Clinical Informatics

Evaluating a Clinical Decision Support System: A basic field study approach


  1. Introduction

  2. Evaluation framework and techniques

  3. Evaluation processes

    1. Basic usability

    2. Field study results

  4. Redesign possibilities

  5. Strengths and weaknesses of the field study approach

  6. Conclusion

  7. References

Field study results 

Due to time constraints, only a small number of issues were identified and explored. The majority of these relate to hardware interactions and only 1 major software interaction issue was identified.

The use of questionnaires and detailed interview could have revealed more issues but this was not performed in this study.

Hardware Design


Feedbacks from the nursing staff have revealed that the tablets were too heavy for sustained use, resulting in arm fatigue. The substantial weight is due to the extra padding and its "shock-protection" design.

Its large form factor has also precluded the possibility of putting it down safely in the space-scarce clinical areas, and hence it must be carried all the time. This issue affects the nursing staff most during their drug dispensing rounds, which may last from half an hour to an hour with no breaks in between.

Data Entry Interface

Data entry in the tablets is another issue identified by all user groups. The dedicated stylus has a “magnetic” tip which attracts the cursor on the screen on close proximity.

However, this process is not reliable, and the cursor movement cannot be controlled accurately despite repeating "calibration". This makes data entry a very laborious and tedious process and not conducive for work on a busy ward.

Battery Power

Battery power is unreliable and many units were often not usable as they have been fully discharged with use or the charging mechanism was not working as well as it should. This puts another barrier to access of the system when it is most needed. Instead of being a "mobile-unit", the units became very expensive "desk-tops personal computers on wheels" permanently tethered to the wall power supply socket over time.

When the batteries fail, no wall socket means no access to the Information Systems in that particular clinical space.

Software Design 

Automatic Log-out

The main software usability issue identified was with regards to the automatic log-out feature after a predefined period of user in-activity.

Although this increases privacy and security of patient details, it does not take into account the fact that work on the ward is based around multiple unpredictable interruptions. This can be up to ten times or more within an hour in a busy unit per individual.

Hence, the user may be forced to log in repeatedly in as many times. This decreases the efficiency of the system dramatically and affects the nursing and medical staff the most. Factor in the difficulty in data entry with the stylus on the tablet and the accessibility of the system in a busy clinical setting becomes a challenging issue in terms of actual usability.

Factor in the need to share terminals in a busy clinical area and short interruptions may morph into prolonged periods of inactivity in between each interruption.

Robust but rigid rules

The robust but rigid rules of the prescribing support system preclude the non-standard use of certain drugs in special situations.

For example, in the palliative care of a dying patient, pain control is paramount and often, the doses and frequencies required are much higher than in normal situations. The route of administration is also unusual (i.e. via a syringe driver, mixed with other medical solutions)


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Page Updated: 17 May, 2017

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