How to investigate levels of Adherence to antiretroviral ... - INRUD

How to Investigate Adherence to Antiretroviral Treatment:
An Indicator-Based Approach
Using clinical records to measure this indicator is possible only if the question has been asked
consistently and recorded routinely. Because of this, self report written in clinical notes is a
complementary adherence indicator. In practice, clinicians or pharmacists may have asked
patients about their adherence but not recorded the answer. Also, the recall period they may
have asked about could vary between their adherence yesterday to their adherence since the
last clinic visit.
The indicator chosen here using self-reporting is indicator 1 below.
Indicator 1. Percentage of patients with full adherence to ART
Rationale
Source of data
Data collection
Perfect (or > 95%) adherence is the primary treatment goal.
Patient self-report: ―In the last 3 days, have you missed any of the ARV
doses you were supposed to take?‖ [Response: yes/no].
Patient interview: Based on sample of 30 patients attending on day of data
collection (or all patients if < 30 attend that day).
Computation (Number of patients responding ―no‖/number of patients asked) × 100.
Comments
The question is standardized to 3 days. In practice this question could be
asked for last 1, 2, 3, 4, or 7 days. For any of these periods, missing one
dose is equivalent to less than 95% adherence (missing 1 dose in 7 days is
7.1% of doses on a twice daily regimen). Calculation can be the same if the
question is asked for 30 days or for the period since the last clinic visit, but
interpretation would differ.
Pitfalls
The only hope of getting an honest answer is if the interviewer is friendly and
non-officious. Interviewers need to be trained to ask the question in a
uniform way.
An example of use may be that, of 30 patients asked this question, four said that they had
missed one or more doses in the last three days. This means that for this facility the selfreported
full adherence rate would be 26/30 which is 86.7%. In practice the percentage is
high and inflated (95% on average in the four field tests) but does correspond to clinical
outcomes where it has been checked. The lowest percentage for a single facility in the four
feasibility studies was 60%. So managers would know to concentrate their attention on that
facility.
Dispensing-based adherence measures
Pharmacy dispensing records are useful to measure longer-term adherence patterns. By
counting the number of days that medication is dispensed over a period, two important
adherence indicators can be calculated—long-term adherence to ARVs and the rate of
patients with significant gaps in treatment.
The dispensing-based adherence measures are defined as follows:
1. Average percentage of days covered by ARVs dispensed for a sample of patients for
a defined period (180 days).
2. Percentage of patients who experienced a gap in ARV availability of more than 30
days in a row during the same defined period.
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