Treatment of Pain Associated With Fibromyalgia

Average daily pain scores (ADPS) reported by the participant that best describes his or her worst pain over the previous 24 hours. A daily pain score has a scale where 0 = no pain to 10 = worst possible pain. Higher scores indicate a worse outcome. For participants with no Week 13 data, the baseline observation was carried forward (BOCF). The mean (multiple imputation estimate) and standard error (multiple imputation) are reported.

Patient global impression of change (PGIC) on a 7-point categorical scale, where 1 = very much improved and 7 = very much worse. Higher scores indicate worse outcomes. The number of participants with 'much improved or better' status (≤2) is being reported.

The total FIQ score is composed of 10 items, with a maximum possible score of 100. The first item contains 11 questions related to physical functioning and are rated on a 4-point Likert-type scale, where 0 indicates 'always' and 3 indicates 'never'. The overall impact items are rated on a 0-7 scale for the number of days that the patient felt well and the number of days they were unable to work (including housework) because of fibromyalgia symptoms. The symptoms items are rated on visual analog scales (0-10 cm), with higher numbers indicated greater symptomatology. Final scores range from 0 (no impairment) to 10 (maximum impairment), where higher scores indicate worse outcome.

For this outcome, the change in total FIQ score from baseline is being reported. Negative values indicate improvement from baseline in impairment.

The ADPS responder rate was defined a priori as the proportion of participants who met the clinically relevant reductions (ie, ≥30% and ≥50%) in ADPS at Week 13 (baseline observation carried forward) compared to Baseline.

MFI is a validated 20-item, self-reported instrument designed to measure fatigue in the following dimensions: general fatigue, physical fatigue, mental fatigue, reduced motivation, and reduced activity. The respondent is asked to mark an 'X' in 1 of 5 boxes arranged linearly where 1 is 'Yes, that is true' and 5 is 'No, that is not true.' Each subscale consists of 4 items, 2 indicative for fatigue and 2 contraindicative. For the indicative questions, a high score indicates a high fatigue level and low scores indicate a low fatigue levels. Conversely, for the contraindicative questions a high score indicates a low fatigue level and a low score indicates a high fatigue level. Overall, respondents are rated on a scale of 0 (no fatigue) to 7 (high fatigue).

For this outcome, the change from baseline in MFI-20 general fatigue subscale score is being reported. Negative values indicate an improvement in fatigue.

The HADS questionnaire is a reliable, widely-used self-assessment scale to assess symptoms of anxiety and depression. The instrument consists of 7 questions related to anxiety and 7 related to depression, each rated on a 4-point scale (score of 0 to 3). Scores for anxiety and depression are independently summed to compute HADS-Anxiety and HADS-Depression subscale scores, with ranges from 0 to 21, where higher scores indicate greater severity.

The SF-36 is a generic health survey that asks 36 questions to measure functional health and well-being from the patient's point of view. The SF-36 provides scores for 8 health domains (physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health) as well as psychometrically-based physical component summary (PCS) and mental component summary (MCS) scores. Each scale is transformed into a 0-100 scale with each question carrying the same weight. The lower the score indicates more disability (ie, worse outcome).

The EQ-5D is an instrument that shows high construct validity and responsiveness in patients with chronic pain and has been used specifically in fibromyalgia. The EQ-5D includes a descriptive section with 5 dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) each with a scale that ranges from 0 (no problems) to 5 (extreme problems). These 5 dimensions are combined into an overall health utilities index, and an numeric rating scale (100 mm visual analog scale) that measures perception of overall health, with 0 indicating worst health and 100 representing best imaginable health. A summary index with a maximum total score of 1 can be derived from these five dimensions by conversion with a table of scores. The maximum total score of 1 indicates the best health outcome.

For this outcome, the change from baseline in total EQ-5D score is being reported. Positive values indicate an improvement in health.

Pain-associated sleep interference will be assessed using the Average Daily Sleep Interference Score that utilize electronic daily diaries with an 11-point numeric rating scale (NRS) for pain, ranging from 0 (pain does not interfere with sleep) to 10 (pain completely interferes with sleep, unable to sleep). Higher scores indicate worse outcomes.

The MOS Sleep Scale is a 12-item questionnaire from which the following subscales were derived: sleep disturbance (4 items), quantity of sleep/optimal sleep (1 item), snoring (1 item), awakening due to shortness of breath or due to headache (1 item), sleep adequacy (2 items), and somnolence (3 items). In addition, values for sleep disturbances index (9 items), optimal sleep scale (1 item), and sleep quantity scale (1 item) were determined. Most subscales range from 0 to 100, where higher scores indicate more of the concept begin measured (eg., higher sleep disturbance scores indicate greater sleep disturbances).

The BPI-SF measures pain severity and interference within the past 24 hours. Items are rated on an 11-point NRS from 0 to 10, where 0 indicates does not interfere and 10 indicates completely interferes. Severity score is the average of the responses to the 4 pain intensity items that assess the Worst/Least/Average pain in the last 24 hours and the Pain Right Now. The individual items being reported (using the same scale as noted above) are Severity, General Activity, Mood, Walking Ability, Normal Work, Relations With Other People, Sleep, and Enjoyment of Life. Percentage relief of treatment pain scale ranges from 100% (complete pain relief) to 0% (no pain relief) and higher percentages indicate better outcome. Interference % is the average of responses for General activity, Mood, Walking ability, Normal work, Relations with other people, Sleep, Enjoyment of life where 0% (no interference) to 100% (completely interferes) and negative (ie. lower) percentages indicate better outcomes.

Proportion of days with rescue medication intake during the double-blind treatment period equals number of days with rescue medication intake/(date of last study drug administration in the double-blind treatment period) - (date of first study drug administration + 1).