Table 6.

Summary table of included quantitative studies

Study	Design duration of study	Country/city setting	Symptom of BPSD sample	Intervention	Control	Effectiveness	Safety	Others
A. RCTs Ballard et al. [80] Cameron et al. [65] Fu et al. [69] Fujii et al. [68]	2-Armed Parallel 4 weeks 2-Armed Crossover 3 weeks' treatment A +1-week washout +3 weeks' treatment B 3-Armed Parallel 6 weeks +6 weeks' follow-up 2-Armed Parallel 4 weeks	UK Nursing homes UK Inpatient unit Australia Nursing homes Japan Long-term care hospital	Agitation n = 71 Subgroup sample: 35/36 Severe dementia Mean age 78.5 years (SD 8.1) Female 59.7% General symptoms of BPSD n= 15 Subgroup sample: 6/9 Moderate-to-severe dementia Disruptive behavior n = 67 Subgroup sample: 22/23/22 Mild-to-severe dementia Mean age 84 years (SD 6.36) Female 59% General symptoms of BPSD n = 28 Subgroup sample: 14/14 Moderate-to-severe dementia Mean age 78 years (SD 10) Female 67.9%	Aromatherapy topical application By a care assistant 2 times a day 1–2 min per time 10% Melissa essential oil Aromatherapy topical application By nursing staff 2 times a day 1 min per time <2% Melissa essential oil Aromatherapy inhalation and massage By a researcher and trained research assistants 2 times a day 3 sprays of mist to chest +5 min of massage 3% lavender mist Aromatherapy inhalation 2 times a day 3 sprays of mist to chest 3% lavender mist Aromatherapy inhalation 3 times a day 2 h per time 100% lavender essential oil 2 drops into the collar	Placebo topical application By a care assistant 2 times a day 1–2 min per time 10% sunflower oil Placebo topical application By nursing staff 2 times a day 1 min per time <1% geranium and 0.5% lemon oil Placebo spray By researcher and trained research assistants 2 times a day Water spray to chest No active treatment	CMAI Significant improvement dppc20.979 NPI Irritability score and aberrant motor behavior score improved significantly in intervention than control QoL parameters Significant reduction in the % of time spent socially withdrawn and significant increase in the % of time engaged in constructive activities CMAI No significant difference between intervention and control Significant increase in the scores during the washout period NPI No significant difference between intervention and control Significant increase in the scores during the washout period PAS No significant difference between intervention and control Significant increase in the scores during the washout period CMAI Mean scores reduced, but not significant No significant improvement with either intervention NPI Significant improvement dppc2 0.703	1 patient receiving aromatherapy topical application experienced 2 days diarrhea Possible adverse effect not described No adverse event was reported No adverse event was reported	Adherence: weighing the bottles weekly, result not described Theoretical basis: not described Adherence: not described Theoretical basis: not described Adherence: not described Theoretical basis: not described Adherence: not described Theoretical basis: not described
Lin et al. [67]	2-Armed Crossover 3 weeks' treatment A +2 weeks' washout +3 weeks' treatment B	Hong Kong Care and attention homes	Agitation n = 70 Subgroup sample: 35/35 Mean age 78.29 years (SD 4.06) Female 58.6%	Aromatherapy inhalation By care and attention homes staff 1 time a day 1 h per time 100% lavender essential oil 2 drops in a diffuser, and 2 diffusers were placed one at each side of the pillow	Placebo inhalation By care and attention homes staff 1 time a day 1 h per times Sunflower oil 2 drops in a diffuser, and 2 diffusers were placed one at each side of the pillow	CCMAI Significant improvement dppc20.244 No significant period and sequential effect CNPI Significant improvement dppc20.674 No significant period effect and sequential effect	No adverse event was reported	Adherence: not described Theoretical basis: not described
Mascherona et al. [75]	2-Armed Parallel 8–14 days	Switzerland Geriatrics department	General symptoms of BPSD n = 32 Subgroup sample: 16/16 Mean age 86.245 years (SD 6.522) Female 68.7%	Aromatherapy inhalation and standard pharmacological treatment By nurses 4 times a day 60 min per time 6 drops 100% sweet orange essential oil into mist diffuser at 07:00, 12:00, and 15:00 6 drops 100% lavender essential oil into diffuser at 20:00 Standard pharmacological treatment	Standard pharmacological treatment	NPI-NH Significant improvement dppc20.68 Distress scores among caregivers delivering aromatherapy inhalation decreased significantly	No adverse event was reported	Adherence: not described Theoretical basis: not described
O'Connor et al. [77]	2-Armed Crossover 3 days' treatment A +4 days' washout +3 days treatment B + 4 days' washout	Australia Nursing homes	Agitation n = 64 Subgroup sample: 37/27 Markedly cognitively impaired Mean age 77.6 years (SD 9.4) Female 59%	Aromatherapy topical application By nursing staff Whenever an agitated behavior was reported 2 min per time 30% lavender essential oil 2 mL per time	Placebo topical application By nursing staff Whenever an agitated behavior was reported 2 min per time Jojoba oil 2 mL per time	Behavioral count Agitated behavior counts were lower with intervention than with control, approaching statistical significance (p = 0.057) No significant treatment-time interactions Philadelphia Geriatric Center Affect Rating Scale Counts of positive effect	No adverse event was reported	Adherence: not described Theoretical basis: not described
Smallwood et al. [71]	3-Armed Parallel 4 weeks	UK Hospital	Disordered behavior n = 20 Subgroup sample: 7/7/7 (1 dropout not described in which group) Severe dementia Mean age 66.8 years (SD 11.5) Female 57.1%	Aromatherapy massage By aromatherapist 2 times per week 1 h per time Lavender essential oil massage Conversation and aromatherapy inhalation By an aromatherapist 2 times per week 1 h per time Conversation and lavender essential oil by diffuser	Placebo massage By aromatherapist 2 times per week 1 h per time Plain oil massage	were higher in all intervention than control periods but not to significantly different degrees Video recorded behavior No overall group differences	Negligible side effects	Adherence: not described Theoretical basis: not described
Turten Kaymaz and Ozdemir [83]	2-Armed Parallel 4 weeks	Turkey Patients' homes	Agitation 28 patients +28 primary caregivers Subgroup sample: 14/14 patient-caregiver pairs Mode rate-to-severe dementia Patients mean age 78.11 years (SD 7.45) Patient female 64.3%	Aromatherapy massage and inhalation Aromatherapy massage by an aromatherapist 3 times per week 5 min per time Mixture of lemongrass and eucalyptus essential oil Aromatherapy inhalation by primary caregivers 1 time a day 1 h per time 6 drops 100% lavender essential oil to the diffuser located in the patient's room 1 m from the bed	No intervention	CMAI Significant improvement in intervention than control NPI Significant improvement in intervention than control Significant improvement for caregiver distress in intervention than control ZBI Significant improvement in intervention than control	Negligible side effects	Adherence: Monitored by massage and inhalation monitoring form, fully compliance was reported Theoretical basis: not described
Yang et al. [47]	2-Armed Parallel 8 weeks	Taiwan Long-term care facilities	Agitation, depression n = 56 Subgroup sample: 27/29 Mean age 92 years (SD 7) Female 61%	Aromatherapy massage By trained research assistants 1 time per week 30 min per time 6% essential oil blend Regular activities	Delay intervention Regular activities Aromatherapy massage was provided after completion of study	CCMAI No significant difference between groups regarding overall agitation CSDD-C Significant improvement dppc20.87	2 participants in the intervention group withdrew due to discomfort after the first aromatherapy massage session	Adherence: not described Theoretical basis: not described
Yang et al. [48]; Yang et al. [78]	3-Armed Parallel 4 weeks' +3 weeks' follow-up	Taiwan Retirement homes for veterans and long-term care facilities	Agitation, depression n = 186 Subgroup sample: 56/73/57 Mean age 84.08 years (SD 5.67) Female 26.3%	Aromatherapy acupressure 5 days per week, 1 time per day No longer than 15 min per time 2.5% lavender essential oil Aromatherapy topical application 5 days per week, 1 time per day No longer than 15 min per time 2.5% lavender essential oil	No intervention	CMAI Both interventions have significant improvement Acupressure dppc2 0.491 Topical application dppc2 0.728 Posttest score lower than post-3-week score CSDD Both interventions have significant improvement Acupressure dppc2 0.967 Topical application dppc2 1.583 Posttest score lower than post-3-week score HRV Aromatherapy acupressure was better able to inhibit the sympathetic nervous system and increase the activity of the parasympathetic nervous system compared with aromatherapy topical application	Negligible side effects	Adherence: not described Theoretical basis: not described
Yoshiyama et al. [82]	2-Armed Crossover 4 weeks' treatment A +4 weeks' washout + 4 weeks' treatment B +4 weeks' follow-up	Japan Nursing homes	General symptoms of BPSD n = 12 Subgroup sample: 7/5 Mean age 82.8 years (SD 9.503) Female 100%	Aromatherapy massage By a single researcher and an aromatherapist 3 times per week 10 min per time 1–2% essential oil blend	Placebo massage By a single researcher and an aromatherapist 3 times per week 10 min per time Jojoba oil	CMAI No significant change for either therapy NPI-Q No significant change for either therapy CSDD The symptoms related to depression improved, but not statistically significantly, after the trials No significant change for either therapy	Negligible side effects	Adherence: not described Theoretical basis: not described
Quasi-experimental studies
Beshara and Giddings [76]	One-group pretest-posttest 6 months	USA Long-term care facility	Agitation n = 10 Female 50%	Aromatherapy inhalation 9:00 a.m. and 5:00 p.m. daily Monday through Saturday with Sundays having no essential oil treatments 1 drop essential oil blend in diffuser	−	MDS Effect of clinical aromatherapy in dementia populations is widely variable	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Gray and Clair [74]	Within-subjects 16 days	USA Residential-care facilities	Difficult-to-manage behaviors n = 13 Female 46.2%	Aromatherapy/ Placebo Inhalation Participants took their morning medications under 4 randomly ordered conditions: lavender, sweet orange, tea tree, or no aroma (placebo control) Each of the conditions was repeated 4 times for a total of 16 administrations 20 min before medications were dispensed, a cotton ball containing an essential oil or without oil (the control condition) was taped to the lapel of each participant	Videotape No statistically significant differences in frequencies of resistive behaviors across the four conditions	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Holmes et al. [70]	Within-subjects 2 weeks	UK Long-stay psychogeriatric ward	Agitation n = 15 Severe dementia Mean age 79.0 years (SD 6.3) Female 60%	Aromatherapy/placebo inhalation 1 time per day 2 h per time 2% lavender essential oil (intervention) or water (control) by diffuser, on alternate days A total of 5 aromatherapy and 5 placebo trials were carried out for each patient	PAS Significant improvement in intervention than control	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Lee and Lee [81]	Nonequivalent control group 2 weeks	Korea Hospitals and nursing homes	Anxiety, aggressive behavior, and wandering behavior n = 43 Subgroup sample: 21/22 Mean age 77.7 years Female 62.8%	Aromatherapy massage By the researcher and trained mental health nurses with aromatherapist certificates 1 time per day, 5 times a week 20 min per time 2% essential oil blend	Delay intervention After completing data collection, intervention was administered to the control group	RAID Significant improvement in intervention than control dppc2 0.761 Ryden aggression scale Significant improvement in intervention than control dppc2 0.42 Algase wandering scale V2 Significant improvement in intervention than control dppc21.37	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Moorman Li et al. [72]	One-group pretest-posttest 2 months	USA Day-care center	Behavioral issues (restlessness/wandering, agitation, anger, and anxiety) n = 23 Mean age 83 years Female 65.3%	Aromatherapy inhalation 2 times per day 20 min per time Lavender essential oil in diffuser	−	Behavior/intervention monthly flow record No. of behavioral issues was lower in the postintervention period, but did not reach statistical significance In the analysis of individual behavioral issues, there was a statistically significant difference found for the frequency of agitation	No adverse effect reported	Adherence: not described Theoretical basis: not described
Ogun-Semore [73]	One-group pretest-posttest 8 weeks	USA. Long-term care setting	Agitation n = 19 Mean age 72 years(SD 8.30) Female 26.3%	Aromatherapy inhalation 4 times a week Cotton napkins with lavender essential oil placed on the table in-between each of the participants	−	Agitation with unknown instrument Statistically significant difference between the pre- and postintervention average ratings of the level of agitation	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Snow et al. [66]	Within-subjects 4 weeks' baseline measurement + 2 weeks for each of the 5 treatment conditions (total 10 weeks) +2 weeks' postintervention measurement	USA. Long-term care facility	Agitation n = 7 Advanced dementia	Aromatherapy/placebo inhalation 3 times per day Treatment conditions order: ABCBA (A = lavender essential oil, B = thyme essential oil, C = unscented grapeseed oil); all participants received all aromas in the same order A 2 × 2 inch absorbent fabric sachet was securely pinned to the front of each participant's shirt near the collarbone 2 drops 100% essential oil or unscented grapeseed oil	Modified CMAI No treatment effect	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Takeda et al. [45]	Within-subjects 20-day control +20-day intervention	Japan Residential-care facilities	Sleep disturbance n = 19 Mean age 80.7 years (SD 9.1) Female 47.4%	Aromatherapy/placebo inhalation By researcher 3 types of essential oils were used for aromatherapy: (1) lavender, (2) lavender and sweet orange oil blend, and (3) Japanese cypress, Virginian cedarwood, cypress, and pine oil blend Essential oil used was selected by participants Researcher visited each participant in his or her room between 18:00 and 20:00 every day and wrapped a towel with essential oil/nothing on it around the subject's pillow before the participant went to bed	NPI No significant difference between intervention and control Vibrometer SL: no significant differences TST: significant improvement seen with the main effect of the control and intervention periods, but no significant difference was seen with the main effect of time or period × time SE: no significant difference DLSSP: Significant improvement with the main effect of the control and intervention periods, but no significant difference was seen with the main effect of time or period × time WTASO: no significant difference EMA: a significant difference between the control and intervention periods	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Ukwuoma [88]	One-group pretest-posttest 4 weeks	USA Outpatient adult day program setting	Anxiety n = 15 Mild dementia Age 65–84 Female 60%	Aromatherapy massage By a researcher 3 times a week 10 min per time 0.5% lavender essential oil 20 mL	−	HAM-A No significant changes between pretest and posttest on 8 items 4 items showed an increase between pre and post: anxious mood, intellectual, GI symptoms, and behavior at intervention The increase in GI symptoms was statistically significant Two items showed a decrease between pre and post: autonomic symptoms and depressed mood The decrease in depressive mood was statistically significant Overall, there was no statistically significant difference	Possible adverse effect not described	Adherence: not described Theoretical basis: not described
Zalomonson et al. [79]	Nonequivalent control group Crossover 4 months: month 1 oil A on face→ month 2 oil A on foot → month 3 oil B on foot → month 4 oil B on face	Israel Psychogeriatric long-term care departments	General symptoms of BPSD n = 42 Subgroup sample: 22/20 Mean age 76.1 years (SD 11.2) Female 57.2%	Aromatherapy topical application By nurses 3 times a day 1–2 min per time 2 drops lavender essential oil	Placebo topical application By nurses 3 times a day 1–2 min per time 2 drops sunflower seed oil	NPI No significant difference between intervention and control Use of psychotropic drugs No significant difference between intervention and control	1 patient with exacerbation of chronic pulmonary disease while on placebo, there were 20 reported adverse events during intervention period (3 nausea, 13 sleepiness, 1 gait instability, 2 skin irritation, 1 fall)	Adherence: adherence rate was 96.4%±7.9% Theoretical basis: not described

RCTs, randomized controlled trials; PWD, persons with dementia; BPSD, behavioral and psychological symptoms of dementia; NPI, Neuropsychiatric Inventory; SD, standard deviation; CMAI, Cohen-Mansfield Agitation Inventory; PAS, Pittsburgh Agitation Scale; CSDD, Cornell Scale for Depression in Dementia; ZBI, Zarit Burden Interview.