TO HAVE OR NOT TO HAVE PSA TEST? IS THE DECISION AFFECTED BY WHETHER INFORMATION IS PRESENTED SEQUENTIALLY VS. ALL-AT-ONCE?

Purpose: An essential prerequisite of patient decision making is that the patient must be fully informed, especially when the decision is a preference-sensitive one, such as whether to undergo prostate cancer screening. However, the way information is provided to individuals might affect their decision. In the present studies, we examined the effect of two information presentation methods on people’s willingness to undergo screening depending on whether the information was presented all-at-once or as a series of sequential decisions.

Method: Participants indicated their willingness to engage in each behavior either right after reading each piece of information (sequential) or after reading all information.

Result: Study 1 examined decision making for a generic cancer on a sample of 336 participants (n = 218 females; age 25 to 71, M = 38.06, SD = 11.24). Relative to when the information was presented all at once, when the presentation was sequential, individuals showed a higher willingness to undergo the screening tests, both blood test (M = 4.07 vs. 4.52, t (334) = -2.52, p = .012) and biopsy (M = 3.66 vs. 4.07, t (334) = -2.09, p = .037), but also a stronger preference for watchful waiting (M = 3.29 vs. 2.65, t (334) = 3.33, p = .001). Study 2 investigated specifically prostate cancer, with a bigger ( N = 1541) and more specific sample (only male participants; age 40 to 71, M = 54.51, SD = 8.27), providing detailed and longer information, similarly to a patient decision aid. The effect of the two presentation methods disappeared (i.e., the differences between conditions were no longer significant) when the complexity of the information provided was increased, the target cancer was identified, and the respondents were in the age range to which the screening is usually proposed.

Conclusion: The results from Study 1 suggest that presenting information sequentially or all at once can affect decision making, in line with previous findings highlighting the potential effect of the way in which information is provided on people’s decision. However, in Study 2 the way in which information was presented did not affect prostate cancer screening decisions. Possible explanations are discussed, among which: a) limited vs. extensive information; b) generic vs. specific topic; and c) gender and age restrictions on the sample.