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The effect of alternative summary statistics for communicating risk reduction on decisions about taking statins: a randomized trial.

Carling CL, Kristoffersen DT, Montori VM, Herrin J, Sch√ľnemann HJ, Treweek S, Akl EA, Oxman AD - PLoS Med. (2009)

Bottom Line: There were no significant differences among the absolute summary statistics in the association between RIS and participants' decisions whether to take statins.Natural frequencies may be the most suitable summary statistic for presenting treatment effects, based on self-reported preference, understanding of and satisfaction with the information, and confidence in the decision.ISRCTN85194921.

View Article: PubMed Central - PubMed

Affiliation: Norwegian Knowledge Centre for the Health Services, Oslo, Norway. cheryl.carling@kunnskapssenteret.no

ABSTRACT

Background: While different ways of presenting treatment effects can affect health care decisions, little is known about which presentations best help people make decisions consistent with their own values. We compared six summary statistics for communicating coronary heart disease (CHD) risk reduction with statins: relative risk reduction and five absolute summary measures-absolute risk reduction, number needed to treat, event rates, tablets needed to take, and natural frequencies.

Methods and findings: We conducted a randomized trial to determine which presentation resulted in choices most consistent with participants' values. We recruited adult volunteers who participated through an interactive Web site. Participants rated the relative importance of outcomes using visual analogue scales (VAS). We then randomized participants to one of the six summary statistics and asked them to choose whether to take statins based on this information. We calculated a relative importance score (RIS) by subtracting the VAS scores for the downsides of taking statins from the VAS score for CHD. We used logistic regression to determine the association between participants' RIS and their choice. 2,978 participants completed the study. Relative risk reduction resulted in a 21% higher probability of choosing to take statins over all values of RIS compared to the absolute summary statistics. This corresponds to a number needed to treat (NNT) of 5; i.e., for every five participants shown the relative risk reduction one additional participant chose to take statins, compared to the other summary statistics. There were no significant differences among the absolute summary statistics in the association between RIS and participants' decisions whether to take statins. Natural frequencies were best understood (86% reported they understood them well or very well), and participants were most satisfied with this information.

Conclusions: Presenting the benefits of taking statins as a relative risk reduction increases the likelihood of people accepting treatment compared to presenting absolute summary statistics, independent of the relative importance they attach to the consequences. Natural frequencies may be the most suitable summary statistic for presenting treatment effects, based on self-reported preference, understanding of and satisfaction with the information, and confidence in the decision.

Clinical trials registration: ISRCTN85194921.

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Related in: MedlinePlus

Introduction to the scenario prior to eliciting values.
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pmed-1000134-g001: Introduction to the scenario prior to eliciting values.

Mentions: After choosing to log onto either the Norwegian or English-language version of the study Web site, participants received information about the study and gave informed consent to participate. Then, participants reviewed a hypothetical scenario involving themselves as patients with elevated cholesterol whose doctors had offered them the option of taking pills (statins) to lower blood cholesterol levels to reduce their risk of CHD (Figure 1). They learned that they had to take a pill each day and incur an out-of-pocket cost for the pills of US $50 (400 NOK) per month.


The effect of alternative summary statistics for communicating risk reduction on decisions about taking statins: a randomized trial.

Carling CL, Kristoffersen DT, Montori VM, Herrin J, Sch√ľnemann HJ, Treweek S, Akl EA, Oxman AD - PLoS Med. (2009)

Introduction to the scenario prior to eliciting values.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2724738&req=5

pmed-1000134-g001: Introduction to the scenario prior to eliciting values.
Mentions: After choosing to log onto either the Norwegian or English-language version of the study Web site, participants received information about the study and gave informed consent to participate. Then, participants reviewed a hypothetical scenario involving themselves as patients with elevated cholesterol whose doctors had offered them the option of taking pills (statins) to lower blood cholesterol levels to reduce their risk of CHD (Figure 1). They learned that they had to take a pill each day and incur an out-of-pocket cost for the pills of US $50 (400 NOK) per month.

Bottom Line: There were no significant differences among the absolute summary statistics in the association between RIS and participants' decisions whether to take statins.Natural frequencies may be the most suitable summary statistic for presenting treatment effects, based on self-reported preference, understanding of and satisfaction with the information, and confidence in the decision.ISRCTN85194921.

View Article: PubMed Central - PubMed

Affiliation: Norwegian Knowledge Centre for the Health Services, Oslo, Norway. cheryl.carling@kunnskapssenteret.no

ABSTRACT

Background: While different ways of presenting treatment effects can affect health care decisions, little is known about which presentations best help people make decisions consistent with their own values. We compared six summary statistics for communicating coronary heart disease (CHD) risk reduction with statins: relative risk reduction and five absolute summary measures-absolute risk reduction, number needed to treat, event rates, tablets needed to take, and natural frequencies.

Methods and findings: We conducted a randomized trial to determine which presentation resulted in choices most consistent with participants' values. We recruited adult volunteers who participated through an interactive Web site. Participants rated the relative importance of outcomes using visual analogue scales (VAS). We then randomized participants to one of the six summary statistics and asked them to choose whether to take statins based on this information. We calculated a relative importance score (RIS) by subtracting the VAS scores for the downsides of taking statins from the VAS score for CHD. We used logistic regression to determine the association between participants' RIS and their choice. 2,978 participants completed the study. Relative risk reduction resulted in a 21% higher probability of choosing to take statins over all values of RIS compared to the absolute summary statistics. This corresponds to a number needed to treat (NNT) of 5; i.e., for every five participants shown the relative risk reduction one additional participant chose to take statins, compared to the other summary statistics. There were no significant differences among the absolute summary statistics in the association between RIS and participants' decisions whether to take statins. Natural frequencies were best understood (86% reported they understood them well or very well), and participants were most satisfied with this information.

Conclusions: Presenting the benefits of taking statins as a relative risk reduction increases the likelihood of people accepting treatment compared to presenting absolute summary statistics, independent of the relative importance they attach to the consequences. Natural frequencies may be the most suitable summary statistic for presenting treatment effects, based on self-reported preference, understanding of and satisfaction with the information, and confidence in the decision.

Clinical trials registration: ISRCTN85194921.

Show MeSH
Related in: MedlinePlus