Multi-Sensory Stimulation in 24-hour Dementia Care - Nivel

Selection method
A first selection for inclusion was performed by the first author (RV). On the basis of
titles and abstracts all studies that clearly did not meet one of the four inclusion
criteria were excluded from the review. If there was any doubt about meeting the
inclusion criteria, the full article was ordered. A second selection was made by two
reviewers independently (RV, JvW). On the basis of the full articles the two
reviewers checked if the studies satisfied all four criteria. Disagreements regarding
inclusion status were resolved by discussion. If no consensus could be met, a third
reviewer (AF) was consulted.
Assessment of methodological quality
The methodological quality of the selected RCTs and CCTs was rated by a list
developed by Van Tulder (1997). This list, containing specified criteria proposed by
Jadad (1996) and Verhagen et al. (1998) consists of 11 criteria for internal validity, 6
descriptive criteria and 2 statistical criteria (table 2.2). The list was developed in
close contact with the Dutch Cochrane Centre.
The criteria mentioned in table 2.2 were operationalised to the specific area of
psychogeriatrics by the first author. After discussion with the second and third
author, agreement about the operationalization was reached. An example is the
operationalization of criterion e 'was the care provider blinded for the intervention?'
to 'did the care provider know which was the experimental condition and which the
control?'. More information about the operationalization of the criteria is available
from the first author. All criteria were scored as yes, no, or unclear. Equal weight was
applied to all items. Studies were considered to be of ‘high quality’ if at least 6
criteria for internal validity, 3 descriptive criteria and 2 statistical criteria were scored
positively. Otherwise, studies were considered of ‘low quality’. The methodological
quality of the included trials was independently assessed by two reviewers (RV,
JvW). The assessments were compared and disagreements were resolved by
discussion.
34 Multi-Sensory Stimulation in 24-h dementia care