Table 8.

Assessment scales for use in opioid-induced constipation (OIC)

Scale	Advantages	Disadvantages
Patient Assessment of Constipation—Symptoms (PAC-SYM)a		Not yet validated for OIC High number of questions → time-consuming and poor applicability in a clinical setting
Patient Assessment of Constipation—Quality of Life (PAC-QoL)
Knowles–Eccersley–Scott Symptom Score
Constipation Assessment Scale
Stool Symptom Screener		Qualitative interviews Not sufficiently validated for comparative or sequential assessment of clinical status in patients with OIC [116]
Bowel Function Diary	Validated for OIC by the FDA Developed according to the methodology based on PRO Assessment of both symptoms and their severity [115]	Not easy to use [114] More suited to controlled clinical trials than to routine clinical practice [114]
Bowel Function Index	Validated and tested for OIC Three simple questions Subjective assessment of OIC Administered by a physician or appropriately trained nurse/nursing assistant Uses numerical rating scales Fast, effective and reliable

FDA US Food and Drug Administration, PRO patient-reported outcomes

^aA version of PAC-SYM is also available for patients with chronic low back pain and OIC