Describing the learning curve of novices for the diagnosis of paediatric distal forearm fractures using point-of-care ultrasound

Purpose

The learning curve of nurse practitioners (NPs) to accurately diagnose paediatric distal forearm fractures using point-of-care ultrasound (POCUS) was investigated.

Methods

Each NP’s learning curve was calculated as cumulative diagnostic accuracy against a number of scans performed. The curve’s plateau represented the attainment of competency. Secondary outcomes were the comparisons before and after this cut-off of diagnostic accuracy, classification of diagnostic errors, pain scores, duration and preference.

Results

Five NPs performed 201 POCUS studies with diagnostic accuracy plateauing at 90%, providing a ‘cut-off’ point at scan 15. Accuracy of POCUS scanning before and after the fifteenth scan was 81% (95% CI 70%–89%) and 90% (95% CI 84%–94%), respectively, demonstrating 9% improvement (P = 0.07). There was a 10% reduction in image interpretation errors. After fifteen scans, POCUS became faster (mean difference (MD) 2.6 min [95% CI 2.0–3.3], P < 0.001), less painful (MD 0.61 points FPSR scale [95% CI 0.04–1.18], P = 0.04) and more preferred by NPs (63% vs 77%, P = 0.03).

Discussion

The learning curve of POCUS-novice NPs independently scanning paediatric distal forearm injuries plateaued with mean diagnostic accuracy of 90% after 15 scans, suggesting competency was attained at this cut-off, supported by higher accuracy, being faster, less painful and more preferred by NPs. Future training packages in forearm POCUS should further address image interpretation and provide ongoing expert feedback.

Conclusions

The findings from this study suggest that competency in paediatric distal forearm POCUS can be attained by novices after a short training course and approximately 15 scans.