delayed or persistent effects/AEs

I have never come up with a totally satisfactory list of terms for this concept.  The search strategy below is an initial stab at the concept.  Of course, not all terms work in all searches and any suggestions are, as always, welcome.

(longterm OR long-term OR "long term" OR extended OR persistent OR prolonged OR protracted OR unremitting OR late-onset OR "late onset" OR "delayed-onset" OR "delayed onset" OR delayed OR decade* OR years OR longitudinal OR follow-up OR "follow up" )