Table 1.

The Quality of Medication Use^3,14,22

Medication-Related Problem	Definition
Suboptimal Drug	The individual is receiving a drug that has no indication, is not effective, or is potentially not safe (i.e., potential for harm exceeds potential for benefit).
Suboptimal Dose, Duration, Frequency, or Administration	The individual is taking an appropriate medication, but the dose, duration, frequency or administration is not optimal to achieve desired response, or has the potential for harm.
Adverse Drug Events	The individual is experiencing an actual adverse consequence at the time of the interview that is attributed to a drug or the inappropriate use of a drug.
Nonadherence*	The individual has not filled a prescription, is not taking a drug, or is not using a drug as prescribed, whether intentional or unintentional.
Less Costly Drug Available	The individual is prescribed a medication for which a less costly, equally effective and safe drug is available, and preferred by the patient, but the patient is receiving a more expensive product; or the patient could benefit from prescription savings, but is not receiving eligible benefits and desires to.
Undertreatment	The individual has a medical condition or risk factors for a disease that would benefit from drug therapy (clear indication) and the patient has no contraindications to the drug, but the drug was not prescribed.
Suboptimal Medication Monitoring	The individual is receiving a drug and monitoring is recommended (according to established practice guidelines) to assess response to therapy or prevent harm, but the monitoring has not been done.

^*We used 2 methods to assess nonadherence: the primary assessment (leading to identification of a medication-related problem of nonadherence) was the clinical pharmacist implicit assessment of adherence for each medication a person was taking (i.e., adherent, nonadherent)following the comprehensive medication review 14 and a validated patient self-report measure.³⁷ Because no gold standard exists for measuring nonadherence, we relied on multiple methods of assessment.