TABLE 6.

Characteristics of included studies—Other.

Author; year of publication; trial registration	Study design; country; setting	Participant characteristics	Eligibility criteria	Interventions; comparisons	Outcome measures (methods); timepoints	Main findings	Safety	Funding; conflict of interest
Anxiety and sleep quality
Ozkaraman; 2018; trial not registered Ozkaraman et al. (2018)	RCT (parallel); Turkey; Outpatient clinic	N = 70 enrolled (n analysed not reported)	Inclusion criteria: cancer diagnosis; age ≥ 18 years; able to smell; weekly chemotherapy with paclitaxel	Intervention group: TTO (botanical species not stated, “commercially available”—not further described)	Anxiety (State-Trait Anxiety Inventory—Turkish version, consisting of two sub-scales: State Anxiety and Trait Anxiety)	State Anxiety no sig. difference in change scores across groups (F = 0.826, p = 0.442), after chemotherapy	Not assessed	Funding: Scientific Research Project Coordination Unit at Eskişehir Osmangazi University
		Age in years, mean (SE) 58.2 (12.8)	Exclusion criteria: chronic disease; psychiatric illness; history of allergies; anxiolytic drug use	Three drops on piece of cotton placed on subjects’ neck and shoulders 10-inches from nose	Sleep quality (Pittsburgh Quality Sleep Index—Turkish version. Total scores range 0–21. Scores < 5 indicate good sleep quality. Scores > 5 points indicate poor sleep quality)	Trait Anxiety sig. difference in change scores across groups (F = 11.002, p < 0.001). Only lavender sig. decreased trait anxiety (p < 0.001)		Conflicts of interest: no data provided
		Female 59/70		Control group 1: Lavender essential oil (Lavandula hybrida)	Timepoints: Baseline (prior to 1st cycle chemotherapy) and after completing chemotherapy treatment	In post-hoc analyses, the decrease in lavender essential oil group was sig. greater than TTO group (p = 0.046), as TTO did not sig. change trait anxiety
				Three drops on piece of cotton placed on subjects’ neck and shoulders 10-inches from nose		Sleep quality sig. difference in change scores across groups (F = 8.991, p < 0.001). Score sig. decreased within both lavender and TTO groups (p < 0.001)
				Control group 2: no treatment

Abbreviations: RCT, randomised controlled trial; SE, standard error; TTO, tea tree oil.