no they donât.
I just tested it for Health on Melee Hit to be 100% sure (unique âtitan heartâ).
same holds for Health regeneration which is scaled by Increased Health Regeneration but not Healing effectiveness (which only scales things that say âhealâ).
Also note that if a minion can heal it is usually not scaled by âHealing effectivenessâ but instead by âminion Healing effectivenessâ.
Healing effectiveness is for healing only, not for health leech, not for health on hit or block nor health regeneration. You need to actively heal with a healing skill to make this stat work.