Page 88 - PhD GT

Chapter 4
Preliminary work - Studies and Samples - the Leeds Dependence Questionnaire
4.0 Introduction
In this chapter, the studies which I conducted for the purpose of investigating the nature of change in substance dependence, the measurement of such change and exploration of the study hypotheses are described.
In the previous chapter, a number of scales for the measurement of dependence were compared and the rationale for selection of the Leeds Dependence Questionnaire (LDQ) was described; the same rationale informed the development and routine use of the scale at the Leeds Addiction Unit, the agency in which the studies in this thesis were conducted. The four response choices in the scale were selected in line with the recommendation of Oppenheim (1992) who suggested avoiding the use of five response choices as this number tends to provide the opportunity for a mid-point to act as a ‘don’t know’ option. I conducted a small scale study at the outset to re-visit the question of the four response choices, their meaning and whether they can be said equally to represent the range of dependence severity. Furthermore, it was my view that for the scale adequately to measure change in dependence, and to measure dependence as a psychological phenomenon, related to but different from use of the substance, it needed to be shown to be capable of measurement of dependence during abstinence. Further work which I conducted to investigate the performance of the scale with abstinent respondents is reported in this chapter.
In the first part of this chapter, the preliminary studies that I conducted for the purpose of investigating further the psychometric properties both of the LDQ and of some of the other main study instruments are listed (see section 4.1 below). The samples which I recruited for these studies are then described and the samples used in each of the studies are presented in Table 4.1. The second part of the chapter, sections 4.2, 4.3 and 4.4, contains descriptions of the further work which I carried out on the LDQ in preparation for the main study.
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