Going to the hospital with COVID-19 symptoms can be a tough call. This Penn text program makes it easier.

Saladin Webb had a sore throat and difficulty breathing in early April. Jessica Waber had the same, plus a fever and upset stomach.

In normal times, many with those symptoms would head to the emergency room. But with hospitals scrambling to preserve resources for the sickest patients in a pandemic, how should people with COVID-19 decide whether to go?

And can they take steps to keep symptoms from getting worse, maximizing their likelihood of being able to stay home?

As with so many other questions about the coronavirus, absolute certainty remains elusive. And physicians remain concerned about a related problem: people with other emergencies who stay away from the hospital for fear of becoming infected. If you have symptoms of a possible heart attack (chest pain) or stroke (drooping face, unexplained weakness in one arm, or sudden confusion and difficulty speaking), do not hesitate. Seek medical attention fast.

For people infected with the coronavirus, one way to obtain clarity may lie in a Penn Medicine project called COVID Watch. Homebound patients are prompted twice a day to text updates on their condition, helping nurses and doctors to identify who needs hospital care.

Webb, 36, of Glassboro, is among more than 3,000 Penn patients who have enrolled in the program since it began March 23. An additional 100 or so have signed up from the Main Line Health system, which joined the program a few weeks later at Penn’s invitation.

The series of automated questions has been tweaked a few times as Penn researchers analyzed how well it was helping them identify the sickest patients, but the two most important have always been “How are you feeling compared to 12 hours ago?” and “Is it harder than usual for you to breathe?”

An answer of “worse” to the first prompt or “yes” to the second results in a phone call from a live person.

On April 12, Webb texted both of those responses. Within 10 minutes, he got a call from Catherine Armetta, a nurse at the Hospital of the University of Pennsylvania.

“I was like, ‘Whoa!’” he recalled.

Difficulty breathing is a warning sign, but it does not necessarily mean a hospital visit is needed.

Armetta asked Webb whether he was able to walk to the bathroom and go about his other daily activities without his breathing growing worse. He was. And he spoke easily, not needing to pause in the middle of sentences. The nurse advised him to stay at home.

“I did not hear any red flags,” she said.

She also gave him tips on using an inhaler that had been prescribed by his primary-care physician, and reminded him he could always text or call back if his symptoms grew worse. (In some cases, patients are given a pulse oximeter — a device that measures oxygen levels in the blood.)

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Roughly 12% to 15% of patients “escalate” to needing a live phone call at some point within two weeks of enrolling in the automated-texting program, said David Asch, director of Penn’s Center for Health Care Innovation.

More than half of those who are called, like Webb, end up being counseled to stay home, suggesting that the program is casting a broad net. But that is fine, Asch said. The real problem would be if it missed patients who did need the hospital, and so far no such “false negatives” seem to have occurred, Asch said.

Clarity has been harder to achieve for Waber, 36, a Center City resident who was not part of the texting program.

She experienced initial symptoms the first week of April, before the virus was widespread in Philadelphia. The symptoms seemed mild at first, and Waber, an English teacher at Masterman School, wondered whether she had COVID-19.

But on the sixth day of her illness, she felt terrible chest pain, almost as if she had a bruise on her sternum. That is not the type of chest pain normally associated with a heart attack, so she thought maybe it was the virus. Her physician suggested she wait a day or two to see whether she felt better.

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She drank Gatorade, walked around her apartment, and stretched her arms, reasoning that staying in motion would help her lung function. She got down on all fours, which immediately made the chest pain subside — a home equivalent of how doctors have been advising hospitalized COVID patients to lie in a prone position.

But two days later, on April 16, she still felt sick, and went to the emergency room at Pennsylvania Hospital. An X-ray showed her lungs were clear. And to her surprise, she tested negative for the virus. Doctors told her she likely had it, but perhaps it was so late in her illness that the virus could no longer be detected.

Waber was not admitted to the hospital, but she was sure that visiting the E.R. had been the right call.

“It felt really good to be seen and heard,” she said.

What about her attempts to manage symptoms at home? As near as physicians can tell so far, the coronavirus is little different from other respiratory illnesses in that regard, said Lawrence L. Livornese Jr., chair of the department of medicine for Main Line Health.

The usual advice to drink fluids is especially important with COVID-19, as the virus can impair kidney function, he said.

Sleep is beneficial, yet the person should try to move about during the day, if possible — to aid both lung function and blood flow. Physicians have reported worrisome blood clots in a minority of patients, so maintaining circulation could help.

One unanswered question: whether to let the fever “burn," in hopes that it will help control the virus, or to lower it with Tylenol or ibuprofen. The jury is out on that one, both for the coronavirus and other fever-inducing illnesses, Livornese said.

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An elevated temperature is part of the body’s response to infection. Yet fever-reducing medication makes sense for patients who otherwise cannot sleep, or who feel too sick to perform daily activities, he said.

Waber is not sure what steps helped the most, if at all. Though her breathing improved, other symptoms dragged on. And her fever, after subsiding, came back in May.

In a final blow of uncertainty, last week she got the results from a blood test to see whether her immune system had made antibodies to the virus. None were detected.

Is she one of the few COVID-19 patients who don’t make antibodies? Or did she have something else entirely?

“It’s very frustrating,” she said. “You just don’t know what your body is doing.”