John M. Gleason

Biases in technical efficiency scores caused by intra-input aggregation: mathematical analysis and a DEA application using simulated data

In Data Envelopment Analysis (DEA) applications involving multiple inputs and outputs, inputs are aggregated into the total amounts of each type of input. For example, if input types ‘labour’ and ‘capital’ are used to produce multiple outputs, the total amount of labour used to produce all outputs is treated as one aggregated input and the total amount of capital as another. Resources are not disaggregated into input variables measuring the amount of labour used to produce the first output, the amount of labour used to produce the second output, the amount of labour used to produce the third output and so on, for both labour and capital. It is shown that such intra-input aggregation causes downward bias in reported technical efficiency scores, with variations in bias unrelated to true technical efficiency. Therefore, with few exceptions, any technical efficiency comparisons among DMUs are invalid. The presence of intra-input aggregation bias is demonstrated mathematically, simulation is used to exhibit its severity, and the exceptions that permit intra-input aggregation without causing bias are identified. It is concluded that, for multiple-input, multiple-output DEA applications, inputs must be disaggregated into the amounts used to produce each output in order to validly report technical efficiency, unless one of the exceptions is present.

Description and evaluation of an interprofessional patient safety course for health professions and related sciences students

Objectives: The structure, process, and outcomes associated with planning, developing, and offering an interprofessional course on the foundations of patient safety is described, including how organizational, structural, cultural, and attitudinal barriers were overcome. Methods: Seventeen faculty members from 7 colleges and schools and medical center participated-from the fields of decision sciences and systems, dentistry, medicine, law, nursing, occupational therapy, pharmacy, physical therapy, social work, health care administration, and outcomes management in health systems. Student assessment included theme analysis of open-ended questions, descriptive analysis of multiple- response option questionnaires, and criterion-based assessment of student performance on case studies. Triangulation of student comments, final course evaluation, and student performance evaluations were performed to learn overarching themes of student experience with the course. Results: The students learned a different way of thinking, found the instructional design and active learning methods useful to learning, and felt prepared to solve problems in the future. Students believed that the content was an essential core knowledge for all health professionals (87%) and should be required for all health professions students (78%). Students achieved an application level of learning (77%) within the cognitive domain and the valuing level within the affective domain. Students agree (96%) that they can define and apply the basic principles and tenets of patient safety, including identification of tools needed to work effectively within the health system and to improve safety and strongly agree (100%) that they value patient safety as a professional practice framework. Conclusion: The universitywide implementation case may offer important lessons to others nationally in health care education.

Fuzzy set computational processes in risk analysis

An article by R. Kangari and L.S. Riggs (see ibid., vol.36, no.2, p.126-31, 1989), which dealt with the use of fuzzy sets in construction risk analysis, contains a number of errors and inconsistencies, most of which appear in examples given to clarify the concepts involved in computations related to fuzzy sets. The errors and inconsistencies are identified, and the computational results are clarified by providing the correct results for enough computations to ensure an understanding of the processes involved. >

Statistical tests of the IBM PC pseudorandom number generator

The widespread use of IBM personal computers in biomedical research and medical practice is evidenced by a variety of journal articles. Many of the application programs are written in the BASIC language, they model a stochastic process, and they depend on the Microsoft random number generator. Unfortunately, the Microsoft generator has exhibited a number of flaws including, for some seeds, a lack of uniformity of generated sequences of numbers, and serial correlation within such sequences. This paper provides evidence of these problems for several seeds, and provides suggestions for acceptable seeds which ensure that the generated sequences of numbers pass two fundamental statistical tests for randomness.

The importance of proper seeding of the Applesoft pseudorandom number generator

The popularity of the use of Apple II/IIe hardware in medical applications is evidenced by the variety of articles devoted to the use of this hardware in biomedical research and medical practice. Many of these applications are of a stochastic nature, including simulations, and depend on the Applesoft random number generator. Unfortunately, the Applesoft generator has exhibited a number of flaws, including lack of uniformity of generated sequences of numbers, and serial correlation within such sequences. This paper provides evidence of these problems for a variety of seeds, and provides suggestions for acceptable seeds which ensure that the generated sequences of numbers pass two fundamental statistical tests for randomness.

A probabilistic analysis of multiple-drug testing procedures in sports doping control

Athletes engaged in competition, particularly those involved in international competitions such as the Olympics, are increasingly being tested for a greater variety of banned substances; it is not unusual for tests to be conducted for 100 drugs and another 400 as metabolites. Previous studies related to the accuracy of drug testing processes have failed to properly consider the effects of testing for more than one drug. In order to identify appropriate indicators for the multiple-drug case, probability theory and accuracy concepts applicable to testing for multiple drugs are developed and applied to illustrative data. The probability that a drug-free individual will test positive for drug use is shown to be much higher than indicated by previous studies, and it is shown that an increase in the number of drugs tested for yields an approximately proportionate increase in the probability that a positive test result is erroneous. Therefore, while testing for one drug may result in a comfortably low rate of false accusations of drug use, testing for multiple drugs may well result in an unacceptably high rate. Finally, a set of empirical measures is suggested for use in cases of tests for multiple drugs; the measures will provide for comparability among laboratory proficiency studies.

Protocol for Comprehensive Efficiency Analysis of Multi-Service Metropolitan Transit Agency Operators

This chapter presents a Data Envelopment Analysis (DEA) protocol for analyzing the efficiency of metropolitan transit agencies that oversee multiple types of transportation services. The protocol is illustrated by applying it to United States transit agencies that can serve their cities with four types of subunits: self-operated motorbus, outsourced motorbus, self-operated demand-responsive, and outsourced demand-responsive. Using DEA models adapted for non-substitutable inputs and outputs, scores estimated for a focus agency include: (1) technical efficiency of the focus agency as a whole, (2) technical efficiency of each of the focus agency’s subunit types when each subunit is compared only to others of the same type, (3) allocation efficiency of the focus agency in apportioning resources among its subunits, and (4) the effect of each subunit’s technical efficiency on its parent agency’s technical efficiency. Finally, a mathematical programming algorithm is illustrated that allocates the focus agency’s resources to its subunits with the objective of decreasing the cost of transit in an urban area while holding total ridership constant. The protocol thereby is a comprehensive analysis and synthesis of a focus transit agency’s efficiency in providing services to its metropolitan area.

Technological incrementalism vs. escalating consumer expectations: a history lesson?

This paper discusses prototype pre-design marketing research conducted as part of a technology transfer and commercialization project, the multimedia access prototype (MAP) project. The MAP project was conducted by a virtual company of seven organizations in collaboration with a federal agency and the R&D group of a telecommunications organization. Its purpose was to create a user-friendly, multimedia-based prototype system to provide timely and accurate information from government geographic information databases to government decision makers and the general public in an easy-to-use interactive visual format. Prototype pre-design marketing research was conducted in meetings with single individuals, small groups and focus groups.

Folly in Trade and Technology Policy (Comments on 'Do we need a technology policy?' by S.J. Kline and D.E. Kash)

The commenters note that S.J. Kline and D.E. Kash (ibid., vol.11, p.18-25, Summer 1992) raise a number of interesting points in their discussion of the functions of government technology policy. The commenters point out that the importance of the issues discussed by Kline and Kash is underscored by a recent tariff imposed on active-matrix liquid-crystal displays (AMLCDs). They suggest that it is important that the Kline and Kash article serve as the basis of continuing discussions within the IEEE community and other scientific and engineering communities, relative to issues of technology policy development. They conclude that perhaps the concerns expressed by Kline and Kash, and by N.W. Buckly (1992), will generate an increased level of understanding, concern, and discourse on this extremely important topic. >

ECONOMIC REPRIORITIZATION OF PET

In a previous issue of the journal Gould, Mullani and Williams wrote an editorial entitled“PET, PTCA and Economic Priorities.”1 The whole subject of positron emission tomography and its use with rubidium to diagnose coronary artery disease vis‐à‐vis thallium imaging is a controversial issue of current interest. As of this writing, scientists and clinicians have vocalized strong views for each imaging technique as the best clinically suitable method to diagnose hemodynamically significant coronary artery disease. I do not pretend to know who is right, but I can assure the reader of the emotionally charged nature of this controversy. The article by Gould and colleagues generated a response by an economist, Dr. Gleason, which subsequently generated a reply by Gould. I thought this topic was of sufficient interest to the readers of Clinical Cardiology that it should be given special article status because of the important issues raised.