The odds of a patient undergoing surgery avoiding morbidity after 90 days seem to increase with the amount of time the surgeon and the anaesthetist had previously worked together – but it depends on the procedure.

According to Canadian researchers, familiarity between the two was associated with better outcomes in spinal, gynaecological oncology, and low- and high-risk gastrointestinal surgeries.

However, there was no significant association for cardiac, orthopaedic, lung, head and neck, vascular, neurological, or genitourinary surgeries. 

The researchers reviewed Canadian public hospital data for more than 711,000 procedures, then investigated how often each surgeon–anaesthetist pair had co-operated over the four years preceding the procedure.