Efficacy And Safety Of Pregabalin For Pain Following Total Knee Replacement

Total cumulative dose calculated as mg of oral morphine equivalent and included opioids given by any route (patient controlled analgesia [PCA] pump, parenteral bolus or oral). Results for daily total not including pregabalin (not an opioid). Statistical model included main effect of treatment group and center. 1 subject at 144 h, 300 mg=non-missing data. Due to small sample size (N=1, 300 mg; N=5, other groups) and large opioid consumption for another subject in same center, least squares mean (300 mg, 144 h) is negative.

The amount of opioid use was calculated as mg of oral morphine equivalent and included opioids administered by any route (PCA pump, parenteral bolus, or oral). Weeks 2, 4, and 6 total daily doses were calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period. This outcome measure does not include pregabalin as it is not an opioid.

Total dose for in-hospital visits was the total dose for the day.

Weeks 2, 4, and 6 total daily doses were calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

Weeks 2, 4, and 6 total daily doses were calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

Weeks 2, 4, and 6 total daily doses were calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

Week 4 total daily dose was calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

Week 4 total daily dose was calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

Week 6 total daily dose was calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

Week 6 total daily dose was calculated by adding the cumulative doses during the 2 week period prior to the visit and dividing them by the number of days in the period.

The OR-SDS was used to assess subject-reported levels of frequency concerning 10 symptoms known to be associated with opioid medication usage: fatigue, drowsiness, inability to concentrate, nausea, dizziness, constipation, itching, difficulty with urination, confusion, and retching/vomiting. Symptom frequency was rated as: 1=rarely, 2=occasionally, 3=frequently, or 4=almost constantly. The average score for each symptom was calculated by taking the mean of patient-reported score. Total possible frequency score: 0 (less frequent) to 4 (more frequent).

The OR-SDS was used to assess subject-reported levels of severity concerning 10 symptoms known to be associated with opioid medication usage: fatigue, drowsiness, inability to concentrate, nausea, dizziness, constipation, itching, difficulty with urination, confusion, and retching/vomiting. Symptom severity was rated as: 1=slight, 2=moderate, 3=severe, or 4=very severe. The average score for each symptom was calculated by taking the mean of patient-reported score. Total possible severity score: 0 (less severe) to 4 (more severe).

The OR-SDS was used to assess subject-reported level of degree of bother concerning 10 symptoms known to be associated with opioid medication usage: fatigue, drowsiness, inability to concentrate, nausea, dizziness, constipation, itching, difficulty with urination, confusion, and retching/vomiting. Symptom degree of bother was rated as: 1=not at all, 2=a little bit, 3=somewhat, 4=quite a bit, or 5=very much. Average score for each symptom was calculated by taking the mean of patient-reported score. Total possible degree of bother score: 0 (less degree of bother) to 5 (greater degree of bother).

The OR-SDS assessed subject-reported levels of frequency, severity and degree of bother for 10 symptoms known to be associated with opioid medication usage: fatigue, drowsiness, inability to concentrate, nausea, dizziness, constipation, itching, difficulty with urination, confusion, retching and vomiting. The overall composite score was the average across frequency, severity, and degree of bother scores. Total possible score: 0 (better) to 4.34 (worse).

CMEs were defined using OR-SDS (assesses subject-reported levels of severity concerning 10 symptoms associated with opioid medication usage: fatigue, drowsiness, inability to concentrate, nausea, dizziness, constipation, itching, difficulty with urination, confusion and retching/vomiting). CME = any symptom rated as severe or very severe, with the exception of confusion. Confusion was defined as a CME if the severity score was at least moderate. Total score = the sum of CMEs across symptoms. Each CME = 1 point. Total CME score ranges from 0 to 9.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Pain interference index = average of pain interference question (Q) 5A to 5G. Questions were asked as follows: how, during the past 24 hours, has pain interfered with general activity (Q5A), mood (Q5B), walking ability (Q5C), normal work (outside home and housework) (Q5D), relations with other people (Q5E), sleep (Q5F), enjoyment of life (Q5G). Scale: 0=does not interfere to 10=completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5E: Subject response to 'how, during the past 24 hours, pain has interfered with your relations with other people'. Scale: 0 = does not interfere to 10 = completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5G: Subject response to 'how, during the past 24 hours, pain has interfered with your enjoyment of life'. Scale: 0 = does not interfere to 10 = completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5A: Subject response to 'how, during the past 24 hours, pain has interfered with your general activity. Scale: 0 = does not interfere to 10 = completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5B: Subject response to 'how, during the past 24 hours, pain has interfered with your mood'. Scale: 0 = does not interfere to 10 = completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5C: Subject response to 'how, during the past 24 hours, pain has interfered with your walking ability'. Scale: 0 = does not interfere to 10 = completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5D: Subject response to 'how, during the past 24 hours, pain has interfered with your normal work (work outside the home and housework)'. Scale: 0 = does not interfere to 10 = completely interferes.

m-BPI-sf questionnaire (7-items) assessed pain interference with functional activities during the past 24 hours. Q5F: Subject response to 'how, during the past 24 hours, pain has interfered with your sleep'. Scale: 0 = does not interfere to 10 = completely interferes.

Subject rated scale for worst pain over the last 24 hours. Scores ranged from 0 (no pain) to 10 (pain as bad as you can imagine). Weekly mean scores were calculated post-discharge.

Subject rated scale for average pain intensity over the last 24 hours. Scores range from 0 (no pain) to 10 (pain as bad as you can imagine). Weekly mean scores were calculated post-discharge.

Subject rated scale for average pain intensity over the last 24 hours. Pain was assessed using the question "How much pain do you have right now?" Scores range from 0 (no pain) to 10 (most possible pain).

The NRS-Sleep: subject rated 11-point numerical rating scale ranging from 0 (did not interfere with sleep) to 10 (completely interfered [unable to sleep due to pain]) rating how pain has interfered with sleep during the past 24 hours. Weekly mean scores were calculated post hospital discharge.

VAS-Anxiety was administered to measure pre-operative anxiety. Score: 0 = no anxiety to 100 = worst imaginable anxiety.

TUG: time taken in seconds to rise from a standard arm chair, walk to a line on the floor 3 meters away, turn, return and sit down again.

The degree of active (patient moving the knee) knee flexion and extension tolerated by each subject was recorded. Active ROM in the sitting position was assessed with a goniometer.

The degree of passive (movement of the knee with the aid of physical therapist or designee) knee flexion and extension tolerated by each subject was recorded. Passive ROM in the sitting position was assessed with a goniometer.

The analysis was performed by Kaplan-Meier method with log-rank test.

The analysis was performed by Kaplan-Meier method with log-rank test.

Measure of subject satisfaction with treatment for acute or chronic pain. Response range: 1 (strongly agree) to 5 (strongly disagree). Mean scores were calculated and transformed onto a scale of 0-100, range: 0 = worst possible satisfaction to 100 = best possible satisfaction with pain treatment.

Measure of subject satisfaction with treatment for acute or chronic pain. Response range: 1 (strongly agree) to 5 (strongly disagree). Mean scores were calculated and transformed onto a scale of 0-100, range: 0 = worst possible satisfaction to 100 = best possible satisfaction with pain treatment.

Measure of subject satisfaction with treatment for acute or chronic pain. Response range: 1 (strongly agree) to 5 (strongly disagree). Mean scores were calculated and transformed onto a scale of 0-100, range: 0 = worst possible satisfaction to 100 = best possible satisfaction with pain treatment.

Measure of subject satisfaction with treatment for acute or chronic pain. Response range: 1 (strongly agree) to 5 (strongly disagree). Mean scores were calculated and transformed onto a scale of 0-100, range: 0 = worst possible satisfaction to 100 = best possible satisfaction with pain treatment.

Measure of subject satisfaction with treatment for acute or chronic pain. Response range: 1 (strongly agree) to 5 (strongly disagree). Mean scores were calculated and transformed onto a scale of 0-100, range: 0 = worst possible satisfaction to 100 = best possible satisfaction with pain treatment.

The Global Evaluation of Study Medication is a subject-administered single item instrument that records the subject's overall impression (global evaluation) of the study medication by asking the following question: how would you rate the study medication you received for pain? The subject chooses based on a scale of 1 (poor), 2 (fair), 3 (good), or 4 (excellent).

The presence of persistent pain was evaluated on the 11-point VRS. The subject answered the question: how much pain did you experience in the last 24 hours in your operated knee? A zero score of VRS was the only number considered as a "no." Any positive score (1-10) of VRS was consider as "yes."

NPSI: subject rated questionnaire to evaluate 5 dimensions of neuropathic pain (dimensions: burning [superficial] spontaneous pain, pressing [deep] spontaneous pain, paroxysmal pain, evoked pain, and paresthesia/dyesthesia). Includes 10 descriptors ranging from 0 (no symptoms) to 10 (worst symptoms imaginable) and 2 temporal items assessing duration of spontaneous ongoing and paroxysmal pain. Questionnaire generates a score in each relevant dimension. Total score is calculated as the sum of scores of the 10 descriptors, range: 0-100. Higher score indicates greater intensity of pain.