Homogeneity of the 23-itemversion of the instrumentwas assessed
with item-total correlations (Spearman rank correlations rs, two tailed
probability). The correlation of each individual item was calculated
when the score of that particular item had been omitted from the total
sum score (Streiner and Norman, 2003). The item-total correlations for
these 23 items are displayed in Table 1 together with Cronbach's alpha
(Cronbach, 1951) values if items were deleted. The homogeneity of the
total scale measured by the Cronbach's alpha coefficient reached a value
of 0.60. Eleven items that did not reach a value of rs≥0.20, as
recommended by Streiner and Norman (2003), or did not correlate
significantlywith the total sumscore,weredeleted fromthe instrument.
This version with 12 items was considered to be the new instrument
that should be tested for reliability and validity in this initial study.