A Prospective Cohort Study Evaluating the Ability of Anticipated Pain, Perceived Analgesic Needs, and Psychological Traits to Predict Pain and Analgesic Usage following Cesarean Delivery

Table 3

(a) Multiple linear regression analysis of all preoperative predictive tests and key clinical outcome response measures postcesarean delivery. (b) Multiple linear regression analysis with only three simple ratings preoperative predictive tests (expected postoperative pain, anticipated analgesic threshold, and perceived analgesic need) and key clinical outcome response measures postcesarean delivery.

(a)

Response outcome	coefficient	value	Predictor tests in model
Opioid used	0.421	0.0002	9.36 – 9.97 ASI – 6.9 × 10^−6  FPQ + 0.023 expected pain^1
Combined (Rest + Move) NVPS AUC	0.443	0.00002	57.68 + 108.96 expected pain^1 – 1.36 perceived analgesic need^2

AUC = area-under-the curve; NVPS = numerical verbal pain score (0–10, 0 = no pain, 10 = worst pain imaginable).
ASI = Anxiety Sensitivity Index; FPQ = Fear of Pain Score III; PCS = Pain Catastrophizing Scale.
The personality categories (psychoticism, extroversion, neuroticism, and lying) were derived from Eysenck Personality Questionnaire Revised-Short Scale (EPQR-S).
Transformations used were as follows.
For opioid used: ASI , FPQ: , and expected postoperative pain: .
For combined (Rest + Move) NVPS AUC: expected postoperative pain: , perceived analgesic need: .
Total amount of supplemental opioid analgesics (oral and intravenous) used in the 48 hours was determined by adding intravenous morphine doses to oxycodone/hydrocodone (converted to morphine mg equivalents for analysis with oral oxycodone/hydrocodone 20 mg being considered equivalent to 10 mg intravenous morphine [14]).
NVPS at rest and at movement (defined as sitting upright at 90 degrees) was measured at 6, 24, and 48 hours, and the pain burden was determined as NVPS over time AUC over the 48-hour study period.
¹Expected postoperative pain: “how much pain do you expect to experience after your surgery on a pain scale of 0–10?”
Anticipated analgesic threshold: “at what point on a pain scale of 0–10 would you likely request postoperative pain relief?”
²Perceived analgesic need: “what do you expect your analgesic requirements will be after surgery? (0 = no analgesia, 10 = highest possible amount).”

(b)

Response outcome	coefficient	value	Predictor tests in model
Opioid used	0.212	0.0027	2.514 + 0.041 expected pain^1
Combined (Rest + Move) NVPS AUC	0.447	0.00001	162.054 + 32.45 expected pain^1 – 1.695 perceived analgesic need^2

AUC = area-under-the curve; NVPS = numerical verbal pain score (0–10, 0 = no pain, 10 = worst pain imaginable).
Transformations used are as follows.
For MSEqui: anticipated postoperative pain: .
For combined (Rest + Move) NVPS AUC: expected postoperative pain: , perceived analgesic need: .
A total of 38 subjects analyzed (3 and 0 outliers were removed for opioid used and combined NVPS AUC, resp.).
Total amount of supplemental opioid analgesics (oral and intravenous) used in the 48 hours was determined by adding intravenous morphine doses to oxycodone/hydrocodone (converted to morphine mg equivalents for analysis with oral oxycodone/hydrocodone 20 mg being considered equivalent to 10 mg intravenous morphine [14]).
NVPS at rest and at movement (defined as sitting upright at 90 degrees) was measured at 6, 24, and 48 hours, and the pain burden was determined as NVPS over time AUC over the 48-hour study period.
¹Expected postoperative pain: “how much pain do you expect to experience after your surgery on a pain scale of 0–10?”
Anticipated analgesic threshold: “at what point on a pain scale of 0–10 would you likely request postoperative pain relief?”
²Perceived analgesic need: “what do you expect your analgesic requirements will be after surgery? (0 = no analgesia, 10 = highest possible amount).”