Experts: Covid-19 severity data could be misleading without better context

The Health Ministry this week began releasing data on the severity of symptoms of the new Covid-19 cases daily, with a majority of them experiencing only mild symptoms.

However, experts said better context was needed or the data could lead to the public letting their guard down, believing that the situation is better than it is or that they will only get mild symptoms, even if they are infected with Covid-19.

Furthermore, the experts said that if the data was gathered at the point of admission, the patients' situations could deteriorate after the admission, therefore giving an inaccurate picture.

Senior consultant paediatrician Dr Amar-Singh HSS said the way this set of data was presented gives an impression that only a minority of Covid-19 cases are severe, but a Health Ministry research paper from last November showed that eight percent of cases end up requiring some form of respiratory support.

“That is quite huge, isn’t it? Even if you add up all the Category 3, 4 and 5, you can’t get eight percent right now in this current data, the way it is being reflected.

“That is because it is dynamic and people are progressing. Today you are Category 1, tomorrow you may be Category 2 and four hours later, you may sink to Category 4.

“So that is the problem with this data. It is reducing anxiety in people and saying things are okay but actually, we are not giving a dynamic portrait of what’s happening,” Amar Singh said when contacted by Malaysiakini yesterday.

The Health Ministry’s study, which was published in the Lancet Regional Health-Western Pacific Journal, involved 5,889 patients, with 471 (7.99 percent) ending up with severe Covid-19.

The participants in the study are confirmed Covid-19 positive patients from 18 designated hospitals between Feb 1, 2020, and May 30, 2020, and they were followed up with until their discharge.

For the record, Category 1 patients are asymptomatic and Category 2 patients have mild symptoms.

Category 3 patients have more serious symptoms like pneumonia but can likely still breathe on their own, whereas those in Category 4 need oxygen supply. Category 5 patients require a ventilator to breathe.

Universiti Malaya (UM) geriatric medicine professor Dr Tan Maw Pin warned that the way the severity data was presented could give people the impression that it is “safe” to contract Covid-19 because they believe most people have mild symptoms or are asymptomatic.

She reminded the people that the healthcare system in the country is already very stretched, with some saying it is on the brink of collapse.

“This kind of information may lead to people indulging in more high-risk behaviours and that will push our healthcare system over,” Tan told Malaysiakini.

She also questioned how this severity data was collected, which would better guide the interpretation of the data.

Universiti Malaya geriatric medicine professor Dr Tan Maw Pin

“Tell us exactly where you got the data from and how to interpret the data.

“How did you get this kind of information, where did you get it from? Is it just from the Covid-19 Assessment Centres (CAC), in which case, of course, you’re going to get a majority of Category 1 and 2 patients,” Tan said.

However, public health expert and UM epidemiology professor Dr Sanjay Rampal noted that the severity data at admission is a good indicator that 98.5 percent of the newly-diagnosed cases were either asymptomatic or with mild symptoms.

“In addition, we are likely to under-ascertain asymptomatic and mild cases compared to those with more severe diseases. The actual proportions of asymptomatic and mild infections are likely to be much higher,” he told Malaysiakini.

Sanjay also acknowledged that the severity of the disease would increase for some as the disease progresses so it would be ideal to have active cases classified by severity daily, but that requires a lot of resources.

Despite his reservations about the way the severity data is presented, Amar-Singh said he is glad the Health Ministry is trying to share more data.

“The more data we share with the public, the better the understanding and the better the response,” he said.

But, he added, it would be more helpful for the government to share four types of data that are:

1. The daily number of patients on oxygen support, including both non-invasive ventilation and normal ventilation (covering Category 3, 4 and 5 patients)
2. The daily number of patients on respiratory support, including non-invasive ventilation and normal ventilation (covering Category 4 and 5 patients)
3. The daily number of patients on normal ventilation (covering Category 5 patients)
4. The daily number of deaths due to Covid-19

Amar-Singh said sharing these data would not only give a better picture of the Covid-19 situation but also help with the management of hospital resources at a time when the facilities are overwhelmed.

“It tells you today this is our severity in the country and how much support we need to give today, and that support is the one we should be developing and growing.

“I don’t care how many beds there are, I want to know how many people are struggling, and then we grow the services to match them,” Amar-Singh said.

He explained that total deaths are another important matrix to look at, as the number of brought-in-dead (BID) cases are a “confounder”.

“(The BID cases) don’t contribute to daily numbers because they just die. They were probably Category 4 or 5 at home at some point.

“This is one number that does not get into these data and that is 10 percent of the deaths,” he said.

Yesterday, Health Ministry director-general Dr Noor Hisham Abdullah also tweeted the daily severity data but added in a separate tweet that even the small number of severe Covid-19 patients are taxing on the healthcare system.

“Even though Category 5 is only 0.9 percent, which is 95 patients, and Category 4 is 0.4 percent, which is 45 patients, the average number of days they spend in the intensive care units (ICU) is 21 days for Category 5 and 14 days for Category 4.

“This adds onto the burden and reduces the capacities of the Health Ministry’s hospitals,” Noor Hisham explained.

 

- Mkini