Biomedical subjects

Liam O'Neill

Publications and source records attributed to Liam O'Neill.

7 recordsLinked to original sources

PubMed2005

Methods for understanding super-efficient data envelopment analysis results with an application to hospital inpatient surgery.

We compare two techniques for increasing the transparency and face validity of Data Envelopment Analysis (DEA) results for managers at a single decision-making unit: multifactor efficiency (MFE) and non-radial super-efficiency (NRSE). Both methods incorporate the slack values from the super-efficient DEA model to provide a more robust performance measure than radial super-efficiency scores. MFE and NRSE are equivalent for unique optimal solutions and a single output. MFE incorporates the slack values from multiple output variables, whereas NRSE does not. MFE can be more transparent to managers since it involves no additional optimization steps beyond the DEA, whereas NRSE requires several. We compare results for operating room managers at an Iowa hospital evaluating its growth potential for multiple surgical specialties. In addition, we address the problem of upward bias of the slack values of the super-efficient DEA model.

Benchmarking↗

PubMed2005

Explaining variation in physician practice patterns and their propensities to recommend services.

Variations in physician practice patterns have important implications for quality and cost. The purpose of this article is to explain variation in physicians' practice patterns in terms of physician personal characteristics, practice setting, patient population, and managed care involvement. Data on 2,455 primary care physicians were derived from the Community Tracking Study Physician Survey (1996-1997). Factor scores were determined based on responses to three clinical scenarios that represent discretionary medical decisions. These scenarios include a specialist referral for benign prostatic hyperplasia, prescription drugs for elevated cholesterol, and an office visit for vaginal discharge. Physician age, being a foreign medical school graduate, being a solo practitioner, and having a larger proportion of Medicaid patients were all associated with higher factor scores, a greater likelihood of ordering a service. Being board certified was associated with lower factor scores. Managed care involvement was not a significant predictor of factor scores.

Adult↗

PubMed2004

A small proportion of mesenchymal stem cells strongly expresses functionally active CXCR4 receptor capable of promoting migration to bone marrow.

Homing of bone marrow stromal cells (MSCs) to bone and bone marrow after transplantation, important for the correction of conditions such as metabolic storage disorders, can occur but with poor efficiency. Substantial improvements in engraftment will be required in order to derive a clinical benefit from MSC transplantation. Chemokines are the most important factors controlling cellular migration. Stromal-derived factor-1 (SDF-1) has been shown to be critical in promoting the migration of cells to the bone marrow, via its specific receptor CXCR4. The aim of our study was to investigate CXCR4 expression on MSCs and its role in mediating migration to bone marrow. We show that CXCR4, although present at the surface of a small subset of MSCs, is important for mediating specific migration of these cells to bone marrow.

Bone Marrow↗

PubMed2004

Market capture of inpatient perioperative services using DEA.

We develop and validate a method to measure "market capture" of inpatient, elective surgery. Data envelopment analysis (DEA) is used to measure the efficiency of the market capture for Perioperative Services at 53 non-metropolitan Pennsylvania hospitals. Eight procedures are studied, representing a wide spectrum of elective, scheduled, inpatient surgery (e.g., abdominal aortic aneurysm resection and hip replacement). Our results address issues in operating room management, such as: How should additional resources be allocated to each surgical specialty? Given existing market conditions, for which specialties can we expect to be able to increase our current workloads? Our results demonstrate DEA's potential as a valuable tool for operating room managers' strategic decision-making.

Benchmarking↗

PubMed2004

The effect of insurance status on travel time for rural Medicare patients.

Managed care has been hypothesized to increase patient travel by directing patients toward network providers. The purpose of this study is to measure the effect of Medicare HMO enrollment on hospital travel time in rural areas. Hospital travel times were determined for 85,586 inpatient discharges among rural Pennsylvania residents admitted to Pennsylvania hospitals in 1998. Medicare HMO enrollees traveled up to 10.2 minutes further for acute care than Medicare fee-for-service patients (39 versus 29 minutes). Medicare HMO enrollees were 50 percent more likely to travel outside their own counties and 70 percent more likely to travel to urban areas for acute care. The distance premium associated with HMO enrollment was largest in counties with the lowest managed care penetration.

Aged↗

PubMed2004

Data envelopment analysis to determine by how much hospitals can increase elective inpatient surgical workload for each specialty.

We apply data envelopment analysis to discharge data from the 115 hospitals in the rural state of a study hospital to answer three questions. We use a case study to investigate the usefulness and limitations of data envelopment analysis for assessing three common questions regarding hospital market capture for elective inpatient surgery. (i) The hospital studied in this paper performs 40% of the neurosurgery and 25% of the inpatient urology surgery in its state. Workloads are twice that of the hospitals with the next largest workloads. In contrast, the hospital performs 9% of its state's cardiac surgery and has a workload half that of the largest volume hospital. The cardiac surgeons want more operating room time, faster turnovers, and capital investment for minimally invasive equipment. Controlling for the distance patients would need to travel for care, would increasing capacity likely increase cardiac surgery workload? (ii) The study hospital has fewer hospitalizations for thoracic surgery than for any other specialty. Is thoracic surgery inpatient workload of 121 lung resections large or small compared with those of orthopedics' 213 hip replacements, urology's 132 nephrectomies, and cardiac surgery's 304 coronary artery bypass grafts? (iii) The hospital's busiest specialty by discharges is orthopedics. How sensitive is the hospital's orthopedic workload to changes in decision making at nearby competing hospitals?

Craniotomy↗

PubMed2003

Estimating out-of-hospital mortality due to myocardial infarction.

We developed a model to estimate out-of-hospital deaths due to Myocardial Infarction (MI), which was based on a detailed database of MI admissions to Pennsylvania hospitals during 1998. Our estimation method addresses the problem of geographical selection bias in inpatient databases, which occurs when MI patients with poor geographic access are undersampled. A Geographic Information System (GIS) was used to determine travel times between hospitals and patients, based on patients' zip code of residence. Nearness to a hospital was positively associated with in-hospital mortality (P < 0.01) and emergency admissions (P < 0.01) and negatively associated with out-of-hospital mortality (P < 0.01). Model predictions were made for a range of input values and validated using empirical data.

Emergency Service, Hospital↗