Chronic PainTAHPNCT02025153
Comprehensive Pain Programme to Determine Mechanism of Transition of Acute to Chronic Postsurgical Pain
A study testing pain testing in people with Chronic Pain and Anaesthesia, run by KK Women's and Children's Hospital at 1 site in Singapore.
Trial summary
To determine whether central sensitization is a mechanism of CPSP (chronic postsurgical pain) in women who will develop CPSP compared to women with no CPSP after hysterectomy. This mechanism is illustrated by a higher pain score in experimental pain models such as tonic heat stimulation, increased evoked mechanical… Read more about this study
- Who is it for?
- Ages 21 to 70 years, women only
- Conditions the study is for
- Chronic Pain, Anaesthesia, Genetics Predisposition
- What is being tested?
- pain testing
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 216 participants
- Where
- 1 siteSingapore
- Study dates
- Sep 2013to Jun 2017
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 21 to 70 years
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Anthropometric profile within the following range: age 21-70 yr, American Society of Anesthesiology status I and II women
- Benign condition such as fibroids or adenomyosis
- Abdominal or laparoscopic hysterectomy
Who cannot join
- Vaginal hysterectomy
- being pelvic pain
- Failure to adequately determine tonic heat stimulation and mechanical temporal summation
- History of drug dependence or recreational drug use
- Allergy to any study drugs
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Comprehensive Pain Programme to Determine Mechanism of Transition of Acute to Chronic Postsurgical Pain- Functional Brain Imaging, Quantitative Sensory Testing, Psychological and Genetic Screening: Prospective Cohort Study
To determine whether central sensitization is a mechanism of CPSP (chronic postsurgical pain) in women who will develop CPSP compared to women with no CPSP after hysterectomy. This mechanism is illustrated by a higher pain score in experimental pain models such as tonic heat stimulation, increased evoked mechanical temporal summation and increased wound hyperalgesia.
Read the detailed description
Chronic pain affects 9% of Singapore population resulting in major socioeconomic burden. Chronic postsurgical pain (CPSP) that persists for over 3 months could be related to nerve injury making this a strategic model to study the transition of acute to chronic pain. CPSP occurs in up to 50% after surgery and up to 32% after hysterectomy. Over 600000 hysterectomies were performed in the US in 2003 making CPSP a significant problem.
Investigators will perform this prospective cohort study to determine whether increased central sensitization and negative psychological experience are involved in the transition of acute to chronic pain after hysterectomy. Investigators will recruit 444 women undergoing hysterectomy and employ validated physical pain testing including tonic heat stimulation, mechanical temporal summation and wound hyperalgesia which had been shown to be related to central sensitization. Pain catastrophizing (negative thoughts of pain) and state trait anxiety scoring will be assessed for the impact of negative cognitive-affective experience on CPSP. A phone survey will be performed at 4 months to determine the primary outcome of CPSP. Arterial spin labeling will be used to delineate cerebral blood flow using arterial spin labeling, functional connectivity and structural connectivity to evaluate insula-anterior cingulate cortex differences in 30 women with CPSP compared to 30 women without CPSP.
In addition to evaluating whether central sensitization, negative psychological experience and activation of brain regions are different in women with CPSP after hysterectomy, the results of this study will elucidate potential mechanisms of CPSP development that will guide in future studies on potential novel therapeutic targets.
- Conditions
- Chronic Pain, Anaesthesia, Genetics Predisposition
- Being tested
- pain testing
- Medical subject headings
- Chronic Pain, Genetic Predisposition to Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
pain testingOther
physical testing, psychological testing, genetics testing and functional brain imaging
| Study group | Role | What they receive |
|---|---|---|
| Cohort | Other | pain testing. All 444 subjects enrolled in the study. Subjects will receive preoperative physical (tonic heat stimulation, mechanical temporal summation and wound hyperalgesia), psychological (State Trait Anxiety Inventory, Pain Catastrophizing Scale), and genetics test; postoperative pain score assessment at 24, 48 hours; postoperative wound hyperalgesia in open abdominal hysterectomy at 72 hours; and phone survey for CPSP at 4 months. Receives: Other: pain testing |
| Chronic Post-surgical Pain | Other | pain testing. physical testing, psychological testing, genetics testing and functional brain imaging Receives: Other: pain testing |
| No Chronic Post-surgical Pain | Other | pain testing. physical testing, psychological testing, genetics testing and functional brain imaging Receives: Other: pain testing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Chronic postsurgical pain (CPSP) after hysterectomy at 4 months on phone survey
This is defined as pelvic pain (lower abdominal or perineal pain) in the last week that affected daily living during the 4 months phone survey.
Measured: 4 months post hysterectomy
Chronic postsurgical pain (CPSP) after hysterectomy at 6 months on phone survey
This is defined as pelvic pain (lower abdominal or perineal pain) in the last week that affected daily living during the 6 months phone survey.
Measured: 6 months post hysterectomy
Secondary outcomes (3)
Pain Catastrophizing Scale
Assessment will be done via Pain Catastrophizing Scale (PCS) questionnaire. Pain catastrophizing refers to the negative thought processes patients have when they are exposed to pain or painful experiences. The PCS is a 13-item scale, with each item rated on a 5-point scale: 0 (Not at all) to 4 (all the time). It is broken into three subscales being magnification (0-12), rumination (0-16), and helplessness (0-24). A higher value in each subscale indicates a higher tendency to that subscale (worse outcome).
Measured: Upon recruitment till 6 months post hysterectomy
Mechanical Temporal Summation as measured by von Frey filament
Assessment will be done via Mechanical Temporal Summation assessment before surgery. A 180 gram von Frey filament is applied on the subject's forearm. Patient will then be asked to rate the pinprick pain score on a verbal rating scale, 0-100. Following this, 10 consecutive touches at random locations are applied with a 1 second interstimulus interval and within a 1 cm diameter circle. The patient will then be asked to rate the 10th pain score (0-100). The Mechanical Temporal Summation Score is obtained by the difference between the 11th pain score and the 1st pain score. If the score is greater than zero, the patient is implied to have presence of Mechanical Temporal Summation.
Measured: 1 day (before surgery)
State Trait Anxiety Inventory
Assessment will be done via State Trait Anxiety Inventory (STAI) before surgery. STAI is a self-reported tool for assessing anxiety via two sub-scales, each containing 20 items on: i) the state anxiety sub-scale measuring transient anxiety at the time of scoring; and ii) trait anxiety measures dispositional anxiety or anxiety in general.
Each item in STAI is rated on a 4-point scale: 1 (Not at all) to 4 (very much so). A higher value in each subscale indicates a higher tendency to that subscale (worse outcome on having greater state anxiety or trait anxiety).
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2013 (estimated)
- Study startSep 2013
- Primary completionJun 2017
- Study completionJun 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic PainStudies of the same condition, open and under way.
- More trials run by KK Women's and Children's HospitalThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 216 participants (actual)
Sponsor and investigators
- Lead sponsor
- KK Women's and Children's Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Sng Ban Leong, KK Women's and Children's Hospital
- Investigators
- Ban Leong Sng, Dr, Principal investigator, KK Women's and Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02025153
- Sponsor's protocol ID
- 2013/512/D
- Acronym
- TAHP
- Status last verified
- Aug 2026
- First submitted
- 29 Dec 2013
- Last updated
- 6 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comprehensive Pain Programme to Determine Mechanism of Transition of Acute to Chronic Postsurgical Pain- Functional Brain Imaging, Quantitative Sensory Testing, Psychological and Genetic Screening: Prospective Cohort Study
- ClinicalTrials.gov ID
- NCT02025153
- Acronym / sponsor ID
- TAHP / 2013/512/D
- Conditions
- Chronic Pain, Anaesthesia, Genetics Predisposition
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 216 participants (actual)
- Lead sponsor
- KK Women's and Children's HospitalOther government
- Study start
- Sep 2013 (actual)
- Primary completion
- Jun 2017 (actual)
- Study completion
- Jun 2017 (actual)
- First posted
- 31 Dec 2013 (estimated)
- 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.
To determine whether central sensitization is a mechanism of CPSP (chronic postsurgical pain) in women who will develop CPSP compared to women with no CPSP after hysterectomy. This mechanism is illustrated by a higher pain score in experimental pain models such as tonic heat stimulation, increased evoked mechanical temporal summation and increased wound hyperalgesia.
Detailed description
Chronic pain affects 9% of Singapore population resulting in major socioeconomic burden. Chronic postsurgical pain (CPSP) that persists for over 3 months could be related to nerve injury making this a strategic model to study the transition of acute to chronic pain. CPSP occurs in up to 50% after surgery and up to 32% after hysterectomy. Over 600000 hysterectomies were performed in the US in 2003 making CPSP a significant problem.
Investigators will perform this prospective cohort study to determine whether increased central sensitization and negative psychological experience are involved in the transition of acute to chronic pain after hysterectomy. Investigators will recruit 444 women undergoing hysterectomy and employ validated physical pain testing including tonic heat stimulation, mechanical temporal summation and wound hyperalgesia which had been shown to be related to central sensitization. Pain catastrophizing (negative thoughts of pain) and state trait anxiety scoring will be assessed for the impact of negative cognitive-affective experience on CPSP. A phone survey will be performed at 4 months to determine the primary outcome of CPSP. Arterial spin labeling will be used to delineate cerebral blood flow using arterial spin labeling, functional connectivity and structural connectivity to evaluate insula-anterior cingulate cortex differences in 30 women with CPSP compared to 30 women without CPSP.
In addition to evaluating whether central sensitization, negative psychological experience and activation of brain regions are different in women with CPSP after hysterectomy, the results of this study will elucidate potential mechanisms of CPSP development that will guide in future studies on potential novel therapeutic targets.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Cohort | Other | Other: pain testingpain testing. All 444 subjects enrolled in the study. Subjects will receive preoperative physical (tonic heat stimulation, mechanical temporal summation and wound hyperalgesia), psychological (State Trait Anxiety Inventory, Pain Catastrophizing Scale), and genetics test; postoperative pain score assessment at 24, 48 hours; postoperative wound hyperalgesia in open abdominal hysterectomy at 72 hours; and phone survey for CPSP at 4 months. |
| Chronic Post-surgical Pain | Other | Other: pain testingpain testing. physical testing, psychological testing, genetics testing and functional brain imaging |
| No Chronic Post-surgical Pain | Other | Other: pain testingpain testing. physical testing, psychological testing, genetics testing and functional brain imaging |
Who may qualify
- Ages
- 21 to 70 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Anthropometric profile within the following range: age 21-70 yr, American Society of Anesthesiology status I and II women
- Benign condition such as fibroids or adenomyosis
- Abdominal or laparoscopic hysterectomy
Key exclusion criteria (5 listed)
- Vaginal hysterectomy
- being pelvic pain
- Failure to adequately determine tonic heat stimulation and mechanical temporal summation
- History of drug dependence or recreational drug use
- Allergy to any study drugs
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 |
|---|---|---|
| pain testingphysical testing, psychological testing, genetics testing and functional brain imaging | Other | Chronic Post-surgical Pain, Cohort, No Chronic Post-surgical Pain |
Primary outcome
Chronic postsurgical pain (CPSP) after hysterectomy at 4 months on phone survey
Time frame: 4 months post hysterectomy
This is defined as pelvic pain (lower abdominal or perineal pain) in the last week that affected daily living during the 4 months phone survey.
Chronic postsurgical pain (CPSP) after hysterectomy at 6 months on phone survey
Time frame: 6 months post hysterectomy
This is defined as pelvic pain (lower abdominal or perineal pain) in the last week that affected daily living during the 6 months phone survey.
3 secondary outcomes
Pain Catastrophizing Scale
Time frame: Upon recruitment till 6 months post hysterectomy
Mechanical Temporal Summation as measured by von Frey filament
Time frame: 1 day (before surgery)
State Trait Anxiety Inventory
Time frame: 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Aug 2026.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Ban Leong Sng, Dr principal investigator
KK Women's and Children's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing pain testing in people with Chronic Pain and Anaesthesia, run by KK Women's and Children's Hospital at 1 site in Singapore.
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 3 inclusion and 5 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: finished, as of the sponsor's last update on 6 Aug 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 Singapore. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Chronic postsurgical pain (CPSP) after hysterectomy at 4 months on phone survey (time frame: 4 months post hysterectomy). The study lists 2 primary outcomes in all. 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 6 Aug 2026.