Word for expressing ongoing problems

single-word-requests

It seems that a good option is to use a verb that captures the concept concisely, such a verb as "perdure" for instance.

  • Despite positive temporal trends, the problems perdured/persisted until the end of the study period.

Wiktionary (intransitive) To continue to exist, last or endure, especially for a great length of time.

perdure is rarely used but its meaning fits your specification.


Despite positive temporal trends, the problems endured until the end of the study period.

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