To empirically describe how independent physicians develop a new cognitive clinical skill through repetition using the initiation of a stroke thrombolysis programme as a model.METHODS
This was a retrospective cohort study from April 2009 to March 2013. The setting was a single-centre, Canadian tertiary-care community hospital. The participants were 52 physicians with no prior formal training in stroke thrombolysis assuming a new role of being front-line hyperacute stroke physicians. The main outcome measures were: time needed to accrue experience, door-to-needle time (DTN), with achievement of expertise defined as an average of ≤ 60 minutes, computed tomography (CT)-to-needle time (CTN), with achievement of expertise defined as an average of ≤ 35 minutes, usage of an outside expert stroke telemedicine service, and complication rates with intracranial haemorrhage (ICH).RESULTS
Seven hundred and fifteen cases of hyperacute stroke were seen over the 4-year study period. On average, a physician saw 0.025 cases per hour of code stroke coverage provided; only seven (13.5%) accrued more than 20 code stroke cases and only six (11.6%) ordered thrombolysis more than 10 times. By regression analysis, the average first DTN was 81.0 minutes (95% confidence interval [CI], 77.1–84.9 minutes) and incrementally improved linearly by 0.259 minutes per case seen (95% CI, 0.182–0.337 minutes per case). An estimated 71 cases needed to be seen for the average physician to achieve expertise. Results using CTN were highly similar. Overall, physicians used the external stroke telemedicine providers 23.2% of the time for their first five cases, a rate that decreased to about 5% by the 45th case. Over time, ICH rates were kept at expected benchmarks.CONCLUSIONS
Accruing sufficient experience of a new cognitive clinical skill can be challenging for independent physicians, with expertise gradually emerging in a largely linear fashion only after much repetition.