Unreliable numbers: error and harm induced by bad design can be reduced by better design

Abstract

Number entry is a ubiquitous activity and is often performed in safety- and mission-critical procedures, such as healthcare, science, finance, aviation and in many other areas. We show that Monte Carlo methods can quickly and easily compare the reliability of different number entry systems. A surprising finding is that many common, widely used systems are defective, and induce unnecessary human error. We show that Monte Carlo methods enable designers to explore the implications of normal and unexpected operator behaviour, and to design systems to be more resilient to use error. We demonstrate novel designs with improved resilience, implying that the common problems identified and the errors they induce are avoidable.

What makes a good clinical app? Introducing the RCP Health Informatics Unit checklist

“…Conversion of a 1 mg dose of oral morphine to methadone resulted in a dose ranging from 0.05 to 0.67 mg methadone (a 13:1 range), with fewer than half the apps recognising that the conversion formula used should depend on the actual dose as well as on the drugs concerned. Thimbleby et al 2 found that the delete key on many apps does not work correctly, so ironically if a user tries to correct an error they notice, that correction may cause an error they do not notice. from app developers, the RCP Health Informatics Unit (HIU) has developed a short checklist (see Fig 1) to support clinicians wishing to assess the quality of apps.…”

Assessing the Status Quo of EHR Accessibility, Usability, and Knowledge Dissemination

“…In general, health IT has been recognized for its direct link to patient safety [9] and poor usability or design of health IT has been identified as an important culprit in medical errors [10], including examples related to medication bar coding [11], physician order entry [12], and other safety domains [13]. More recently, safety concerns have been linked to EHRs in particular, specifically as they relate to workflow and data display [14].…”

Issues in number entry user interface styles: Recommendations for mitigation

“…Numeric user interfaces seem easy to implement, so it is surprising that many have bugs [13][14][15], perhaps a consequence of programmers thinking number entry is so easy to program they do not think it is worth adopting best practice they would use for problems recognised as being hard.…”

“…An unlimited number of bugs is possible, and any can interact badly with use error, so the recommendations for mitigation are to use formal methods [13] and testing [15], as well as development environments that support tools for rigorous development.…”

“…For example, the delete key on serial number entry user interfaces is often incorrectly implemented [15], and on some independent digit entry systems there are modes where previous numbers interfere with the number the user is entering [4].…”