Snoezelen for dementia.

BACKGROUND: Snoezelen, multi-sensory stimulation, provides sensory stimuli to stimulate the primary senses of sight, hearing, touch, taste and smell, through the use of lighting effects, tactile surfaces, meditative music and the odour of relaxing essential oils (Pinkney 1997). The clinical application of snoezelen has been extended from the field of learning disability to dementia care over the past decade. The rationale for its use lies in providing a sensory environment that places fewer demands on intellectual abilities but capitalizes on the residual sensorimotor abilities of people with dementia (e.g. Buettner 1999, Hope 1998). Practitioners are keen to use snoezelen in dementia care, and some encouraging results have been documented in the area of promoting adaptive behaviours (e.g. Baker, Long 1992, Spaull 1998). However, the clinical application of snoezelen often varies in form, nature, principles and procedures. Such variations not only make examination of the therapeutic values of Snoezelen difficult, but also impede the clinical development of snoezelen in dementia care. A systematic review of evidence for the efficacy of snoezelen in the care of people with dementia is therefore needed to inform future clinical applications and research directions.

OBJECTIVES: This review aims to examine the clinical efficacy of snoezelen for older people with dementia.

SEARCH STRATEGY: "Snoezelen", "multi-sensory", "dement*", "Alzheimer*", "randomized control/single control/double control" were used as keywords to search seven electronic databases (e.g. MEDLINE, PsyLIT). The list of trials was compared with those identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group.

SELECTION CRITERIA: All RCTs in which Snoezelen or multi-sensory programmes were used as an intervention for people with dementia were included in the review. Trial data included in the review were restricted to those involving people aged over 60 years suffering from any type of dementia, except one subject of Baker's study was aged below 60 years.

DATA COLLECTION AND ANALYSIS: Only two RCTs fulfill the inclusion criteria for this systematic review. Two reviewers independently extracted the data from these two inclusion studies. Quantitative synthesis of the comparable data from the two trials was performed.

MAIN RESULTS: Two trials were included. Both Baker (and Kragt examined the short-term values of snoezelen on the behaviours of people with dementia. Although the pooled results were insignificant, the trend was in the direction of favouring treatment (hence a negative value of the SMD). The standardized mean difference (SMD) was -1.22, with a 95% confidence interval (CI) (-4.08, 1.64). Kragt's result, weighted 47%, was significant in favour of treatment, with a SMD of -2.77 and a 95% CI (-4.24, -1.29). During the snoezelen session, Kragt's subjects presented significantly fewer apathetic behaviours (t=-8.22, p<0.01), fewer restless behaviours (t=-3.00, p=0.01), fewer repetitive behaviours (t=-.822, p<0.01), and fewer disturbances (t=-4.91, p<0.01). Baker's result was slightly not in favour of the treatment, with a SMD of 0.16 and a 95% CI (-0.41, 0.73). The control subjects touched objects/equipment more appropriately within the activity sessions than the subjects who participated in snoezelen sessions (F(1,47)=5.96, p=.001). Kragt did not examine the carryover and long-term effects of snoezelen, so only Baker's results were analysed. Baker used the Behavioural and Mood Disturbance scale (BMD), the REHAB, the CAPE and MMSE to assess patients mood, behaviour and cognition after (but not immediately after) four treatment sessions and eight treatment sessions. Some assessments were carried at home, some at day hospital. There were many subscores and mostly there were no differences between treatment and control. The following significant differences were found with benefit in favour of snoezelen compared with control after four sessions: apathy ezelen compared with control after four sessions: apathy score of the BRS (CAPE) (MD -3.00, 95%CIs -5.87 to -0.13, P=0.04), after eight sessions: mood score of the BRS (CAPE) (MD -2.60, 95%CIs -4.92 to -0.28, P=0.03), total score of the BRS (CAPE) (MD -6.92, 95%CIs -13.13 to -0.7, P=0.03), speech skills of the REHAB (MD 1.46, 95%CIs 0.01 to 2.82, P=0.03), psychomotor subscore of the cognitive assessment scale of CAPE (MD -3.12, 95%CIs -5.31 to -0.93, P<0.01).

REVIEWER'S CONCLUSIONS: Two trials were reviewed. Although both studies examined the short-term values of snoezelen on people with dementia, it is not feasible to draw a firm conclusion at this stage, for two main reasons. Firstly, very limited data were available for analysis, thus limiting data inference and generalization. Secondly, different methodology and control conditions were adopted in the two trials. Such variations not only require a careful interpretation of results but also make the comparison of results across studies less valid. Hence, there is an urgent need for more systematic and scientific research studies to examine the clinical value of snoezelen for people with dementia. To our knowledge, there are four RCTs currently in progress. It is hoped that the data and results of these trials will enrich the systematic review of snoezelen for dementia in the next update.