A 52-year-old female with chronic insomnia disorder has been participating in cognitive behavioral therapy for insomnia (CBT-I) for six weeks, including sleep restriction, stimulus control, and cognitive restructuring. She completed a two-week sleep diary prior to the visit. Her baseline sleep diary two months ago showed average sleep onset latency (SOL) of 55 minutes, wake after sleep onset (WASO) of 80 minutes, total sleep time (TST) of 4.8 hours, time in bed (TIB) of 8.5 hours, and sleep efficiency (SE) of 56%. Her current sleep diary shows average SOL of 18 minutes, WASO of 25 minutes, TST of 5.5 hours, TIB of 6.25 hours, and SE of 88%. She reports feeling more rested despite sleeping fewer total hours and states her daytime fatigue has improved substantially. However, she expresses concern that she is sleeping only 5.5 hours per night and worries this is insufficient for her health. She asks whether CBT-I is actually working since she is sleeping less total time than before she started treatment. The PMHNP is evaluating the treatment response based on the sleep diary data. Which of the following best represents the appropriate evaluation?