Fig. 4

Precision, recall and F1 score by quality of reporting and clinical application category. Legend: NLP system performance reported as precision, recall and F1 score from included studies. Size of the bubbles represents the relative sizes of corpora in each graph. a Studies were categorised into high (> 5 qualities) and low (≤ 5 qualities) reporting quality based on the median number of qualities reported as the cut-off point. Reporting of F1 score was not a quality criterion. b Performance stratified by clinical application