Table 1.

Latent Dirichlet allocation topic modeling for all Facebook posts, showing topic keywords and weights, topic interpretation, and example posts (N=34,885).

Topic number	Topic name	Top 10 keywords and weightsa	Interpretation by authors	Example of Facebook posts (paraphrased)
1	Heart health promotion	0.052*heart 0.022*health 0.018*disease 0.013*american 0.012*stroke 0.011*association 0.011*thank 0.011*join 0.010*live 0.009*support	Heart health–, heart disease–, and stroke-related events and support by organizations (eg, the American Heart Association)	The Heart Walk is how the American Heart Association mainly raises funds to prevent heart disease and stroke. It promotes physical activity and healthy heart living, and creates a family-friendly environment. On April 1st, a Saturday, the AHA is holding their annual Franklin County Heart Walk at the Washington City Fairgrounds Swine Pavilion at 9 a.m., with the walking starting at 10.
2	Sharing personal experiences	0.043*heart 0.018*attack 0.009*know 0.009*life 0.008*time 0.008*day 0.008*go 0.007*years 0.007*feel 0.007*family	Sharing personal and family stories related to heart disease and encouraging people to share their stories to increase public awareness	It's been 5 years since I had my heart attack. I waited for about 15 hours with symptoms coming and going before I decided to drive myself to the hospital. After my heart attack, I was traumatized by the fear of death, and I started to exercise and eat healthier. It’s important it is to know the symptoms and listen to your body because one day it could save your life.
3	Risk-reduction education	0.052*heart 0.027*disease 0.024*risk 0.023*blood 0.015*health 0.013*pressure 0.011*high 0.010*stroke 0.009*cholesterol 0.008*study	Risk reduction (eg, blood pressure and cholesterol) and lifestyle modification for heart health and disease and stroke	Eat something healthy and delicious in Barbecued salmon, sauteed zucchini, sweet potatoes, and asparagus. Control your heart health by lowering cholesterol and salt intake.
4	Heart disease and heart health promotion for women	0.053*women 0.048*heart 0.040*red 0.028*disease 0.012*attack 0.010*wear 0.008*available 0.008*symptoms 0.008*awareness 0.007*abstract	Promoting awareness of myocardial infarction symptoms for women and emphasizing characteristics of women’s myocardial infarction by the Go Red for Women Campaign	#GoRedForWomen today. We're bringing attention to women’s heart disease. Women have different warning signs for heart attacks.
5	Educational information sharing	0.050*article 0.047*video 0.042*content 0.035*presentation 0.023*information 0.021*health 0.013*heart 0.012*purpose 0.012*attack 0.012*general	Presenting articles and videos related to heart health and myocardial infarction information	Dr. A, Consulting Physical, discusses heart attack prevention.
6	Physicians’ live discussion sessions	0.065*dr 0.036*heart 0.027*cardiology 0.026*attack 0.023*discuss 0.020*page 0.018*cardiologist 0.018*facebook 0.016*pm 0.014*live	Live Facebook sessions by physicians to discuss myocardial infarctions	Dr. B discussed how to reduce cardiovascular events in a Facebook LIVE session.

^aThe asterisk (*) shows the weight of each keyword.