Page 153 - PhD GT

the purpose of collecting the same data again were given a brief explanation of the purpose of the project, were informed of what would happen to the data collected and were assured anonymity and confidentiality. Complete separation of the follow-up data from clinical case notes was assured and participants were informed that data collected at the first data collection point would be used for clinical decision making as well as for the follow-up project in the usual way. Assistance was offered in the event of difficulty understanding the instructions or the questions themselves. Encouragement to view follow-up as an opportunity (for reporting success, for remaining in contact) was given as was emphasis on the importance of knowing outcomes for patients attending a treatment agency.
For the purpose of the present study it was concluded that there was sufficient evidence for the accuracy of self-report data compared to more time consuming and intrusive methods to justify obtaining drinking and drug use data in as few questions as possible. The time scale was the past week unless the instrument used was validated specifically for a longer time frame. An attempt was made to ensure that participants who were intoxicated were not expected to complete the battery until they were sober. Even so it is acknowledged that, in the absence of concurrent breath and blood tests, it is not possible to establish sobriety with complete confidence and a rough and ready test of fitness to respond was applied.
The main instrument designed to measure dependence had been examined for readability and found to be satisfactory. Potential problems of recall were addressed by targeting a time span of one week in the brief interview and two of the instruments and the question "what do you usually do?" for another of the instruments. There was some question as to whether participants would have difficulty with recall for the Impaired Control Scale which enquires about the past three months, but this had already been reduced from six months with the first author's (Nick Heather, see Chapter 5) consent and problems in coming up with a summary for the past three months were thought to overshadow problems of recall. Nonetheless the usual problems of recall, usual that is, to the whole population and to excessive drinkers and drug users in particular, would apply.
Additional justification for the particular study protocol chosen was the availability of resources for the research and the pursuit of a set of instruments and methods that would be suitable for routine use in a busy clinic. To these were added the instruments designed to elucidate the nature of change in the condition being studied, namely dependence and these would not form part of the routine measures. Requirements for this were consistent with the restrictions on the research resource. The questions and the questionnaires should be as unintrusive as possible in that they were capable of completion within 10-20 minutes and they were a combination of a short interview
147