Pregabalin Versus Placebo In The Treatment Of Neuropathic Pain Associated With HIV Neuropathy

Change From Baseline in Numeric Rating Scale (NRS)-Current Pain Score at Week 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 and Endpoint (up to Week 16)

Weekly current pain score was defined as the mean of the daily current pain diary ratings split into 7 day intervals. Participants rated current ("right now") HIV neuropathy pain an 11-point NRS ranging from 0 = no pain to 10 = worst possible pain. A rating of 1-3 was considered as mild pain; 4-6 = moderate pain; and 7-10 = severe pain. Endpoint was the last observation for a participant assessed using specified imputation method.

Time frame: Baseline, Week 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, Endpoint (up to Week 16)

Change From Baseline in Brief Pain Inventory-Short Form (BPI-sf) Score at Week 4, 8, 12, 16 and Endpoint (up to Week 16)

BPI-sf:5-item self-administered questionnaire to assess severity,impact of pain on daily functions. Pain Severity Index (PSI):average of Question 1-4 each measured severity of pain over past 24-hours on 11-point scale (0=no pain to 10=worst possible pain). Pain Interference Index (PII):average of 7 pain interference items of Question 5 that measured level of interference of pain on daily function on 11-point scale (0=does not interfere to 10=completely interferes). For PSI, PII range:0-10 higher score=higher pain/interference. Endpoint=last observation for participant as per imputation method.

Time frame: Baseline, Week 4, 8, 12, 16, Endpoint (up to Week 16)

Change From Baseline in Neuropathic Pain Symptom Inventory (NPSI) Item Scores at Endpoint (up to Week 16)

NPSI: participant-rated questionnaire to evaluate different symptoms of neuropathic pain. It includes 10 descriptors and 2 temporal items. Results reported for the 10 descriptors (burning, squeezing, pressure, electric shocks, stabbing, light touching of area, pressure of area, cold of area, pins and needles, tingling) quantified on a 0 (no symptoms) to 10 (worst symptoms imaginable) scale. Endpoint was the last observation for a participant assessed using specified imputation method.

Time frame: Baseline, Endpoint (up to Week 16)

Neuropathic Pain Symptom Inventory (NPSI): Change From Baseline in Number of Participants With Duration of Spontaneous Pain and Number of Pain Attacks at Endpoint (up to Week 16)

NPSI: participant-rated questionnaire to evaluate different symptoms of neuropathic pain. It includes 10 descriptors, and 2 temporal items. Results reported for categorical change in temporal items assessed on 5-point scale for duration of spontaneous pain (1=continuously, 2=8-12 hours \[hrs\], 3=4-7 hrs, 4=1-3 hrs, 5=less than 1 hr), numbers of pain attacks (1=more than 20, 2=11-20 attacks, 3=6-10 attacks, 4=1-5 attacks, 5=no attack). Change data categorized as worsened (negative change), unchanged (no change), and improved (positive change). Endpoint=last observation as per imputation method.

Time frame: Baseline, Endpoint (up to Week 16)

Change From Baseline in Neuropathic Pain Symptom Inventory (NPSI) Subscales and Total Intensity Score at Endpoint (up to Week 16)

NPSI: participant rated questionnaire to evaluate different symptoms of neuropathic pain (subscales: burning \[superficial\] spontaneous pain, pressing \[deep\] spontaneous pain, paroxysmal pain, evoked pain, and paresthesia/dyesthesia \[P/D\]). Includes 10 descriptors quantified on a 0 (no symptoms) to 10 (worst symptoms imaginable) and 2 temporal items assessing duration of spontaneous ongoing and paroxysmal pain. The relevant subscales and total score were transformed to 0-1, higher score indicates a greater intensity of pain. Endpoint=last observation for participant as per imputation method.

Time frame: Baseline, Endpoint (up to Week 16)

Total Sleep Time (TST) and Minutes of Interrupted Sleep (MIS)

Total sleep time is the number of minutes asleep between time of sleep onset to morning awakening and MIS is the number of minutes spent awake after sleep onset to final awakening. TST and MIS were determined by actigraphy. Actigraphy was performed with an accelerometer that was worn on the wrist like a watch. It was programmed to record movements while the device was being worn. Endpoint was the last observation for a participant assessed using specified imputation method.

Time frame: Baseline (Day -14 to 1), Week 1 through Week 4, Week 12 through Week 16, Endpoint (up to Week 16)

Sleep Fragmentation Index (SFI)

SFI is a measure to quantify sleep restlessness. SFI calculated from analysis of the periods that participant was not moving (immobile bouts). It is number of immobile bouts that were exactly 1 minute long divided by total number of immobile bouts. Value ranges from 0-100 percent, with low number representing more restful sleep. SFI determined by actigraphy. Actigraphy was performed with an accelerometer that was worn on wrist like a watch. It was programmed to record movements while device was being worn. Endpoint was the last observation for a participant assessed using imputation method.

Time frame: Baseline (Day -14 to 1), Week 1 through Week 4, Week 12 through Week 16, Endpoint (up to Week 16)

Sleep Efficiency

Sleep efficiency is the time spent asleep divided by total time between sleep onset and sleep end, multiplied by 100. Sleep efficiency was determined by actigraphy. Actigraphy was performed with an accelerometer that was worn on the wrist like a watch. It was programmed to record movements while the device was being worn. Endpoint was the last observation for a participant assessed using specified imputation method.

Time frame: Baseline (Day -14 to 1), Week 1 through Week 4, Week 12 through Week 16, Endpoint (up to Week 16)

Total Activity Counts

Activity counts are the units of motion. It is equal to the sum of peak accelerations each second during the epoch (60 seconds). Total activity counts per day is the sum of the activity counts for each epoch (60 seconds) during the "day" (non sleep period). A total activity count was determined by actigraphy. Actigraphy was performed with an accelerometer that was worn on the wrist like a watch. It was programmed to record movements while the device was being worn. Endpoint was the last observation for a participant assessed using specified imputation method.

Time frame: Baseline (Day -14 to 1), Week 1 through Week 4, Week 12 through Week 16, Endpoint (up to Week 16)

Percentage Day Time Above Sedentary Level

Percentage of time above sedentary level is number of epochs (60 seconds) with greater than (\>) 200 activity counts per minute divided by total number of epochs during the "day" (non sleep period) multiplied by 100. This was determined by actigraphy. Actigraphy was performed with an accelerometer that was worn on the wrist like a watch. It was programmed to record movements while the device was being worn. Endpoint was the last observation for a participant assessed using specified imputation method.

Time frame: Baseline (Day -14 to 1), Week 1 through Week 4, Week 12 through Week 16, Endpoint (up to Week 16)

Change From Baseline in Medical Outcomes Study-Sleep Scale (MOS-SS) at Endpoint (up to Week 16)

Participant-rated 12-item questionnaire to assess constructs of sleep over past week; 7 subscales: sleep disturbance (range 0-100), snoring (range 0-100), awaken short of breath (SOB) or with headache (range 0-100), sleep adequacy (range 0-100), somnolence (range: 0-100); sleep quantity (range: 0-24), optimal sleep (yes/no), and 9 item index measures of sleep disturbance provide composite scores: sleep problems index (range 0-100). Except adequacy, optimal sleep and quantity, higher scores=more impairment. Endpoint was the last observation for a participant assessed using imputation method.

Time frame: Baseline, Endpoint (up to Week 16)

Medical Outcomes Study-Sleep Scale (MOS-SS): Number of Participants With Optimal Sleep

MOS-SS: participant-rated 12 item questionnaire to assess constructs of sleep over past week. It included 7 subscales: sleep disturbance, snoring, awaken short of breath or with headache, sleep adequacy, somnolence, sleep quantity, optimal sleep, and 9 item index measures of sleep disturbance provide composite scores: sleep problems index. Participants responded whether their sleep was optimal or not optimal by choosing yes or no. Endpoint was the last observation for a participant assessed using imputation method.

Time frame: Baseline, Endpoint (up to Week 16)

Change From Baseline in Hospital Anxiety and Depression Scales (HADS) at Endpoint (up to Week 16)

HADS: participant rated questionnaire with 2 subscales. HADS-A assesses state of generalized anxiety (anxious mood, restlessness, anxious thoughts, panic attacks); HADS-D assesses state of lost interest and diminished pleasure response (lowering of hedonic tone). Each subscale comprised of 7 items with range 0 (no presence of anxiety or depression) to 3 (severe feeling of anxiety or depression). Total score 0 to 21 for each subscale; higher score indicates greater severity of anxiety and depression symptoms. Endpoint was the last observation for a participant assessed using imputation method.

Time frame: Baseline, Endpoint (up to Week 16)

Change From Baseline in 36-Item Short-Form Health Survey (SF-36) at Endpoint (up to Week 16)

SF-36 is a standardized survey evaluating 8 domains of functional health and well being: physical and social (So) functioning (Fn), physical and emotional role (role-physical \[R-P\], role-emotional \[R-E\]) limitations, bodily pain (BP), general health (GH), vitality (Vit), mental health (MnH). Two summary scores include Physical Component (Ph C) and Mental Component (Mn C). The score for a section is an average of the individual question scores. Score range for domain scores and summary scores: 0-100 (100=highest level of functioning).

Time frame: Baseline, Endpoint (up to Week 16)

Number of Participants Who Were Employed or Unemployed Assessed by Work Productivity and Activity Impairment: Specific Health Problem (WPAI: SHP) Questionnaire

WPAI: 6-question participant rated questionnaire to determine the degree to which specific health problem (SHP) affected work productivity while at work and affected activities outside of work. It assesses amount of absenteeism, presenteeism and daily activity impairment attributable to a HIV neuropathy pain. Number of participants who responded "Yes/No" to Question 1: Are you currently employed (working for pay)? are reported.

Time frame: Baseline, Week 16, 17

Absenteeism and Presenteeism Assessed by Work Productivity and Activity Impairment: Specific Health Problem (WPAI: SHP) Questionnaire

WPAI: 6-question participant rated questionnaire to determine the degree to which SHP affected work productivity while at work and affected activities outside of work. It assesses amount of absenteeism, presenteeism and daily activity impairment attributable to a HIV neuropathy pain. Question 2 and 3 assesses absenteeism as: Hours of work missed in past 7 days due to leg/foot pain or other reason, respectively. Question 4 assesses presenteeism as: Hours of work performed in past 7 days. A participant who had responded 'no' to question 1 regarding employment status reported hours of work and as this was a self-reported questionnaire the source data were included.

Time frame: Baseline, Week 16, 17

Productivity and Activity Impairment Assessed by Work Productivity and Activity Impairment: Specific Health Problem (WPAI: SHP) Questionnaire

WPAI: 6-question participant rated questionnaire to determine the degree to which SHP affected work productivity while at work and affected activities outside of work. It assesses amount of absenteeism, presenteeism and daily activity impairment attributable to a HIV neuropathy pain. Question 5 and 6 assesses: How much leg/foot pain affect productivity and daily activity, respectively in past 7 days? on 11-point scale, where 0 (not affected/no impairment) to 10 (completely affected/impaired).

Time frame: Baseline, Week 16, 17

Diagnostic Neuropathy Assessment

Time frame: Screening