Brief report: An extension of the sequential alternating treatment design using reversals with subjects not available concurrently
✍ Scribed by Daniel D. Houlihan; Robert N. Jones; Howard N. Sloane; Joni Cook
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 395 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1072-0847
No coin nor oath required. For personal study only.
✦ Synopsis
This brief report proposes an extension of the traditional Alternating Treatments Design that would be acceptable to use in hospital and residential settings where subjects are often not concurrently available. Concerns about the inability of traditional designs to work in these special situations and the emergence of a "scientist-practitioner split" are discussed. An example of how the Extended Alternating Treatments Design might be used is provided. Recently, Wacker et al. (1990) described what they call the sequential alternating treatments design to compare two treatments. The design involves three phases with each subject. A traditional baseline is not required. In the initial phase, Treatment A and Treatment B alternate, each presented in a different location or at a different time. In Phase 2, Treatment A is presented in both situations and in Phase 3 Treatment B is presented in both situations. In addition, to increase internal validity, Wacker et al. (1990) suggested presenting the three phases in a time-lagged manner over three or more subjects. This is necessary as there are no reversals or comparisons in adjacent phases after the initial alternating treatment component. Thus, the design combines aspects of an alternating treatments design and a multiple baseline design.
Often, a no-treatment baseline is not possible due to clinical considerations or other ethical or pragmatic concerns, and the design proposed by Wacker