Addressing omission bias in the treatment of osteoporosis: evidence from a cross-sectional study and a randomized experiment.

Objective: The use of bisphosphonates to manage osteoporosis has diminished as reports of rare, serious side effects have gained attention. Experts have warned of a 'crisis in osteoporosis treatment', calling for research on psychological processes underlying medication decisions. We observed that people's tendency to judge the lower risk of action (i.e. side effects) as worse than the higher risk of inaction (i.e. osteoporotic fracture) may be consistent with an omission bias. The present work explored psychological predictors of this phenomenon.

Methods: Two online studies were conducted with samples of female participants at risk for osteoporosis. Study 1 (N = 245) examined willingness to accept bisphosphonates in a series of risk statements as well as beliefs associated with medication acceptance. Study 2 (N = 396) randomly assigned participants to review educational (versus control) materials targeting these beliefs.

Results: In Study 1, 83% of participants exhibited an omission bias, and participants' willingness to accept medication was associated with certain beliefs (e.g. medication efficacy, susceptibility). However, the targeted educational materials in Study 2 did not significantly improve medication acceptance.

Conclusion: Findings elucidate the role of decision making biases in the treatment of osteoporosis and highlight the need for further intervention work in this area.