The instrument consists of 4 questions related to medication use:
(1) not missed any doses over the past 4 days
(2) took all of the pills on at least 1 of the past 4 days
(3) usually followed special instructions over the past 4 days
(4) good compliance over the past month
Responses are yes or no, which are scored 1 or 0 points respectively.
adherence score =
= SUM(points for responses to the 4 questions)
Interpretation:
• minimum score: 0
• maximum score: 4
• A score of 4 was termed adherent, while a score <= 3 was considered nonadherent.
• A person who appears to be nonadherent may be a suitable candidate for drug level monitoring or other interventions to confirm nonadherence.
• An algorithm using the score to help evaluate virologic failure in a patient on an antiretroviral drug regimen is discussed in the chapter on antibiotic therapy.
Performance of questionnaire:
• sensitivity for virologic response: 74%; specificity 54%
• positive predictive value 83%; negative predictive value 40%
