OCTA projection on COVID-19 problematic, using incomplete data, says medical expert

Department of Health Technical Advisory Group member Dr. Edsel Salvana (Photo from PCOO-OGMPA)

MANILA, Philippines — OCTA Research’s modeling for making projections on COVID-19 cases is “problematic” since it is based on “incomplete” and “erroneous” data, a member of the Department of Health’s (DOH) Technical Advisory Group said Monday.

Dr. Edsel Salvaña, an infectious disease expert, noted that OCTA is calculating the COVID-19 reproduction number based on cases that were reported in the last two weeks, which he said is not valid since there are backlogs in the reporting of cases.

“Even a student of clinical epidemiology will tell you that that is not valid because cases that happened within the last two weeks are subject to error because some get tested later or earlier. There are backlogs, so if you are making projections based on data that is incomplete or erroneous, you are going to come out with erroneous projections,” Salvaña said in an interview on ABS-CBN News Channel.

“I am not saying that they don’t know what they are doing. There are mathematicians, political scientists, and doctors there, but their model is problematic because they are using data that is incomplete and inconsistent. There are other things that you have to look at,” he added.

OCTA Research earlier said Metro Manila is “officially in a surge” as it urged the government to impose “circuit-breaking” lockdowns to stem the imminent spread of the COVID-19 Delta variant.

Projection of COVID-19 case trend in Metro Manila if a circuit-breaking lockdown will not be imposed (Graph from OCTA Research)

Salvaña, however, noted that there is no definitive definition for the term “surge.”

Official? says who?

“What is so official about that? First of all hindi naman sila government. Pangalawa, walang epidemiologic, definite definition ang surge. You have to look at healthcare capacity,” he explained.

(What’s so official about that? First of all they are not the government. Second, there is no definite definition of surge in epidemiology. You have to look at healthcare capacity.)

“So that’s really my only point, that it’s okay guys, please do help, go ahead and do your analysis. But please make sure that you are doing the correct analysis because if you don’t, then it just confuses people and the government may make the wrong decision because nagpanic na ‘yung ibang tao (some people have already panicked),” he added.

“I have no personal quarrel with them. In fact some of the OCTA people are my good friends, but if they are going to make projections, I wish they would be more circumspect,” Salvaña also said.

‘Fortune telling’

Salvaña also described as “fortune-telling” the projection of OCTA on July 22 that new COVID-19 cases could reach over 8,000 on that day.

The DOH, however, only reported over 5,800 new cases on the said date.

“Fortune-telling ‘yan eh. Because in the first place, you can’t exactly calculate how many cases will come out in one day. There are backlogs. There are all these things. We don’t do that in science,” he said.

But according to Fr. Nicanor Austriaco, a molecular biologist and member of the OCTA Research, all modeling is fortune-telling.

“All modeling is fortune-telling. You can ask any modeler that. They will all say that all models are wrong, some are useful,” he said in a separate interview with ABS-CBN News Channel.

“These models, the data that we are producing have been consistent with the trends and dynamics of the pandemic for the past 15, 16 months,” he added.

Careful…

In an earlier statement, the DOH, without naming any group, likewise called on independent experts to be more careful in making statements about the COVID-19 pandemic in order to avoid causing panic.

OCTA Research, in response, maintained that it is careful in using the term “surge” but noted that the increase of COVID-19 cases being observed now in Metro Manila can undeniably be considered a surge in infections.

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