Adherence terminology and nomenclature
| Term | Description# |
| Adherence | Process by which patients take their therapy (i.e. medications) as prescribed |
| Initiation | Moment at which the patient takes the first dose of a prescribed therapy and/or medication |
| Implementation | Extent to which a patient's actual dosing corresponds to the prescribed dosing regimen from initiation until the last dose taken |
| Discontinuation | Being the end of therapy, when the next dose to be taken is omitted and no more doses are taken thereafter |
| Persistence | Length of time between initiation and the last dose which immediately precedes discontinuation |
| Compliance | Extent to which patients follow healthcare provider directions |
| Patient expectations | Anticipation or belief of perceived benefit of therapy, related to adherence (i.e. patients may adhere well because of strong expectations for treatment success) |
| Dimensions of adherence | Factors related to maintenance of adherence as outlined by the World Health Organization |
| Patient | Age, socioeconomic group, motivation, knowledge of disease, perceived risks of disease, perceived benefit of treatment |
| Healthcare system | Patient–provider relationship, care continuity, wait times |
| Condition | Symptom severity, concurrent depression |
| Social and economic | Cultural beliefs, language barriers, community support, therapy costs |
| Therapy | Complexity of medical regimen, duration of therapy, actual or perceived side-effects |
#: adapted from [30, 50, 51].