​than是比较级吗？

A difficult airway presents high risk in several respects, even when it is anticipated and when there is time to plan for it. There are few instances in medicine when cause and effect of a devastating outcome are so closely related temporally than when trying to secure the difficult airway. When it is not successfully secured in a timely fashion, adverse outcomes are possible and some would say likely. These adverse outcomes include airway trauma (including bleeding, edema, esophageal perforation, tracheal perforation, pneumothorax), damage to teeth or airway, aspiration, death, brain injury, cardiopulmonary arrest, and unnecessary surgical airway.

than是比较级吗？和哪个比较呢？谢谢