Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “stratification”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,189 records · Page 66Linked to original sources
PubMed2001

Emergency department admissions to inpatient cardiac telemetry beds: a prospective cohort study of risk stratification and outcomes.

PURPOSE: Little is known about physicians' use of inpatient cardiac telemetry units among emergency department patients at risk for cardiac complications. We therefore studied the outcomes of patients admitted to inpatient telemetry beds to identify a subset of patients from whom cardiac monitoring could be withheld safely. SUBJECTS AND METHODS: We conducted a prospective cohort study of 1, 033 consecutive adult patients admitted to an inpatient telemetry unit from the emergency department of a 700-bed urban public teaching hospital. Subjects with or without chest pain were risk-stratified using a prediction rule and observed for in-hospital cardiac complications, acute myocardial infarction, and transfer to an intensive care unit (ICU). RESULTS: There were no significant differences between patients with (n = 677) or patients without chest pain (n = 356) in the rates of major cardiac complications, myocardial infarctions, or transfers to an ICU. Among 318 patients with chest pain who were classified as being very low risk, none suffered major complications (negative predictive value 100%; 95% confidence interval [CI]: 98.8% to 100%). Among 214 very low risk patients without chest pain, 1 (0.5%) had a major complication (negative predictive value 99.5%; 95% CI: 97.4% to 99.9%). CONCLUSIONS: The prediction rule accurately identified patients with or without chest pain who were at very low risk of major complications, identifying a subset from whom cardiac monitoring could be withheld safely.

Adolescent↗
PubMed1996

Abnormal nuchal findings on screening ultrasonography: aneuploidy stratification on the basis of ultrasonographic anomaly and gestational age at detection.

OBJECTIVE: Our purpose was to determine the specific likelihood of different aneuploidies by gestational age in patients with nuchal folds and simple and septated nuchal membranes. STUDY DESIGN: Retrospective database analysis was performed of 158 consecutive patients with a nuchal fold or simple or septated nuchal membrane on either abdominal or vaginal ultrasonography. RESULTS: Thirty-eight patients with nuchal folds, 65 with simple nuchal membranes, and 55 with septated nuchal membranes were evaluated. Septated nuchal membranes were associated with the highest incidence of karyotypic abnormalities (> 50%). A peak incidence of trisomy 21 (27%) was found in the early midtrimester, leveling off to 11% by the late midtrimester. The late first trimester had a high incidence of trisomy 18 (22%), occurring more frequently than 45,X. CONCLUSION: Ultrasonographic anomalies in the posterior neck are associated with aneuploidy from 21% to 58% of the patients in this selected population. Each anomaly has different risks for aneuploidy type, varying with gestational age at diagnosis.

Aneuploidy↗
PubMed2001

Risk stratification in acute type A dissection: proposition for a new scoring system.

BACKGROUND: The aim of this study was to develop a scoring system for operative mortality of patients with acute type A aortic dissection. METHODS: Between 1974 and 1999, a total of 252 patients were operated on for an acute type A aortic dissection. We reviewed retrospectively preoperative and intraoperative records to conduct an analysis of risk factors associated with surgery. Multivariate analysis was used to predict operative mortality and to provide a preoperative risk profile of each individual patient that could be used for future patients. RESULTS: Operative mortality was 25.0% (n = 63). A logistic regression model with three explanatory variables to predict operative death showed a good fit: the risk factors associated with operative mortality were preoperative cardiopulmonary resuscitation (p = 0.0013, odds ratio = 15.7) and iatrogenic dissection (p = 0.0014, odds ratio = 9.8). Drained pericardial tamponade (p = 0.0386, odds ratio = 0.12) appeared to be a protective factor associated with decreased mortality. CONCLUSIONS: Because existing scoring systems do not fit this pathologic condition, we propose the use of this Antonius Dissection Scoring System, based on the logistic regression model, to predict the chances of operative mortality for each patient before operation. The survival of patients with concomittant pericardial tamponade may benefit from pericardial drainage.

Acute Disease↗
PubMed1997

Risk stratification for open heart operations: comparison of centers regardless of the influence of the surgical team.

BACKGROUND: Risk-adjusted mortality was previously used to compare institutions as a whole or surgeons. Because the same surgical team is working in two different hospitals, the aim of our study was to assess whether the institution can make a difference in surgical mortality. METHODS: Preoperative data of 554 patients in institution A and 500 in institution B were prospectively collected during the same period of time. All patients were operated on by the same surgeon with the same first assistant and anesthesiology staff in both institutions. Patient population was stratified according to Parsonnet's predictive model, in five risk groups, and mortality was adjusted by the direct standardization method. RESULTS: At institution A it was observed that in-hospital mortality was 2.3% (95% confidence interval, 1.3% to 4.0%), and in institution B 4.0% (95% confidence interval, 2.5% to 6.1%). The difference between the two mortality rates (1.7%; 95% confidence interval, -0.5% to 3.8%) is not statistically significant (p = 0.16), nor is the difference within each class. The standardized mortality ratio was 3.6% (95% confidence interval, 2.7% to 4.8%) and 5.8% (95% confidence interval, 4.6% to 7.2%), respectively. The difference of 2.2% (95% confidence interval, 0.5% to 3.8%) is statistically significant (p = 0.01). CONCLUSIONS: The institution can affect mortality of patients undergoing open heart operations, regardless of the influence of the surgical team.

Cardiac Surgical Procedures↗
PubMed1997

Risk stratification for adverse economic outcomes in cardiac surgery.

BACKGROUND: Recent emphasis on cost-containment in the health-care environment has focused attention on the cost of medical procedures. Selection of the appropriate treatment for coronary artery disease is of increasing concern. Coronary artery bypass grafting is common and very expensive, and this procedure will continue to be examined closely by reimbursement systems, particularly with regard to the lower initial cost of coronary angioplasty as a competing therapy. METHODS: Duke University Medical Center has a sophisticated accounting system that enables individual cost components to be identified, facilitates prospective analysis of cost/benefit, and aids allocation of limited hospital resources. In 1996, 1,114 coronary artery bypass procedures were performed at Duke. Preoperative patient characteristics were also analyzed in an attempt to predict risk factors for increased cost. RESULTS: The median cost for these procedures was $20,682, excluding professional fees. Sixty percent of the costs were directly associated with patient care, and the other 40% were accounted for by indirect costs to support patient care. The most significant preoperative predictor of increased postoperative cost was the mortality estimate. If this variable was excluded from the analysis, other variables (for example, ejection fraction, age, identity of the surgeon, and congestive heart failure) were all related to increased costs. CONCLUSIONS: Predicting costs based on preoperative variables offers the potential to reduce total costs through case-management strategies and aids in negotiating a risk-shared contract. However, cost reduction in routine care will have more financial impact than cost reduction by patient selection.

Aged↗
PubMed2001

Variability in fibrinogen measurements: an obstacle to cardiovascular risk stratification.

The clinical utility of fibrinogen measurement has been limited by large intraindividual variability. Several approaches that have been shown to improve the repeatability of fibrinogen include acquisition of samples at the same time of day, standardized sample procurement techniques, and multiple replicate sampling. This study employed established pre-analytical and analytical techniques known to reduce fibrinogen variability, including the acquisition of three replicate samples, each analyzed in duplicate, to evaluate the impact of intraindividual variability in fibrinogen measurement at baseline and 3 months on cardiovascular risk in 60 healthy subjects. Classification accuracy was evaluated by the ability to categorize subjects into tertiles of fibrinogen. Only 55% (33/60) of the subjects were correctly assigned to the appropriate fibrinogen tertile. Fibrinogen measurements varied by more than 10% in 45% of subjects and by 5% in 80% of subjects. Intraindividual variability in fibrinogen measurement with a functional assay limits cardiovascular risk assessment even when three replicates are averaged.

Adult↗
PubMed1995

Numeric processing of Lorenz plots of R-R intervals from long-term ECGs. Comparison with time-domain measures of heart rate variability for risk stratification after myocardial infarction.

The so-called "Lorenz plots" are scatterplots that show the R-R interval as a function of the preceding R-R intervals. Repeatedly, it has been proposed that these plots might be used for visualizing the variability of the heart rate and that the assessment of heart rate variability (HRV) from these plots might be superior to conventional measures of HRV. However, a precise numeric evaluation of the images of Lorenz plots have never been suggested. To classify the images of Lorenz plots, a computer package that measures their density was developed. For each rectangular area of the plot, the relative number of R1/R2 samples in that area is established and a function is created that assigns the maximum relative number of samples (i.e., the maximum density) to each size of an area of the plot. Plots that are very compact result in a sharply falling density function, while plots that are more diffuse lead to a flat density function. The distinction between such types of density function may be expressed as a logarithmic integral of the density function to express the "compactness" of the plot numerically. As the computational demands of this approach are intensive, an approximate method that restricts the measurement of the density to the area around the peak of the plot was also developed. The results of this approximate method correlate strongly with the full results (r = .98), and approximate measurement of one plot requires less than 1 minute of computer time. The approximate method has been applied to a set of 24-hour Holter records obtained from 637 survivors of acute myocardial infarction. For each record, the SDNN and SDANN values were also calculated as conventional measures of HRV. Both the density of the Lorenz plots and the conventional measures of HRV were used to investigate the differences among 48 patients who suffered an arrhythmic event (sudden death or sustained symptomatic ventricular tachycardia) during a 2-year follow-up period and the remaining 589 patients without arrhythmic postinfarction complications. At a sensitivity of 30%, the Lorenz plot density distinguished the patients with events with a positive predictive accuracy of 58%, while the SDNN and SDANN led to a positive predictive accuracy of only 23 and 18%, respectively. Thus, a detailed analysis of Lorenz plots is feasible and more clinically useful than the conventional measures of HRV.

Adult↗
PubMed1990

Masking procedure, randomization and stratification, and compliance monitoring in the Growth Failure in Children with Renal Diseases Study.

Ensuring the integrity of a study such as the GFRD Study requires close cooperation among all groups involved with the study and the patient. Many factors may influence the outcome and validity of a multicenter, double-masked, randomized trial. Any dosage modifications that may need to be made rely totally on established communication between the centers, the DCC, and the Core Pharmacy. When the procedures outlined above are followed, masking is ensured and patient compliance can be measured.

Calcitriol↗
PubMed1996

Long-term outcome, survival analysis, and risk stratification of dynamic cardiomyoplasty.

METHODS: To analyze the long-term outcome of dynamic cardiomyoplasty, we retrospectively studied 127 consecutive patients who underwent this procedure in Paris, France (n = 76), São Paulo, Brazil (n = 37), and Portland, Oregon (n = 14). Preoperative data were collected for patients operated on between January 1985 and June 1994 and examined with respect to effect on long-term survival. Patients had a mean age of 50 +/- 13 years and were predominantly male (82%). In 46% the cause of disease was ischemic. Concomitant operations were performed in 22 patients. RESULTS: Operative mortality was 12% (15/127). Kaplan-Meier survival +/- standard error at 1 through 5 years was 73% +/- 4%, 57% +/- 5%, 49% +/- 6%, 44% +/- 6%, and 40% +/- 7%, respectively. There was a distinct improvement at 6 months in New York Heart Association functional class (3.2 +/- 0.05 vs 1.7 +/- 0.07, p < 0.0001) and a small but significant increase in left ventricular ejection fraction (20% +/- 0.8% vs 23% +/- 1.5%, p = 0.04). Ninety-day mortality was associated with low right ventricular ejection fraction, a blunted hemodynamic response to exercise testing, and requirement for an intraaortic balloon pump at the time of the operation. Using a stepwise Cox regression method of multivariable survival analysis (n = 101), we determined that atrial fibrillation, New York Heart Association class IV, high pulmonary capillary wedge pressure, and balloon pump use were independent variables simultaneously associated with poor overall survival. When metabolic testing variables were added to this model, peak oxygen consumption eliminated both pulmonary capillary wedge pressure and functional class from the model, albeit with fewer (n = 74) patients. CONCLUSION: Dynamic cardiomyoplasty is an evolving therapy for symptomatic congestive heart failure, the results of which may be enhanced by intelligent, risk-sensitive patient selection.

Cardiomyoplasty↗
PubMed1983

Stratification and square pattern arrangements in the dorsal inner plexiform layer in the retina of Callionymus lyra L.

The dorsal inner plexiform layer in the retina of Callionymus lyra consists of successive fibrous F layers and geometrically organized P layers. In the F layers no pattern arrangement of the bipolar synaptic buttons was observed. In the P layers, on the contrary, the bipolar synaptic buttons are grouped by three distinct square patterns. The alpha pattern measures 5 micron and corresponds to the square pattern of the photoreceptor cells. The beta and the gamma pattern measure 7 micron. One of both patterns corresponds to the single cone arrangement, while the other coincides with the crossings of the rows of double cone pairs. The alternation of F and P layers results in the stratified appearance of the inner plexiform layer.

Animals↗
PubMed1999

The incidence of intersexuality in children with cryptorchidism and hypospadias: stratification based on gonadal palpability and meatal position.

PURPOSE: The combined findings of cryptorchidism and hypospadias often indicate the existence of an intersex state. Testicular maldescent and incomplete tubularization of the urethral plate occur in a spectrum with the severity of the 2 processes likely dependent on the degree of pathophysiology in the androgenic hormonal axis. The incidence of intersexuality in children with undescended testes, hypospadias and otherwise nonambiguous male genitalia has been reported to be 27%. Although the likelihood of genotypic or gonadal ambiguity has previously been associated with meatal position in this population, to our knowledge our study is the first to evaluate the incidence of intersexuality relative to whether the undescended testis is palpable or nonpalpable. MATERIALS AND METHODS: The database at our hospital was searched for all cases of undescended testes (2,105) and hypospadias (1,057) between 1982 and 1996. Radiographic, histological and karyotypic data were compiled for all patients presenting with both diagnoses. Gonadal palpability (palpable versus nonpalpable) and meatal position (anterior versus mid versus posterior) were recorded and correlated with the likelihood of identifying an intersex condition. Ten boys with a diagnosis of undescended testes subsequent to inguinal hernial repair were excluded from study. Patients with congenital adrenal hyperplasia or complete testicular feminization were also excluded from study due to the clearly female appearance of the external genitalia. Statistical significance was assessed using Fisher's exact test. RESULTS: We identified 79 patients presenting with undescended testes, hypospadias and a phallus that was believed to be a possible penis. Intersex conditions were identified with nearly equal frequency in the 44 cases of unilateral (30%) and 35 of bilateral (32%) cryptorchidism. In the unilateral undescended testes group patients with a nonpalpable testis were at least 3-fold more likely to have an intersex condition than those with a palpable undescended testis (50 versus 15%, p = 0.02). In the bilateral group patients with 1 or more nonpalpable testes were also nearly 3-fold as likely to have an intersex condition than those with bilateral palpable undescended gonads (47 versus 16%, p = 0.07). Meatal position was graded as anterior in 33% of cases, mid in 25% and posterior in 41% with the more posterior location conferring a significantly greater likelihood of an intersex condition (anterior 2 of 26, mid 1 of 20 and posterior 21 of 33). CONCLUSIONS: Gonadal palpability is an important predictor of an intersex state in unilateral and bilateral cases of cryptorchidism with hypospadias. Patients with an undescended testis that cannot be palpated are significantly more likely to have an intersex condition than those in whom the undescended testis may be palpated on physical examination. The severity of hypospadias likewise has a strong positive correlation with an intersex state.

Child↗
PubMed1990

Flow cytometric assessment of deoxyribonucleic acid content in renal adenocarcinoma: does ploidy status enhance prognostic stratification over stage alone?

Flow cytometry was used to analyze deparaffinized primary renal cell carcinoma specimens from 106 patients to evaluate deoxyribonucleic acid ploidy as a predictor of disease progression and survival. Of these specimens 62 (58%) demonstrated aneuploid stem lines: 30 (48%) of these were tetraploid aneuploid while 32 were nontetraploid aneuploid. Two or more specimens were analyzed from a single primary tumor in 17 patients and heterogeneity of ploidy status was observed in 5 (30%). Specimens of the primary tumor, and regional and/or distant metastases from 11 patients were analyzed; 5 (45%) demonstrated discordance between the ploidy of the primary and the metastatic site. A significant correlation was noted between the presence of aneuploid stem lines and high stage disease (p equals 0.004) but there was no significant correlation between ploidy status and tumor grade. Although there was a significant difference (p equals 0.037) in the incidence of disease progression in patients with diploid tumors (13%) versus those with aneuploid tumors (35%) in the total population, and Kaplan-Meier disease-specific survival curves demonstrated a survival advantage for patients with diploid tumors in the total population, no clear survival advantage was demonstrated for evaluable patients with diploid tumors when controlled for tumor, nodes and metastases stage. In conclusion, the heterogeneity of ploidy status in primary renal cell carcinoma, the high incidence of disease progression in patients with diploid primary tumors and the lack of a clearly demonstrable stage-independent impact of ploidy on prognosis currently would not support widespread clinical application of ploidy status of the primary tumor in the management of individual patients with renal cell carcinoma.

Adult↗
PubMed1993

Cardiac risk stratification prior to vascular surgery.

A cardiac etiology is the cause of death in approximately 40% to 60% of patients who die in the early postoperative period following vascular surgery. A variety of modalities has been proposed to identify the patient at risk before the surgical procedure. This article puts these modalities in perspective and discusses the increased risk of cardiac complication for the vascular surgery patient, identifies the patient at risk, and defines methods to decrease patient risk.

Coronary Disease↗
PubMed2001

Effective risk stratification of surgical and nonsurgical patients for venous thromboembolic disease.

Effective and safe methods of preventing venous thromboembolism (VTE) are now widely available, but a significant proportion of patients develop VTE either because thromboprophylaxis has not been used or because the intensity of thromboprophylaxis is not matched to the level of risk. Thromboembolic risk varies widely according to the clinical setting and presence of underlying risk factors, but VTE may not be suspected even in high-risk patients. Clinical risk factors for VTE include recent surgery, cancer, stroke, previous VTE, immobilization, and advanced age. Recent attention has focused on the role of inherited and acquired molecular factors in determining overall thromboembolic risk. These factors include the classic thrombophilias-deficiencies of antithrombin III, protein C, and protein S-and several newly described molecular risk factors: factor V Leiden, the prothrombin 20210A gene mutation, and hyperhomocysteinemia. Based on emerging knowledge of risk factors, several risk assessment models (RAMs) have been devised that stratify patients according to overall VTE risk, allowing thromboprophylaxis to be tailored appropriately. Compared with older risk assessment formulas, current RAMs are simpler and include specific recommendations for thromboprophylaxis based on the available scientific evidence. Consensus documents on VTE prevention classify patients into low-, moderate-, and high-risk categories. More recently, a new risk group, very high risk, has been described. Very-high-risk patients are especially prone to thromboembolic complications and need intensive and in some cases prolonged thromboprophylaxis.

Humans↗