Probability estimates of angiographic coronary artery disease made by experienced, board-certified staff cardiologists were compared with those of cardiologists in training (fellows). In addition, estimates made before coronary angiography were compared with those made several months later based on written clinical summaries of 15 items of objective clinical and test data. Cardiologists were asked to estimate the probabilities of coronary artery disease, multivessel disease, and triple-vessel or left main disease. The study population consisted of 510 consecutive patients without valvular disease referred for the first time for coronary angiography to three hospitals. Both staff and fellows consistently overestimated the pre-angiographic probability of coronary artery disease. The probabilities estimated from patient summaries were always significantly lower than the pre-angiographic assessments. Only staff cardiologists reliably assessed the probabilities of coronary artery disease during the second assessment (p less than 0.05). Thus, estimates of disease probability based on clinical judgment vary according to the source of information, and these estimates are more accurate when physicians have objective data on hand and do not know the identities of the patients.

Coronary Angiography↗

PubMedDate not supplied

The effect of disease-prevalence adjustments on the accuracy of a logistic prediction model.

The accuracy of a logistic prediction model is degraded when it is transported to populations with outcome prevalences different from that of the population used to derive the model. The resultant errors can have major clinical implications. Accordingly, the authors developed a logistic prediction model with respect to the noninvasive diagnosis of coronary disease based on 1,824 patients who underwent exercise testing and coronary angiography, varied the prevalence of disease in various "test" populations by random sampling of the original "derivation" population, and determined the accuracy of the logistic prediction model before and after the application of a mathematical algorithm designed to adjust only for these differences in prevalence. The accuracy of each prediction model was quantified in terms of receiver operating characteristic (ROC) curve area (discrimination) and chi-square goodness-of-fit (calibration). As the prevalence of the test population diverged from the prevalence of the derivation population, discrimination improved (ROC-curve areas increased from 0.82 +/- 0.02 to 0.87 +/- 0.03; p < 0.05), and calibration deteriorated (chi-square goodness-of-fit statistics increased from 9 to 154; p < 0.05). Following adjustment of the logistic intercept for differences in prevalence, discrimination was unchanged and calibration improved (maximum chi-square goodness-of-fit fell from 154 to 16). When the adjusted algorithm was applied to three geographically remote populations with prevalences that differed from that of the derivation population, calibration improved 87%, while discrimination fell by 1%. Thus, prevalence differences produce statistically significant and potentially clinically important errors in the accuracy of logistic prediction models. These errors can potentially be mitigated by use of a relatively simple mathematical correction algorithm.

Adult↗

PubMedDate not supplied

Restenosis rate after percutaneous transluminal coronary angioplasty: a literature overview.

In order to elucidate factors affecting the rate of angioplasty restenosis, we reviewed 212 published reports on restenosis after percutaneous transluminal coronary angioplasty. We used five specific methodologic standards to select the 31 reports most likely to produce unbiased results. Sixty one factors judged to be related to restenosis rate were investigated. Only shorter duration of data collection (p=0.0003) was related to higher restenosis rate. This factor may be related to inexperience in choosing subjects or performing procedures. Other factors whose association with restenosis rate did not reach our predetermined level of statistical significance (p less than .01) were angioplasties of the left circumflex artery (p=.02), angioplasty of total occlusions (p=.02) and advanced age (p=.05). The association of shorter data collection with higher restenosis rates suggests that improved outcome may result from consolidation to a few centers specializing in this technique.

Angioplasty, Balloon, Coronary↗

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The De Vega tricuspid annuloplasty. Perioperative mortality and long term follow-up.

One hundred and fifty-three patients undergoing De Vega tricuspid annuloplasty, with or without other associated cardiac procedures between January, 1979, and June, 1987, were evaluated. There were 136 hospital survivors. The follow-up was 98.1% complete for a mean of 3.7 years/patient. Operative mortality was 11.1%; preoperative NYHA class and length of CPB were significant risk factors of perioperative mortality. The actuarial survival of operative survivors at 9 years was 73.5 +/- 11.8%. There were 7 late cardiac deaths among a total of 12 late deaths. Eleven patients required reoperation (2.1 +/- 0.6% patient-year). In seven patients it was necessary for recurrence of tricuspid regurgitation; six of these had also a mitral prosthesis malfunction or a periprosthetic leak. Residual tricuspid regurgitation was judged as mild, moderate or severe in 29.9%, 11.9% and 4.3% of the patients respectively. De Vega tricuspid annuloplasty is the method of choice for mild and moderate tricuspid insufficiency; in selected cases, with a more severe degree of regurgitation, better results could be achieved with a different surgical approach.

Adolescent↗

PubMedDate not supplied

[Heart palpitation. Interpretation of a symptom by dynamic electrocardiography].

Explore the source record for details and available documents.

Adult↗

PubMedDate not supplied

[The trap of percentages].

It is still controversial which is the correct way to report and to interpret different event rates of clinical trials. Results can be expressed in terms of several measures: absolute risk reduction, relative risk reduction, relative improvement, number needed to be treated. Each measure leads to a different interpretation of study results. In the present article data from a clinical study on serum cholesterol reduction are analyzed and compared with different measures. Investigators, physicians, nurses and patients should be aware that the presentation of trials' results can be misleading even if statistically exact.

Nursing Methodology Research↗