Postoperative PainNCT07846878
Prospective External Validation of an Early Prediction Model for Adverse Postoperative Pain Trajectories After Orthopedic Surgery
An observational study of Postoperative Pain, run by First Affiliated Hospital of Chongqing Medical University at 1 site in China.
Trial summary
This prospective observational study will externally validate a previously developed and locked prediction model for identifying adult patients at risk of adverse postoperative pain trajectories after elective orthopedic surgery. Read more about this study
- Who is it for?
- Ages 18 to 90 years
- Conditions the study is for
- Postoperative Pain
- What is being tested?
- Elective Orthopedic Surgery
- Type of treatment
- Surgery or procedure
- How many people
- 400 participants
- Where
- 1 siteChina
- Study dates
- 7 Oct 2026to Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 90 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients undergoing elective orthopedic surgery at the First Affiliated Hospital of Chongqing Medical University who are expected to remain hospitalized for at least 48 hours after surgery. Eligible procedures include major categories of elective orthopedic surgery, such as spinal surgery, hip or knee arthroplasty, pelvic or extremity fracture fixation, and orthopedic corrective surgery. Participants will be prospectively and consecutively screened and enrolled according to the prespecified eligibility criteria.
Who may be able to join
- Aged 18 to 90 years, regardless of sex.
- Scheduled to undergo an eligible elective orthopedic surgical procedure at the First Affiliated Hospital of Chongqing Medical University.
- Expected to remain hospitalized for at least 48 hours after surgery.
- Conscious before surgery, with sufficient understanding and communication ability to understand and complete the 0-10 Numeric Rating Scale for pain.
- Able and willing to provide written informed consent before any study-specific data collection.
Who cannot join
- Younger than 18 years or older than 90 years.
- Emergency surgery, unplanned surgery, or a surgical procedure outside the prespecified orthopedic surgical scope of the study.
- Unable to reliably understand the study or complete the Numeric Rating Scale because of impaired consciousness, severe cognitive impairment, psychiatric disorder, persistent deep sedation, mechanical ventilation, severe hearing impairment, language or communication difficulties, or similar conditions.
- Lacks full capacity to provide valid informed consent.
- Concurrent participation in another clinical study that may affect pain assessment, analgesic treatment, or study outcomes.
- Expected discharge or transfer within 48 hours after surgery, or inability to complete the main study observation because of clinical circumstances.
- Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in the study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
The First Affiliated Hospital of Chongqing Medical University
Chongqing
Lihua Peng, +86 15823443968, plhcqmu@163.com
About this study
Official title: Single-Center Prospective External Validation Study of an Early Prediction Model for Adverse Postoperative Pain Trajectories After Orthopedic Surgery
This prospective observational study will externally validate a previously developed and locked prediction model for identifying adult patients at risk of adverse postoperative pain trajectories after elective orthopedic surgery. Approximately 400 patients will be consecutively recruited at the First Affiliated Hospital of Chongqing Medical University.
Postoperative pain will be assessed during the first 48 hours after surgery using the 0-10 Numeric Rating Scale. Pain scores will be organized into eight consecutive 6-hour time windows to determine each participant's postoperative pain trajectory according to prespecified rules. Clinical information available at the predefined prediction time point will be entered into the locked prediction model to calculate each participant's predicted probability of an adverse pain trajectory.
The study will evaluate the model's discrimination, calibration, overall prediction performance, and potential clinical utility. The model will not be modified or retrained using data from this validation cohort. Individual prediction results will not be provided to patients or treating clinicians and will not be used to guide treatment during the study.
Read the detailed description
This is a single-center, prospective, observational external validation study of an early prediction model for adverse postoperative pain trajectories in adult patients undergoing elective orthopedic surgery at the First Affiliated Hospital of Chongqing Medical University.
Eligible participants will receive routine perioperative care. The study will not assign any experimental treatment or alter the participants' surgical, anesthetic, analgesic, nursing, or rehabilitation management. Study personnel will collect prespecified clinical variables from patient interviews, electronic medical records, anesthesia information systems, nursing records, and standardized postoperative pain assessments.
The end of surgery will be defined as postoperative hour 0. Postoperative pain intensity will be assessed using the 0-10 Numeric Rating Scale during the first 48 hours after surgery. This period will be divided into eight consecutive 6-hour windows: 0-6, 6-12, 12-18, 18-24, 24-30, 30-36, 36-42, and 42-48 hours. When more than one valid pain score is available within a time window, the median value will be used for the primary analysis.
Before enrollment of the first participant, the prediction model, prediction time point, predictor definitions, variable coding, data-processing procedures, missing-data handling rules, model structure, model parameters and hyperparameters, and outcome classification rules will be locked. Data from the external validation cohort will not be used to reselect predictors, retune hyperparameters, redefine cutoffs, or otherwise modify the original model.
After completion of the 48-hour observation period and data verification, each participant's probability of developing an adverse postoperative pain trajectory will be calculated using the locked model. The observed postoperative pain trajectory will be determined independently according to the prespecified trajectory classification and mapping rules.
External model performance will be evaluated using the area under the receiver operating characteristic curve, Brier score, calibration curve, calibration intercept, and calibration slope. Additional analyses will include sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and decision curve analysis at prespecified risk thresholds. Exploratory analyses may describe model performance across major orthopedic surgical categories.
Model predictions will be calculated offline and will not be communicated to participants, surgeons, anesthesiologists, nurses, or other treating clinicians during the study. Prediction results will therefore not influence clinical management.
- Conditions
- Postoperative Pain
- Being tested
- Elective Orthopedic Surgery
- Keywords
- Postoperative Pain, Pain Trajectory, Orthopedic Surgery, Prediction Model, External Validation, Prospective Cohort, Clinical Prediction Model
- Medical subject headings
- Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Elective Orthopedic SurgeryProcedure or surgery
Participants will undergo elective orthopedic surgery as part of routine clinical care. The surgical procedure, anesthetic management, postoperative analgesia, nursing care, and rehabilitation plan will be determined by the treating clinical team according to standard practice. The study investigators will not assign, modify, or influence these treatments. The study will prospectively collect prespecified perioperative variables and postoperative pain assessments for external validation of a locked prediction model.
| Study group | Role | What they receive |
|---|---|---|
| Prospective External Validation Cohort | Adult patients undergoing elective orthopedic surgery at the First Affiliated Hospital of Chongqing Medical University will be prospectively enrolled and followed for 48 hours after surgery. Postoperative pain scores and prespecified clinical variables will be collected according to the study protocol. All participants will receive routine perioperative care, and no treatment will be assigned or modified by the study investigators. The locked prediction model will be applied offline to evaluate the risk of an adverse postoperative pain trajectory. Receives: Procedure: Elective Orthopedic Surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of Participants With an Adverse Postoperative Pain Trajectory
Participants will be classified as having an adverse or non-adverse postoperative pain trajectory based on pain scores collected during the first 48 hours after surgery and the prespecified, locked trajectory classification and mapping rules. The number and percentage of participants classified as having an adverse postoperative pain trajectory will be reported.
Measured: From the end of surgery through 48 hours postoperatively
Secondary outcomes (8)
Area Under the Receiver Operating Characteristic Curve (AUC)
The area under the receiver operating characteristic curve (AUC) will be used to assess the discrimination of the locked prediction model for distinguishing participants with and without an adverse postoperative pain trajectory. The AUC ranges from 0.5, indicating no discrimination, to 1.0, indicating perfect discrimination. The AUC and its 95% confidence interval will be reported.
Measured: Through 48 hours postoperatively
Brier Score
The Brier score will be used to evaluate the overall predictive performance of the locked prediction model by comparing predicted probabilities with the observed binary adverse postoperative pain trajectory outcome. Lower values indicate better overall predictive performance. The Brier score and its 95% confidence interval will be reported.
Measured: Through 48 hours postoperatively
Calibration Intercept
Calibration intercept will be used to assess systematic overestimation or underestimation of predicted risk by the locked prediction model. A value of 0 indicates ideal calibration. The calibration intercept and its 95% confidence interval will be reported.
Measured: Through 48 hours postoperatively
Calibration Slope
Calibration slope will be used to assess the agreement between the spread of predicted probabilities and observed outcomes. A value of 1 indicates ideal calibration. The calibration slope and its 95% confidence interval will be reported.
Measured: Through 48 hours postoperatively
Calibration Curve
A calibration curve will be used to visually assess agreement between predicted probabilities of an adverse postoperative pain trajectory and observed outcome frequencies across the range of predicted risk. The calibration curve and its 95% confidence interval will be presented.
Measured: Through 48 hours postoperatively
Classification Performance at the Prespecified Risk Threshold
Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the locked prediction model will be evaluated at the prespecified risk threshold and reported with 95% confidence intervals where applicable. The threshold will not be selected or optimized using the external validation cohort.
Measured: Through 48 hours postoperatively
Decision Curve Analysis
Decision curve analysis will be used to evaluate the clinical net benefit of the locked prediction model across a prespecified range of clinically relevant risk thresholds, compared with strategies of treating all participants or treating no participants as being at increased risk.
Measured: Through 48 hours postoperatively
Distribution and Characteristics of Postoperative Pain Trajectory Classes
The number and percentage of participants assigned to each prespecified postoperative pain trajectory class will be described. Class-specific mean pain trajectories over the first 48 postoperative hours and prespecified indicators of classification uncertainty will also be summarized.
Measured: From the end of surgery through 48 hours postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start7 Oct 2026
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postoperative PainStudies of the same condition, open and under way.
- More trials run by First Affiliated Hospital of Chongqing Medical UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lihua Peng, First Affiliated Hospital of Chongqing Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07846878
- Sponsor's protocol ID
- CQMUFAH-PT-EXT-2026-01
- Status last verified
- Oct 2026
- First submitted
- 23 Sep 2026
- Last updated
- 15 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared with external researchers because the study involves sensitive patient-level clinical information and is subject to institutional data protection and confidentiality requirements. Study data will be securely stored and accessible only to authorized study personnel. Aggregated, de-identified study findings will be disseminated through peer-reviewed scientific publications. Any future change to the IPD sharing plan will be subject to applicable ethical and institutional approvals.
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Single-Center Prospective External Validation Study of an Early Prediction Model for Adverse Postoperative Pain Trajectories After Orthopedic Surgery
- ClinicalTrials.gov ID
- NCT07846878
- Acronym / sponsor ID
- CQMUFAH-PT-EXT-2026-01
- Conditions
- Postoperative Pain
- Keywords
- Postoperative Pain, Pain Trajectory, Orthopedic Surgery, Prediction Model, External Validation, Prospective Cohort, Clinical Prediction Model
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- First Affiliated Hospital of Chongqing Medical UniversityUniversity, hospital or other
- Study start
- 7 Oct 2026 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 29 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective observational study will externally validate a previously developed and locked prediction model for identifying adult patients at risk of adverse postoperative pain trajectories after elective orthopedic surgery. Approximately 400 patients will be consecutively recruited at the First Affiliated Hospital of Chongqing Medical University.
Postoperative pain will be assessed during the first 48 hours after surgery using the 0-10 Numeric Rating Scale. Pain scores will be organized into eight consecutive 6-hour time windows to determine each participant's postoperative pain trajectory according to prespecified rules. Clinical information available at the predefined prediction time point will be entered into the locked prediction model to calculate each participant's predicted probability of an adverse pain trajectory.
The study will evaluate the model's discrimination, calibration, overall prediction performance, and potential clinical utility. The model will not be modified or retrained using data from this validation cohort. Individual prediction results will not be provided to patients or treating clinicians and will not be used to guide treatment during the study.
Detailed description
This is a single-center, prospective, observational external validation study of an early prediction model for adverse postoperative pain trajectories in adult patients undergoing elective orthopedic surgery at the First Affiliated Hospital of Chongqing Medical University.
Eligible participants will receive routine perioperative care. The study will not assign any experimental treatment or alter the participants' surgical, anesthetic, analgesic, nursing, or rehabilitation management. Study personnel will collect prespecified clinical variables from patient interviews, electronic medical records, anesthesia information systems, nursing records, and standardized postoperative pain assessments.
The end of surgery will be defined as postoperative hour 0. Postoperative pain intensity will be assessed using the 0-10 Numeric Rating Scale during the first 48 hours after surgery. This period will be divided into eight consecutive 6-hour windows: 0-6, 6-12, 12-18, 18-24, 24-30, 30-36, 36-42, and 42-48 hours. When more than one valid pain score is available within a time window, the median value will be used for the primary analysis.
Before enrollment of the first participant, the prediction model, prediction time point, predictor definitions, variable coding, data-processing procedures, missing-data handling rules, model structure, model parameters and hyperparameters, and outcome classification rules will be locked. Data from the external validation cohort will not be used to reselect predictors, retune hyperparameters, redefine cutoffs, or otherwise modify the original model.
After completion of the 48-hour observation period and data verification, each participant's probability of developing an adverse postoperative pain trajectory will be calculated using the locked model. The observed postoperative pain trajectory will be determined independently according to the prespecified trajectory classification and mapping rules.
External model performance will be evaluated using the area under the receiver operating characteristic curve, Brier score, calibration curve, calibration intercept, and calibration slope. Additional analyses will include sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and decision curve analysis at prespecified risk thresholds. Exploratory analyses may describe model performance across major orthopedic surgical categories.
Model predictions will be calculated offline and will not be communicated to participants, surgeons, anesthesiologists, nurses, or other treating clinicians during the study. Prediction results will therefore not influence clinical management.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Prospective External Validation Cohort | – | Procedure: Elective Orthopedic SurgeryAdult patients undergoing elective orthopedic surgery at the First Affiliated Hospital of Chongqing Medical University will be prospectively enrolled and followed for 48 hours after surgery. Postoperative pain scores and prespecified clinical variables will be collected according to the study protocol. All participants will receive routine perioperative care, and no treatment will be assigned or modified by the study investigators. The locked prediction model will be applied offline to evaluate the risk of an adverse postoperative pain trajectory. |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients undergoing elective orthopedic surgery at the First Affiliated Hospital of Chongqing Medical University who are expected to remain hospitalized for at least 48 hours after surgery. Eligible procedures include major categories of elective orthopedic surgery, such as spinal surgery, hip or knee arthroplasty, pelvic or extremity fracture fixation, and orthopedic corrective surgery. Participants will be prospectively and consecutively screened and enrolled according to the prespecified eligibility criteria.
Key inclusion criteria (5 listed)
- Aged 18 to 90 years, regardless of sex.
- Scheduled to undergo an eligible elective orthopedic surgical procedure at the First Affiliated Hospital of Chongqing Medical University.
- Expected to remain hospitalized for at least 48 hours after surgery.
- Conscious before surgery, with sufficient understanding and communication ability to understand and complete the 0-10 Numeric Rating Scale for pain.
- Able and willing to provide written informed consent before any study-specific data collection.
Key exclusion criteria (7 listed)
- Younger than 18 years or older than 90 years.
- Emergency surgery, unplanned surgery, or a surgical procedure outside the prespecified orthopedic surgical scope of the study.
- Unable to reliably understand the study or complete the Numeric Rating Scale because of impaired consciousness, severe cognitive impairment, psychiatric disorder, persistent deep sedation, mechanical ventilation, severe hearing impairment, language or communication difficulties, or similar conditions.
- Lacks full capacity to provide valid informed consent.
- Concurrent participation in another clinical study that may affect pain assessment, analgesic treatment, or study outcomes.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Elective Orthopedic SurgeryParticipants will undergo elective orthopedic surgery as part of routine clinical care. The surgical procedure, anesthetic management, postoperative analgesia, nursing care, and rehabilitation plan will be determined by the treating clinical team according to standard practice. The study investigators will not assign, modify, or influence these treatments. The study will prospectively collect prespecified perioperative variables and postoperative pain assessments for external validation of a locked prediction model. | Procedure or surgery | Prospective External Validation Cohort |
Primary outcome
Proportion of Participants With an Adverse Postoperative Pain Trajectory
Time frame: From the end of surgery through 48 hours postoperatively
Participants will be classified as having an adverse or non-adverse postoperative pain trajectory based on pain scores collected during the first 48 hours after surgery and the prespecified, locked trajectory classification and mapping rules. The number and percentage of participants classified as having an adverse postoperative pain trajectory will be reported.
8 secondary outcomes
Area Under the Receiver Operating Characteristic Curve (AUC)
Time frame: Through 48 hours postoperatively
Brier Score
Time frame: Through 48 hours postoperatively
Calibration Intercept
Time frame: Through 48 hours postoperatively
Calibration Slope
Time frame: Through 48 hours postoperatively
Calibration Curve
Time frame: Through 48 hours postoperatively
Classification Performance at the Prespecified Risk Threshold
Time frame: Through 48 hours postoperatively
Decision Curve Analysis
Time frame: Through 48 hours postoperatively
Distribution and Characteristics of Postoperative Pain Trajectory Classes
Time frame: From the end of surgery through 48 hours postoperatively
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be shared with external researchers because the study involves sensitive patient-level clinical information and is subject to institutional data protection and confidentiality requirements. Study data will be securely stored and accessible only to authorized study personnel. Aggregated, de-identified study findings will be disseminated through peer-reviewed scientific publications. Any future change to the IPD sharing plan will be subject to applicable ethical and institutional approvals.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Postoperative Pain, run by First Affiliated Hospital of Chongqing Medical University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lihua Peng (+86 15823443968, plhcqmu@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of Participants With an Adverse Postoperative Pain Trajectory (time frame: From the end of surgery through 48 hours postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.