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PubMed1998

Successful strategies for improving operating room efficiency at academic institutions.

UNLABELLED: In this prospective study, we evaluated the etiology of operating room (OR) delays in an academic institution, examined the impact of multidisciplinary strategies to improve OR efficiency, and established OR timing benchmarks for use in future OR efficiency studies. OR times and delay etiologies were collected for 94 cases during the initial phase of the study. Timing data and delay etiologies were analyzed, and 2 wk of multidisciplinary OR efficiency awareness education was conducted for the nursing, surgical, and anesthesia staff. After the education period, timing data were collected from 1787 cases, and monthly reports listing individual case delays and timing data were sent to the Chiefs of Service. For the first case of the day, patient in room, anesthesia ready, surgical preparation start, and procedure start time were significantly earlier (P < 0.01) in the posteducation period compared with the preeducation period, and the procedure start time for the first case of the day occurred, on average, 22 min earlier than all other procedures. For all cases combined, turnover time decreased, on average, by 16 min. Unavailability of surgeons, anesthesiologists, and residents decreased significantly (P < 0.05) as causes of OR delays. Anesthesia induction times were consistently longer for the vascular and cardiothoracic services, whereas surgical preparation time was increased for the neurosurgical and orthopedic services (P < 0.05). Identification of the etiology of OR inefficiency, combined with multidisciplinary awareness training and personal accountability, can improve OR efficiency. The time savings realized are probably most cost-effective when combined with more flexible OR staffing and improved OR scheduling. IMPLICATIONS: We achieved significant improvements in operating room efficiency by analyzing operating room data on causes of delays, devising strategies for minimizing the most common delays, and subsequently measuring delay data. Personal accountability, streamlining of procedures, interdisciplinary team work, and accurate data collection were all important contributors to improved efficiency.

Academic Medical Centers↗

PubMedDate not supplied

Does capitated contracting improve efficiency? Evidence from California hospitals.

This study examines the effect of capitated contracting on hospital efficiency to better understand strategies related to the recent financial crisis in the California health care market. Our findings indicate that less efficient hospitals are more likely to participate in capitated contracting. As a result, hospitals with capitated contracts are, on average, less efficient than hospitals without capitated contracts. Hospital efficiency generally increases with respect to the degree of capitation involvement. The efficiency improvement, however, becomes insignificant when capitation exposures are already high. Thus, hospital executives should not be overly optimistic about efficiency gains obtained in capitated contracting and should control the degree of capitation involvement.

California↗

PubMed1990

Mechanical work and efficiency in treadmill running at aerobic and anaerobic thresholds.

Mechanical work, mechanical power, energy consumption and mechanical efficiency were studied in constant-speed treadmill running of 5 min at seven different exercises around aerobic (AerT) and anaerobic (AnT) thresholds. The true efficiency of concentric (positive) mechanical work and gross efficiency of the whole body in seven male subjects were calculated. The total mechanical work was calculated from film through the translational, potential and rotational energy states as the sum of the changes of all the mechanical energy states in all body segments allowing energy transfer between segments and from energy state to state. The total energy consumption was measured by combining aerobic and anaerobic energy production in resting and working conditions. When the speed of the treadmill was increased from the velocity of 10 km h-1 (2.8 m s-1) to 22 km h-1 (6.1 m s-1), the concentric mechanical work per one step increased from 129 +/- 45 J to 228 +/- 82 J (P less than 0.01). Oxygen consumption increased from 2.22 +/- 0.27 1 min-1 to 4.47 +/- 0.24 1 min-1. The amount of blood lactate increased from 0.94 +/- 0.53 mmol l-1 at the lowest speed to 9.90 +/- 2.89 mmol l-1 at the highest speed (P less than 0.001). The true efficiency of concentric work decreased from 74 +/- 14% to 56 +/- 8% (P less than 0.05). At the speed of the AerT, the economy of running, the vertical rise of different body segments and mechanical efficiency of positive work were high. The highest gross efficiency was found at the running speed between the AerT and AnT.

Adolescent↗

PubMed2021

Spray-induced gene silencing for disease control is dependent on the efficiency of pathogen RNA uptake.

Recent discoveries show that fungi can take up environmental RNA, which can then silence fungal genes through environmental RNA interference. This discovery prompted the development of Spray-Induced Gene Silencing (SIGS) for plant disease management. In this study, we aimed to determine the efficacy of SIGS across a variety of eukaryotic microbes. We first examined the efficiency of RNA uptake in multiple pathogenic and non-pathogenic fungi, and an oomycete pathogen. We observed efficient double-stranded RNA (dsRNA) uptake in the fungal plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani, Aspergillus niger and Verticillium dahliae, but no uptake in Colletotrichum gloeosporioides, and weak uptake in a beneficial fungus, Trichoderma virens. For the oomycete plant pathogen, Phytophthora infestans, RNA uptake was limited and varied across different cell types and developmental stages. Topical application of dsRNA targeting virulence-related genes in pathogens with high RNA uptake efficiency significantly inhibited plant disease symptoms, whereas the application of dsRNA in pathogens with low RNA uptake efficiency did not suppress infection. Our results have revealed that dsRNA uptake efficiencies vary across eukaryotic microbe species and cell types. The success of SIGS for plant disease management can largely be determined by the pathogen's RNA uptake efficiency.

Ascomycota↗

PubMed1980

Exercise efficiency: validity of base-line subtractions.

In evaluating the efficiency of humans performing exercise, base-line subtractions have been used in an attempt to determine the efficiency of the muscles in performing the external work. Despite the fact that base lines have been criticized previously, they have been widely used without adequate analysis of the implications involved. Calculations of efficiencies using data available in the literature for isolated muscle preparations revealed that base-line subtractions result in unreasonably high efficiencies. This suggests strongly that the base lines are invalid. To be valid, a base line must continue unchanged under all the conditions in which it is applied. Previously published data indicate clearly that exercise base lines change with increasing work rate and are therefore invalid. The use of base lines is further complicated by elastic energy storage in some types of exercise. Although exercise efficiencies using base line subtractions may be useful, they do not indicate muscle efficiency. Perhaps future studies of exercise metabolism should be directed less at refining base lines and more toward describing and quantifying the determinants of energy expenditure.

Efficiency↗

PubMed2003

Efficiency and productivity change in the English National Health Service: can data envelopment analysis provide a robust and useful measure?

OBJECTIVE: Several tools are available to health care organisations in England to measure efficiency, but these are widely reported to be unpopular and unusable. Moreover, they do not have a sound conceptual basis. This paper describes the development and evaluation of a user-friendly tool that organisations can use to measure their efficiency, based on the technique of data envelopment analysis (DEA), which has a firm basis in economic theory. METHODS: Routine data from 57 providers and 14 purchasing organisations in one region of the English National Health Service (NHS) for 1994-1996 were used to create information on efficiency based on DEA. This was presented to them using guides that explained the information and how it was to be used. They were surveyed to elicit their views on current measures of efficiency and on the potential use of the DEA-based information. RESULTS: The DEA measure demonstrated considerable scope for improvements in health service efficiency. There was a very small improvement over time with larger changes in some hospitals than others. Overall, 80% of those surveyed gave high scores for the potential usefulness of the DEA-based measures compared with 9-45% for existing methods. The quality of presentation of the information was also consistently high. CONCLUSIONS: There is dissatisfaction with efficiency information currently available to the NHS. DEA produces potentially useful information, which is easy to use and can be easily explained to and understood by potential users. The next step would be the implementation, on a developmental basis, of a routine DEA-based information system.

Data Interpretation, Statistical↗

PubMed1978

Chewing efficiency and state of dentition. A methodologic study.

Chewing efficiency, defined as the ability to grind a certain portion of a test food during a given time, was tested in 139 Skolt Lapps, ages 14-65. 94 persons had natural teeth and the remaining 45 wore dentures (partial and/or complete). The test food was almonds. Number of chewing strokes, swallowings and chewing time was denoted. The chewing efficiency was classified after a scale from 1 to 5 where 1 meant very good and 5 very poor ability to reduce the particle size of the test food. Clear associations were found between chewing efficiency and dental state. Number of occluding pairs of teeth was closely correlated with chewing efficiency and individuals with less than 20 teeth had a higher index score than those with more than 20 teeth. The values noted for number of chewing strokes, swallowings and chewing time were smaller for those with a good chewing efficiency, but the variation was not linear and not always significant. Denture wearers had statistically significantly higher chewing efficiency score than those with natural teeth, without dentures, and needed more chewing time before swallowing.

Adolescent↗

PubMed2006

The improving efficiency frontier of religious not-for-profit hospitals.

By using data-envelopment analysis (DEA), this study evaluates the efficiency of religious not-for-profit hospitals. Hospital executives, healthcare policy makers, taxpayers, and other stakeholders benefit from studies that improve hospital efficiency. Results indicate that overall efficiency in religious hospitals improved from 72% in 1998 to 74% in 2001. What is more important is that the number of religious hospitals operating on the efficiency frontier increased from 40 in 1998 to 47 in 2001. This clearly documents that religious hospitals are becoming more efficient in the management of resources. From a policy perspective, this study highlights the economic importance of encouraging increased efficiency throughout the healthcare industry.

Efficiency, Organizational↗

PubMedDate not supplied

Practice efficiency and physician compensation: a case study.

One of the major challenges facing today's health care executive is that of achieving maximum efficiency. The public also requires an efficient health care system. However, a problem occurs when the health care executive defines "efficiency" in a manner that is diametrically opposed to the public's definition. Maximum efficiency in the physician practice is defined by productivity equal to capacity. Maximum efficiency of the health care system is defined by lower health care costs. If the physician practice is achieving its goal of maximum efficiency, the market economy will likely force a failure in achieving the public's goal of a lower cost health care system! The following case study provides an opportunity to review this health care management conundrum and offers insights into a possible approach for some solution through attention to physician compensation.

Boston↗

PubMed1993

A national study of the efficiency of hospitals in urban markets.

Using a sample of 3,000 urban hospitals, this article examines the contributions of selected hospital characteristics to variations in hospital technical efficiencies, while it accounts for multiple products and inputs, and controls for local environmental variations. Four hospital characteristics are examined: hospital size, membership in a multihospital system, ownership, and payer mix (managed care contracts, percent Medicare, and percent Medicaid). Ownership and percent Medicare are consistently found to be related significantly to hospital efficiency. Within the ownership variable, government hospitals tend to be more efficient and for-profit hospitals less efficient than other hospitals. Higher percentages of Medicare payment are negatively related to efficiency. While not consistently significant across all five of the MSA size categories in which the analyses are conducted, possession of managed care contracts, membership in a multihospital system, and size all are consistently related positively to hospital technical efficiency. These variables are also all significant when the hospitals are examined in a combined analysis. Percent Medicaid was not significant in any of the analyses. Implications for policy and the need for methodological work are discussed.

Analysis of Variance↗

PubMed1996

Efficiency measurement and the operationalization of hospital production.

OBJECTIVE: To discuss the usefulness of efficiency measures as instruments of monitoring and resource allocation by analyzing their invariance to changes in the operationalization of hospital production. STUDY SETTING: Norwegian hospitals over the three-year period 1989-1991. STUDY DESIGN: Efficiency is measured using Data Envelopment Analysis (DEA). The distribution of efficiency and the ranking of hospitals is compared across models using various distribution-free tests. DATA COLLECTION: Input and output data are collected by the Norwegian Central Bureau of Statistics. PRINCIPAL FINDINGS: The distribution of efficiency is found to be unaffected by changes in the specification of hospital output. Both the ranking of hospitals and the scale properties of the technology, however, are found to depend on the choice of output specification. CONCLUSION: Extreme care should be taken before resource allocation is based on DEA-type efficiency measures alone. Both the identification of efficient and inefficient hospitals and the cardinal measure of inefficiency will depend on the specification of output. Since the scale properties of the technology also vary with the specification of output, the search for an optimal hospital size may be futile.

Efficiency, Organizational↗

PubMed1996

Activity-based costing for clinical paths. An example to improve clinical cost & efficiency.

How much does this medical service or surgical procedure cost the hospital to provide? What is the most efficient clinical pathway that maximizes the quality of patient care while minimizing costs? More and more hospitals are discovering that they don't have solid answers to these critically important questions. In an age of managed care and capitation, however, it is imperative for management to know if the patient care services they provide are making or losing money-and by how much. This article discusses how a powerful new tool called activity-based costing (ABC) can be used to help hospitals accurately determine patient care costs. We show how to build a model that combines both clinical and financial data to measure how efficiently the operation allocates human, material and capital resources to provide its services. The modeling approach described in this article can be used to better analyze a wide range of important operational and financial issues, including: How to efficiently allocate resources, and what resources will be needed as patient demand changes-ideal for operational management and planning; How efficiently activities and processes are performed to meet patient needs-effective for measuring performance and improving quality; Determining clinical pathway profitability-essential for understanding where you're making or losing money; Cycle time, throughput and the impact of resource capacity constraints-critical for meeting patient demand; Costs of idle capacity-important for using resources more efficiently. We will illustrate with an example how this modeling technique can be used to develop and implement efficient clinical pathways.

Accounting↗

PubMed1999

Size matters: molecular weight affects the efficiency of poly(ethylenimine) as a gene delivery vehicle.

Poly(ethylenimine) (PEI) samples of various molecular weights and pHs were used to transfect endothelial cells to achieve levels of gene expression for comparison. PEIs with nominal molecular weights of 600, 1200, 1800, 10,000, and 70,000 Da were examined at pHs of 5. 0, 6.0, 7.0, and 8.0, and the results were recorded in terms of transfection efficiencies at 24, 48, 68, 92, and 120 h post-transfection. Trials were performed on the human endothelial cell-derived cell line EA.hy 926. We found that, for the polymers tested, transfection efficiency increased as the molecular weight of PEI increased. Representative values of PEIs at pH 6 and molecular weight 70,000 produced average transfection efficiencies of 25.6 +/- 7.9% (n = 8) at the greatest average expression levels, while PEI of molecular weight 10,000 yielded efficiencies of only 11.4 +/- 1.7% (n = 6). Transfection efficiencies for molecular weight 1,800 PEI were essentially zero, and PEIs of lower molecular weights produced no transfection at all. In contrast, the pH of the PEI solutions had no discernible effect on transfection. Optimal expression of the green fluorescent protein reporter occurred between 2 and 3 days post-transfection. The amount of reporter expression also was noted, as determined by the brightness of fluorescing cells under UV. The data obtained demonstrate that the molecular weight of the PEI carrier has an effect on transfection efficiency while the pH of the PEI solutions prior to DNA complexation has no such effect.

Chromatography, Gel↗

PubMed2000

Cryopreservation of competent intact yeast cells for efficient electroporation.

We have developed a simple method for cryopreserving Schizosaccharomyces pombe and Saccharomyces cerevisiae competent intact cells that permits high transformation efficiency and long-term storage for electroporation. Transformation efficiency is significantly decreased if intact cells are frozen in common permeating cryoprotectants such as glycerol or dimethyl sulphoxide. On the other hand, we found that a high transformation efficiency could be maintained if the cells were frozen in a non-permeating cryoprotectant such as sorbitol. The optimum concentration of sorbitol was found in a hypertonic solution of around 2 M. It was also very important to use S. pombe cells grown in minimal medium and S. cerevisiae cells grown in nutrient medium in the exponential growth phase. A slow freezing rate of 10 degrees C/min and a rapid thawing rate of 200 degrees C/min resulted in the highest transformation efficiency. We also found it necessary to wash the thawed cells with 1.0 M of non-electrolyte sorbitol, since the intracellular electrolytes had leaked as a result of cryoinjury. The frozen competent cells stored at -80 degrees C could be used for more than 9 months without any loss of transformation efficiency. This cryopreservation method for electroporation is simple and useful for routine transformations of intact cells. Frozen competent cells offer the advantages of long-term storage with high efficiency and freedom from the preparation of fresh competent cells for each transformation.

Adenosine Triphosphate↗

PubMed2000

Using a superconducting tunnel junction detector to measure the secondary electron emission efficiency for a microchannel plate detector bombarded by large molecular ions

An energy-sensitive superconducting tunnel junction (STJ) detector was used to measure the secondary electron emission efficiency, epsilon(e), for a microchannel plate (MCP) detector bombarded by large (up to 66 kDa), slow moving (<40 km/s) molecular ions. The method used is new and provides a more direct procedure for measuring the efficiency of secondary electron emission from a surface. Both detectors were exposed simultaneously to nearly identical ion fluxes. By exposing only a small area of the MCP detector to ions, such that the area exposed was effectively the same as the size of the STJ detector, the number of ions detected with each detector were directly comparable. The STJ detector is 100% efficient for detecting ions in the energy regime investigated and therefore it can be used to measure the detection efficiency and secondary electron emission efficiency of the MCP. The results are consistent with measurements made by other groups and provide further characterization of the loss in sensitivity noted previously when MCP detectors have been used to detect high-mass ions. Individual molecular ions of mass 66 kDa with 30 keV kinetic energy were measured to have about a 5% probability of producing one or more electrons when impacting the MCP. When ion energy was reduced to 10 keV, the detection probability decreased to 1 %. The secondary electron yield was calculated from the secondary electron emission efficiency and found to scale linearly with the mass of the impinging molecular ion and to about the fourth power of ion velocity. Secondary electrons were observed for primary ion impacts >5 km/s, regardless of mass, and no evidence of a velocity (detection) threshold was observed. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗

PubMed2002

Efficiency of Iε promoter-directed switch recombination in GFP expression-based switch constructs works synergistically with other promoter and/or enhancer elements but is not tightly linked to the strength of transcription.

One key unresolved issue in immunoglobulin class switch recombination (CSR) is how the accessibility of the switch region for CSR is controlled. To better understand the nature of accessibility control for human Ig CSR, we developed a novel inducible switch recombination assay based on expression of green fluorescence protein (GFP) from switch constructs undergoing substrate switch recombination (SSR). Efficient SSR depends on the cytokine-inducible Iepsilon promoter and co-stimulation with IL-4+anti-CD40. Characterization of SSR reveals that both S-S deletional recombination and S-S inversion occur. We show that the IL-4-inducible Iepsilon promoter (pIepsilon) selectively determines the efficiency of the accessibility for SSR. However, the pIepsilon-induced transcription, by itself,is not sufficient to direct efficient SSR. For efficient SSR, both pIepsilon-driven transcriptional activity and an additional promoter/enhancer-derived activity are required. The efficiency of SSR is not tightly correlated with the strength of the combined transcriptional activity. Our results suggest that the mechanism(s) underlying the transcriptional activity, e.g. DNA modification is important for controlling the accessibility for efficient switch recombination.

Animals↗

PubMed2003

Large-scale transient transfection of serum-free suspension-growing HEK293 EBNA1 cells: peptone additives improve cell growth and transfection efficiency.

Large-scale transient transfection of mammalian cells is a recent and powerful technology for the fast production of milligram amounts of recombinant proteins (r-proteins). As many r-proteins used for therapeutic and structural studies are naturally secreted or engineered to be secreted, a cost-effective serum-free culture medium that allows their efficient expression and purification is required. In an attempt to design such a serum-free medium, the effect of nine protein hydrolysates on cell proliferation, transfection efficiency, and volumetric productivity was evaluated using green fluorescent protein (GFP) and human placental secreted alkaline phosphate (SEAP) as reporter genes. The suspension growing, serum-free adapted HEK293SF-3F6 cell line was stably transfected with an EBNA1-expression vector to increase protein expression when using EBV oriP bearing plasmids. Compared to our standard serum-free medium, concomitant addition of the gelatin peptone N3 and removal of BSA slightly enhanced transfection efficiency and significantly increased volumetric productivity fourfold. Using the optimized medium formulation, transfection efficiencies between 40-60% were routinely obtained and SEAP production reached 18 mg/L(-1). To date, we have successfully produced and purified over fifteen r-proteins from 1-14-L bioreactors using this serum-free system. As examples, we describe the scale-up of two secreted his-tagged r-proteins Tie-2 and Neuropilin-1 extracellular domains (ED) in bioreactors. Each protein was successfully purified to >95% purity following a single immobilized metal affinity chromatography (IMAC) step. In contrast, purification of Tie-2 and Neuropilin-1 produced in serum-containing medium was much less efficient. Thus, the use of our new serum-free EBNA1 cell line with peptone-enriched serum-free medium significantly improves protein expression compared to peptone-less medium, and significantly increases their purification efficiency compared to serum-containing medium. This eliminates labor-intensive and expensive chromatographic steps, and allows for the simple, reliable, and extremely fast production of milligram amounts of r-proteins within 5 days posttransfection.

Bioreactors↗

PubMed2005

The efficiency of electrokinetic pumping at a condition of maximum work.

Numerical methods are employed to examine the work, electric power input, and efficiency of electrokinetic pumps at a condition corresponding to maximum pump work. These analyses employ the full Poisson-Boltzmann equations and account for both convective and conductive electric currents, including surface conductance. We find that efficiencies at this condition of maximum work depend on three dimensionless parameters, the normalized zeta potential, normalized Debye layer thickness, and a fluid property termed the Levine number indicating the nominal ratio of convective to conductive electric currents. Efficiencies at maximum work exhibit a maximum for an optimum Debye layer thickness when the zeta potential and Levine number are fixed. This maximum efficiency increases with the square of the zeta potential when the zeta potential is small, but reaches a plateau as the zeta potential becomes large. The maximum efficiency in this latter regime is thus independent of the zeta potential and depends only on the Levine number. Simple analytical expressions describing this maximum efficiency in terms of the Levine number are provided. Geometries of a circular tube and planar channel are examined.

Models, Theoretical↗