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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Cultural Influence of Postoperative Pain
Scientific title
A prospective cohort comparing post-operative opioid requirement and other pain related behaviours and effects after major surgery in two Chinese populations from Hong Kong and Mainland China
Secondary ID [1] 283506 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Post operative pain 290305 0
Post operative opioid requirements
290424 0
Beliefs and attitudes of patients and carers in relation to post operative analgesia
290425 0
Condition category
Condition code
Surgery 290695 290695 0 0
Other surgery
Anaesthesiology 292332 292332 0 0

Study type
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Observational cohort study of pain perception and opioid requirements post major abdominal surgery in chinese adults that are culturally different.
Observations will occur preoperatively and then twice daily for 3 days postoperatively.
Intervention code [1] 288212 0
Not applicable
Comparator / control treatment
Comparison of two groups; One group of patient from mainland china which is traditional chinese society, the other from Hong Kong which is heavily westernised.
Both groups having major abdominal surgery with standardised postoperative management.
Standardised postoperative analgesia includes 3 days of morphine IV via patient controlled analgesia. Rescue analgesia includes paracetamol as first line, Non-steroidal anti-inflammatory as second line.
Control group

Primary outcome [1] 290811 0
comparison of opioid requirement after major abdominal surgery between chinese patients living in two distinct cultures
Timepoint [1] 290811 0
Cumulative opioid requirements measured over first 3 days after surgery
Primary outcome [2] 290812 0
Compare beliefs and attitudes and anxiety in relation to post operative analgesia among chinese patients in two different cultures.
Timepoint [2] 290812 0
Prior to surgery patients will be surveyed with a questionaire 'beliefs and attitudes regarding pain management'.
Prior to surgery patients will complete the Hospital Anxiety and depression (HAD) to evaluate pre-existing levels of anxiety and depression
Primary outcome [3] 290813 0
Compare the threshold pain score betweeen that that is associated with request for further analgesai or leading to pain related interference with daily activities.
Timepoint [3] 290813 0
Using a numerical rating scale pain score will be measured at rest, with coughing, and upon waking from surgery. Patients will be visited at least twice daily for 3 days after surgery. During the visit, patient will be asked if they will consider their current level of pain tolerable, and if they wish to receive further analgesia. Patient satisfaction with analgesia will be ranked as 1 = very satisfied, 2 = somewhat satisfied, 3 = unsatisfied, 4 = unsure. Pain-related interference with: physical activity (walking, movement); coughing and deep breathing, sleep, and mood since last visit using the numeric rating scale of 0-10, where 0 = no interference and 10 = worst interference.
Secondary outcome [1] 305348 0
Nursing staff will also be surveyed on their beliefs and attitudes regarding pain management preoperatively.
Timepoint [1] 305348 0
Preoperatively, the nurse will surveyed and respond by saying whether they strongly disagree, disagree a little, have neutral feelings, agree a little or strongly agree:
(1) “I prefer to give my patient less opioid because of addiction”
(2) “My patient should expect to have severe pain after surgery”
(3) “My patient should control their own analgesia therapy”.

We will also ask the carers about their expectations regarding analgesic regimen for their patients:
“The analgesia I expect that my patient will need is: no analgesics / weak analgesics / strong analgesics / combinations of weak and strong analgesics”,
Secondary outcome [2] 305351 0
Opioid side effects
Timepoint [2] 305351 0
opioid-related symptom distress scale (ORSDS) recorded daily for 3 days
Secondary outcome [3] 305352 0
quantify the biologic equivalence of patients recruited from the two hospitals (same race) we plan to determine the single nucleotide polymorphism (SNP) of opioid receptor, mu-1 (OPRM1).
Timepoint [3] 305352 0
Genomic deoxyribonucleic acid (DNA) will be extracted from 5 ml venous blood samples collected before surgery using QIAamp DNA mini kit 250 (Qiagen, Valencia, CA). Genotyping will be performed using Taqman SNP assays

Key inclusion criteria
Patients are eligible for the study if
1.18 and 80 years
2.undergoing major abdominal surgery requiring a wound incision > 10 cm in length.
3. All patients should have strong Chinese features and lived in their respective cities (Hong Kong or Hangzhou) for most of their lives.
Minimum age
18 Years
Maximum age
80 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients are excluded if they:
1. do not agree to receive patient controlled analgesia (PCA) with morphine for at least three days after surgery
2. do not demonstrate adequate understanding on the principles involving the use of PCA during the preoperative visit.
3. Allergy to morphine, paracetamol or non-steroidal anti-inflammatory drugs.
4. Patients with pre-existing severe renal and liver disease, 5. chronic pain for > 3 months in the 6 months leading to surgery or who require opioid therapy in the preceding 2 weeks prior to surgery

Study design
Defined population
Statistical methods / analysis
Data will be expressed as means (+/- standard deviation), median (interquartile range) or numbers, as appropriate. Continuous data (opioid consumption) will be compared between groups using unpaired t test. Categorical and ordinal data (brief and attitude statements) will be analysed using Fisher’s exact test and Mann-Whitney test, respectively. The difference in pain scores between patients from mainland hospital (SSRSH) and those in Hong Kong (PWH) will be analysed using a generalized linear model for repeated measures. Covariates will include patient characteristics (anxiety, education level), operative details, SNP, briefs and attitudes, and pain thresholds. Multiple comparisons will be adjusted by Dunn-Sidak procedure.

We will calculate the threshold significant pain by comparing NRS pain scores in patients that request for further analgesia or patients who reported pain-related interference with daily activities using the largest F-value approach. The threshold pain scores will be compared between groups using unpaired t-test. A p value < 0.05 is considered significant.
Analysis of opioid requirement of Hong Kong patients from a recently published study from the same principal investigator revealed a mean opioid requirement (intravenous morhpine equivalents) in the first 24 hours after surgery to be 46.5 mg with a standard deviation of 23.7. Assuming 55 type 1 error and 20% type two error 70 participants were required in each population to show a significant difference. We have added 50 participants to each group to enable closer analysis of secondary end points

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 5567 0
State/province [1] 5567 0
Country [2] 5568 0
Hong Kong
State/province [2] 5568 0

Funding & Sponsors
Funding source category [1] 288208 0
Name [1] 288208 0
Australian and New Zealand College of Anaesthetists
Address [1] 288208 0
630 St Kilda Rd
Victoria 3004
Country [1] 288208 0
Primary sponsor type
Dr Alex Konstantatos
The Alfred Hospital
C/O Department of Anaesthesia and Pain medicine
PO Box 315
Prahran, Victoria 3181
Secondary sponsor category [1] 286932 0
Name [1] 286932 0
Dr Matthew Chan
Address [1] 286932 0
Prince of Wales Hospital
Department of Anaesthesia and Intensive Care
New Territories
Hong Kong Special
Country [1] 286932 0
Hong Kong

Ethics approval
Ethics application status
Ethics committee name [1] 290117 0
Sir Run Run Shaw Ethics Committee
Ethics committee address [1] 290117 0
Ethics committee country [1] 290117 0
Date submitted for ethics approval [1] 290117 0
Approval date [1] 290117 0
Ethics approval number [1] 290117 0

Brief summary
We hypothesize that cultural differences within the same race (Chinese) will lead to changes in opioid requirement after major abdominal surgery. This will be reflected by the differences in briefs and attitudes towards postoperative pain between patients living in the two cities.
Trial website
Trial related presentations / publications
Public notes
Prince of Wales Hospital, Shatin, New Territories, Hong Kong Sir Run Run Shaw Hospital, Hangzhou, Zhejiang

Principal investigator
Name 43658 0
Dr Alex Konstantatos
Address 43658 0
Dept of Anaesthesia and Perioperative Medicine
Alfred Hospital
PO Box 315
Victoria 3181
Country 43658 0
Phone 43658 0
Fax 43658 0
Email 43658 0
Contact person for public queries
Name 43659 0
Dr Alex Konstantatos
Address 43659 0
Dept of Anaesthesia and Perioperative Medicine
Alfred Hospital
PO Box 315
Victoria 3181
Country 43659 0
Phone 43659 0
Fax 43659 0
Email 43659 0
Contact person for scientific queries
Name 43660 0
Dr Alex Konstantatos
Address 43660 0
Dept of Anaesthesia and Perioperative Medicine
Alfred Hospital
PO Box 315
Victoria 3181
Country 43660 0
Phone 43660 0
Fax 43660 0
Email 43660 0

No information has been provided regarding IPD availability
Summary results
No Results