Testing verbal quantifiers for social norms messages in cancer screening: evidence from an online experiment

Sandro T. Stoffel,Maria Goodwin,Christian von Wagner,Monika Sieverding,Ivo Vlaev

doi:10.1186/s12889-019-6997-5

Abstract

BackgroundStudies have shown that presenting correct information about group norms to correct misperceptions of norms can influence health behaviours. In two online studies we investigated how different ways of communicating the current uptake of 43% of the English Bowel Scope Screening (BSS) programme affects intention among disinclined men and women.MethodsIn the first study, 202 participants were asked to interpret eight quantifiers for 43% uptake (‘few’, ‘many’, ‘a considerable number’, ‘a large number’, ‘a great number’, ‘a lot’, ‘numerous’ and ‘nearly half’) and to indicate how misleading they perceived each of them to be. In the second study, with 1245 participants, we compared the motivational impact of two quantifiers (‘a large number’ and ‘nearly half’ which were associated with the highest perceived uptake (48.9%) and considered least misleading in study 1 respectively) with a control message that did not contain any information on uptake, and a message which communicated actual uptake as a proportion (43%).ResultsWhile we found that both verbal quantifiers increased screening intentions compared with the control group (from 7.8 to 12.5%, aOR 1.72; 95%CI 1.00–2.96 in the case of ‘a large number’ and 14.3%, aOR 2.02; 95%CI 1.20–3.38 for ‘nearly half’), simply communicating that 43% do the test, however, had no impact on intentions (9.9% vs. 7.8% aOR 1.25; 95%CI 0.73–2.16).ConclusionVerbal quantifiers can be used to improve the perception of low uptake figures and avoid a demotivating effect.

Highlights

Studies have shown that presenting correct information about group norms to correct misperceptions of norms can influence health behaviours
There was a strong positive correlation between perceived accuracy and the quantifier rated best for public communication, indicating that participants thought that the public information campaigns should communicate accurate information (r (202) = .716, p < 0.001)
While most participants who read the additional information about the risk and benefits of the screening test got around 2 out of 3 comprehension questions right, a Kruskal-Wallis test did not reveal any differences in Bowel Scope Screening (BSS) knowledge across the conditions (χ2 = 2.59, p = 0.274, df = 2)

Summary

Introduction

Studies have shown that presenting correct information about group norms to correct misperceptions of norms can influence health behaviours. Two studies have failed to encourage screening behaviour by communicating high uptake and preferences for a specific screening test, but they used relatively low social norms messages [15;16]. In Sieverding and colleagues’ experimental study with men aged 45 or older, they compared intentions following either a high (65%), low (18%) or no prevalence message [15]. They found that men in the low-prevalence group reported less intention to undergo cancer screening and were less likely to leave

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Results

Conclusion