Reacción a "Reactions: persistent covid studies have created misunderstandings because of their limitations, says analysis"

The paper is a careful assessment of the pitfalls of epidemiological studies. It is worth remembering that some of these were conducted during a time of significant upheaval.

The authors make good points regarding the lack of consistency in case-definitions, and other potential sources of bias. It is worth noting that all definitions, including the one used in Aotearoa New Zealand, are broadly consistent, other than the American one (CDC). 

These are useful reminders about how to carry out careful epidemiological investigations. 

However, the authors do not appear to have been informed by the Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome literature; they appear to prefer to focus on a set of pre-defined, persisting, single post-COVID symptoms, rather than considering Long COVID as a term for a syndrome or collection of symptoms which can fluctuate in presence/ absence as well as severity.

"There is no evidence for the “unintended consequences” listed in the key messages box, these are not mentioned in the paper, and appear to be the authors’ impressions, rather than evidence-based statements.