Diagnosis under pressure

It is true to say that our judgement is not always at it’s best when we are stressed or under time pressure. In a recent paper (Plessas et al., 2019 ) a research team  placed 40 dentist under time pressure to assess a number of dental radiographs and compared it to the same groups results if they has as much time as they felt necessary.  Their conclusion was:

Time pressure negatively impacts one aspect of dentists’ diagnostic performance, namely sensitivity (increased diagnostic errors and omissions of pathology), which can potentially affect patient safety and the quality of care delivered.

Since this study was based about diagnostic test accuracy (DTA) I felt it might be interesting to express this result graphically, and the author was kind enough to provide me with the raw data from the research. The  data was extracted into  excel and then analysed using the statistical package ‘mada’ in R to  create a summary receiver operator characteristic (sROC).

The Results

The ellipse with circle surrounded by the solid line represents the summary estimate for diagnosis with time pressure (TP) and 95% confidence interval, and the ellipse with triangle surrounded by the dotted line represents the summary estimate for diagnosis with no time pressure (NTP).

Diagnostic test accuracy (sROC curve)Time pressure

Sensitivity = 0.551 (95%CI: 0.439 to 0.658)

False positive rate = 0.006 (95%CI: 0.004 to 0.01)

No time pressure

Sensitivity = 0.797 (95% CI: 0.692 to 0.873)

False positive rate = 0.009 (95%CI: 0.006 to 0.13)

Summary result

The difference between TP and NTP are statistically significant p=0.0007

In absolute terms there was a 24.6% reduction in correct diagnosis under TP.

In relative terms there was a 40% reduction in correct diagnosis under TP.

My conclusion

When under stress or significant time pressure there was a significant reduction in the clinician ability to diagnose pathology (from 80% to 55%) but a misdiagnosis of ‘normal’ was very low in both scenarios.

Acknowledgements

I would like to thank the authors for allowing me access to their data

Plessas, A., Nasser, M., Hanoch, Y., O’Brien, T., Bernardes Delgado, M. and Moles, D. (2019) ‘Impact of time pressure on dentists’ diagnostic performance’, Journal of Dentistry, 82, pp. 38–44. doi: 10.1016/j.jdent.2019.01.011.