Gabapentin for Insomnia Symptoms and Nighttime Vasomotor Symptoms (VMS) in Peri- and Postmenopausal Women

Tolerability of gabapentin was assessed by self-report at the week 1, week 4 and week 7 contacts by asking participants to complete the SAFTEE-SI and CPFQ questionnaires and prompting subjects to report any adverse events at each study visit. Tolerability of gabapentin is defined as the proportion of participants that is able to increase the dose from 300-mg to 600-mg and to remain on the higher dose for the duration of the trial.

Reason why subjects who initiated treatment with gabapentin chose to discontinue before study completion

Vasomotor symptoms (VMS) were tracked and quantified prospectively using a daily hot flash diary. The hot flash diary was adapted from a 7-day self-report tool for vasomotor symptoms originally developed by the North Central Cancer Treatment Group (NCCTG). The diary asks for the subject to log number of hot flashes during the day and night, severity of hot flashes during day and night, and how bothersome the hot flashes were during day and night. Vasomotor symptoms were also systematically assessed at baseline, week 4, and week 7 using the Hot Flash-Related Daily Interference Scale (HFRDIS), a 10-item self-report questionnaire to determine perceived hot flash interference with quality of life and daily activities.

Vasomotor symptoms (VMS) were tracked and quantified prospectively using a daily hot flash diary. The hot flash diary was adapted from a 7-day self-report tool for vasomotor symptoms originally developed by the North Central Cancer Treatment Group (NCCTG). The diary asks for the subject to log number of hot flashes during the day and night, severity of hot flashes during day and night, and how bothersome the hot flashes were during day and night. Vasomotor symptoms were also systematically assessed at baseline, week 4, and week 7 using the Hot Flash-Related Daily Interference Scale (HFRDIS), a 10-item self-report questionnaire to determine perceived hot flash interference with quality of life and daily activities.

Severity of insomnia was measured throughout the study using the Insomnia Severity Index (ISI) .The ISI is a 7-item scale that evaluates the severity of insomnia retrospectively over the past week. The scale is more specific to insomnia symptoms than the Pittsburgh scale (PSQI), which focuses more broadly on overall sleep quality.

The ISI score ranges from a minimum of 0 to 28. A score of 0-7=no clinically significant insomnia, 8-14=subthreshold insomnia, 5-21=clinical insomnia (moderate severity), 22-28=clinical insomnia (severe), with higher values indicating more severe insomnia.

Sleep quality and disturbances during the past month were assessed with the Pittsburgh Sleep Quality Index (PSQI). The PSQI also incorporates daytime functioning into the total score.

In scoring the PSQI, seven component scores are derived, each scored 0 (no difficulty) to 3 (severe difficulty). The component scores are summed to produce a global score (range 0 to 21). Higher scores indicate worse sleep quality.

Quality of life-Overall was assessed with the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q). The Q-LES-Q is a 16-item self-report questionnaire that assesses enjoyment of and satisfaction with life. The scoring of the Q-LES-Q-SF involves summing only the first 14 items to yield a raw total score. The last two items are not included in the total score but are standalone items. The raw total score ranges from 14 to 70 with higher scores indicating higher quality of life enjoyment and satisfaction.

The Quality of life-Menopause specific is assessed by the Menopause Specific Quality of Life (MENQOL).

The MENQOL is self-administered and consists of a total of 29 items in a Likert-scale format. Each item assesses the impact of one of four domains of menopausal symptoms, as experienced over the last month: vasomotor (items 1-3), psychosocial (items 4-10), physical (items 11-26), and sexual (items 27-29). Items pertaining to a specific symptom are rated as present or not present, and if present, how bothersome on a zero (not bothersome) to six (extremely bothersome) scale. Means are computed for each subscale by dividing the sum of the domain's items by the number of items within that domain. Non-endorsement of an item is scored a "1" and endorsement a "2," plus the number of the particular rating, so that the possible score on any item ranges from 1-8. Total score also ranges from 1-8.