Step 7: Excluding non-dependence items

The 66 items were reviewed to ensure that they assessed dependence on BZDs. Items that asked about the frequency and strength of problems that the respondents thought were caused by BZDs were discarded. Other items unrelated to BZD dependence were also excluded leaving 51 items. The items excluded in this step are marked in Table 7 with a cross. The coefficient alpha of the 51 item scale was 0.916.