Methods: Using freely available online news items, we created a composite news article about a health decision that evokes diverse views: home birth. We then selected comments that had been posted on the original articles and classified them as either (a) positive or negative about the topic of home birth and (b) fact-oriented or story-oriented. We conducted a between-subjects factorial online experiment in a demographically diverse, US-based sample population: N = 1703; mean age 49 (SD 16); 51% female; 80% white; 49% no college. All participants read the same mock news article, but we experimentally manipulated whether or not comments were posted to the article and what types of comments were shown. After participants viewed the materials, we asked them to indicate their overall opinion of home birth on a scale from ‘extremely negative opinion’ (value 0) to ‘extremely positive opinion’ (value 100). We also asked their likelihood of planning a home birth if they or a partner were to be expecting a child, and of recommending home birth to others (secondary outcomes). To account for the potential influence of prior opinions and knowledge, we asked them to indicate how much they felt they knew about home birth before reading the article: ‘Nothing’, ‘A little bit’, or ‘A lot’.
Results: Opinions of home birth ranged widely (median 51, IQR 46) and were significantly influenced by the presence of positive versus negative comments (means: 63 for positive versus 39 for negative, p<.0001). Story-oriented comments exerted greater influence on opinions than fact-oriented comments (differences between positive and negative: 27 for story-oriented versus 19 for fact-oriented, p<.0001). Although people who felt more knowledgeable about home birth had more positive opinions overall, effects of experimental factors were consistent regardless of prior knowledge. Results for secondary outcomes followed similar patterns.
Conclusions: Comments posted on an online health news article can powerfully influence readers’ opinions and potential decision intentions, regardless of their prior knowledge on the topic. Last year, 72% of US-based Internet users sought health information online, suggesting that this finding may be very broadly applicable.
See more of: The 35th Annual Meeting of the Society for Medical Decision Making