“…This ‘chronic' time frame ranged between 1 and 36 months [63,64,65,66,67]. Second, some studies included the quantitative factor PI in their definition of CPIP, which was either expressed using descriptive terms [68,69,70,71,72,73,74,75], a visual analog scale (VAS) score, or a QOL score [31,76,77,78,79,80,81,82,83,84,85]. …”