Towards a benchmark of abdominal CT use during duty shifts: 15-year sample from the Netherlands

Did medical doctors who order abdominal CT scans during on-call hours truly become worse at clinical reasoning? Yes, they did

OBJECTIVE

To investigate temporal changes in clinical reasoning quality of physicians who requested abdominal CT scans at a tertiary care center during on-call hours within a 15-year period.

METHODS

This retrospective study included 531 patients who underwent abdominal CT at a tertiary care center during on-call hours on 36 randomly sampled unique calendar days in each of the years between 2005 and 2019. Clinical reasoning quality was expressed as a percentage (0-100%), taking into account the degree by which the differential diagnoses on the CT request form matched the CT diagnosis. Temporal changes in the quality of clinical reasoning and number of CT scans were assessed using Mann-Kendall tests. Associations between the quality of clinical reasoning with patient age and gender, requesting department, and time of CT scanning were determined with linear regression analyses.

RESULTS

The median annual clinical reasoning score was 0.4% (interquartile range: 0.3 to 0.6%; range: 0.1 to 1.9%). The quality of clinical reasoning significantly decreased between 2005 and 2019 (Mann-Kendall Tau of -0.829, p < 0.001), while the number of abdominal CT scans significantly increased (Mann-Kendall tau of 0.790, p < 0.001). There was a significant association between the quality of clinical reasoning and patient age (β coefficient of 0.210, p = 0.002). The quality of clinical reasoning was not significantly associated with patient gender, requesting department, or time of CT scanning.

CONCLUSION

The clinical reasoning quality of physicians who request abdominal CT scans during on-call hours has deteriorated over time. Clinical reasoning appears to be worse in younger patients.

KEY POINTS

• In patients with suspected acute abdominal pathology who are scheduled to undergo CT scanning, referring physicians generally have difficulties in making an accurate pretest (differential) diagnosis. • Clinical reasoning quality of physicians who request acute abdominal CT scans has deteriorated over the years, while the number of CT scans has shown a significant increase. • Clinical reasoning quality appears to be worse in younger patients in this setting.

On-call abdominal ultrasonography: the rate of negative examinations and incidentalomas in a European tertiary care center

Objectives

To determine the proportions of abdominal US examinations during on-call hours that are negative and that contain an incidentaloma, and to explore temporal changes and determinants.

Methods

This study included 1615 US examinations that were done during on-call hours at a tertiary care center between 2005 and 2017.

Results

The total proportion of negative US examinations was 49.2% (795/1615). The total proportion of US examinations with an incidentaloma was 8.0% (130/1615). There were no significant temporal changes in either one of these proportions. The likelihood of a negative US examination was significantly higher when requested by anesthesiology [odds ratio (OR) 2.609, P = 0.011], or when the indication for US was focused on gallbladder and biliary ducts (OR 1.556, P = 0.007), transplant (OR 2.371, P = 0.005), trauma (OR 3.274, P < 0.001), or urolithiasis/postrenal obstruction (OR 3.366, P < 0.001). In contrast, US examinations were significantly less likely to be negative when requested by urology (OR 0.423, P = 0.014), or when the indication for US was acute oncology (OR 0.207, P = 0.045) or appendicitis (OR 0.260, P < 0.001). The likelihood of an incidentaloma on US was significantly higher in older patients (OR 1.020 per year of age increase, P < 0.001) or when the liver was evaluated with US (OR 3.522, P < 0.001).

Discussion

Nearly 50% of abdominal US examinations during on-call hours are negative, and 8% reveal an incidentaloma. Requesting specialty and indication for US affect the likelihood of a negative examination, and higher patient age and liver evaluations increase the chance of detecting an incidentaloma in this setting. These data may potentially be used to improve clinical reasoning and restrain overutilization of imaging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-022-03525-1.