China acknowledged Friday that the coronavirus death toll for the epicenter of Wuhan was 50% higher than previously reported — a major revision that underscored how countries facing an unprecedented public health crisis are struggling to keep accurate counts of the pandemic’s true toll.

China is certainly not the only country with incomplete or unreliable figures about the pandemic and accurate numbers are difficult to come by in the midst of a crisis. But those numbers have a huge influence on governments’ actions, as medical staffs struggle to figure out how to cope with surges of sick people and officials have to make crucial decisions about how they can begin easing lockdown restrictions to resuscitate their ailing economies.