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Biomedical subjects

W Henderson

Publications and source records attributed to W Henderson.

At least 55 records · Page 3Linked to original sources
PubMed1997

Impact of home care on hospital days: a meta analysis.

OBJECTIVE: To examine the impact of home care on hospital days. DATA SOURCES: Search of automated databases covering 1964-1994 using the key words "home care," "hospice," and "healthcare for the elderly." Home care literature review references also were inspected for additional citations. STUDY SELECTION: Of 412 articles that examined impact on hospital use/cost, those dealing with generic home care that reported hospital admissions/cost and used a comparison group receiving customary care were selected (N = 20). STUDY DESIGN: A meta-analytic analysis used secondary data sources between 1967 and 1992. DATA EXTRACTION: Study characteristics that could have an impact on effect size (i.e., country of origin, study design, disease characteristics of study sample, and length of follow-up) were abstracted and coded to serve as independent variables. Available statistics on hospital days necessary to calculate an effect size were extracted. If necessary information was missing, the authors of the articles were contacted. METHODS: Effect sizes and homogeneity of variance measures were calculated using Dstat software, weighted for sample size. Overall effect sizes were compared by the study characteristics described above. PRINCIPAL FINDINGS: Effect sizes indicate a small to moderate positive impact of home care in reducing hospital days, ranging from 2.5 to 6 days (effect sizes of -.159 and -.379, respectively), depending on the inclusion of a large quasi-experimental study with a large treatment effect. When this outlier was removed from analysis, the effect size for studies that targeted terminally ill patients exclusively was homogeneous across study subcategories; however, the effect size of studies that targeted nonterminal patients was heterogeneous, indicating that unmeasured variables or interactions account for variability. CONCLUSION: Although effect sizes were small to moderate, the consistent pattern of reduced hospital days across a majority of studies suggests for the first time that home care has a significant impact on this costly outcome.

Aged↗
PubMed1997

Risk adjustment of the postoperative mortality rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs Surgical Risk Study.

BACKGROUND: The National Veterans Affairs Surgical Risk Study was designed to collect reliable, valid data on patient risk and outcomes for major surgery in the Veterans Health Administration and to report comparative risk-adjusted postoperative mortality rates for surgical services in Veterans Health Administration. STUDY DESIGN: This cohort study was conducted in 44 Veterans Affairs Medical Centers. Included were 87,078 major noncardiac operations performed under general, spinal, or epidural anesthesia between October 1, 1991, and December 31, 1993. The main outcomes measure was all-cause mortality within 30 days after the index procedure. Multivariable logistic regression risk-adjustment models for all operations and for eight surgical subspecialties were developed. Risk-adjusted surgical mortality rates were expressed as observed-to-expected ratios and were compared with unadjusted 30-day postoperative mortality rates. RESULTS: Patient risk factors predictive of postoperative mortality included serum albumin level, American Society of Anesthesia class, emergency operation, and 31 additional preoperative variables. Considerable variability in unadjusted mortality rates for all operations was observed across the 44 hospitals (1.2-5.4%). After risk adjustment, observed-to-expected ratios ranged from 0.49 to 1.53. Rank order correlation of the hospitals by unadjusted and risk-adjusted mortality rates for all operations was 0.64. Ninety-three percent of the hospitals changed rank after risk adjustment, 50% by more than 5 and 25% by more than 10. CONCLUSIONS: The Department of Veterans Affairs has successfully implemented a system for the prospective collection and comparative reporting of risk-adjusted postoperative mortality rates after major noncardiac operations. Risk adjustment had an appreciable impact on the rank ordering of the hospitals and provided a means for monitoring and potentially improving the quality of surgical care.

Cohort Studies↗
PubMed1997

Risk adjustment of the postoperative morbidity rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs Surgical Risk Study.

BACKGROUND: The National Veterans Affairs Surgical Risk Study was designed to collect reliable, valid data on patient risk and outcomes for major surgery in the Veterans Health Administration and to report comparative risk-adjusted postoperative mortality and morbidity rates for surgical services in the Veterans Health Administration. STUDY DESIGN: This was a cohort study conducted at 44 Veterans Affairs Medical Centers closely affiliated with university medical centers. Included were 87,078 major noncardiac operations performed under general, spinal, or epidural anesthesia between October 1, 1991, and December 31, 1993. The main outcomes measures in this report are 21 postoperative adverse events (morbidities) occurring within 30 days after the index procedure. Multivariable logistic regression risk-adjustment models for all operations and for eight surgical subspecialties were developed. RESULTS: Patient risk factors predictive of postoperative morbidity included serum albumin level, American Society of Anesthesia class, the complexity of the operation, and 17 other preoperative risk variables. Wide variation in the unadjusted rates of one or more postoperative morbidities for all operations was observed across the 44 hospitals (7.4-28.4%). Risk-adjusted observed-to-expected ratios ranged from 0.49 to 1.46. The Spearman rank order correlation between the ranking of the hospitals based on unadjusted morbidity rates and risk-adjusted observed-to-expected ratios for all operations was 0.87. There was little or no correlation between the rank order of the hospitals by risk-adjusted morbidity and risk-adjusted mortality. CONCLUSIONS: The Department of Veterans Affairs has successfully implemented a system for the prospective collection and comparative reporting of postoperative mortality and morbidity rates after major noncardiac operations. Risk adjustment had only a modest effect on the rank order of the hospitals.

Female↗
PubMed1997

Validating risk-adjusted surgical outcomes: site visit assessment of process and structure. National VA Surgical Risk Study.

BACKGROUND: Risk-adjusted mortality and morbidity rates are often used as measures of the quality of surgical care. This study was conducted to determine the validity of risk-adjusted surgical morbidity and mortality rates as measures of quality of care by assessing the process and structure of care in surgical services with higher-than-expected and lower-than-expected risk-adjusted 30-day mortality and morbidity rates. STUDY DESIGN: A structural survey of 44 Veterans Affairs Medical Center surgical services and site visits to 20 surgical services with higher-than-expected and lower-than-expected risk-adjusted outcomes were conducted. Main outcome measures included assessment of technology and equipment, technical competence of staff, leadership, relationship with other services, monitoring of quality of care, coordination of work, relationship with affiliated institutions, and overall quality of care. RESULTS: Surgical services with lower-than-expected risk-adjusted surgical morbidity and mortality rates had significantly more equipment available in surgical intensive care units than did services with higher-than-expected outcomes (4.3 versus 2.9, p < 0.05). Site-visitor ratings of overall quality of care were significantly higher for surgical services with lower-than-expected morbidity and mortality rates (6.1 versus 4.5 for high outliers, p < 0.05); technology and equipment were rated significantly better among low-outlier services (7.1 versus 4.8 for high outliers, p < 0.001). Masked site-visit teams correctly predicted the outlier status (high versus low) of 17 of the 20 surgical services visited (p < 0.001). CONCLUSIONS: Significant differences in several dimensions of process and structure of the delivery of surgical care are associated with differences in risk-adjusted surgical morbidity and mortality rates among 44 Veterans Affairs Medical Centers.

Hospital Mortality↗
PubMed1996

Classifying general medicine readmissions. Are they preventable? Veterans Affairs Cooperative Studies in Health Services Group on Primary Care and Hospital Readmissions.

OBJECTIVES: To describe a new quality assessment method used to classify the preventability of hospitalization in terms of patient, clinician, or system factors. DESIGN: The instrument was developed in two phases. Phase 1 was a prospective comparison of admitting residents' and their attending physicians' classifications of the perceived preventability of consecutive admissions to one Veterans Affairs Medical Center (VAMC) excluding admissions to the intensive care unit (ICU). In phase 2, a panel of 10 physicians rated 811 abstracted records of readmissions from nine VAMCs. SETTING: Nine VAMCs across the United States with varying degrees of university hospital affiliation. PATIENTS: Phase 1, 156 patients admitted to the general medicine service at the Durham VAMC. Phase 2, 514 patients accounting for 811 readmissions within 6 months of a general medicine service discharge at nine VAMCs. MEASUREMENTS AND MAIN RESULTS: Physicians used a checklist to record the reason for hospitalization, the preventability of the hospitalization, and, if preventable, a reason defining preventability, which was classified in terms of system, clinician, and patient factors. In phase 2, two physician panelists assessed preventability for each chart. When two panelists disagreed on the preventability of hospitalization, a third panelist, blind to the original assessments, rated the chart. In phase 1, residents and attending physicians rated 33% and 34% of admissions as preventable (kappa = 0.41), respectively. In phase 2, 277 (34%) of 811 readmissions were deemed preventable. Intraobserver accuracy for the assessment of preventability was 96% (kappa = 0.89). interobserver accuracy was 73% (kappa = 0.43). Hospital system factors accounted for 37% of preventable readmissions, clinician factors for 38%, and patient factors for 21%. The nine hospitals differed markedly in their profile of reasons for preventable readmissions (p = .005). CONCLUSIONS: Using a new method of determining the preventability of hospitalizations, we identified several factors that might avert hospitalizations. Focusing efforts to identify preventable hospitalizations may yield better methods for managing patients' total health care needs; however, the content of those efforts will vary by institution.

Adult↗
PubMed1995

Custom CAD/CAM total temporomandibular joint reconstruction system: preliminary multicenter report.

PURPOSE: The purpose was to test the outcome of a custom computer assisted design/computer assisted manufactured (CAD/CAM) total temporomandibular joint (TMJ) reconstruction system. PATIENTS AND METHODS: There were 215 patients (13 males and 202 females); the average age at reconstruction was 40.9 +/- 10.3 years (range, 15 to 77 years). There were 363 joints placed, 296 bilateral and 67 unilateral. The patients had TMJ problems for an average of 10.3 +/- 7.0 years (range, 1 to 44 years), and had undergone a mean of 5.4 +/- 4.8 (range, 0 to 28) prior unsuccessful surgeries. Preoperative and postoperative data were collected for up to 48 months using a standardized data collection format. Subjective data related to pain, function of the lower jaw, and diet, were obtained using a visual analogue scale. Objective measures of mandibular range of motion were made directly on the patient preoperatively and postoperatively. RESULTS: Preliminary analysis of these data reveals a statistically significant decrease in pain, an increase in function, and improvement in diet (P < .0001) from the preoperative measurements to 1 and 2 years postoperatively. There was also improvement in mandibular vertical range of motion. The number of previous surgeries was a strong predictor of postoperative pain, function, and diet scores, as well as of maximal interincisal opening. A life table analysis of failures indicates good durability of the prosthesis over time. CONCLUSION: These preliminary data indicate that this custom CAD/CAM total TMJ reconstruction system seems to be useful in the treatment of the multiply operated, and/or anatomically mutilated TMJ.

Adolescent↗
PubMed1995

Measuring activities in clinical trials using random work sampling: implications for cost-effectiveness analysis and measurement of the intervention.

Determining research-related costs from intervention-related costs is important for both clinical and health services research. Often this task involves estimating what proportion of the workday personnel spend on a variety of activities. We used a portable random reminder beeper to measure the daily work activities and contacts of study nurses within the context of a multi-site randomized trial designed to assess the effectiveness of primary care. Nurses recorded 4920 work activities over 140 consecutive workdays. Research-related activities consumed the largest proportion of the workday, 42.5% (95% CI, 38.1-46.7) followed by patient care, 28.8% (24.1-33.2), personal time 16.4% (12.0-20.7), and time spent in transit 12.5% (9.1-15.9). Because this research-related time is spent performing tasks specific to the enrollment of patients and measurement of outcome variables, we will use an adjusted annual salary for these nurses (from $56,392-$32,425) when attributing costs of the intervention in cost-effectiveness analyses and for future management projections. Work sampling is a flexible, inexpensive method that was well accepted by the nurses in this study. Our results provide important insights into the costs analysis of complex interventions involving health professionals and may allow us to explore why the intervention worked or did not work at individual sites.

Clinical Trials as Topic↗
PubMed1995

Veterans Affairs Cooperative Study on glycemic control and complications in type II diabetes (VA CSDM). Results of the feasibility trial. Veterans Affairs Cooperative Study in Type II Diabetes.

OBJECTIVE: It is not clear whether intensive pharmacological therapy can be effectively sustained in non-insulin-dependent diabetes mellitus (NIDDM). The relative risks and benefits of intensive insulin therapy in NIDDM are not well defined. Accordingly, we designed a feasibility study that compared standard therapy and intensive therapy in a group of NIDDM men who required insulin due to sustained hyperglycemia. RESEARCH DESIGN AND METHODS: A prospective trial was conducted in five medical centers in 153 men of 60 +/- 6 years of age who had a known diagnosis of diabetes for 7.8 +/- 4 years. They were randomly assigned to a standard insulin treatment group (one morning injection per day) or to an intensive therapy group designed to attain near-normal glycemia and a clinically significant separation of glycohemoglobin from the standard arm. A four-step plan was used in the intensive therapy group along with daily self-monitoring of glucose: 1) an evening insulin injection, 2) the same injection adding daytime glipizide, 3) two injections of insulin alone, and 4) multiple daily injections. Patient accrual and adherence, glycohemoglobin (HbA1c), side effects, and measurements of endpoints for a prospective long-term trial were assessed. RESULTS: Accrual goals were met, mean follow-up time was 27 months (range 18-35 months), and patients kept 98.6% of scheduled visits. After 6 months, the mean HbA1c in the intensive therapy group was at or below 7.3% and remained 2% lower than the standard group for the duration of the trial. Most of the decrease in the mean HbA1c in the intensive group was obtained by a single injection of evening intermediate insulin, alone or with daytime glipizide. By the end of the trial, 64% of the patients had advanced to two or more injections of insulin a day, aiming for normal HbA1c. However, only a small additional fall in HbA1c was attained. Severe hypoglycemia was rare (two events per 100 patients per year) and not significantly different between the groups, nor were changes in weight, blood pressure, or plasma lipids. There were 61 new cardiovascular events in 40 patients and 10 deaths (6 due to cardiovascular causes). CONCLUSIONS: Intense stepped insulin therapy in NIDDM patients who have failed glycemic control on pharmacological therapy is effective in maintaining near-normal glycemic control for > 2 years without excessive severe hypoglycemia, weight gain, hypertension, or dyslipidemia. Cardiovascular event rates are high at this stage of NIDDM. A long-term prospective trial is needed to assess the risk-benefit ratio of intensified treatment of hyperglycemia in NIDDM patients requiring insulin.

Aged↗
PubMed1995

The National Veterans Administration Surgical Risk Study: risk adjustment for the comparative assessment of the quality of surgical care.

BACKGROUND: The use of surgical outcome in the comparative assessment of the quality of surgical care is predicted on the development of proper models that adjust for the severity of the preoperative risk factors of the patient. The National Veterans Administration Surgical Risk Study was designed to collect reliable, valid data about patient risk and outcome for major surgery in the Veterans Health Administration (VHA) and to report comparative risk-adjusted surgical morbidity and mortality rates for surgical services in VHA. This study describes the rationale and methods used in the Risk Study and reports on the frequency distribution of the data elements that will be used in the development of risk-adjusted reporting of surgical outcome. STUDY DESIGN: This study was a prospective observational study in which dedicated nurses collected preoperative, intraoperative, and outcome data on patients undergoing noncardiac operations using general, spinal, and epidural anesthesia in 44 Veterans Administration Medical Centers. Outcome measures included all cause mortality within the 30 days after the index procedure and 21 major morbidities. RESULTS: Eighty-three thousand nine hundred fifty-eight cases meeting inclusion criteria were entered in the study between October 1, 1991 and December 31, 1993. Ninety-seven percent of patients were men, with a mean age of 60.1 +/- 13.6 (standard deviation) years. The most common preoperative risk factors were smoking (40.7 percent) and hypertension (36.1 percent). Of the patients, 84.6 percent had one or more risk factors. The most common procedures were transurethral resection of the prostate gland (6.7 percent), total knee replacement (3.1 percent), thromboendarterectomy (2.4 percent), partial colectomy (2.2 percent), and total hip replacement (2 percent). The unadjusted mortality rate was 3.1 percent at 30 days. The most common postoperative morbidities were pneumonia (3.6 percent), urinary tract infection (3.5 percent), and failure to wean from the ventilator at 48 hours postoperatively (3.2 percent). Seventeen percent of the patients have one or more major complications. CONCLUSIONS: The Veterans Health Administration has successfully implemented an outcome reporting system for major surgery that prospectively collects patient risk and outcome information reliably and validly. Risk adjustment models and comparative hospital-specific rates of risk-adjusted outcomes are currently being developed.

Aged↗
PubMed1994

Lack of association between patients' measured burden of disease and risk for hospital readmission.

Identifying patients at increased risk for hospital readmission is important for clinicians, health policy-makers, hospital administrators, and researchers. We used a retrospective case-control design to compare the clinimetric properties of five validated indices that measure a patient's disease burden. The study was conducted on a random sample of patients discharged from the general medicine service at the Durham Department of Veterans Affairs Medical Center. Trained observers (two research assistants, one nurse, and two physicians) blinded to readmission status abstracted the required data elements from the medical record for three indices (Charlson, Kaplan-Feinstein, Index of Coexistent Disease). The hospital's computer provided data elements for two indices (Smith, adapted Charlson). Indices varied in the time required to complete, the ability to capture individual heterogeneity, and inter-observer variability. However, none of the indices discriminated among patients who did and those who did not have 6-month hospital readmissions. Factors other than summary scores derived from these indices should be used to identify patients at high risk for readmission.

Aged↗
PubMed1994

Long-term graft patency (3 years) after coronary artery surgery. Effects of aspirin: results of a VA Cooperative study.

BACKGROUND: The long-term success of coronary bypass surgery is dependent on graft patency after surgery. This trial was designed to determine if aspirin improved saphenous vein graft or internal mammary artery (IMA) graft patency between 1 and 3 years after coronary artery bypass grafting (CABG). METHODS AND RESULTS: After receiving aspirin 325 mg/d for 1 year after CABG and undergoing a 1-year postoperative cardiac catheterization, patients were randomized to receive either aspirin (325 mg) or placebo for 2 additional years. Angiography was performed 3 years after surgery to determine the primary end point-saphenous vein graft patency in 288 patients and IMA graft patency in 167 patients. At 3 years after CABG, the saphenous vein graft occlusion rate was 17.0% (62 of 365) for patients treated with aspirin compared with 19.7% (74 of 376) for those who received placebo (P = .404). For saphenous vein grafts that were patent at 1 year, the occlusion rate at 3 years was 4.8% (15 of 313) for patients treated with aspirin compared with 4.2% (13 of 310) for patients who received placebo (P = .757). At 3 years, the IMA graft occlusion rate was 10.3% (8 of 78) for patients treated with aspirin compared with 7.9% (7 of 89) for patients who received placebo (P = .594). For IMA grafts that were patent at 1 year, the occlusion rate was 4.3% (3 of 70) for patients treated with aspirin compared with 2.5% (2 of 81) for patients who received placebo (P = .541). CONCLUSIONS: These data suggest that aspirin treatment does not improve saphenous vein graft or IMA graft patency between 1 and 3 years after CABG.

Aspirin↗
PubMed1992

Glycemic control and complications in type II diabetes. Design of a feasibility trial. VA CS Group (CSDM)

OBJECTIVE: To determine, after 1 yr of follow-up in type II diabetes patients, whether a statistically and clinically significant difference can be achieved in HbA1c between a standard therapy group and an intensively treated group, while maintaining HbA1c levels in both groups within ranges acceptable in regular community practice. Secondary objectives include assessment of patient adherence to protocol, side effects, and accuracy of data collection. RESEARCH DESIGN AND METHODS: This is a prospective, randomized, controlled VA CS conducted with 151 patients at five VAMCs. Patients are males, age 40-69 yr, treated at entry with a maximum dose of sulfonylurea or with insulin, exhibiting an HbA1c level > 3 SDs above the normal mean (5.05 + 3 x 0.50 = > 6.55%). Standard control is achieved with insulin and intensive control with a step-up regimen including insulin alone or insulin/glipizide combinations. Education and management of cardiovascular risk factors are handled similarly in both groups. Primary macrovascular end points are nonfatal myocardial infarction, congestive heart failure, stroke, amputation, and cardiovascular death. Primary microvascular end points are appearance and progression of retinopathy, documented by centrally read seven-field-stereo fundus photographs. Other measured indicators include resting and ambulatory ECGs, ventricular function (MUGA scan), serum lipid and apolipoprotein levels, plasma fibrinogen, nonsymptomatic peripheral vasculopathy, neuroautonomic status by heart-beat variation on Valsalva maneuver, and microalbuminuria. CONCLUSIONS: This study may be the basis for a long-term trial, involving 1400 patients, to assess the long-term effects of metabolic control on macro- and microvascular end points.

Adult↗
PubMed1991

Starting aspirin therapy after operation. Effects on early graft patency. Department of Veterans Affairs Cooperative Study Group.

BACKGROUND: Although aspirin therapy started before operation improves vein graft patency after coronary artery bypass grafting, it also causes bleeding. The objective of this prospective, centrally directed, randomized, double-blind, placebo-controlled trial was to compare the effects of aspirin therapy started before operation with aspirin started 6 hours after operation on early (7-10-day) graft patency. METHODS AND RESULTS: Patients were randomized to receive either aspirin 325 mg or placebo the night before surgery; after operation, all patients received aspirin 325 mg daily, with the first dose administered through the nasogastric tube 6 hours after operation. Angiography was performed in 72% of the analyzed patients an average of 8 days after operation, and the primary end point was saphenous vein graft patency in 351 patients. Internal mammary artery graft patency was also assessed in 246 patients because many individuals received both internal mammary artery and vein grafts. In the patients given preoperative aspirin, the vein graft occlusion rate was 7.4 +/- 1.3% compared with 7.8 +/- 1.5% in those who received preoperative placebo (p = 0.871). In the subgroup of patients receiving Y grafts, 0.0% of the grafts were occluded in the preoperative aspirin group compared with 7.0 +/- 3.6% in the preoperative placebo group (p = 0.066). The internal mammary artery occlusion rate was 0.0% (0 of 131) in the aspirin group compared with 2.4 +/- 1.4% (three of 125) in the placebo group (p = 0.081). Patients in the aspirin group received more transfusions than those in the placebo group (median, 900 versus 725 ml, p = 0.006). The reoperation rate for bleeding in the aspirin group was 6.3% compared with 2.4% in the placebo group (p = 0.036). Median chest tube drainage within the first 6 hours after operation was 500 ml in the aspirin group compared with 448 ml in the placebo group (p = 0.011). CONCLUSIONS: Thus, preoperative aspirin is associated with increased bleeding complications and offers no additional benefit in early vein graft patency compared with starting aspirin therapy 6 hours after operation. There was a trend, although not significant, toward improved early patency for Y grafts and internal mammary artery grafts with preoperative aspirin.

Aged↗
PubMed1991

Comparison of postoperative complications between saphenous vein and IMA grafts to left anterior descending coronary artery.

Considerable controversy exists regarding relative morbidity associated with the saphenous vein graft (SVG) and internal mammary artery (IMA) graft in patients undergoing myocardial revascularization. As a part of the cooperative study on use of antiplatelet drugs for graft patency, operative and postoperative data were prospectively collected on 1,150 patients who underwent either SVG (n = 656) or IMA anastomosis (n = 494) to the left anterior descending coronary artery. There were no differences in baseline characteristics of patients, distribution of randomization among treatment groups, and total number of distal anastomoses performed between the two groups. The aortic cross-clamp time, cardiopulmonary bypass duration, operative time, and chest tube drainage were greater (p = 0.0001) in the patients with IMA grafts compared with SVG. However, there was no difference in the operative mortality rate, the amount of blood and blood products received, the reoperation rate for control of postoperative bleeding, and incidence of wound complications between the two groups. The early and 1-year patency rates for the IMA were slightly but not significantly better than the SVG patency rates (92.8% versus 90.1% for 1-year patency; p = 0.309). In conclusion, use of IMA is associated with a longer operative time as well as increased postoperative bleeding compared with the SVG. It, however, does not increase operative mortality or postoperative morbidity.

Aged↗
PubMed1991

Impact of resident training on postoperative morbidity in patients undergoing single valve replacement. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease.

As one of the requirements of the Department of Veterans Affairs cooperative study on valvular heart disease, operative and postoperative data were prospectively collected in 964 patients undergoing single valve replacement. The procedure was performed either by a resident under the direct supervision of an attending surgeon (49.5%) or by an attending surgeon (50.5%). There was no difference in operative mortality between the two groups of surgeons when adjusted for patient-related and disease-related risk factors. The proportion of patients who had at least one postoperative complication was slightly but not significantly higher in the attending group (35.8% versus 30.4% for aortic valve replacement, 38% versus 28% for mitral valve replacement, and 36% versus 30% for all single valve replacement procedures). As the significance of each complication varies, we weighted each complication to the associated operative mortality to formulate the morbidity score. An expected complication rate for each group was derived from a multivariate logistic model, and the ratio of observed to expected morbidity was calculated to adjust observed morbidity according to the risk of patients. There was no difference in the observed/expected morbidity ratio between the two groups of surgeons. We conclude that currently used teaching techniques and philosophy to educate cardiac surgical residents, which allow them to take progressive responsibility for cardiac surgical procedures, are well justified, and patient care does not suffer when resident training is enhanced.

Aortic Valve↗
PubMed1990

Internal mammary artery and saphenous vein graft patency. Effects of aspirin.

As part of two Department of Veterans Affairs Cooperative Trials, we obtained angiographic patency data for internal mammary artery (IMA) and saphenous vein grafts to the left anterior descending (LAD) coronary artery at 1 year after coronary artery bypass surgery. Patients received either aspirin 325 mg q.d., aspirin 325 mg t.i.d., aspirin 325 mg and dipyridamole 75 mg t.i.d., or placebo. Aspirin was initiated either 12 hours before or 6 hours after operation. Patients were stratified preoperatively for extent of disease and randomized to the therapies outlined above. There was no randomization to IMA versus saphenous vein grafts to the LAD. When the patients taking placebo were compared with those taking aspirin, there were no differences in the IMA (100.0% versus 92.1%, p = 0.385) or vein graft (88.8% versus 90.4%, p = 0.675) patency rates. The patency rate, irrespective of treatment, for all IMA grafts was 92.8% (220 of 237) versus 90.1% (345 of 383) for all vein grafts to the LAD (p = 0.309). Thus, both the IMA and vein grafts had excellent patency rates at 1 year. Aspirin did not alter this at 1 year, and there were no differences between IMA and vein graft patency to the LAD.

Aspirin↗
PubMed1989

Saphenous vein graft patency 1 year after coronary artery bypass surgery and effects of antiplatelet therapy. Results of a Veterans Administration Cooperative Study.

To determine whether antiplatelet therapies improve saphenous vein graft patency after coronary artery bypass grafting, we compared 1) aspirin (325 mg once daily), 2) aspirin (325 mg three times daily), 3) aspirin and dipyridamole (325 mg and 75 mg, respectively, three times daily), 4) sulfinpyrazone (267 mg three times daily), and 5) placebo (three times daily). Therapy with dipyridamole and sulfinpyrazone was started 48 hours before bypass graft surgery, and aspirin treatment was begun 12 hours before surgery as a single 325-mg dose. Postoperative treatment was started 6 hours after surgery and continued for 1 year. Graft patency data were obtained early (median, 9 days) and late (median, 367 days) after surgery. The early graft occlusion rate was decreased with all aspirin treatment regimens compared with that of the placebo regimen. At 1 year, in 406 patients with 1,315 grafts, the graft occlusion rate in all of the aspirin groups combined was 15.8% compared with 22.6% for the placebo group (p = 0.029). The patients taking aspirin once daily had a lower occlusion rate (13.2%) compared with the patients receiving placebo (p = 0.050). At 1 year, in the vein grafts placed to vessels less than or equal to 2.0 mm in diameter (804 distal sites), the graft occlusion rate in all of the aspirin groups was 20.1% compared with 32.3% for the placebo group (p = 0.008). In the vein grafts placed to vessels greater than 2.0 mm in diameter (511 distal sites), there was no difference in the occlusion rates between aspirin and the placebo group at 1 year (8.7% vs. 9.0%, p = 0.918).(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗