Prospective Observational Study on Postoperative Pain and Side Effect


PAIN OUT is a multi-national, non-interventional registry and benchmark project, assessing and analysing clinical and patient-reported outcome data of postoperative pain.

Full Title of Study: “Improvement in Postoperative Pain Outcome”

Study Type

  • Study Type: Observational [Patient Registry]
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: December 31, 2020

Detailed Description

PAIN OUT offers a large registry as well as a system for benchmarking and feedback of outcome quality and decision support in acute pain conditions. It collects demographic, clinical and outcome data, using a validated assessment tool available in multiple languages.

The registry part of the project aims at performing population-based research. Furthermore, its infrastructure allows for the conduct of prospective studies comparing the effectiveness of processes of care.

The benchmark part of the project provides the medical community with a unique, user-friendly system to improve treatment of patients with postoperative pain. A web-based information system, featuring two main functions, was developed:

a feedback and benchmarking system which provides participating sites with continuously updating data and analyses about the quality of care they provide compared to other institutions and allows identification of best clinical practice.

a knowledge library which provides clinicians with easily accessible and regularly updated summaries of evidence-based recommendations tailored to specific post-operative situations.

From 2016 on, sub-projects in Mexico, China and several European countries have started. This programs take place over a period of two years during which collaborators carry out a Quality Improvement project in their hospital using methodology provided by PAIN OUT. This includes collection of baseline data in a first phase, analysis of findings according to a protocol provided by PAIN OUT, review of findings and developement of improvement measures, implementation of the improvements and assessment of outcomes after a second phase of data collection.


  • Behavioral: postoperative pain intensity
    • estimate the postoperative pain intensity by using a scaling system via questionnaire
  • Behavioral: preoperative pain frequency
    • estimate the preoperative pain intensity by using a scaling system via questionnaire
  • Behavioral: Side effect
    • investigate the presence of any side effect

Arms, Groups and Cohorts

  • post-surgical patients
    • post-surgical patients > 18 years
  • pediatric patients post-op day 1
    • pediatric patients > 4 years on post-op day 1 (sub-project QUIPSI – PAIN OUTinfant)

Clinical Trial Outcome Measures

Primary Measures

  • Questionnaire on postoperative pain treatment
    • Time Frame: first postoperative day

Secondary Measures

  • Questionnaire on patients’ perception of pain treatment outcome
    • Time Frame: first postoperative day
    • questions related to worst pain since surgery, least pain since surgery, time in pain, interference of pain with activities, affect of pain on mood and emotions, pain therapy side effects, pain relief, wish for more treatment, information on treatment, participation in decisions, satisfaction, non-medical treatment methods and pre-hospital existence of pain.

Participating in This Clinical Trial

Inclusion Criteria

  • >= 18 years or >= 4 years for sub-project QUIPSI/PAIN OUTinfant
  • patient is post-op day 1
  • patient is at least 6 hours on the ward
  • patient has given consent

Exclusion Criteria

  • patient cannot communicate
  • patient is cognitively impaired
  • patient is asleep
  • patient is too ill
  • patient does not want to fill in the questionnaire

Gender Eligibility: All

Minimum Age: 4 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • The University of Hong Kong
  • Provider of Information About this Clinical Study
    • Principal Investigator: Dr. Chi-Wai Cheung, Professor Cheung Chi Wai – The University of Hong Kong
  • Overall Official(s)
    • Winfried Meissner, Study Director, Jena University Hospital
    • Chi Wai Cheung, MD, Principal Investigator, The University of Hong Kong
  • Overall Contact(s)
    • Chi Wai Cheung, 22553303,

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