Postoperative Pain
Conditions
Brief summary
The purpose of this study is to determine the effect of intrathecal oxytocin on speed of reduction in pain for the first 60 days after hip surgery.
Detailed description
This is a single-center, NIH funded clinical study at Wake Forest Baptist Medical Center. The investigators anticipate that intrathecal oxytocin will speed recovery from pain after major surgery (hip arthroplasty). For this study, the investigators will use a randomized, controlled and blinded study of intrathecal oxytocin in patients scheduled for hip arthroplasty, with primary outcome being the slope of change in pain over the first 60 days following surgery, using growth curve modeling and a ln(time) function.
Interventions
DRUGOxytocin
spinal injection of oxytocin
DRUGPlacebo
spinal injection of placebo
Sponsors
Wake Forest University Health Sciences
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Scheduled for unilateral, primary total hip replacement * American Society of Anesthesiologists physical status 1-3
Exclusion criteria
* Pregnancy * Currently Workman's Comp litigation related to hip replacement * Taking greater than 100 milligrams of morphine (or equivalent) * Suffering from a psychotic disorder or a recent psychiatric hospitalization
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Intercept | The first day after hospital discharge | Daily pain intensity report for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. The daily pain intensity was the WORST pain (not the average pain) in the past 24 hr on a scale where 0 is no pain and 10 is worst imaginable pain. Values represent an intercept of modeled worst daily pain on the first day after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model. |
| Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Slope | Postoperative Day 1 through Postoperative Day 60 | Daily pain intensity report for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. The daily pain intensity was the WORST pain in the past 24 hr on a scale where 0 is no pain and 10 is worst imaginable pain. Slope is defined as change in pain . Values represent the slope of modeled worst daily pain (0-10 scale as described above) divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Intercept | Modeled WHODAS 2.0 one week after hospital discharge | Weekly World Health Organization Disability Assessment Score 2.0 (WHODAS 2.0) value for each subject was fitted using growth curve model with parameters of intercept (modeled initial score) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Scale is 12 to 36 with higher scores meaning greater disability. Values represent an intercept of modeled WHODAS 2.0 score one week after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model. |
| Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Slope | Postoperative Day 7 through Postoperative Day 56 | Weekly World Health Organization Disability Assessment Score 2.0 (WHODAS 2.0) value for each subject was fitted using growth curve model with parameters of intercept (modeled initial score) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Scale is 12 to 36 with higher scores meaning greater disability. Values represent the slope of WHODAS 2.0 score divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model. |
| Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Intercept | The first day after hospital discharge | Daily probability of taking opioids for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Values represent an intercept of modeled probability of taking opioid, on a 0-1 probability scale, on the first day after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with standard deviation based on the model. |
| Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Intercept | The first day after hospital discharge | Daily steps for each subject were fitted using growth curve model with parameters of intercept (modeled initial steps) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. This is considered as the modeled change in activity listed in the protocol. Values represent an intercept of modeled daily steps on the first day after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model. |
| Iowa Gambling Task | Preoperative, 2 months after surgery | This is a computer based card game which assesses risk taking and impulsivity in which a score of -100 to 100 is calculated. Lower numbers indicate greater impulsiivity |
| Wisconsin Card Sort Task | Preoperative, 2 months after surgery | This is a physical card sorting game which measures attention to shifts in implicit rules as the game progresses. Perseverative errors are the number of sequential errors when rules of the game shift and reflect dysfunction of attention. This score ranges from 0 to 64 with larger numbers reflecting more dysfunction of attention. |
| Tampa Scale of Kinesiophobia | Preoperative, 2 months after surgery | This 17-question scale assesses the degree of fear of pain from joint movement and is commonly used in orthopedic injury or surgery studies. The scale ranges from 17 to 68 with 17 indicating no fear of movement and 68 indicating severe fear. |
| Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Slope | Postoperative Day 1 through Postoperative Day 60 | Daily probability of taking opioids for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Values represent the slope of daily probability of taking opioids divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model |
| Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Slope | Postoperative Day 1 through Postoperative Day 60 | Daily steps for each subject were fitted using growth curve model with parameters of intercept (modeled initial steps) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. This is considered as the modeled change in activity listed in the protocol. Values represent the slope of daily steps divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model. |
Countries
United States
Participant flow
Recruitment details
Enrollment occurred from January 12, 2017 to August 3, 2020 at the Orthopeadic Clinics of Atrium Wake Forest Baptist and Davie County facilities.
Pre-assignment details
Enrollment occurred greater or equal to 2 weeks prior to surgery. A total of 28 individuals were excluded prior to assignment to groups during the period prior to surgery because of withdrawal of consent (n=25) or cancellation of the planned surgery (n=3).
Participants by arm
| Arm | Count |
|---|---|
| Oxytocin Oxytocin 100 micrograms administered intrathecally
Oxytocin: spinal injection of oxytocin | 44 |
| Placebo Placebo injection administered intrathecally
Placebos: spinal injection of placebo | 46 |
| Total | 90 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Did not receive study drug: blood pressure or heart rate instability before spinal injection | 3 | 2 |
| Overall Study | Did not receive study drug: unable to obtain study drug from formulating pharmacy | 1 | 0 |
| Overall Study | Did not receive study drug: unable to place spinal needle | 2 | 0 |
Baseline characteristics
| Characteristic | Oxytocin | Placebo | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 20 Participants | 14 Participants | 34 Participants |
| Age, Categorical Between 18 and 65 years | 24 Participants | 32 Participants | 56 Participants |
| Age, Continuous | 62 years STANDARD_DEVIATION 8.7 | 59 years STANDARD_DEVIATION 10 | 61 years STANDARD_DEVIATION 9.5 |
| Daily steps | 6440 Steps per day STANDARD_DEVIATION 4120 | 6918 Steps per day STANDARD_DEVIATION 4613 | 6672 Steps per day STANDARD_DEVIATION 4511 |
| Disability | 20.8 units on a scale STANDARD_DEVIATION 6.1 | 21.6 units on a scale STANDARD_DEVIATION 5 | 21.2 units on a scale STANDARD_DEVIATION 5.7 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 44 Participants | 46 Participants | 90 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants | 3 Participants | 7 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 40 Participants | 43 Participants | 83 Participants |
| Region of Enrollment United States | 44 participants | 46 participants | 90 participants |
| Sex: Female, Male Female | 26 Participants | 26 Participants | 52 Participants |
| Sex: Female, Male Male | 18 Participants | 20 Participants | 38 Participants |
| Worst daily pain | 5.0 units on a scale STANDARD_DEVIATION 2.9 | 5.8 units on a scale STANDARD_DEVIATION 2.3 | 5.4 units on a scale STANDARD_DEVIATION 2.7 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 44 | 0 / 46 |
| other Total, other adverse events | 0 / 44 | 0 / 46 |
| serious Total, serious adverse events | 0 / 44 | 0 / 46 |
Outcome results
Primary
Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Intercept
Daily pain intensity report for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. The daily pain intensity was the WORST pain (not the average pain) in the past 24 hr on a scale where 0 is no pain and 10 is worst imaginable pain. Values represent an intercept of modeled worst daily pain on the first day after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model.
Time frame: The first day after hospital discharge
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Intercept | 8.5 score on a scale |
| Placebo | Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Intercept | 8.6 score on a scale |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline pain, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.7595% CI: [0, 0.2]Mixed Models Analysis
Primary
Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Slope
Daily pain intensity report for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. The daily pain intensity was the WORST pain in the past 24 hr on a scale where 0 is no pain and 10 is worst imaginable pain. Slope is defined as change in pain . Values represent the slope of modeled worst daily pain (0-10 scale as described above) divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model.
Time frame: Postoperative Day 1 through Postoperative Day 60
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Slope | -1.9 Score on a scale |
| Placebo | Comparison of Adjusted Trajectory Model for Pain Between Oxytocin and Placebo--Slope | -2 Score on a scale |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline pain, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.05795% CI: [0, 0.2]Mixed Models Analysis
Secondary
Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Intercept
Daily steps for each subject were fitted using growth curve model with parameters of intercept (modeled initial steps) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. This is considered as the modeled change in activity listed in the protocol. Values represent an intercept of modeled daily steps on the first day after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model.
Time frame: The first day after hospital discharge
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Intercept | 144 Daily Steps |
| Placebo | Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Intercept | 546 Daily Steps |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline pain, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.4195% CI: [-1358, 553]Mixed Models Analysis
Secondary
Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Slope
Daily steps for each subject were fitted using growth curve model with parameters of intercept (modeled initial steps) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. This is considered as the modeled change in activity listed in the protocol. Values represent the slope of daily steps divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model.
Time frame: Postoperative Day 1 through Postoperative Day 60
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Slope | 562 Daily steps |
| Placebo | Comparison of Adjusted Trajectory Model for Daily Steps Between Oxytocin and Placebo--Slope | 218 Daily steps |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline pain, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.~The slope is the number of daily steps divided by the natural log of time in days.p-value: <0.00195% CI: [173, 515]Slope Difference
Secondary
Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Intercept
Daily probability of taking opioids for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Values represent an intercept of modeled probability of taking opioid, on a 0-1 probability scale, on the first day after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with standard deviation based on the model.
Time frame: The first day after hospital discharge
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Intercept | 0.9995 Probability of taking opioids |
| Placebo | Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Intercept | 0.9998 Probability of taking opioids |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.53795% CI: [-0.00085, 0.0015]Intercept difference: Opioid probability
Secondary
Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Slope
Daily probability of taking opioids for each subject was fitted using growth curve model with parameters of intercept (modeled initial pain) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Values represent the slope of daily probability of taking opioids divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model
Time frame: Postoperative Day 1 through Postoperative Day 60
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Slope | -0.953 Probability of taking opioids/ln(days) |
| Placebo | Comparison of Adjusted Trajectory Model for Probability of Taking Opioids Daily Between Oxytocin and Placebo--Slope | -0.787 Probability of taking opioids/ln(days) |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline pain, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.0195% CI: [-0.172, -0.16]Mixed Models Analysis
Secondary
Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Intercept
Weekly World Health Organization Disability Assessment Score 2.0 (WHODAS 2.0) value for each subject was fitted using growth curve model with parameters of intercept (modeled initial score) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Scale is 12 to 36 with higher scores meaning greater disability. Values represent an intercept of modeled WHODAS 2.0 score one week after hospital discharge across all participants, extracted from the mixed effect model. The intercept is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model.
Time frame: Modeled WHODAS 2.0 one week after hospital discharge
Population: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline World Health Organization Disability Assessment Score 2.0 value, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Intercept | 23.2 score on a scale |
| Placebo | Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Intercept | 29.1 score on a scale |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline World Health Organization Disability Assessment Score 2.0 value, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.00295% CI: [-9.5, -2.3]Mixed Models Analysis
Secondary
Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Slope
Weekly World Health Organization Disability Assessment Score 2.0 (WHODAS 2.0) value for each subject was fitted using growth curve model with parameters of intercept (modeled initial score) and slope of change in natural log of time, adjusted for prognostic predictors for oxytocin and placebo group separately. Scale is 12 to 36 with higher scores meaning greater disability. Values represent the slope of WHODAS 2.0 score divided by the natural log of time (days) across all participants, extracted from the mixed effect model. The slope is a number representative of all participants in the Arm and is an estimate with confidence limits based on the model.
Time frame: Postoperative Day 7 through Postoperative Day 56
Population: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline World Health Organization Disability Assessment Score 2.0 value, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Oxytocin | Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Slope | -7.1 Score on a scale/ln(days) |
| Placebo | Comparison of Adjusted Trajectory Model for World Health Organization Disability Assessment Score 2.0 Value Between Oxytocin and Placebo--Slope | -5.6 Score on a scale/ln(days) |
Comparison: The estimates were conducted using a linear mixed effects model contrasting differences in the oxytocin group versus placebo. In all cases, these differences are adjusted for prognostic variables including baseline pain, baseline opioid use, age, sex, baseline PROMIS depression and number of other painful conditions.p-value: 0.00195% CI: [0.6, 2.4]Mixed Models Analysis
Secondary
Iowa Gambling Task
This is a computer based card game which assesses risk taking and impulsivity in which a score of -100 to 100 is calculated. Lower numbers indicate greater impulsiivity
Time frame: Preoperative, 2 months after surgery
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxytocin | Iowa Gambling Task | Preoperative | 13 units on a scale | Standard Deviation 30 |
| Oxytocin | Iowa Gambling Task | 2 Months postoperative | 20 units on a scale | Standard Deviation 38 |
| Placebo | Iowa Gambling Task | Preoperative | 21 units on a scale | Standard Deviation 31 |
| Placebo | Iowa Gambling Task | 2 Months postoperative | 22 units on a scale | Standard Deviation 37 |
Comparison: Scores were compared statistically at baseline and 2 months between groups using a generalized linear model with time as a fixed factor.p-value: 0.55Regression, Linear
Secondary
Tampa Scale of Kinesiophobia
This 17-question scale assesses the degree of fear of pain from joint movement and is commonly used in orthopedic injury or surgery studies. The scale ranges from 17 to 68 with 17 indicating no fear of movement and 68 indicating severe fear.
Time frame: Preoperative, 2 months after surgery
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxytocin | Tampa Scale of Kinesiophobia | Preoperative | 37 units on a scale | Standard Deviation 4.8 |
| Oxytocin | Tampa Scale of Kinesiophobia | 2 month postoperative | 36 units on a scale | Standard Deviation 3.8 |
| Placebo | Tampa Scale of Kinesiophobia | Preoperative | 38 units on a scale | Standard Deviation 4.6 |
| Placebo | Tampa Scale of Kinesiophobia | 2 month postoperative | 36 units on a scale | Standard Deviation 5.6 |
Comparison: Groups were compared between preoperative and 2 month postoperative sessions using linear regression with time as a fixed factor.p-value: 0.38Regression, Linear
Secondary
Wisconsin Card Sort Task
This is a physical card sorting game which measures attention to shifts in implicit rules as the game progresses. Perseverative errors are the number of sequential errors when rules of the game shift and reflect dysfunction of attention. This score ranges from 0 to 64 with larger numbers reflecting more dysfunction of attention.
Time frame: Preoperative, 2 months after surgery
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxytocin | Wisconsin Card Sort Task | Preoperative | 6.3 units on a scale | Standard Deviation 4.2 |
| Oxytocin | Wisconsin Card Sort Task | 2 Months postoperatively | 8.4 units on a scale | Standard Deviation 4.2 |
| Placebo | Wisconsin Card Sort Task | Preoperative | 6.8 units on a scale | Standard Deviation 4.9 |
| Placebo | Wisconsin Card Sort Task | 2 Months postoperatively | 7.7 units on a scale | Standard Deviation 6.7 |
Comparison: Groups were compared over time from baseline to 2 months using a generalized linear model with time as a fixed factor.p-value: 0.46Regression, Linear