Genetic screening for Alzheimer's disease: what factors predict intentions to take a test?

The authors investigated factors that predict intention to take a genetic test for Alzheimer's disease (AD). The 449 men and women were surveyed in two groups: (a) those told that a positive result meant a 90% chance of developing AD (increased certainty) and (b) those told that a positive result meant a 50% chance of developing AD (decreased certainty). Participants completed measures of the Theory of Planned Behavior (TPB), anticipated regret, risk perception, likelihood of taking a genetic test for cancer, and AD risk factors. Just over 50% of the variance in intentions was related to TPB variables, likelihood of taking a genetic test for cancer, number of people the participants knew who had AD, experimental condition, and anticipated regret. The subjective norm was the strongest predictor of intention in the increased certainty group, whereas positive belief was the strongest predictor in the decreased certainty group.