At the end of a long day I made a mistake at work. No patient was harmed and yet it weighs on me

‘One interpretation is that human error is inevitable and that the system worked as intended. But that is false comfort. When lives are at stake, the error should not occur.’ Photograph: Wavebreak Media Premium/Alamy

The other day, I made a mistake at work.

It was the end of a long day. I had already run an outpatient cancer clinic with dozens of unwell patients and then moved on to inpatient rounds on a busy medical unit.