A. R. Bakker

Evaluation of automated information systems in health care: an approach to classifying evaluative studies

In this paper we discuss an approach to classifying evaluative studies of automated information systems in health care. Selected literature (76 studies) is classified according to the type of automated information system (based on relationship to the care process), the study design used, the data collection methods used, the effect(s) measured and the type of evaluation (e.g. cost-benefit analysis). First results show that certain types of automated information systems have not been evaluated much, going by the number of studies selected. Furthermore, it is observed that certain study designs (time-series design), data collection methods (modelling and simulation) and effect measures (job satisfaction) are hardly to be found in the literature. Only 10 of 76 selected studies used a type of evaluation for which both consequences and costs are considered. Detailed investigation of the literature may provide information for the development of a general framework for the evaluation of different types of automated information systems.

A package for cost and critical analysis of picture archiving and communication indicating its true yield (CAPACITY)

The hospital-wide use of picture archiving and communication systems (PACS) promises a number of advantages in the future. These benefits will only be obtained at considerable costs, however. In view of the rapidly developing technology the costs of hardware can be expected to decrease. The ideas about the expected moment when the benefits will exceed the costs show wide variation. In order to get a better view on the cost comparison between PACS and the classical film-based system and also to stimulate discussions on this topic, a software package called CAPACITY (cost and critical analysis of picture archiving and communication indicating its true yield) has been developed by BAZIS within the scope of its IMAGIS (image information system) project. CAPACITY calculates the costs in the year of introduction for both situations, conventional and PACS, based on the consumption or use of the various resources (e.g. film, optical disks, manpower in the archive, operators, network, workstations etc.) needed for the production of the radiological department. These two costs are calculated for a series of years, thus giving an indication for the moment of breakeven. User-supplied data is interrelated and checked for plausibility against a number of expert given rules of thumb by CAPACITYs critique module. The first results and experiences acquired during a pilot study using a prototype version of the package will be discussed. The CAPACITY package is available for evaluation and trial (only distribution costs will be charged if experiences and results are returned).

Picture archiving and communication system design issues: The importance of modelling and simulation

Picture archiving communication system (PACS) development turns out to be very complex. Due to both the vast amount of data and the complexity of hospital organizations, currently only small-scale systems have been realized. And although the experiences obtained with these systems are essential, there is a risk for underestimating the complexity and requirements inherent in hospital-wide PACS systems. In this paper, it is advocated that modelling and simulation be used as tools to obtain insight into the behavior and structure of future PACS systems. Modelling and simulation can also be used to actively support the design of PACS, especially its software. In order to capture the full complexity of PACS in a simulation model, and to take full advantage of simulation as a design tool, the development of a new modelling method has begun. This method is based on semantic data models and decision processes, and can be used for both system analysis and design. The first systems modelled with this method were imaging procedures in a hospital and a computer network. The resulting simulation models are a direct reflection of reality, and have a high degree of modularity. Consequently, in spite of the complexity of the systems, their models are easy to understand and maintain.

An analysis of the costs of a hospital-wide Picture Archiving and Communication System with the software package CAPACITY

Within the scope of the Dutch PACS project, the costs of a hospital wide PACS in the Utrecht University Hospital were estimated, with the help of the software package CAPACITY. The cost analysis was based on the most recent specifications of the costs of the equipment, on extrapolations, and on the experience acquired with a PACS prototype in the Utrecht University Hospital. Savings due to a possible reduction in the length of stay, or due to logistic improvements were not taken into account. The results indicate that the extra costs of a hospital wide PACS would amount to 3.2% of the total hospital budget. By taking into account the expected price movements, it is predicted that a hospital wide PACS may allow enough savings to pay itself back, when installed near the turn of the century. The result of this cost analysis depends on a large number of assumptions. Therefore two sensitivity analyses are carried out, i.e., concerning the number of workstations required and concerning the organizational impact of PACS.

First results with the software package CAPACITY for cost modeling of PACS

An essential element in the decision of introducing a PACS will be its financial implication. We all hope PACS will come affordable at a certain point in time because of the decreasing hardware prices. However there is a wide variety of opinions about the moment the savings of PACS will exceed its costs. A software package for cost modelling of PACS, named CAPACITY, was developed by BAZIS in order to to get a better understanding of the cost characteristics of PACS. CAPACITY makes a cost comparison over the years thus indicating the moment of break even. User given input values are checked by a critique module and a file of cases can be maintained. One of the activities within the Dutch PACS project, a cooperative effort of BAZIS, the Utrecht University Hospital (UUH) and Philips Medical Systems is to indicate the costs of a PACS in the Utrecht University Hospital. A number of scenarios for a PACS in the Utrecht University Hospital have been defined and evaluated with the software package CAPACITY. The results will be discussed and it will be shown that the workstations play a major role.

Introduction to Pacs for Those Interested in Image Processing

This paper gives a brief overview of PACS, including the basic components of a PACS system and what operations are or should be provided by it. This includes as well, a discussion of desired response time.

Considerations On An Algorithm For Activation Of Images In A Multi-Layered Storage System Within A PACS

One of the major bottlenecks in realizing a full size PACS is the image storage component. Further technological developments are necessary before sufficient capacity can be realized. It can be expected that a multi-layered storage structure will be necessary where large capacity with relatively long access times will be offered at the lowest level. The higher levels will show decreasing access times combined with decreasing capacity. Both in the judgement of images acquired in the diagnostic study and in the work of the clinician historical images of the patient concerned may be needed. If these images had to be retrieved from the lowest storage level at the moment they are needed, the service time would definitely be unacceptable. So a strategy is necessary for the anticipation of the need of access to images. In this paper a first attempt is made to identify relevant parameters to be used in such a look ahead algorithm for the activation of images to a next level. A simple algorithm is suggested; the need for further study is emphasized.

Assessment of effects and costs of information systems

Insight into the effects and costs of information systems is becoming increasingly important. A key problem is to provide evidence which is transportable among sites. Transportability demands agreement on how to carry out assessment of information systems. In the VISTA study, three Dutch hospitals developed together an evaluation protocol for the assessment of the effects and costs of the nursing information system VISION. This protocol is based on a quasy-experimental study design allowing filtering for non-VISION influences. The protocol also included a uniform cost model. Based on a cost calculation for the three hospitals, the costs for hospital-wide implementation of VISION in a 445- and 800-bed hospital were extrapolated. VISTA is considered as a trial for application of one evaluation protocol at various sites. It is recommended to extend this national trial to a multi-national one, for instance by applying the cost model more broadly.

Prefetching Offers Prospects for a Quick Responding PACS

A quick retrieval of the images will be one of the main promises to be fulfilled by the next generation of PACS systems. Even when present day advanced technology is applied the waiting times will be far too long. This is mainly due to the tremendous amounts of digital data needed to represent radiological images.

PACS Efficiency : A Detailed Quantitative Study Of The Distribution Process Of Films In A Clinical Environment In The Utrecht University Hospital

One of the goals of the Dutch PACS-project (a collaborative effort of the Utrecht University Hospital (UUH), Philips Medical Systems and BAZIS Central Development and Support Group Hospital Information Systems) is to perform a clinical evaluation and equipment testing at the UUH. In earlier publications a setup for this clinical evaluation is presented. A target ward, a subdivision of the department of Internal Medicine (IM) with a total number of 15 beds, is selected to be treated fully digital. Two other wards, similar to the target ward, were not digitally treated and served as control group. To exploit the efficiency potential of PACS, a comparison will be made between current procedures and PACS procedures. From February 1st until June 1st 1988, a detailed timing and logistic study of examinations and folder tracking has been carried out for all patients of the 3 wards of Internal Medicine, mentioned above. The first part of the study regarding the conventional distribution process is now completed. For this purpose time-registration forms were added to the patients application-forms for radiological examinations. These forms were required to be filled in by all personnel involved (receptionist, archive, technologist, radiologist, etc.). A total number of 500 usable time-registration forms were gathered. One of the results, indicated that the mean time interval for examinations to cover the total conventional distribu-tion process comes to 53.9 hours. An analysis of the number of disturbances in the conventional distribution process indicated that in 24.1 % of all examinations, some exponent was lacking (missing, loaned, delayed, etc.). These disturbances are analyzed in relation to time-intervals. Data were analyzed statistically by means of the SPSS statistical package. This paper describes and explains in detail: - frequencies and means of the total distribution time and different parts of the current distribution process - total number of disturbances in the current distribution process - disturbances analyzed in relation to time intervals The three wards were statistically not significantly different, so they can be compared with each other. This analysis shows clearly the possibilities for efficiency of the PACS distribution process and the consequences of this innovation for the organization and organizational communication.