Skip to main content

Table 1 Outcome measures

From: The Opioid Analgesic Reduction Study (OARS)—a comparison of opioid vs. non-opioid combination analgesics for management of post-surgical pain: a double-blind randomized clinical trial

Brief description/justification of outcome measure Outcome measured by Timing
Primary outcome measures  
Pain: For pain level, Brief Pain Inventory (BPI) using the Numerical Rating Scale (NRS) was chosen because:
 • BPI with NRS is widely used and accepted
 • Reliability and validity for BPI and NRS have been established
 • BPI with NRS is clinically relevant (patients want to minimize pain experienced after surgery)
 • BPI with NRS is a sensitive measure
 • BPI with NRS allows for direct comparisons across studies
Satisfaction: For satisfaction, overall satisfaction questions from the Pain Treatment Satisfaction Scale (PTSS) were chosen because:
 • While patients want to minimize pain, patients are willing to tradeoff some pain relief to minimize side effects, maintain their ability to sleep, maintain their ability to engage in normal activities, and minimize exposure to opioids
 • PTSS has been shown to be valid and reliable
Pain: NRS is used on a scale of 0 to 10 where 0 = no pain and 10 = worst imaginable pain for average pain level, pain at its worst, pain at its least, pain experiencing now.
Satisfaction (measures from PTSS):
 • How satisfied are you with the time that it takes your pain medication to work? (scale: 1 = very satisfied, 2 = satisfied, 3 = neither satisfied nor dissatisfied, 4 = dissatisfied, 5 = very dissatisfied)
 • How satisfied are you with the level of amount of pain relief provided by your pain medication? (scale: 1 = very satisfied, 2 = satisfied, 3 = neither satisfied nor dissatisfied, 4 = dissatisfied, 5 = very dissatisfied)
 • How satisfied are you with the duration of pain relief provided by your pain medication? (scale: 1 = very satisfied, 2 = satisfied, 3 = neither satisfied nor dissatisfied, 4 = dissatisfied, 5 = very dissatisfied)
 • Overall, how satisfied are you with your pain medication? (scale: 1 = very satisfied, 2 = satisfied, 3 = neither satisfied nor dissatisfied, 4 = dissatisfied, 5 = very dissatisfied)
 • Overall, how does your level of pain relief meet your expectations of pain relief? (scale: 1 = greatly exceeds my expectations, 2 = somewhat exceeds my expectations, 3 = meets my expectations, 4 = does not quite meet my expectations, 5 = does not meet my expectations at all)
 • Do you think that your pain medication could be more effective in relieving your pain? (scale: 1 = yes, definitely, 2 = probably yes, 3 = I do not know, 4 = probably not, 5 = definitely not)
Participants report their pain experience and rate their overall satisfaction using a REDCap application developed for electronic phones and tablets.
Pain:
 • Visit 1 (in the last 24 h)
 • Each morning days 2 to 8
 • Each evening days 1 to 7
 • Visit 2 (in the last 24 h)
Satisfaction:
Satisfaction recorded during post-op visit (visit 2)
Secondary outcome measures  
Adverse events:
As medications have side effects, a list of possible adverse events (side effects) related to the intervention has been developed, and participants are asked if they are experiencing any of them. (This is separate from serious adverse events which are captured. Serious adverse events result in a participant being exited from the study. An analysis of serious adverse events is included in the study analysis.)
Sleep quality:
 • Pain and Sleep Questionnaire 3-item index (PSQ-3) was selected because it is a validated measure and because of its ease of use for the eDiary on a smart phone.
 • A question from the PTSS was selected because it provides an overall rating of the quality of sleep.
Pain interference (daily function):
The PROMIS Short 6b was selected because it is a standard NIH measure of pain interference and can be recorded during the post-operative visit.
Future opioid-seeking behavior:
The PDMP is accessed; 6 months was selected because it is the maximum follow-up time which could be completed within the study time frame.
Potential diversion:
Participants are instructed to bring the pill bottle and unused capsules to the follow-up appointment.
Adverse events:
 • Adverse events include excessive fatigue or drowsiness, inability to concentrate, nausea, diarrhea, dizziness, constipation, skin rashes, stomach aches, heartburn, vomiting, euphoria, headache, urinary retention, and unintentional weight gain with a binary yes/no scale. Self-reported binary response (yes/no) is ascertained. If yes, was the adverse event bothersome to a minor or major extent?
o For visit 1, participants are asked how much were you bothered by … over the last 24 h.
o At the time of getting up in the morning, participants are asked how much were you bothered with …. during the night
o Right before going to sleep at night, participants are asked how much they were bothered by … during the day.
o For visit 2, participants are asked how much were you bothered by … over the last 24 h.
Sleep ability:
 • From the PSQ-3: (a) Last night did you have trouble falling asleep? (b) Last night were you awakened by pain during the night? (c) Were you awakened by pain this morning? {binary yes/no scale during the post-operative period; NRS scale where 0 = never, 10 = always at visits 1 and 2}
 • From PTSS: rating the overall quality of last night’s sleep {NRS where 0 = excellent and10 = very poor}
 • From ActiGraph: Sleep quality is monitored, and data collected
Pain interference:
 • PROMIS Short 6b: During the post-operative period, how much did pain interfere with your day to day activities, work around the home, ability to participate in social activities, enjoyment of life, the things you usually do for fun, enjoyment of social activities, household chores, family life, your ability to concentrate, enjoyment of recreational activities, tasks away from home {scale: 1 = not at all, 2 = a little bit, 3 = somewhat, 4 = quite a bit, 5 = very much} and how often did pain keep you from socializing with others? {scale: 1 = never, 2 = rarely, 3 = sometimes, 4 = often, 5 = always}
Future opioid-seeking behavior:
 • # of new opioid prescriptions recorded in the Prescription Monitoring Database Program at approximately 6 months following the surgical procedure
Potential diversion:
 • # returned capsules at visit 2 determined by counting the returned capsules or via electronic monitoring device
 • # unaccounted for capsules at visit 2 (not recorded as used and not returned)
Participants report whether they have experienced each adverse event and rate their sleep ability and pain interference in a daily electronic diary using a REDCap application developed for electronic phones and tablets.
Adverse events:
 • Visit 1
 • Each night for days 2–8
 • Each day for days 1–7
 • Visit 2
Ability to sleep:
 • Visit 1
 • Each morning on days 2 thru 8 and
 • Visit 2 (in the last 24 h)
Pain interference:
 • Visit 1
 • Each evening on days 1 through 7
 • Visit 2
Future drug-seeking behavior:
 • Opioid prescriptions filled within 6 months after visit 2
Potential diversion:
 • Visit 2