We consider a stage life testing model and assume that the information at which levels the failures occurred is not available. In order to find estimates for the lifetime distribution parameters, we propose an EM-algorithm approach which interprets the lack of knowledge about the stages as missing information. Furthermore, we illustrate the implementation difficulties caused by an increasing nu...

Stage theories of health behavior change assume that individuals pass through qualitatively different stages on their way to the adoption of health behaviors. Three common stages (preintention, intention and action) can be defined by stage transitions included in current stage theories and supported by evidence. The present study examines whether transitions between these stages can be predicte...

Insight into stage transition determinants is necessary to develop and evaluate stage-tailored health-promoting interventions. A three-round Delphi study among stages of change researchers was conducted to make an inventory of opinions and examine agreement on determinants of forward transitions between Transtheoretical stages of change. In the first round, 10 experts completed an electronic qu...