Part II. Telomerase expression in cerebrospinal fluid specimens as an adjunct to cytologic diagnosis

The diagnosis of meningeal carcinomatosis hinges on the cytologic examination of cerebrospinal fluid (CSF), which has a known low sensitivity for the identification of malignant cells. Often only 'suspicious' or 'atypical' diagnoses can be rendered, and specimens are commonly unsatisfactory for evaluation due to poor morphologic preservation. Telomerase is widely expressed in most brain metastases, medulloblastomas, lymphomas, oligodendrogliomas, and is expressed focally in glioblastomas. Little is known about the level of telomerase expression in these tumors, except for brain metastases, where a four-fold variation in telomerase levels exists. In our laboratory, as few as ten carcinoma cells can be detected by a sensitive polymerase chain reaction-based assay, the telomeric repeat amplification protocol (TRAP), for telomerase, but it was unclear whether varying levels of telomerase expressed by different types of metastases would influence detection. Using the TRAP protocol, we studied 281 CSF samples from a wide variety of patients with neurologic and non-neurologic conditions for telomerase expression. An adjusted specificity of 90% and a sensitivity of 64% were achieved for detection of malignant cells in CSF by telomerase expression. The TRAP assay for telomerase detection may serve as an adjunct to the traditional examination of CSF. Neither previously documented four-fold variation in the levels of telomerase expression in brain metastases, high CSF protein levels nor high white blood cell counts precluded detection of malignant cells in CSF.

Creative payment strategy helps ensure a future for teaching hospitals

The Colorado Medicaid Program in years past relied on disproportionate share hospital (DSH) payment programs to increase access to hospital care for Colorado citizens, ensure the future financial viability of key safety-net hospitals, and partially offset the state's cost of funding the Medicaid program. The options to finance Medicaid care using DSH payments, however, recently have been severely limited by legislative and regulatory changes. Between 1991 and 1997, a creative Medicaid refinancing strategy called the major teaching hospital (MTH) payment program enabled $131 million in net payments to be distributed to the two major teaching hospitals in Colorado to provide enhanced funding related to their teaching programs and to address the ever-expanding healthcare needs of their low-income patients. This new Medicaid payment mechanism brought the state $69.5 million in Federal funding that otherwise would not have been received.

Infant heart transplantation: improved intermediate results

OBJECTIVES

Our objectives were to (1) review our experience with heart transplants in infants (age < 6 months), (2) delineate risk factors for 30-day mortality, and (3) compare outcomes between our early and recent experience.

METHODS

Records of all infants listed for transplantation in our center before September 1996 were analyzed. Early and recent comparisons were made between chronologic halves of the accrual period. Univariate analysis was used to analyze potential risk factors for 30-day mortality (categorical variables, Fisher's exact test; continuous variables, nonparametric Wilcoxon rank-sum test). Multivariable analysis included univariate variables with p values < or = 0.10. Actuarial survivals were estimated (Kaplan-Meier) and compared by the log-rank test.

RESULTS

Fifty-one of the 60 infants listed for transplantation were operated on (waiting list mortality 15%). Thirty-day mortality was 18% overall, 30% in the first 3 years and 10% in the last 3 years (p = 0.07). Sepsis was the commonest cause of early death (4/9). Univariate analysis suggested four potential risk factors for early death: preoperative mechanical ventilation (p = 0.01), prior sternotomy (p = 0.002), preoperative inotropic drugs (p = 0.08), and warm ischemia time (p = 0.08). Multivariable analysis indicated that prior sternotomy (p = 0.01) was an independent risk factor for 30-day mortality. Actuarial survivals were 80%, 78%, and 70% at 1, 2, and 3 years, and these figures improved between early and recent groups (p = 0.05). Late deaths were most commonly due to acute rejection (3/5).

CONCLUSIONS

Results of heart transplantation in infancy improve with experience. Prior sternotomy increases initial risk. Intermediate-term survival for infants with end-stage heart disease is excellent.

Detection of telomerase expression in fine-needle aspirations and fluids

The cytologic examination of fine-needle aspirates and fluid specimens is plagued by a persistent false negative rate. The rate of false negative results will be decreased if sensitive molecular assays can be developed to detect cytologically malignant cells. The current study investigated telomerase expression as a potential marker of malignancy, using the telomeric repeat amplification protocol (TRAP) in fine-needle aspirates and fluid specimens. TRAP was performed on 24 fine-needle aspirate and 24 fluid specimens from different body sites and of different histological diagnoses. We found that 6 of 12 fine-needle aspirate specimens that were cytologically positive for malignant cells expressed telomerase activity, while no specimens that were cytologically suspicious for malignancy, atypical, or negative tested positive for telomerase activity. Of the fluid specimens, 4 of 6 cytologically positive cases and 1 of 18 cytologically negative cases expressed telomerase. Seven of eight telomerase negative, cytologically positive specimens contained only rare malignant cells in a very bloody background. Peripheral blood contamination is a possible pitfall in the TRAP assay, as applied in the current study, because the assay is standardized to protein concentration that may be derived from lysed red blood cells. We conclude that with further technical refinement, the TRAP assay could become a useful adjunct in the cytologic examination of fine-needle aspirates and fluid samples.

Early extubation following cardiac surgery in a veterans population

BACKGROUND

Early tracheal extubation is an important component of the "fast track" cardiac surgery pathway. Factors associated with time to extubation in the Department of Veterans Affairs (DVA) population are unknown. The authors determined associations of preoperative risk and intraoperative clinical process variables with time to extubation in this population.

METHODS

Three hundred four consecutive patients undergoing coronary artery bypass graft, valve surgery, or both on a fast track clinical pathway between October 1, 1993 and September 30, 1995 at a university-affiliated DVA medical center were studied retrospectively. After univariate screening of a battery of preoperative risk and intraoperative clinical process variables, stepwise logistic regression was used to determine associations with tracheal extubation < or = 10 h (early) or > 10 h (late) after surgery. Postoperative lengths of stay, complications, and 30-day and 6-month mortality rates were compared between the two groups.

RESULTS

One hundred forty-six patients (48.3%) were extubated early; one patient required emergent reintubation (0.7%). Of the preoperative risk variables considered, only age (odds ratio, 1.80 per 10-yr increment) and preoperative intraaortic balloon pump (odds ratio, 7.88) were multivariately associated with time to extubation (model R) ("late" association is indicated by an odds ratio >1.00; "early" association is indicated by an odds ratio <1.00). Entry of these risk variables into a second regression model, followed by univariately significant intraoperative clinical process variables, yielded the following associations (model R-P): age (odds ratio, 1.86 per 10-yr increment), sufentanil dose (odds ratio, 1.54 per 1-microg/kg increment), major inotrope use (odds ratio, 5.73), platelet transfusion (odds ratio, 10.03), use of an arterial graft (odds ratio, 0.32), and fentanyl dose (odds ratio, 1.45 per 10-microg/kg increment). Time of arrival in the intensive care unit after surgery was also significant (odds ratio, 1.42 per 1-h increment). Intraoperative clinical process variables added significantly to model performance (P < 0.001 by the likelihood ratio test).

CONCLUSIONS

In this population, early tracheal extubation was accomplished in 48% of patients. Intraoperative clinical process variables are important factors to be considered in the timing of postoperative extubation after fast track cardiac surgery.

Updates to the Data Quality Review Program: the Society of Thoracic Surgeons Adult Cardiac National Database

To ensure the credibility of this voluntary database, The Society of Thoracic Surgeons' National Database Audit and Validation Sub-Committee has been working during the past year to update and expand the group practice-based indicators used to assess the completeness, accuracy, and generalizability of the Adult Cardiac National Database. With increasing frequency, questions have been raised by third-party payors and regional/state-based groups as to the integrity of the data retained in the Adult Cardiac National Database. To work in conjunction with the Audit and Validation Sub-Committee to explicitly examine these issues, The Society of Thoracic Surgeons initiated a new Expert Advisory Panel review mechanism. This article describes the expanded data completeness and quality criteria that will be implemented in the coming year and summarizes the Expert Advisory Panel's recommendations for improvement.

Telomerase expression shows differences across multiple regions of oligodendroglioma versus high grade astrocytomas but shows correlation with Mib-1 labelling

AIMS/BACKGROUND

Telomerase is an enzyme that is expressed in most human neoplasms and is associated with tumour immortality. Determination of the point in neoplastic transformation at which telomerase is expressed may aid the understanding of tumour pathogenesis and progression. Despite numerous reports on telomerase, few studies have investigated its expression in high grade glial tumours. These studies, performed on archival banked, single brain tumour specimens, have shown conflicting results for oligodendrogliomas and unexpectedly negative results for telomerase expression in high grade astrocytomas, with one third to one half of glioblastoma multiformes being negative.

METHODS

34 rapidly banked glioma specimens taken from patients undergoing gross total surgical resection of their tumours were studied. Telomerase expression was assessed across 3-8 sampled regions from each tumour by the telomeric repeat amplification protocol (TRAP) assay. Matched mirror image tissue samples were taken for histological analysis of tissue adequacy, statistical correlation of telomerase with tumour histological features, Mib-1 (a marker for cell cycling) labelling, and p53 immunohistochemistry.

RESULTS

All five well differentiated oligodendrogliomas were homogeneously telomerase negative and two of three untreated anaplastic oligodendrogliomas were homogeneously positive. In contrast, 10 of 14 high grade astrocytomas showed heterogeneity for telomerase expression across the multiple regions sampled. All glioblastoma multiformes and two of three anaplastic astrocytomas showed at least one region positive for telomerase. When test samples were individually assessed in both oligodendrogliomas and high grade astrocytomas, telomerase expression was associated with Mib-1 labelling (p < 0.001). For the entire group, telomerase expression was associated with grade of tumour, age of patient, and vascular endothelial proliferation (all p < 0.001).

CONCLUSIONS

This regional study clarifies that all glioblastoma multiformes are at least focally positive and that telomerase expression correlates with tumour grade in oligodendrogliomas. Homogeneity versus heterogeneity for telomerase expression across multiple regions of oligodendrogliomas versus high grade astrocytomas may provide important preclinical data on the use of antitelomerase agents in these adult glial tumours.

1995 coronary artery bypass risk model: The Society of Thoracic Surgeons Adult Cardiac National Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Adult Cardiac National Database has recently completed the development of the 1995 risk model to be used to estimate the risk of operative death for isolated coronary artery bypass graft (CABG) procedures. This article describes the detailed methodology used, as well as a new Expert Advisory Panel review mechanism that was initiated by The Society.

METHODS

Placing emphasis on clinical relevance, data quality, data completeness, and univariate analyses, a logistic regression analysis was used to develop the 1995 CABG-only risk model. The STS National Office invited an Expert Advisory Panel (composed of nationally recognized, independent biostatisticians) to review the modeling process used.

RESULTS

The 1995 CABG-only model details are reported. Standard performance measures indicated the model had high predictive power and an acceptable level of calibration. The Expert Advisory Panel reviewed the 1995 CABG model and concluded that the current modeling techniques were adequate. Suggestions for future model development and reporting were proposed by the Panel.

CONCLUSIONS

The most current STS risk model of CABG operative mortality is a reliable and statistically valid tool. Its development and performance have been critically examined and approved by an independent panel of experts.

Time series monitors of outcomes. A new dimension for measuring quality of care

OBJECTIVES

Despite the popularity of risk-adjusted outcomes as quality of health care indicators, their instability with time and their inability to provide reliable comparisons of small volume providers have raised questions about the feasibility and credibility of using these measures. In this article the authors describe a new analytic strategy to address these problems by examining risk-adjusted mortality with time, "Time Series Monitors of Outcome" (TSMO), and its application to cardiac surgery performed throughout the Department of Veterans Affairs between April 1987 and September 1992.

METHODS

Expected operative mortality for 24,029 patients undergoing coronary artery bypass surgery at all 43 centers performing this procedure was estimated using a logistic regression model to adjust for patient-specific risk factors. The ratio of observed-to-expected operative mortality was calculated for each hospital for each of the 11 6-month periods. Poisson regression models were used to identify high and low outlier hospitals based on significant deviation from the 5.5 year overall mean and/or the individual hospital's trend of observed-to-expected ratios with time.

RESULTS

This method identified four high and one low outlier hospitals based on significant deviations from the overall mean and three upward and seven downward trending outlier hospitals based on significant deviations in trend with time. A significant downward trend in observed-to-expected ratios of 4% per year also was observed for all coronary artery bypass graft procedures performed throughout the Department of Veterans Affairs during the last 5.5 year period.

CONCLUSIONS

Time Series Monitors of Outcome should help reduce misclassification of outliers due to random variation in outcomes as well as provide more reliable comparative information from which to evaluate provider performance.

Telomerase expression in normal epithelium, reactive atypia, squamous dysplasia, and squamous cell carcinoma of the uterine cervix

Telomerase activity has been detected in a broad range of human malignant neoplasms, and its expression may represent an essential step in the malignant transformation of tissues; however, the expression of telomerase in premalignant lesions remains relatively unexplored. We tested tissue sections of cervical squamous cell carcinomas and squamous intraepithelial lesions, samples of benign reactive atypia, and normal cervical mucosa from hysterectomy and cone biopsy specimens for the expression of telomerase. Mirror-image sections from each sample were paraffin embedded and processed for histologic analysis. The test samples of cervical tissue were crushed under liquid nitrogen, and telomerase activity was determined by the telomeric repeat amplification protocol. Telomerase activity was detected in 18 of 18 cases (100%) of invasive squamous cell carcinoma. Twenty-five of 26 samples (96%) of high-grade squamous intraepithelial lesion also tested positively for telomerase activity, including 10 of 10 samples of moderate dysplasia, 12 of 13 samples of severe dysplasia, and 3 of 3 samples of carcinoma in situ. Telomerase activity was detected in 14 of 25 samples (56%) of low-grade squamous intraepithelial lesion and in 10 of 18 samples (56%) of reactive atypia but was detected in only 9 of 50 samples (18%) of histologically normal cervical mucosa. These results suggest that telomerase expression may be a marker of premalignant and malignant squamous cell lesions of the uterine cervix, although it is also expressed in a high proportion of cases of reactive atypia.

Detection of human papillomavirus in squamous cell carcinomas of the lung by polymerase chain reaction

Existing evidence supports the hypothesis that human papillomavirus (HPV) may play an etiologic role in the malignant transformation of squamous epithelial cells. Although HPV DNA has been identified in a high proportion of squamous cell carcinomas (SCC) of the cervix, anorectum, skin, and upper airways, few studies have tested for HPV in SCC of the lung. To confirm the presence of HPV in lung SCC, we tested for HPV DNA extracted from formalin-fixed tissues of 34 patients by polymerase chain reaction (PCR). DNA amplification was performed using HPV L1 consensus sequence primers (MY11 and MY09; Perkin-Elmer Cetus, Norwalk, CT) which recognize a broad spectrum of HPV types including 6, 11, 16, 18, 31, and 33, among many other known types, as well as at least 20 other unidentified types. PCR products were analyzed by agarose gel electrophoresis and Southern blot hybridization with [32P]-labeled generic HPV probes. HPV DNA positive cases were subsequently analyzed by slot-blot hybridization of the PCR products with specific probes for HPV types 6, 11, 16, 18, and 33. HPV type 18 was detected in two cases, including one case from a 44-year-old female and one from a 64-year-old male, with the remaining 32 cases negative. In situ hybridization for HPV DNA failed to detect HPV types 6/11, 16/18, or 31/33/35 in any of the cases. We conclude that a small proportion of cases of primary pulmonary SCC test positive for HPV type 18 but that the great majority of cases are not associated with HPV.

Atrial fibrillation after cardiac surgery: a major morbid event?

OBJECTIVE

The purpose of the study was to investigate the incidence, predictors, morbidity, and mortality associated with postoperative atrial fibrillation (AF) and its impact on intensive care unit (ICU) and postoperative hospital stay in patients undergoing cardiac surgery in the Department of Veterans Affairs (VA).

SUMMARY BACKGROUND DATA

Postoperative AF after open cardiac surgery is rather common. The etiology of this arrhythmia and factors responsible for its genesis are unclear, and its impact on postoperative surgical outcomes remains controversial. The purpose of this special substudy was to elucidate the incidence of postoperative AF and the factors associated with its development, as well as the impact of AF on surgical outcome.

METHODS

The study population consisted of 3855 patients who underwent open cardiac surgery between September 1993 and December 1996 at 14 VA Medical Centers. Three hundred twenty-nine additional patients were excluded because of lack of complete data or presence of AF before surgery, and 3794 (98.4%) were male with a mean age of 63.7+/-9.6 years. Operations included coronary artery bypass grafting (CABG) (3126, 81%), CABG + AVR (aortic valve replacement) (228, 5.9%), CABG + MVR (mitral valve replacement) (35, 0.9%), AVR (231, 6%), MVR (41, 1.06%), CABG + others (95, 2.46%), and others (99, 2.5%). The incidence of postoperative AF was 29.6%. Multivariate logistic regression analysis of factors found significant on univariate analysis showed the following predictors of postoperative AF: preoperative patient risk predictors: advancing age (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.48-1.75, p < 0.001), chronic obstructive pulmonary disease (OR 1.37, 95% CI 1.12-1.66, p < 0.001), use of digoxin within 2 weeks before surgery (OR 1.37, 95% CI 1.10-1.70, p < 0.003), low resting pulse rate <80 (OR 1.26, 95% CI 1.06-1.51, p < 0.009), high resting systolic blood pressure >120 (OR 1.19, 95% CI 1.02-1.40, p < 0.026), intraoperative process of care predictors: cardiac venting via right superior pulmonary vein (OR 1.42, 95% CI 1.21-1.67, p < 0.0001), mitral valve repair (OR 2.86, 95% CI 1.72-4.73, p < 0.0001) and replacement (OR 2.33, 95% CI 1.55-3.55, p < 0.0001), no use of topical ice slush (OR 1.29, 95% CI 1.10-1.49, p < 0.0009), and use of inotropic agents for greater than 30 minutes after termination of cardiopulmonary bypass (OR 1.36, 95% CI 1.16-1.59, p < 0.0001). Postoperative median ICU stay (3.6 days AF vs. 2 days no AF, p < 0.001) and hospital stay (10 days AF vs. 7 days no AF, p < 0.001) were higher in AF. Morbid events, hospital mortality, and 6-month mortality were significantly higher in AF (p < 0.001): ICU readmission 13% AF vs. 3.9% no AF, perioperative myocardial infarction 7.41 % AF vs. 3.36% no AF, persistent congestive heart failure 4.57% AF vs. 1.4% no AF, reintubation 10.59% AF vs. 2.47% no AF, stroke 5.26% AF vs. 2.44% no AF, hospital mortality 5.95% AF vs. 2.95% no AF, 6-month mortality 9.36% AF vs. 4.17% no AF.

CONCLUSIONS

Atrial fibrillation after cardiac surgery occurs in approximately one third of patients and is associated with an increase in adverse events in all measurable outcomes of care and increases the use of hospital resources and, therefore, the cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.

Fast-track cardiac surgery in a Department of Veterans Affairs patient population

BACKGROUND

"Fast-track" (FT) cardiac surgery is popular in the private and university sectors. This study was designed to examine its safety and efficacy in the Department of Veterans Affairs elderly, male patient population, a population with multiple comorbid risk factors, often decreased social functioning, and impaired support systems.

METHODS

Time to extubation, hospital length of stay, perioperative morbidity, and mortality were studied in two consecutive cohorts undergoing cardiac operations requiring cardiopulmonary bypass before (pre-FT: n = 255, January 1992 to September 1993) and after (FT: n = 304, October 1993 to October 1995) institution of an FT protocol at a university-affiliated teaching Department of Veterans Affairs medical center. Preoperative risk factors, including a Department of Veterans Affairs risk-adjusted estimate of operative mortality, and perioperative surgical and anesthetic processes of care were evaluated.

RESULTS

The mean Department of Veterans Affairs risk estimate of perioperative mortality was not different between the pre-FT and FT cohorts (3.5% versus 3.7%, p = 0.13). In the FT cohort, median time to extubation decreased significantly (19.2 versus 10.2 hours; p < 0.001) along with median surgical intensive care unit stay (96 versus 49 hours; p < 0.001) and total postoperative length of stay (222 versus 167 hours; p < 0.001). Median postoperative day of hospital discharge decreased from day 10 to 7 (p < 0.001). One patient (0.3%) required emergent reintubation directly related to early extubation. Reintubation for medical reasons was unchanged between pre-FT and FT groups (6.3% versus 5.0%; p = 0.48). Postoperative morbidity was similar between groups except for nosocomial pneumonia, the rate of which decreased significantly in the FT cohort (14.7% versus 7.3%; p < 0.005). Thirty-day (3.9% versus 4.6%; p = 0.69) and 6-month mortality (6.7% versus 6.9%; p = 0.91) were unchanged.

CONCLUSIONS

An FT cardiac surgery protocol has been instituted in a university-affiliated teaching Department of Veterans Affairs medical center, with decreased length of stay and no significant increase in postoperative morbidity, 30-day mortality, or 6-month mortality. It was associated with a lower rate of nosocomial pneumonia, a finding that must be validated in a prospective study.

Telomerase expression in normal endometrium, endometrial hyperplasia, and endometrial adenocarcinoma

Telomerase activity has been detected in a broad range of human cancers and its expression could be an important step in tumor progression. Here, telomerase activity by the telomeric repeat amplification protocol in cases of benign endometrium, endometrial hyperplasia, and endometrial adenocarcinoma was tested. Telomerase expression was detected in 13 of 14 cases of proliferative phase endometrium, in 7 of 12 cases of secretory phase endometrium, but was not detected in any of 7 cases of atrophic endometrium. Three of three cases with evidence of luteal phase defect and one of four cases of chronic endometritis also expressed telomerase activity. Hyperplastic endometrium was positive for telomerase in 13 of 17 cases. Telomerase activity was detected in 40 of 48 cases of endometrial adenocarcinoma, which included 36 of 43 cases of endometrioid adenocarcinoma and four of five cases of papillary serous carcinoma. The detection of telomerase in endometrial adenocarcinoma was not associated with either architectural grade, myometrial invasion, or stage. There was statistically significant association, however, between telomerase activity in benign atrophic endometrium versus any endometrial abnormality in women 52 years of age or older.

Telomerase activity in benign and malignant thyroid tumors

Thyroid nodules are found in 5% to 10% of the population. While these nodules carry only a 5% to 10% risk of malignancy, tests that complement fine-needle aspiration (FNA) cytology in preoperative diagnosis and risk stratification are lacking. Telomerase is a ribonucleoprotein polymerase with activity found in many malignant tissues, but absent from most normal adult tissue. In this study, we have investigated telomerase activity in 24 thyroid tumors, 14 matched adjacent thyroid tissues, and 3 chronic thyroiditis tissue samples. Using a telomeric repeat amplification protocol (TRAP) assay on frozen tissue, telomerase activity was detected in 11 of 20 thyroid carcinomas, including 10 of 14 papillary carcinomas and a Hurthle cell carcinoma. Telomerase activity was not detected in 4 benign adenomas, 3 follicular carcinomas, or a single case each of medullary and anaplastic thyroid carcinoma. Telomerase activity was detected in 3 of 14 samples of adjacent thyroid tissue from patients with thyroid tumors. Interestingly, all 3 cases of adjacent thyroid tissue that tested positive had a moderate to marked degree of chronic inflammation. In addition, 3 of 3 samples from chronic thyroiditis specimens tested positive for telomerase activity. When tumor invasiveness (vascular and/or capsular) was compared with telomerase activity in papillary carcinomas, only 1 of 4 telomerase-negative tumors was invasive, while 6 of 10 of telomerase-positive tumors were invasive. Moreover, 6 of 7 invasive papillary carcinomas had telomerase activity. In summary, this is the first report of telomerase activity in thyroid tissue and nodules. This activity was detected in a large percentage of papillary thyroid carcinomas, but not benign adenomas, follicular carcinomas, or most normal thyroid tissue. Telomerase activity may also correlate with tumor invasiveness. Further studies will focus on larger numbers of tumors, metastatic tissue, and undifferentiated carcinomas, as well as application of this assay to products from fine-needle aspirates as a potential diagnostic and prognostic marker in thyroid neoplasms.

Telomerase expression in human breast cancer with and without lymph node metastases

Telomerase is a ribonucleoprotein enzyme that synthesizes telomeric DNA onto the ends of chromosomes, thereby preventing the replication-dependent shortening of these ends. Telomerase activity is detected in a wide range of cancers of various tissues, and its expression may be a critical step in tumor progression. The telomeric repeat amplification protocol was used to compare telomerase activity in breast cancers with and without lymph node metastases, as well as in fibroadenomas and normal breast tissue. Expression of telomerase was detected in 22 (79%) of 28 primary breast cancers, which included 16 (73%) of 22 cancers positive and 6 (100%) of 6 cancers negative for axillary lymph node metastases. It was detected in 1 (11%) of 9 fibroadenomas but was negative in 13 normal breast tissues. There was no statistical difference in expression of telomerase between axillary node-negative primary breast cancers and similar tumors with nodal metastasis (P = .289). Further, no statistical association was found between telomerase activity and tumor size (P = .679) or hormonal status (P = .178). The difference in telomerase activity among breast cancers vs fibroadenomas and normal breast tissues, however, was statistically significant (P < .001). Although normal breast tissue does not express telomerase, both node-positive and node-negative breast cancers express telomerase. The possible significance of telomerase expression in fibroadenomas remains open to further investigation.

The Society of Thoracic Surgeons National Cardiac Surgery Database: current risk assessment

BACKGROUND

The Society of Thoracic Surgeons National Cardiac Surgery Database has recently completed gathering patient data from 1990 through 1994. Using information from more than 300,000 patients undergoing isolated coronary artery bypass grafting in this period, new risk models of operative mortality were developed.

METHODS

Logistic regression analysis was used to develop a risk model for each calendar year. A standard "training set/test set" approach was used for each model.

RESULTS

Five validation techniques were used to evaluate the reliability of the risk models. All models were found to predict operative mortality with good accuracy in this population.

CONCLUSIONS

The new risk models for isolated coronary artery bypass operations serve as reliable predictors of operative mortality for the most recent harvest of patient data from The Society of Thoracic Surgeons National Cardiac Surgery Database.

Calculating risk and outcome: the Veterans Affairs database

The methodology used by the Department of Veterans Affairs for data collection and analysis to derive observed/expected mortality ratios in cardiac surgical patients is reviewed. The Department of Veterans Affairs' use of univariate and multivariate analysis to develop risk ratios for individual risk factors is described. Its experience with tracking observed/expected mortality and morbidity associated with cardiac surgery and length of hospital stays is reviewed. Results of the Department of Veterans Affairs study of the relationship between hospital surgical volume and observed/expected ratios are reported. Feasible goals for the improvement of the predictive capability of database models and the limitations affecting model accuracy are discussed.

Data quality review program: the Society of Thoracic Surgeons Adult Cardiac National Database

In summary, the National Database Committee's Audit and Validation Subcommittee is working to maximize the data completeness and quality of the STS National Database. Toward this end, we welcome your suggestions for improvement.

No continuous relationship between Veterans Affairs hospital coronary artery bypass grafting surgical volume and operative mortality

BACKGROUND

The purpose of this study was to determine whether risk-adjusted coronary artery bypass grafting mortality rates are significantly related to coronary artery bypass grafting surgical procedure volume within the Department of Veterans Affairs hospital system.

METHODS

From April 1987 to September 1992, expected mortality rates were calculated for 23,986 coronary artery bypass grafting procedures performed at 44 different Veterans Affairs hospitals.

RESULTS

This study found a statistically significant relationship between annual hospital coronary artery bypass grafting volume and observed mortality rates (p < 0.02). However, no statistically significant relationship between coronary artery bypass grafting volume and risk-adjusted operative mortality was found (p = 0.10). Using analysis of variance on hospital-level data, hospitals with 100 or less cases per year have higher observed to expected mortality ratios than hospitals performing more than 100 cases per year (p = 0.03). Using Poisson regression models, however, a volume threshold could not be found.

CONCLUSIONS

These findings are consistent with the current Veterans Affairs policy requirements to periodically review quality at low-volume hospitals.

Quality initiatives and the power of the database: what they are and how they run

The criteria by which healthcare is judged or measured are quality, accessibility, and cost effectiveness. To evaluate these criteria it is important to have a database. There are many strengths and weakness to large databases. They can be used as an indicator of the level of performance or quality, for clinical decision making, and as a measurement of cost effectiveness. They can also be useful in the evaluation and development of treatment algorithms and critical pathways for patients with entry level disease. In addition, they can measure patient access to healthcare and the appropriateness of care. It is important for these databases to appropriately adjust for preoperative risk factors that may influence outcome. Outcome in most of the databases is measured by mortality, but morbidity, functional status, quality of life, cost of care, length of stay, return to work, and patient satisfaction are also important outcomes. Factors that can influence the quality of the outcome data are the methods by which the data are collected, standardization of definitions, the currentness of the database, adequate numbers of patients and outcomes, and appropriate analytic techniques. It is important to feed back the data to the healthcare providers in a timely enough fashion so that processes and structures of care can be modified to improve treatment and results. The reliability of the databases and the validity must be substantiated for the healthcare provider to have confidence in the database.(ABSTRACT TRUNCATED AT 250 WORDS)

Statistical methods and strategies for working with large data bases

This article describes the statistical methods and strategies to be used in establishing the linkages between processes and structures of care with risk-adjusted outcomes in a large multicenter Veterans Affairs cooperative study in health services of patients undergoing cardiac surgery. The statistical analyses consist of test involving nine specific hypotheses related to the effect of processes and structures of care on risk-adjusted outcomes. From the statistical point of view, the major obstacles of this study are the need for data reduction and imputation of missing data. The former obstacle is addressed through the use of data-reduction techniques, such as principal components and cluster of variables. The latter is addressed through the use of classic and new techniques for imputation of missing data, such as MISSGEN, principal components for qualitative data, and the expectation and maximization algorithm. Data reduction and imputation of missing data are done with clinically derived variable groups called "dimensions" or "subdimensions." The effect of processes and structures of care is assessed by a two-step process. First, outcomes are modeled using only patient risk factors. The selection of risk factors in the modeling process is discussed in detail. Second, these risk-adjusted outcomes are modeled using one of the nine process or structure subhypotheses. The relationship of the processes and structures of care dimensions and/or subdimensions that are linked to risk-adjusted outcomes are identified.

Variations in the processes and structures of cardiac surgery nursing care

Nurses play an invaluable role as key members of the cardiac surgery patient's medical care team. Over the last century, the nursing profession has become more independent and autonomous. Despite the widespread use of nursing quality indicators, the effect of nursing-specific processes and structures of care on patient outcomes is unknown. Thus, the Processes, Structures, and Outcomes of Care in Cardiac Surgery (PSOCS) study was initiated, in part, to determine the potential effect of nursing processes and structures of care on cardiac surgery patients' risk-adjusted outcomes. In this article, the authors summarize the key components of nursing structures of care incorporated in the PSOCS study. Nursing process variables were not sufficiently designed into the study to address hypotheses relating nursing care processes to patient outcomes. An analysis of the pilot test data from September 1992 to September 1993 demonstrated potentially important variations between the six pilot centers regarding nursing care provider profiles (eg, educational preparation, specialty certification, and experience levels) and nursing staff ratios (eg, within the surgical intensive care unit). When linked to risk-adjusted patient outcomes, these variations in nursing structure of care may offer important insights toward improving the quality of care of cardiac surgery patients.

Why it is important to demonstrate linkages between outcomes of care and processes and structures of care

This first article of the supplement describes the rationale for the Department of Veterans Affairs Cooperative Study, Processes, Structures, and Outcomes in Cardiac Surgery, which was designed to demonstrate statistically and clinically meaningful linkages between processes and structures of care and the outcomes of that care. United States health care is in an era of great enthusiasm for the use of health care outcomes to assess and improve quality of care. An important reason for this enthusiasm is the concern that processes and structures of care, which traditionally have been selected arbitrarily without valid linkages to favorable outcomes, may not result in the desired outcomes of care. Furthermore, health care outcomes are intrinsic to the definition of quality of care and should be relatively free of preconceived biases about how care should be provided. However, the limitations to outcomes-directed quality improvement have been inadequately recognized. These limitations include the following: (1) mortality, the most commonly used outcome, is usually sufficiently rare, resulting in inadequate statistical power; (2) nonfatal outcomes are much more difficult to measure reliably; (3) outcomes may not be measurable for an extended period of time after the care episode, making linkage to quality improvement inefficient; and (4) patients often desire good processes of care as well as favorable outcomes. A review of the literature found relatively few reports linking processes and structures of care to favorable outcomes. Significant relationships between processes of care and outcomes have been reported for several medical conditions (congestive heart failure, acute myocardial infarction, pneumonia, and stroke) when the patient has been considered the unit of analysis. However, there is a paucity of published meaningful process-outcome or structure-outcome linkages for surgical conditions or for any conditions when the hospital has been the focus of analysis. The authors concluded that quality improvement will proceed most efficiently and effectively if all three elements of Donabedian's quality triad (processes, structures, and outcomes) are used and if the processes and structures chosen have been demonstrated to be associated with desired outcomes of care.

An analysis of interobserver reliability and representativeness of data from the Veterans Affairs Cooperative Study on Processes, Structures, and Outcomes in Cardiac Surgery

The authors made some preliminary judgments regarding the reliability and representativeness of the data in the early stages of the Veterans Affairs Cooperative Study entitled Processes, Structures, and Outcomes of Care in Cardiac Surgery (PSOCS). Preliminary PSOCS interobserver reliability and potential patient and site selection bias reported were based on comparisons with identical risk, procedure, and outcome data items collected independently in the Continuous Improvement in Cardiac Surgery Study. PSOCS interobserver reliability for this limited set of variables was good to excellent. At the six pilot centers, there were few important differences between patients entered into PSOCS and those not entered. The 14 Veterans Affairs medical centers that will participate in the full-scale PSOCS study and the 29 nonparticipating centers exhibited similar patient populations. will be valuable.