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mid-15c., "attachment to a person, support," from Middle French adhérence, from Latin adhaerentia, noun of action from adhaerentem (nominative adhaerens), present participle of adhaerare (see adherent).
adherence ad·her·ence (ād-hǐr'əns, -hěr'-)
The extent to which the patient continues the agreed-upon mode of treatment under limited supervision when faced with conflicting demands, as distinguished from compliance or maintenance.