Pregabalin In Partial Seizures (PREPS): An Open-Label, Multicenter Add On Therapy Trial (PREPS MEXICO)

28-day seizure rate (at observation period [obs]) = [(number of seizures obs ) divided by (duration of period based on observed last dosing date and Visit 3 [Week 9] date)] * 28. Percent change = [(28-day seizure rate obs minus 28-day seizure rate at baseline [b]) divided by 28-day seizure rate b] * 100. Negative values indicate a decrease in seizure frequency and positive values reflect an increase in seizure frequency.

Response ratio (RR) = comparison between baseline 28-seizure frequency with the 12 week observation phase. RR = [(28-day seizure rate in observation period [obs] minus 28-day seizure rate at baseline [b] ) divided by (28-day seizure rate obs plus 28-day seizure rate b)] * 100. Range: -100 to 100; negative values for the RR indicate reductions in seizures.

Percent change from Baseline = [(28-day seizure rate at 21 weeks minus 28-day seizure rate at baseline [b]) divided by (28-day seizure rate b) * 100. Negative values indicate a decrease in seizure frequency, positive values reflect an increase in seizure frequency.

Negative values indicate a decrease in seizure frequency; positive values reflect an increase in seizure frequency.

Seizure-free = no seizures during observation period (100 percent reduction in seizures from baseline).

Seizure-free = no seizures during last 4 weeks of observation period (100 percent reduction in seizures from baseline).

Patient General Impression to Change (PGIC): participant rated instrument to measure participant's change in overall status since beginning study medication on a 7-point scale; range: 1 (very much improved) to 7 (very much worse). Not done = participant did not complete the PGIC.

Participant rated questionnaire to assess sleep quality and quantity; 9-item overall sleep problems index and 7 subscales. Sleep disturbance, snoring, awaken short of breath, somnolence, and adequacy subscale scores (s) rated 1 (all the time) to 6 (none of the time); transformed s; total range (r): 0 to 100; higher s = greater intensity of attribute; negative values (v) = reduction from baseline (b), positive v = increase from b. Sleep Quantity score r: 0-24 hours. Higher s = greater quantity of sleep. Change = (MOS score at observation period minus MOS score at b) divided by MOS score b.

Optimal Sleep subscale of the MOS subject rated questionnaire to assess sleep quality and quantity. Optimal Sleep (1 of 7 subscales) was derived from sleep quantity: average hours of sleep each night during the past week. Number of subjects with response: YES=1 (optimal sleep: quantity of sleep was 7 or 8 hours per night) or No= 0 (no optimal sleep). Negative value indicates a decrease in attribute; positive value indicates an increase in attribute. Change = (MOS score at observation period minus MOS score at baseline [b]) divided by MOS score b.

Participant rated questionnaire with 2 subscales: HADS-A assesses generalized anxiety (anxious mood, restlessness, anxious thoughts, panic attacks); HADS-D: state of lost interest and diminished pleasure response (lowering of hedonic tone). Each subscale has 7 items; range: 0 (no anxiety or depression) to 3 (severe anxiety or depression). Total score 0 to 21 for each subscale; higher score = greater severity of symptoms. Negative value = reduction from baseline (b), positive value = increase from b. Change = (HADS score at observation period minus HADS score at b) divided by HADS score b.