Table 5.

Post-hoc examination of interactions: United States, 2017–2018

	Trust		Perceived risk
Tweet elements	Proportion with trust	OR (95% CI)	Proportion with high perceived risk	OR (95% CI)
Misinformation × Source
Misinformation, from a person
Yes	50%		27%	Ref
No	47%	n/a	14%	0.30 (0.17, 0.51)**
Misinformation, from an organization
Yes	46%		25%	Ref
No	63%	n/a	27%	0.91 (0.61, 1.36)
Misinformation × Topic
Misinformation, about vaccine safety
Yes	52%		30%
No	50%	n/a	9%	0.18 (0.10, 0.32)**
Misinformation, about vaccine effectiveness
Yes	44%		23%	Ref
No	61%	n/a	32%	1.49 (1.01, 2.20)
Misinformation × Source × Topic
Misinformation, from a person about vaccine safety
Yes	59%	Ref
No	40%	0.45 (0.28, 0.72)**		n/a
Misinformation, from a person about vaccine effectiveness
Yes	40%	Ref
No	55%	1.84 (1.15, 2.94)*		n/a
Misinformation, from an organization about vaccine safety
Yes	44%	Ref
No	60%	1.91 (1.21, 3.04)**		n/a
Misinformation, from an organization about vaccine effectiveness
Yes	48%	Ref
No	66%	2.18 (1.38, 3.47)**		n/a
Source × Narrative style × Topic
Source, of story about vaccine safety
Person	50%	Ref	16%	Ref
Organization	54%	1.18 (0.75, 1.88)	26%	3.09 (1.34, 7.11)**
Source, of story about vaccine effectiveness
Person	59%	Ref	32%	Ref
Organization	55%	0.84 (0.53, 1.33)	40%	1.39 (0.86, 2.24)
Source, of data about vaccine safety
Person	49%	Ref	21%	Ref
Organization	50%	1.04 (0.65, 1.65)	14%	0.80 (0.38, 1.70)
Source, of data about vaccine effectiveness
Person	36%	Ref	13%	Ref
Organization	60%	2.70 (1.68, 4.33)**	24%	2.18 (1.18, 4.02)*

Note. Findings are from a post-hoc tests of statistically significant interactions (p<.01) present for both trust and perceived risk (see Table 4). OR = Odds ratio; CI = confidence interval; Ref = Reference group; n/a = Not applicable, interaction was not statistically significant for perceived risk and 2-way interactions (misinformation × source and misinformation × topic) were part of 3-way interaction for trust.

^*p=.01;

^**p<.01