Efficacy and Safety of the Lidoderm Patch Applied to Patients With Osteoarthritis of the Knee

Time-to-exit was defined as the number of days at which a patient either met the switching criterion [a 2-category change in the Pain Relief Scale (PRS) score in the worsening direction (increasing pain or decreasing pain relief) for 2 consecutive days] or discontinued from the study. The PRS is a 9-point categorical rating scale to assess pain relief in the last 24 hours in which 0 = completely worse and 8 = complete pain relief. Traditional survival models that consider event times (e.g. median survival time) as independent and homogeneous across patients were not suitable for this study.

Time-to-exit due to lack of efficacy was defined as a patient that met the switching criterion (a 2-category change in Pain Relief Scale (PRS) in the worsening direction [increasing pain or decreasing pain relief] for 2 consecutive days) or was discontinued from the current period or study due to lack of efficacy. The PRS is a 9-point categorical rating scale to assess pain relief in the last 24 hours in which 0 = completely worse and 8 = complete pain relief.

No patients discontinued from the study due to lack of efficacy.

Exit status from a current study treatment was categorized as yes or no for patients who exited prior to the 4-week planned duration. This analysis supports the results of the primary analysis. The number of patients exiting (yes) is reported.

The Numerical Rating Scale (NRS) is an 11-point categorical rating scale to assess pain intensity (PI-NRS); 0= no pain and 10= worst possible pain. The scale is anchored on the left with "No Pain" and on the right with "Worst Possible Pain." Patients were to complete this assessment at approximately the same time each day during the double-blind treatment period in their e-diary. The overall treatment difference for the Lidoderm (lidocaine patch 5%) and placebo patch was compared by combining data for patients receiving the respective treatment regardless of the randomized study sequence.

The Pain Relief Scale (PRS) is a 9-point categorical rating scale to assess pain relief during the 24-hours since the last assessment; 0= completely worse and 8= complete pain relief. Patients completed this assessment each day during the run-in period and each day during the double-blind treatment phase in their e-diary.

The PQAS measures individual pain qualities and the impact of treatment on those qualities. Items 1-19 are each rated on an 11-point scale ranging from 0 (lowest score - no pain of that type) to 10 (highest score - the highest level of that type of pain). Average surface pain = average of PQAS items: cold, sensitive, itchy, numb, and tingling. Average deep pain = average of PQAS items: dull, cramping, throbbing, aching, and heavy. Average paroxymal pain = average of PQAS items: sharp, shooting, electric, and radiating.

Patients rated their overall impression of change from Baseline to the end of each period during the double-blind treatment period, including premature discontinuation. Change was rated using a categorical scale indicating: "very much worse" (0); "much worse" (1); "minimally worse" (2); "no change" (3); "minimally improved" (4); "much improved" (5); and "very much improved" (6).

Investigators rated their overall impression of change from Baseline to the end of each period during the double-blind treatment period, including premature discontinuation. Change was rated using a categorical scale ranging from "very much worse" to "very much improved." A similar questionnaire was completed by the Investigator.

At the end of each period, patients rated their overall satisfaction with study treatment using a 5-point categorical scale indicating: 0 - very dissatisfied; 1 - dissatisfied; 2 - no preference; 3 - satisfied; and 4 - very satisfied.

At the end of each period, investigators rated their overall satisfaction with study treatment using a 5-point categorical scale ranging from 0 (very dissatisfied) to 4 (very satisfied).

The BDI-II is a 21-item self-report instrument intended to assess the existence and severity of symptoms of depression. Patients were to consider each item as it related to the way they felt for the previous 2 weeks. Each of the 21 items corresponding to a symptom of depression was summed to give a single score for the BDI-II, with a 4-point scale for each item ranging from 0-3. A total score of 0-13 is minimal, 14-19 is mild, 20-28 is moderate, and 29-63 is severe. Values were based on measurements taken at Screening, at Baseline (Visit 3), and at the end of each period.

The BDI-II is a 21-item self-report instrument intended to assess the existence and severity of symptoms of depression. Patients were to consider each item as it related to the way they felt for the previous 2 weeks. Each of the 21 items corresponding to a symptom of depression was summed to give a single score for the BDI-II, with a 4-point scale for each item ranging from 0-3. A total score of 0-13 is minimal, 14-19 is mild, 20-28 is moderate, and 29-63 is severe. Values were based on measurements taken at Screening, at Baseline (Visit 3), and at the end of each period.

Health status was assessed using the EuroQol Quality of Life Instrument (EQ-5D). Patients completed the EQ-5D assessment at Baseline (Day 0) and at each clinic visit (at least every 4 weeks) or at premature discontinuation. Values of the EQ-5D index score range from -1 (worst) to 1 (best).

Health status was assessed using the EuroQol Quality of Life Instrument (EQ-5D). Patients completed the EQ-5D assessment at Baseline and at the end of each period or at premature discontinuation. Values of the continuous EQ-5D health state today (VAS) ranged from 0 (worst imaginable health state) to 100 (best imaginable health state).

Health status was assessed using the EuroQol Quality of Life Instrument (EQ-5D). Patients completed the EQ-5D assessment at Baseline and at the end of each period or at premature discontinuation. Categories included Better, Much the Same, and Worse.

The VSH Sleep Scale is contained in a 15 item self-report instrument that measures the quality of a patient's sleep over the last 24 hours. Each item is scored on a 0-100 visual analog scale. The VSH is categorized into 3 sleep scales: disturbance (which measures delays and interruptions in sleep)[maximum score = 700], effectiveness (which measures how well sleep refreshed the individual) [maximum score = 600], and supplementation (which measures the need for napping) [maximum score = 400]. The higher the score the greater the value of the sleep characteristic for that patient.