Reducing demand for ineffective health remedies: overcoming the illusion of causality

Authors: MacFarlane, D., Hurlstone, M.J. and Ecker, U.K.H.

Journal: Psychology and Health

Volume: 33

Issue: 12

Pages: 1472-1489

eISSN: 1476-8321

ISSN: 0887-0446

DOI: 10.1080/08870446.2018.1508685

Abstract:

Objective: We tested a novel intervention for reducing demand for ineffective health remedies. The intervention aimed to empower participants to overcome the illusion of causality, which otherwise drives erroneous perceptions regarding remedy efficacy. Design: A laboratory experiment adopted a between-participants design with six conditions that varied the amount of information available to participants (N = 245). The control condition received a basic refutation of multivitamin efficacy, whereas the principal intervention condition received a full contingency table specifying the number of people reporting a benefit vs. no benefit from both the product and placebo, plus an alternate causal explanation for inefficacy over placebo. Main outcome measures: We measured participants’ willingness to pay (WTP) for multivitamin products using two incentivized experimental auctions. General attitudes towards health supplements were assessed as a moderator of WTP. We tested generalisation using ratings of the importance of clinical-trial results for making future health purchases. Results: Our principal intervention significantly reduced participants’ WTP for multivitamins (by 23%) and increased their recognition of the importance of clinical-trial results. Conclusion: We found evidence that communicating a simplified full-contingency table and an alternate causal explanation may help reduce demand for ineffective health remedies by countering the illusion of causality.

Source: Scopus

Reducing demand for ineffective health remedies: overcoming the illusion of causality.

Authors: MacFarlane, D., Hurlstone, M.J. and Ecker, U.K.H.

Journal: Psychol Health

Volume: 33

Issue: 12

Pages: 1472-1489

eISSN: 1476-8321

DOI: 10.1080/08870446.2018.1508685

Abstract:

OBJECTIVE: We tested a novel intervention for reducing demand for ineffective health remedies. The intervention aimed to empower participants to overcome the illusion of causality, which otherwise drives erroneous perceptions regarding remedy efficacy. DESIGN: A laboratory experiment adopted a between-participants design with six conditions that varied the amount of information available to participants (N = 245). The control condition received a basic refutation of multivitamin efficacy, whereas the principal intervention condition received a full contingency table specifying the number of people reporting a benefit vs. no benefit from both the product and placebo, plus an alternate causal explanation for inefficacy over placebo. MAIN OUTCOME MEASURES: We measured participants' willingness to pay (WTP) for multivitamin products using two incentivized experimental auctions. General attitudes towards health supplements were assessed as a moderator of WTP. We tested generalisation using ratings of the importance of clinical-trial results for making future health purchases. RESULTS: Our principal intervention significantly reduced participants' WTP for multivitamins (by 23%) and increased their recognition of the importance of clinical-trial results. CONCLUSION: We found evidence that communicating a simplified full-contingency table and an alternate causal explanation may help reduce demand for ineffective health remedies by countering the illusion of causality.

Source: PubMed

Reducing demand for ineffective health remedies: overcoming the illusion of causality.

Authors: MacFarlane, D., Hurlstone, M.J. and Ecker, U.K.H.

Journal: Psychology & health

Volume: 33

Issue: 12

Pages: 1472-1489

eISSN: 1476-8321

ISSN: 0887-0446

DOI: 10.1080/08870446.2018.1508685

Abstract:

Objective

We tested a novel intervention for reducing demand for ineffective health remedies. The intervention aimed to empower participants to overcome the illusion of causality, which otherwise drives erroneous perceptions regarding remedy efficacy.

Design

A laboratory experiment adopted a between-participants design with six conditions that varied the amount of information available to participants (N = 245). The control condition received a basic refutation of multivitamin efficacy, whereas the principal intervention condition received a full contingency table specifying the number of people reporting a benefit vs. no benefit from both the product and placebo, plus an alternate causal explanation for inefficacy over placebo.

Main outcome measures

We measured participants' willingness to pay (WTP) for multivitamin products using two incentivized experimental auctions. General attitudes towards health supplements were assessed as a moderator of WTP. We tested generalisation using ratings of the importance of clinical-trial results for making future health purchases.

Results

Our principal intervention significantly reduced participants' WTP for multivitamins (by 23%) and increased their recognition of the importance of clinical-trial results.

Conclusion

We found evidence that communicating a simplified full-contingency table and an alternate causal explanation may help reduce demand for ineffective health remedies by countering the illusion of causality.

Source: Europe PubMed Central