Predictors of future behaviour: A review of the psychological literature on blood donation

Purpose. This paper explores the relative efficacy of different theoretical models to predict future behaviour. The behaviour studied in this case was the number of future blood donations. Based on this review, a commentary is provided on possible practical interventions. Method. Studies were included if they tested a theory and measured the number of actual donations over time. Both conventional and meta-analytic techniques were used to ascertain the efficacy of various theoretical models to predict the number of future blood donations. Results. Intentionality, from the theory of planned/reasoned action, emerged as the best predictor of future donor behaviour, but appeared to offer little in the way of suggesting interventions. The predictive power of intentionality reduced as the time interval between its measurement and the recording of actual donor behaviour increased. A number of organizational factors (e.g. waiting time) were identified as important and good predictors of future behaviour. Such factors offer possible interventions. Further, the stage-like nature of blood donor behaviour is highlighted. Conclusions. The transtheoretical model of behaviour change is introduced both as a viable alternative to theories like reasoned action and a conceptual framework for organizing interventions. The transtheoretical model is seen as applicable to the blood donation situation as it captures something of the stages of blood donation. It is also argued that other theoretical perspectives (e.g. self-efficacy) need to be examined in this context.