Page 69 - PhD GT

“There are few items which directly correspond to a ‘drive to consume alcohol’ as indicated by, for example ‘the salience of drink seeking behaviour’ or ‘narrowing of drinking repertoire’ since it was felt that such variables were too subtle for a simple inventory to cope with.” (p. 80)
It is not clear then, what is the basis of the earlier claim. Factor analysis of the SADQ can neither be claimed as evidence of the unidimensionality of the core construct of alcohol dependence nor can it be said to measure this core construct on the basis of the statement made by the authors of the questionnaire that some of the elements of the syndrome were not addressed in the questionnaire at all.
It has been argued that the factorial structure of a particular scale may ultimately tell us more about the scale items than the syndrome (Davidson et al. 1989) and the application of factor analysis alone cannot tell us about source constructs; it needs to be applied within a rigorous and comprehensive programme of scientific work. Further validation of the SADQ was reported in 1983 (Stockwell et al. 1983) when the authors again claimed:
“support for the existence of a cluster of related phenomena, arranged upon a continuum of severity and corresponding to the essential elements of the ‘alcohol dependence syndrome’.” (p. 146)
By this time the SADQ had been reduced to a 20 item scale in five sections with four items in each section. The respondent is asked about a previous month “typical of their heavy drinking” and this instruction could be varied according to the needs of the study in which the scale was being used. Test re-test reliability is reported as well as the ability of the scale to discriminate between patient populations being treated for problems of alcohol dependence compared to patients being treated at a liver unit.
SADQ scores were compared with a measure of ‘narrowing of drinking repertoire’ which was ascertained by the Drinking Pattern Interview, an interview schedule designed as a variability index with which it was hypothesised that SADQ scores would show negative correlation. This was shown to be the case. Again it is not entirely clear how the authors can claim that the SADQ measures the core elements of the alcohol dependence syndrome, of which narrowing of the
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