Objectives: To compare the effectiveness of lavender (Lavandula angustifolia) and sleep hygiene versus sleep hygiene alone on sleep quantity and sleep quality and to determine sustained effect at two-week follow-up.
Design: A randomized controlled trial with investigator blinding and steps taken to blind the participants.
Setting: Participants' usual sleep setting.
Subjects: Seventy-nine college students with self-reported sleep issues.
Interventions: The intervention took place over five nights with baseline, postintervention, and two-week follow-up assessments. Both groups practiced good sleep hygiene and wore an inhalation patch on their chest at night. One group wore a patch with 55 μl of lavender essential oil and the other group wore a blank patch.
Outcome measures: Sleep quantity was measured using a Fitbit(®) tracker and a sleep diary, and sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI) and the NIH Patient-Reported Outcomes Measurement Information System (PROMIS) sleep disturbance short form.
Results: The lavender and sleep hygiene group demonstrated better sleep quality at postintervention and two-week follow-up (PSQI p=0 .01, <0.001 and PROMIS p=0.04, 0.007, respectively). The sleep-hygiene-only group also demonstrated better sleep quality but to a lesser extent (PSQI p=0.02, 0.06 and PROMIS p=0.03, 0.03, respectively). Additionally, a clinical effect was found for the lavender group at postintervention, along with a significant finding for waking feeling refreshed (p=0.01). Sleep quantity did not differ between groups.
Conclusions: Lavender and sleep hygiene together, and sleep hygiene alone to a lesser degree, improved sleep quality for college students with self-reported sleep issues, with an effect remaining at follow-up.