PubMed Health⌕ Search

Biomedical subjects

Alfred F Connors

Publications and source records attributed to Alfred F Connors.

At least 19 recordsLinked to original sources
PubMed2006

Present-at-admission diagnoses improved mortality risk adjustment among acute myocardial infarction patients.

OBJECTIVE: Hospital mortality outcomes for acute myocardial infarction (AMI) patients are a focus of quality improvement programs conducted by government agencies. AMI mortality risk-adjustment models using administrative data typically adjust for baseline differences in mortality risk with a limited set of common and definite comorbidities. In this study, we present an AMI mortality risk-adjustment model that adjusts for comorbid disease and for AMI severity using information from secondary diagnoses reported as present at admission for California hospital patients. STUDY DESIGN AND SETTING: AMI patients were selected from California hospital administrative data for 1996 through 1999 according to criteria used by the California Hospital Outcomes Project Report on Heart Attack Outcomes, a state-mandated public report that compares hospital mortality outcomes. We compared results for the new model to two mortality risk-adjustment models used to assess hospital AMI mortality outcomes by the state of California, and to two other models used in prior research. RESULTS: The model using present-at-admission diagnoses obtained substantially better discrimination between predicted survival and inpatient death than the other models we considered. CONCLUSION: AMI mortality risk-adjustment methods can be meaningfully improved using present-at-admission diagnoses to identify comorbid disease and conditions related closely to AMI.

California↗
PubMed2006

Physician-attributable differences in intensive care unit costs: a single-center study.

RATIONALE: Variation in practice and outcomes, not explained by patient or illness characteristics, is common in health care, including in intensive care units (ICUs). OBJECTIVE: To quantify within-ICU, between-physician variation in resource use in a single medical ICU. METHODS: This was a prospective, noninterventional study in a medical ICU where nine intensivists provide care in 14-d rotations. Consecutive sample consisted of 1,184 initial patient admissions whose care was provided by a single intensivist. Multivariate models were constructed for average daily discretionary costs, ICU length of stay, and hospital mortality, adjusting for patient and illness characteristics, and workload. MEASUREMENTS AND MAIN RESULTS: The identity of the intensivist was a significant predictor for average daily discretionary costs (p < 0.0001), but not ICU length of stay (p = 0.33) or hospital mortality (p = 0.83). The intensivists had more influence on costs than all other variables except the severity and type of acute illness. Average daily discretionary costs varied by 43% across the different intensivists, equating to a mean difference of 1,003 dollars per admission between the highest and lowest terciles of intensivists. CONCLUSIONS: There are large differences among intensivists in the amount of resources they use to manage critically ill patients. Higher resource use was not associated with lower length of stay or mortality.

Adult↗
PubMed2006

Do patient preferences influence decisions on treatment for patients with steroid-refractory ulcerative colitis?

BACKGROUND & AIMS: Patients with steroid-refractory ulcerative colitis face a difficult treatment decision between colectomy and therapy with infliximab or cyclosporine. The aim of this study was to understand how individual patient preferences for the various treatment outcomes influence the optimal treatment decision for a given patient. METHODS: A Markov model was used to simulate treatment with total colectomy with an ileo pouch-anal anastomosis (TC/IPAA), cyclosporine (CSA), infliximab (INFLX), and infliximab followed by cyclosporine for treatment failures (INFLX-->CSA). Utility weights for treatment outcomes were elicited from 48 patients using both time trade-off and visual rating scale methods. Preference sets were applied to the model to identify the therapy that maximized quality-adjusted life years (QALYs) for each patient. Sensitivity analyses were performed to assess model robustness. RESULTS: Optimal treatment was highly variable among patients (INFLX-->CSA = 42%, 20/48; TC/IPAA = 37%, 18/48; CSA = 21%, 10/48; INFLX = 0%, 0/48). However, when average preference weights from our sample were applied to the model, medical treatments were superior to TC (CSA = .26 QALYs gained vs TC/IPAA; INFLX-->CSA = .25 QALYs gained vs TC/IPAA). CONCLUSIONS: Patient preferences have a clear impact on the optimal treatment for steroid-refractory ulcerative colitis. Although averaged preferences support the use of medical interventions, a third of individual patients may benefit most from proceeding directly to colectomy. Failure to fully assess individual preferences may result in suboptimal treatment for these patients.

Adult↗
PubMed2006

Pulmonary-artery versus central venous catheter to guide treatment of acute lung injury.

BACKGROUND: The balance between the benefits and the risks of pulmonary-artery catheters (PACs) has not been established. METHODS: We evaluated the relationship of benefits and risks of PACs in 1000 patients with established acute lung injury in a randomized trial comparing hemodynamic management guided by a PAC with hemodynamic management guided by a central venous catheter (CVC) using an explicit management protocol. Mortality during the first 60 days before discharge home was the primary outcome. RESULTS: The groups had similar baseline characteristics. The rates of death during the first 60 days before discharge home were similar in the PAC and CVC groups (27.4 percent and 26.3 percent, respectively; P=0.69; absolute difference, 1.1 percent; 95 percent confidence interval, -4.4 to 6.6 percent), as were the mean (+/-SE) numbers of both ventilator-free days (13.2+/-0.5 and 13.5+/-0.5; P=0.58) and days not spent in the intensive care unit (12.0+/-0.4 and 12.5+/-0.5; P=0.40) to day 28. PAC-guided therapy did not improve these measures for patients in shock at the time of enrollment. There were no significant differences between groups in lung or kidney function, rates of hypotension, ventilator settings, or use of dialysis or vasopressors. Approximately 90 percent of protocol instructions were followed in both groups, with a 1 percent rate of crossover from CVC- to PAC-guided therapy. Fluid balance was similar in the two groups, as was the proportion of instructions given for fluid and diuretics. Dobutamine use was uncommon. The PAC group had approximately twice as many catheter-related complications (predominantly arrhythmias). CONCLUSIONS: PAC-guided therapy did not improve survival or organ function but was associated with more complications than CVC-guided therapy. These results, when considered with those of previous studies, suggest that the PAC should not be routinely used for the management of acute lung injury. (ClinicalTrials.gov number, NCT00281268.).

Analysis of Variance↗
PubMed2006

Comparison of two fluid-management strategies in acute lung injury.

BACKGROUND: Optimal fluid management in patients with acute lung injury is unknown. Diuresis or fluid restriction may improve lung function but could jeopardize extrapulmonary-organ perfusion. METHODS: In a randomized study, we compared a conservative and a liberal strategy of fluid management using explicit protocols applied for seven days in 1000 patients with acute lung injury. The primary end point was death at 60 days. Secondary end points included the number of ventilator-free days and organ-failure-free days and measures of lung physiology. RESULTS: The rate of death at 60 days was 25.5 percent in the conservative-strategy group and 28.4 percent in the liberal-strategy group (P=0.30; 95 percent confidence interval for the difference, -2.6 to 8.4 percent). The mean (+/-SE) cumulative fluid balance during the first seven days was -136+/-491 ml in the conservative-strategy group and 6992+/-502 ml in the liberal-strategy group (P<0.001). As compared with the liberal strategy, the conservative strategy improved the oxygenation index ([mean airway pressure x the ratio of the fraction of inspired oxygen to the partial pressure of arterial oxygen]x100) and the lung injury score and increased the number of ventilator-free days (14.6+/-0.5 vs. 12.1+/-0.5, P<0.001) and days not spent in the intensive care unit (13.4+/-0.4 vs. 11.2+/-0.4, P<0.001) during the first 28 days but did not increase the incidence or prevalence of shock during the study or the use of dialysis during the first 60 days (10 percent vs. 14 percent, P=0.06). CONCLUSIONS: Although there was no significant difference in the primary outcome of 60-day mortality, the conservative strategy of fluid management improved lung function and shortened the duration of mechanical ventilation and intensive care without increasing nonpulmonary-organ failures. These results support the use of a conservative strategy of fluid management in patients with acute lung injury. (ClinicalTrials.gov number, NCT00281268 [ClinicalTrials.gov].).

Blood Pressure↗
PubMed2005

Present-at-admission diagnoses improve mortality risk adjustment and allow more accurate assessment of the relationship between volume of lung cancer operations and mortality risk.

BACKGROUND: Mortality risk adjustment is a key component of studies that examine the statistical relationship between hospital lung cancer operation volume and in-hospital mortality. Previous studies of this relationship have used different methods of adjusting for factors that influence mortality risk, but none have adjusted for differences in comorbid disease using only diagnoses identified as present-at-admission. METHODS: This study uses adjustments for conditions identified as present-at-admission to examine the statistical relationship between the volume of lung cancer operations and mortality among 14,456 California hospital patients, and compares these results to other methods of risk adjustment similar to those used in previous studies. RESULTS: Mortality risk adjustment using present-at-admission diagnoses yielded better discrimination and explained more of the variability in observed deaths. Large increases in hospital procedure volume were associated with much smaller decreases in mortality risk than those estimated using comparable risk-adjustment models. CONCLUSIONS: Present-at-admission diagnoses can be used to improve mortality risk adjustment and may allow a more accurate assessment of the relationship between procedure volume and mortality risk.

Comorbidity↗
PubMed2005

Variation in outcomes in Veterans Affairs intensive care units with a computerized severity measure.

OBJECTIVE: To quantify the variability in risk-adjusted mortality and length of stay of Veterans Affairs intensive care units using a computer-based severity of illness measure. DESIGN: Retrospective cohort study. SETTING: A stratified random sample of 34 intensive care units in 17 Veterans Affairs hospitals. PARTICIPANTS: A consecutive sample of 29,377 first intensive care unit admissions from February 1996 through July 1997. INTERVENTIONS: Standardized mortality ratio (observed/expected deaths) and observed minus expected length of stay (OMELOS) with 95% confidence intervals were estimated for each unit using a hierarchical logistic (standardized mortality ratio) or linear (OMELOS) regression model with Markov Chain Monte Carlo simulation. We adjusted for patient characteristics including age, admission diagnosis, comorbid disease, physiology at admission (from laboratory data), and transfer status. MEASUREMENTS AND MAIN RESULTS: Mortality across the intensive care units for the 12,088 surgical and 17,289 medical cases averaged 11% (range, 2-30%). Length of stay in the intensive care units averaged 4.0 days (range, mean unit length of stay 3.0-5.9). Standardized mortality ratio of the intensive care units varied from 0.62 to 1.27; the standardized mortality ratio and 95% confidence interval were <1 for four intensive care units and >1.0 for seven intensive care units. OMELOS of the intensive care units ranged from -0.89 to 1.34 days. In a random slope hierarchical model, variation in standardized mortality ratio among intensive care units was similar across the range of severity, whereas variation in length of stay increased with severity. Standardized mortality ratio was not associated with OMELOS (Pearson's r = .13). CONCLUSIONS: We identified intensive care units whose indicators for mortality and length of stay differ substantially using a conservative statistical approach with a severity adjustment model based on data available in computerized clinical databases. Computerized risk adjustment employing routinely available data may facilitate research on the utility of intensive care unit profiling and analysis of natural experiments to understand process and outcome links and quality efforts.

Adolescent↗
PubMed2004

The relation of autopsy rate to physicians' beliefs and recommendations regarding autopsy.

PURPOSE: Multiple factors have affected the decline in autopsy rates. Our goal was to determine the relation of physicians' recommendations regarding autopsy, as well as patient and surrogate decision-maker characteristics, to autopsy performance. METHODS: We assessed measures related to autopsy performance using data from two teaching institutions in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments. We included patients who had died within 6 months of their index hospitalization and for whom information was available on autopsy performance, physicians' response to questions about autopsy, and interviews with surrogate decision makers about autopsy performance. We assessed the association between autopsy performance and the strength of a physician's recommendation for autopsy, adjusting for patient, surrogate, and physician characteristics. RESULTS: Of the 680 patients who died, 59% (n = 402) met our inclusion criteria. Based on physician and surrogate responses, the expected autopsy rate was 42% while the actual autopsy rate was 23%. The autopsy rate was higher when the physician's recommendation for autopsy was strong or very strong at the time of death compared with when autopsy was not recommended strongly or not at all (P <0.001). The strength of the physician's postmortem recommendation was independently associated with autopsy performance after adjusting for patient, surrogate, and physician characteristics (P <0.001). CONCLUSION: Autopsies are less likely to be performed when not recommended strongly or not at all. Training physicians (or others) how to recommend autopsies may increase autopsy rates.

Aged↗
PubMed2004

Risk adjustment effect on stroke clinical trials.

BACKGROUND AND PURPOSE: The ischemic stroke population is heterogeneous. Even in balanced randomized trials, patient heterogeneity biases estimates of the treatment effect toward no effect when dichotomous end points are used. Risk adjustment statistically addresses some of the heterogeneity and can reduce bias in the treatment effect estimate. The purpose of this study was to estimate the treatment effect of tissue plasminogen activator (tPA) in the National Institute of Neurological Disorders and Stroke (NINDS) tPA data set with and without adjustment for baseline differences. METHODS: Using a prespecified predictive model, we calculated unadjusted and risk-adjusted odds ratios (ORs) for favorable outcome for the Barthel Index, National Institutes of Health Stroke Scale, and Glasgow Outcome Scale for the patients in the NINDS tPA stroke trial. To assess the importance of the difference, a new sample size was calculated through the use of the risk-adjusted analysis. RESULTS: We analyzed 615 subjects. The ORs for the Barthel Index were 1.76 (unadjusted) and 2.04 (adjusted). The National Institutes of Health Stroke Scale and Glasgow Outcome Scale analyses also demonstrated increased ORs after adjustment. The estimated sample size required for the adjusted comparison was 13% smaller than the unadjusted sample. CONCLUSIONS: Risk adjustment in this data set suggests that the true treatment effect was larger than estimated by the unadjusted analysis. Stroke clinical trials should include prospective risk adjustment methodologies.

Aged↗
PubMed2004

Hospital discharge abstract data on comorbidity improved the prediction of death among patients hospitalized with aspiration pneumonia.

OBJECTIVE: To use diagnoses reported as present at admission in California hospital discharge abstract data to identify categories of comorbid disease and conditions related to aspiration pneumonia and to assess their association with hospital mortality. STUDY DESIGN AND SETTING: The study population included all persons hospitalized in California from 1996 through 1999, with a principal diagnosis of aspiration pneumonia. Present at admission diagnoses representing comorbid diseases were separated from conditions closely related to aspiration pneumonia by a physician panel through a computer supported Delphi process. Multivariable logistic regression was used to assess the probability of hospital death after adjusting for these patient characteristics. The statistical performance of this method was compared to the performance of two independent methods for measuring comorbid disease. The practical significance of differences in statistical performance was assessed by comparing the estimated effects of age, race, and ethnicity after adjustments using each method. RESULTS: Mortality risk adjustment using present at admission diagnoses resulted in substantially better statistical performance and in different measurements of the adjusted effects of age, race, and ethnicity. CONCLUSION: Reporting present at admission diagnoses in hospital discharge data yields meaningful improvements in hospital mortality risk adjustment.

Adolescent↗
PubMed2004

Outcomes up to 5 years after severe, acute respiratory failure.

STUDY OBJECTIVE: To use an existing database from a large cohort study with follow-up as long as 5.5 years to assess the extended prognosis of patients who survived their hospitalizations for severe acute respiratory failure (ARF). DESIGN, SETTING, AND PATIENTS: Secondary analysis of an inception cohort of 1,722 patients with ARF requiring mechanical ventilation from five major medical centers who were entered into the prospective Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment. The 1,075 patients (62.4%) who survived hospitalization had systematic follow-up of vital status for a median time of 662 days (interquartile range, 327 to 1,049 days; range, 2 to 2,014 days). Interviews performed a median of 5 months after hospital discharge assessed functional capacity and quality of life (QOL). The main outcome measure was survival after hospital discharge. Secondary measures were functional status and QOL. Cox proportional hazard regression identified factors influencing posthospital survival. RESULTS: The median survival time after hospital discharge for ARF was > 5.3 years. The posthospital survival time was shorter for those with older age, male gender, several preexisting comorbid conditions, worse prehospital functional status, greater acute physiologic derangement, and a do-not-resuscitate order while in the hospital, and for those discharged to a location other than home. Five months after hospital discharge, 48% of survivors needed help with at least one activity of daily living, and 27% rated their QOL as poor or fair. However, most of these impairments were present before respiratory failure occurred. CONCLUSIONS: Extended survival is common among patients with ARF who require mechanical ventilation and who survive hospitalization. Among these patients, only a small fraction of the impairment in activity and QOL can be considered to be a sequela of the respiratory failure or its therapy. These findings are relevant to the care decisions for such critically ill patients.

Activities of Daily Living↗
PubMed2004

Comorbid disease and the effect of race and ethnicity on in-hospital mortality from aspiration pneumonia.

BACKGROUND: Racial and ethnic disparities in mortality have been demonstrated in several diseases. African Americans are hospitalized at a significantly higher rate than whites for aspiration pneumonia; however, no studies have investigated racial and ethnic disparities in mortality in this population. OBJECTIVE: To assess the independent effect of race and ethnicity on in-hospital mortality among aspiration pneumonia discharges while comprehensively controlling for comorbid diseases, and to assess whether the prevalence and effects of comorbid illness differed across racial and ethnic categories. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study of 41,581 patients admitted to California hospitals for aspiration pneumonia from 1996 through 1998, using principal and secondary diagnoses present on admission. MEASUREMENT: The primary outcome measure was in-hospital mortality. RESULTS: The adjusted odds of in-hospital death for African-American compared with white discharges [odds ratio (OR)=1.01; 95% confidence interval (CI), 0.91-1.11] was not significantly different. The odds of death for Asian compared with white discharges was significantly lower (OR=0.83; 95% CI, 0.75-0.91). Hispanics had a significantly lower odds of death (OR=0.90; 95% CI, 0.82-0.988) compared to non-Hispanics. Comorbid diseases were more prevalent among African Americans and Asians than whites, and among Hispanics compared to non-Hispanics. Differences in effects of comorbid disease on mortality risk by race and ethnicity were not statistically significant. CONCLUSION: Asians have a lower risk of death, and the risk of death for African Americans is not significantly different from whites in this analysis of aspiration pneumonia discharges. Hispanics have a lower risk of death than non-Hispanics. While there are differences in prevalence of comorbid disease by racial and ethnic category, the effects of comorbid disease on mortality risk do not differ meaningfully by race or ethnicity.

Adult↗
PubMed2003

Automated intensive care unit risk adjustment: results from a National Veterans Affairs study.

CONTEXT: Comparison of outcome among intensive care units (ICUs) requires risk adjustment for differences in severity of illness and risk of death at admission to the ICU, historically obtained by costly chart review and manual data entry. OBJECTIVE: To accurately estimate patient risk of death in the ICU using data easily available in hospital electronic databases to permit automation. DESIGN AND SETTING: Cohort study to develop and validate a model to predict mortality at hospital discharge using multivariate logistic regression with a split derivation (17,731) and validation (11,646) sample formed from 29,377 consecutive first ICU admissions to medical, cardiac, and surgical ICUs in 17 Veterans' Health Administration hospitals between February 1996 and July 1997. MAIN OUTCOME MEASURES: Mortality at hospital discharge adjusted for age, laboratory data, diagnosis, source of ICU admission, and comorbid illness. RESULTS: The overall hospital death rate was 11.3%. In the validation sample, the model separated well between survivors and nonsurvivors (area under the receiver operating characteristic curve = 0.885). Examination of the observed vs. the predicted mortality across the range of mortality showed the model was well calibrated. CONCLUSIONS: Automation could broaden access to risk adjustment of ICU outcomes with only a small trade-off in discrimination. Broader use might promote valid evaluation of ICU outcomes, encouraging effective practices and improving ICU quality.

Adult↗
PubMed2003

Predicting outcome in ischemic stroke: external validation of predictive risk models.

BACKGROUND: Six multivariable models predicting 3-month outcome of acute ischemic stroke have been developed and internally validated previously. The purpose of this study was to externally validate the previous models in an independent data set. SUMMARY OF REPORT: We predicted outcomes for 299 patients with ischemic stroke who received placebo in the National Institute of Neurological Disorders and Stroke rt-PA trial. The model equations used 6 acute clinical variables and head CT infarct volume at 1 week as independent variables and 3-month National Institutes of Health Stroke Scale, Barthel Index, and Glasgow Outcome Scale as dependent variables. Previously developed model equations were used to forecast excellent and devastating outcome for subjects in the placebo tissue plasminogen activator data set. Area under the receiver operator characteristic curve was used to measure discrimination, and calibration charts were used to measure calibration. The validation data set patients were more severely ill (National Institutes of Health Stroke Scale and infarct volume) than the model development subjects. Area under the receiver operator characteristic curves demonstrated remarkably little degradation in the validation data set and ranged from 0.75 to 0.89. Calibration curves showed fair to good calibration. CONCLUSIONS: Our models have demonstrated excellent discrimination and acceptable calibration in an external data set. Development and validation of improved models using variables that are all available acutely are necessary.

Aged↗
PubMed2002

The accuracy of endometrial biopsy and saline sonohysterography in the determination of the cause of abnormal uterine bleeding.

OBJECTIVE: The purpose of this study was to determine the accuracy of outpatient endometrial biopsy and saline sonohysterography for the evaluation of abnormal uterine bleeding. STUDY DESIGN: Eligible participants included women aged 25 to 69 years who complained of persistent uterine bleeding, despite medical treatment. One hundred forty-four patients consented and were followed up prospectively: 1 patient did not successfully complete a saline sonohysterography because of discomfort, 143 patients underwent an endometrial biopsy and saline sonohysterography as outpatients, 113 patients underwent a definitive surgical intervention (hysteroscopy/dilatation and curettage or hysterectomy), 20 patients did not complete a gold standard measure, and 10 patients were lost to follow-up. RESULTS: The combination of endometrial biopsy and saline sonohysterography for the 113 patients who completed the study had a sensitivity and specificity for the detection of abnormal pathologic features of 97.0% (95% CI, 88.6-99.5) and 70.2% (95% CI, 55.0-82.2) and a positive and negative predictive value of 82.1% (95% CI, 71.4-89.5) and 94.3% (95% CI, 79.6-99.0) compared with hysteroscopy/curettage or hysterectomy. CONCLUSION: The high sensitivity and high negative predictive value of saline sonohysterography combined with endometrial biopsy make this technique useful for the evaluation of abnormal uterine bleeding. It may allow some patients to avoid more invasive operative procedures; however, it is important to recognize the limitations in the predictive value of this diagnostic modality.

Adult↗