density was 1.05 × 10(5) ± 0.12 × 10(5) cells/cm(2) with a cell viability of 95.5 ± 1.5%. Operative mortality was 7.1% (one patient). Patency rate at discharge was 95.2%, and at a mean follow-up of 27 months was 90.5%. The proven patency rate at up to 72 months was at least 50.0%, as five patients refused angiographic evaluation. None of these five patients suffered from angina pectoris and so the best scenario would have shown a patency rate of 85.7%. Angioscopy and intravascular ultrasonography showed absence of atheroma or stenosis in the investigated patent grafts. Autologous vascular endothelial cell seeding improves patency rate of small-caliber expanded polytetrafluoroethylene grafts in patients without suitable autologous graft material.

Aortocoronary endothelial cell-seeded polytetrafluoroethylene graft: 9-year patency.

We report a 71-year old man with coronary artery disease. Complete coronary revascularization was not possible with autologous grafts; therefore, a 4-mm expanded polytetrafluoroethylene graft was implanted that had been seeded preoperatively with autologous vascular endothelial cells. At 9-year follow-up, the patient is asymptomatic and shows a patent graft.

Reducing the incidence and severity of pericardial adhesions with a sprayable polymeric matrix.

PURPOSE: This study was undertaken to evaluate the antiadhesive properties of a polymeric agent in infants undergoing staged surgical correction of congenital heart abnormalities. DESCRIPTION: Sixteen infants having staged surgical repair were treated with a polymeric matrix at the completion of the initial surgery. There were 5 untreated controls. The tenacity and extent of adhesions at five separate regions of the heart were evaluated at the follow-up surgery. EVALUATION: For all sites combined, there was a threefold difference in median tenacity scores in favor of the experimental treatment (1.0 vs 3.0, p < 0.01). Significant differences were achieved separately at the right ventricle and the anterior surface of the great vessels (p = 0.02 for both comparisons). Analysis of adhesion scores reflecting the extent of adhesions similarly favored the experimental treatment for all sites (80 vs 270, p < 0.01), with significant differences persisting at the right atrium (p < 0.01) and the anterior surface of the great vessels (p = 0.04). There were no treatment-related adverse events. CONCLUSIONS: Use of this polymeric agent at the completion of open cardiac surgery may prevent the occurrence or reduce the severity of pericardial adhesions.

[Certification and quality management of a complex university cardiac center according to law EN ISO 9001: 2000]. / Zertifizierung von Teileinrichtungen komplexer Grosskliniken nach DIN EN ISO 9001: 2000 dargestellt am Beispiel einer herzchirurgischen Universitätsklinik.

Quality management systems can improve quality in health care units. The introduction of a quality management system according to ISO 9001: 2000 in a university department of cardiovascular surgery is described. First a thorough analysis of all processes of patient treatment and clinical research was obtained. Multiple interfaces had to be defined to different departments as well as to administration units. All necessary resources were evaluated and optimised. Customer satisfaction was evaluated by surveys of patients and collaborating physicians. Quality rounds including physicians, nurses and technicians were instituted. Based on these preparatory works all processes including their responsibilities and necessary resources were redefined and described in the quality manual. After 18 months' of certification of our quality management system according to ISO 9001: 2000 was recommended by an independent, accredited organisation. In summary, certification of a university department of cardiovascular surgery according to ISO 9001: 2000 is possible and may represent the first step towards total quality management. In complex health care units the certification of individual departments may help to generate a consciousness for quality on the road to total quality management.

Genomic amplification and oncogenic properties of the KCNK9 potassium channel gene.

Representational difference analysis (RDA) of human breast cancer was used to discover a novel amplicon located at chromosomal region 8q24.3. We examined a series of breast cancer samples harboring amplification of this region and determined that KCNK9 is the sole overexpressed gene within the amplification epicenter. KCNK9 encodes a potassium channel that is amplified from 3-fold to 10-fold in 10% of breast tumors and overexpressed from 5-fold to over 100-fold in 44% of breast tumors. Overexpression of KCNK9 in cell lines promotes tumor formation and confers resistance to both hypoxia and serum deprivation, suggesting that its amplification and overexpression plays a physiologically important role in human breast cancer.