Designing a gamma hydroxybutyrate (GHB) structured telephone-administered survey instrument.

Abstract

As part of a larger study assessing the covariates and outcomes of GHB use, we developed a telephone-survey instrument for hospitalized GHB exposed patients identified through poison control center surveillance and for self-identified GHB users recruited from the general public. We used an iterative review process with an interdisciplinary team, including pharmacists, a physician, and a medical anthropologist. In designing the structured, telephone-survey instrument, we prioritized inclusion of validated, drug-specific, and generic questionnaire batteries or individual items related to GHB or to other drugs of abuse. Only one published survey instrument specific to GHB use was identified, which we extensively expanded and modified. We also developed a number of GHB-specific items new to this survey. Finally, we included items from the National Survey on Drug Use & Health, CAGE questionnaire items on alcohol abuse, the SF-12 instrument, and selected National Health Interview items. The final questionnaire consisted of 272 content items, the majority of which required simple yes or no responses. The bulk of the items (74%) were GHB-specific. The questionnaire was easily administered using computer-assisted telephone interview (CATI) software. A total of 131 interviews were administered with a mean administration time of 33+/-10 minutes. The instrument can also be used in other interview formats. Developing a successful questionnaire calls for a multidisciplinary and systematic process. Structured, telephone administered surveys are particularly suited to expand and explore the basic information obtained by poison centers for case management.