Case study

A hospital would like to acquire a new medical device (surgical microscope) to improve the success rate of eye surgery. An evaluation team is charged with making recommendations about the best option among a large set of new generation medical devices for the disease. The team is composed of two surgeons, two nurses, one health economist and the financial manager of the hospital. The team was able to narrow down this set to four medical devices: A, B, C and D. Since the team members (referred to as decision-makers) want to make an informed recommendation, they request the assistance of an expert in clinical decision-making. To help the decision-makers (DMs) in their recommendation process, the analyst has to guide the DMs in identifying the decision (evaluation) criteria that are both relevant and meaningful to them. Imagine that, for the purpose of this case-study, the DMs suggest that the following decision criteria matter in the process: cost, sensor size, zoom, and weight, and optical image stabilizer. An explanation of the rationale for the use of these criteria is provided below.

Cost is selected as an evaluation criterion since the DMs have a limited budget. Therefore, they have to take this criterion into account to ensure they can afford the desired medical device. They want to obtain the best value for money which is consistent with economic theory stipulating that consumers want to maximize their profit while minimizing their costs. This criterion is measured in hundreds of dollars, and this measurement scale is expected to be minimized.

Sensor size is chosen as a criterion as it allows gaining more information to produce accurate images (resolution), which in surgical procedures is a "must". It is generally measured in megapixels, with "the bigger size, the better". Thus, the measurement scale of this criterion is to maximize.

Zoom is another important criterion identified through the discussion with the DMs. In fact, this feature permits magnifying the pixels of the image. This criterion is measured on a quantitative scale and is to be maximized.

The weight of the surgical device is important to the DMs provided that it allows surgeons to work conveniently, particularly when moving. This criterion is measured on a quantitative scale (kilograms) and is expected to be minimized.

Optical image stabilizer is a relevant criterion in the decision-making process regarding the purchase of a surgical microscope and is expected to be maximized.

Table 1 shows the records about the performance of each medical device across the selected evaluation criteria. These data are collected by the medical team and then processed by the expert.

Table 1. Performance matrix

h$: Hundreds of dollars; x: Magnifying factor; mp; megapixels; kg: kilograms

Illustration: As the expert in clinical decision making, you are asked to conduct a detailed Multi-criteria decision analysis to help the medical team in the selection of the best medical device for eye surgery.