An observational study in Pain Management, sponsored by University Health Network, Toronto. Recruiting at 1 site in Canada. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-06-10.
Sponsored by University Health Network, Toronto · Observational
This study seeks to define what constitutes an MCID and a PASS in patients undergoing a variety of elective major orthopedic surgery.
Acute postoperative pain after orthopaedic surgery is common and approximately 40% of all surgical patients experience moderate-severe acute postoperative pain. Treatment of acute pain after surgery is important to relieve patient suffering, expedite resumption of activities of daily living, mitigate the risk of postoperative complications, speed ambulation and rehabilitation and hospital discharge. Good pain treatment requires proper and sound pain assessment to guide analgesic therapy. Past studies have determined the MCID values for a variety of chronic pain disorders. There are however limited data on the MCID for acute pain.At the present time, most perioperative acute pain studies use MCID values that are extrapolated from chronic pain studies yet the validity of MCID extrapolation remains unknown. Procedure-specific MCID for pain after most major orthopedic surgery has not been reported.The MCID for a patient reported outcome can be determined using an anchor and a distribution based method.The anchor based method uses a subjective Global Rating Scale (GRS) scale to assess patient's perception of pain relief after treatment. This is a 15-point Likert scale that ranges from -7 to +7 .Another method to determine the MCID value in pain is the distribution based method using mathematical calculations to generate 3 MCID values - 1) 0.3 standard deviation (SD) of mean change in NRS scores, 2) the standard error of measurement (SEM), and 3) 5% of the instrument range of the mean change in the NRS scores after an analgesic intervention according to patient-rated GAR scale. The SEM is calculated as the SD multiplied by the square root of 1 minus the intraclass correlation coefficient. The final MCID value is the average of 4 values, 1 generated from the anchored and 3 generated from the distribution based methods.
The Patient Acceptable Symptom State (PASS) is another measure for patient-reported outcomes. It represents the threshold beyond which patients consider themselves well (satisfied) after an intervention. The PASS is an absolute value, not a change but this value will vary among patients. In essence, PASS indicates a state of wellbeing (feeling good) as opposed to MCID, a state of improvement (feeling better). The 2 concepts are complementary but contrary to MCID, the PASS is the outcome of interest, instead of the extent of improvement. To determine PASS, the patients are asked this question "In your opinion, do you consider your current pain state satisfactory after your operation?" Patients responding "yes" are considered having an acceptable pain state. The PASS is the 75th centile of the pain scale in those who rated their pain state as satisfactory. Higher baseline pain scores are often associated with higher PASS estimates. Little is known about PASS for acute pain after surgery thus a need to determine this benchmark to properly evaluate the clinical benefits of analgesic interventions.
Quality of Recovery (QoR) is another important PRO measure when evaluating the impact of novel intervention strategies. Quality of recovery can be assessed using the QoR-15 questionnaire (scores 0-150) which measures physical \& mental well-being as an indication of the quality of recovery after surgery and anaesthesia.
To determine MCID for QoR, both the anchor and distribution based methods will be used. The patient will be asked "How would you rate your overall recovery from surgery since yesterday?" Patients will use the same GRS (-7 to +7) to measure their response. With the anchored-based method, the MCID is the mean change in the QoR-15 score when the patient reports a GRS score of +2 or +3. The distribution-based method will generate 3 other MCID values: 1) 0.3 standard deviation (SD) of the mean change in the QoR score; 2) the standard error of measurement (SEM); and 3) 5% of the instrument range. Again, the final MCID value is the average of 4 values, 1 generated from the anchored and 3 generated from the distribution based methods.
To determine PASS for QoR, the patients will be asked, "In your opinion, have you made a good recovery from your operation?" with response options of yes, no, or unsure. Those who give a positive response is considered having made a good recovery. The PASS for QoR is the 75th centile of the QoR-15 score in those who rated their recovery as good. The only MCID and PASS study by Myles reported a QoR-15 score of 8 \& 118 (out of 150), respectively, in patients undergoing a broad range of surgical procedures. Procedure-specific MCID \& PASS for QoR-15 after major orthopaedic surgery are currently unknown. Our proposed observational study seeks to define what constitutes an MCID and a PASS in patients undergoing a variety of elective major orthopedic surgery.
1,190 studies on the registry are indexed under Agnosia; 508 are open to participants now.
This study's planned enrollment of 300 is above the median of 120 across 147 observational studies indexed under Agnosia.
Browse Agnosia studies →University Health Network, Toronto is the lead sponsor of 1,411 studies on the registry; 292 are open to participants now.
Of its 17 completed or terminated interventional studies of FDA-regulated products, 3 (18%) have results posted.
Counted across the registry records on this site, refreshed daily.
Study patients will be recruited at Toronto Western Hospital
Exclusion Criteria:
All study patients will be managed per routine clinical practice and institutional standard for the performed surgery.
Other: 1.Baseline Measurements Before Surgery · Other: 2.Intraoperative Anesthetic Management · Other: 3.Postoperative Analgesic Management · Other: 4.Postoperative NRS Pain Assessment · Other: 5.Postoperative Global Rating Scale (GRS) Pain Assessment · Other: 6.Postoperative Patient Acceptable Symptom State (PASS) Assessment for Pain · Other: 7.Postoperative Quality of Recovery Assessment · Other: 8.Other Postoperative Assessments
* Baseline demographic data * Baseline physiological variables (blood pressure, heart rate, respiratory rate, oxygen saturation) * Baseline investigations (hemoglobin, coagulation profile, serum electrolytes) if appropriate. * Preoperative pain state using NRS (0-10) * Preoperative functional state using the QoR-15 questionnaire * Pain expectation - patients will be asked preoperatively with the question "In a scale from 0 to 10 (where 0 = no pain and 10 = worst pain imaginable), what do you consider is an acceptable pain score for your first (and second) day after surgery?... Two weeks after surgery?" * Pain castastrophizing scale
All study patients will be managed per routine clinical practice and institutional standard for the performed surgery.
postoperative pain will be managed on the ward using a multimodal analgesic regimen as appropriate. This includes: 1. acetaminophen 650 - 1,000 mg given orally every 6 hours around the clock 2. NSAIDs e.g., celecoxib or other agents given orally around the clock per clinical guideline; omit if contraindicated or per surgeon's preference 3. Opioids e.g., hydromorphone 1-2 mg or oxycodone 15-30 mg given orally every 1-2 hours as required by the patient per standard nurse administered analgesic protocol. 4. In the event of severe pain refractory to the above treatments, the patient will be offered IV opioid e.g., intermittent doses of 0.2-0.4 mg hydromorphone IV every 10 minutes until pain becomes tolerable
Pain assessment using NRS pain scores (0 = no pain and 10 = worst possible pain) will be performed by an independent research staff, starting immediately in the PACU and serially over the first 48 hours after surgery or until hospital discharge.
Also, the degree of pain relief after treatment is assessed using a subjective 15-point Global Rating Scale (GRS) as mentioned above (Background). This is performed at the same time of each NRS assessment and a minimum of twice daily
During each NRS pain assessment before or after an analgesic intervention on POD 0, 1 and 2, the patient will also be asked this question- ""In your opinion, do you consider your current pain state satisfactory after your operation?" Patients giving a positive response are considered having an acceptable pain state. The PASS is the 75th centile for the pain NRS score in those with a satisfactory pain state.
The quality of recovery 15 questionnaire (QoR-15) to measure the dimension of quality of recovery will be administered once in the morning of POD 1 and POD 2. The MCID and PASS for QoR are determined in the same way as for NRS score. The final MCID value will be average of 4 values, 1 generated by the anchor based method and 3 generated by the distribution based method. The PASS for QoR is the 75th centile of the QoR-15 score in those patients who rated their recovery as good.
Additionally, opioid related adverse effects e.g., nausea, vomiting, itchiness, constipation, sedation (RASS + Ramsay)/ and respiratory depression will be assessed daily.
MCID for NRS pain score after orthopedic surgery
The MCID value represents the change in NRS score after treatment when the patient reports a small improvement of pain relief that corresponds to a GAR score of 2 or 3.
Time frame: The first 48 hours after 4 types of major orthopedic
The PASS for NRS pain score after orthopedic surgery
The PASS for NRS pain score after orthopedic surgery
Time frame: The first 48 hours after 4 types of major orthopedic
The amount of opioid consumption required to achieve MCID and PASS
The amount of opioid consumption required to achieve MCID and PASS for acute pain after orthopedic surgery.
Time frame: The first 48 h hours 4 types of major orthopedic
Quality of recovery
Quality of recovery as assessed using the QoR-15 questionnaire (0-150), higher score means better recovery
Time frame: The first 2 days after surgery
The MCID and PASS for QoR-15
The MCID and PASS for QoR-15 (0-150), higher score means better recovery
Time frame: The first 2 days after surgery
The incidence of opioid related adverse reactions and treatments required
The incidence of opioid related adverse reactions and treatments required
Time frame: The first 2 days after surgery
Plan to share: No
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University Health Network, Toronto