“…For example, Maltoni et al 20 reported three categories (PPS 10-20%, PPS 30-50%, PPS ‡60%). Of the 13 studies, the 6 remaining 2,5,12,13,23,24 reported the initial PPS scores as discrete variables, which had different ranges of PPS scores (e.g., PPS 10-70%, PPS 40-90%). Of the six studies, two studies 2,5 reported PPS ranging from 10% to 70%, while the four remaining studies reported various ranges.…”