Compared with placebo , zolpidem was associated with improved sleep : longer sleep times ( weeks 1 through 4 , p < .05 ) , greater sleep quality ( weeks 1 through 4 , p < .01 ) , and reduced number of awakenings ( weeks 1 , 2 , and 4 ; p < .05 ) , together with feeling significantly more refreshed , less sleepy , and more able to concentrate .
