3. Results
3.1. Normality and outlying data
Prior to the analysis, and on the basis of Tabachnick and Fidell’s
(1996) criteria, data were screened for univariate and multivariate
outliers and for normality. Functional status scores were negatively
skewed, so that a reflect and square root transformation of
this variable was carried out. Negative kurtosis was found for the
cognitive status scores, and a reflect and logarithm transformation
was performed. Mental health scores were positively skewed, and
a square root transformation was carried out. As regards outlying
data, one univariate outlier was found for the leisure time variable,
and was deleted. No multivariate outliers were found (Mahalanobis
distance at p < 0.001). Sociodemographic data for the
resulting sample are shown in Table 1 and the descriptive statistics
for the assessed variables are in Table 2.
Cognitive status: Care recipient’s cognitive status was measured
with the Short Portable Mental Status Questionnaire (Pfeiffer,
1975), a 10-item instrument for detecting the presence of
intellectual impairment. The scale had good internal consistency
(Cronbach’s a = 0.94).