Table 1. Concepts and corresponding variables.

Concept	Variable	Category	Connotation	Examplea
Completeness	Completeness	Completeness of individual information	Disclosure of demographic and biographic information, including name, age, ID number, phone number, geographical information, photo [28,85].	Name: Real name of the patient, such as Aixia Li
				Age: Such as 65
				ID number: ID card number (18 digits in China)
				Phone number: Phone number of the patient or related person
				Geographical information: Such as Qibiao Community, Hongshan Ave.
				Photo: Photo of the patient
		Completeness of disease status	Disclosure of disease status, including disease development, diagnostic report, chest X-ray photo, medical record, underlying disease, personal experience [45,86].	Disease development: "My father couldn't get out of bed four days ago. In the next two days, he became unconscious!"
				Diagnostic report: Such as blood test report
				Chest X-ray photo: Photo of chest X-ray
				Medical record: Such as treatment record
				Underlying disease: Such as history of hypertension
				Personal experience: "I have asked the @Wuhan Hotline account and Guanshan Community for help, but none of them can arrange hospitalization."
Proximity	Reporting type	Reporting self-illness	Seeking help by disclosing one's own and immediate family members' COVID-19 sickness [4].	"I was infected with coronavirus, need help."
		Reporting others' illness	Seeking help by mentioning or reporting others' COVID-19 sickness [4].	"I forward this post from a confirmed patient in Wuhan City, he was infected with COVID-19 but is in a severe shortage of medical care."
		Both	Reporting self-illness and others' illness simultaneously.	"I got infected when taking care of my sick mother. My friend, who lives outside Hubei Province, also infected with this pneumonia."
Support typology	Support seeking type	Emotional support seeking	Emotional support involves acting as a confidant for someone, providing empathy or other positive affection toward people who suffer from misfortune [59–61].	"I have a low fever these nights, so afraid. Can someone give me some comfort?"
		Instrumental support seeking	Instrumental support means offering assistance tangibly or physically, such as donating money, providing medical supplies to someone in sickness [59–61].	"My mother is in urgent need of a sickbed, can someone help me contact an available hospital?"
		No specific kind of support	Not mention any specific kind of support seeking.	“Who can help them?”
Severity	Stage of illness	Suspected	Patients with some COVID-19 infection symptoms but not get laboratory-confirmed [87].	"I took a chest X-ray, and the doctor said I am a suspected case. But I haven't taken a nucleic acid test yet."
		Confirmed	Patients who get laboratory-confirmed [87].	"The nucleic test is positive. It turns out I was infected with the coronavirus."
		Others	Unknown status.	Illness status is not mentioned.
Emotion	Emotional type	Fear	An emotion experienced in anticipation of some specific pain or danger. Fear is predicated on the belief that the individual faces impending danger over which he or she may have little or no control [73].	"At present, Mr. Zhao is in critical condition. He has been sent to the intensive care unit of Central South Hospital. He is in urgent need of blood plasma of type O from recovered patients."
		Anger	The health system and government may evoke anger due to their incapability to provide the necessary protection. Particular individuals can also stir up anger for transmitting the disease [88].	"I'm furious at the work efficiency of local hospitals!!!"
		Sadness	Sorrow and sadness are commonly experienced for loss [88] and irrevocable failure to meet the goal [73].	"I feel too sad and helpless in front of this pneumonia, will you help me?"
		Others	Other emotions except fear, anger, and sadness.	"I hope everything will get better soon."

^a All examples come from posts in our research corpus (translated from Chinese).