Self-Reported Measures

Self-Reported Measurement

This page highlights different self-reported measurement types explaining each modality, as well as results from self-reported measure recall times. Explore examples and considerations from various studies and results about shorter versus longer recall timeframes.

Self-Reported Measure Types

Self-report measures are widely used in clinical studies and healthcare settings to collect qualitative information. These tools include questionnaires, assessments, and evaluations that prompt participants to describe their personal experiences, thoughts, perspectives, behaviors, or symptoms.

Percentage Time Adherence

Explanation: This type of measure asks what percent of time the participant was adherent (or not) in a given time frame.

Examples

This example of Percentage Time Adherence is from Comparison of Antiretroviral Adherence Questions:

“In past 4 weeks, what percent of the time were you able to take all your medications as your doctor prescribed them?” with response options: 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%”

Read the abstract here.

Other Considerations

This question type requires higher-level analytical health numeracy skills (i.e. calculating a percentage) that not all participants may possess

Learn about health numeracy here.

Learn about optimal recall periods and response task for self-reported HIV medication adherence here.

Visual Analog Scale (VAS)

Explanation: This type of measure shows participants a line and asks them to mark the percentage of medication they have taken (or missed) in a given time frame.

Examples

This VAS example is from Comparison of Antiretroviral Adherence Questions.

“Place an “X” on the line at the point showing how much of your HIV antiretroviral medications you have taken in the past 4 weeks. Zero percent means you have taken no antiretroviral medications, 50% means you have taken half your antiretroviral
medications, 100% means you have taken every single dose of your antiretroviral medications during the past 4 weeks. The line had hatch marks and numeric labels at 10% intervals and ranged from 0% to 100%.”

Read the abstract here.

Other Considerations

The way researchers administer the VAS may impact the results. Collecting data through interviews could help measure medication adherence through VAS by providing detailed or personalized instructions. VAS relies on a good understanding of numeracy, so clear instructions are be crucial.

Read a VAS measurement of antiretroviral adherence in people living with HIV here.

Rating

Explanation: This type of measure asks participants to rate their adherence behavior in a given time frame.

Examples

This example is from Comparison of Antiretroviral Adherence Questions:

“Thinking about the past 4 weeks, on average, how would you rate your ability to take all your medications as your doctor prescribed them? Response options: very poor, poor, fair, good, very good, excellent.”

Read the abstract here.

Other Considerations

Evaluative responses, such as “excellent,” can imply normative expectations and prompt comparisons with how well the participant believes peers adhere to medications.

Learn more about question-response limitations here.

Participants may be more comfortable acknowledging imperfect adherence using qualitative terms rather than quantitative ones. For example, “80%” might be perceived more negatively, both cognitively and emotionally, compared to “very good,” which is generally seen as a positive assessment. (Berg et al 2012)

Frequency

Explanation: This type of measure asks participants to describe how frequently they took their medication in a given time frame.

Examples

This frequency example is from Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China:

“In last month, how often did you take all your HIV medications as your doctor prescribed them?” with a 5-point response option (none of the time, few of the time, some of the time, most of the time, all of the time)”

Read the abstract here.

Other Considerations

This question type requires higher-level analytical health numeracy skills that not all participants may possess.

Learn more about health numeracy here.

Yes/No

Explanation: This type of measure asks participants to describe their adherence behavior in a given time frame through yes/no responses.

Examples

This example is from Evaluation of antidiabetic medication adherence in the Lebanese population: development of the Lebanese Diabetes Medication Adherence Scale:

“Do you sometimes stop taking your medication when feeling well?, Do you sometimes forget taking your medication if travelling or doing daily activity?”

Read the abstract here.

Other Considerations

These measures are typically asked with many other adherence questions to create a composite adherence score.

Composite Adherence Scores

Explanation: This type of method considers the answers to multiple measures about adherence before creating a composite adherence score or percentage.

Examples

The 8-item Morisky Medication Adherence Scale (MMAS-8), where a score less than 6 indicates low adherence, a score between 6-7 indicates medium adherence, and a score of 8 indicates high adherence.

Other Considerations

This is the most common type of adherence measure type and includes all adherence measurement scales.

Self-Reported Measure Recall Times

Shorter Recall Timeframe

Including a weekend day in measures with shorter recall periods may help increase accuracy as routines often change on weekends, which can disrupt adherence. (1)
An error recalling even a single dose can largely affect the accuracy of short recall adherence measurements. (2)

Recall Times	Explanation	Example
1-day adherence	Question about adherence to medication over the previous day	“Did you take your medicine yesterday?”(3)
Weekend adherence	Question about adherence to medication over the previous weekend	“Participants were asked whether they took their HIV medication on both, either, or neither days over the past weekend.” (1)
Weekend non-adherence	Question about non-adherence to medication over the previous day	“Did you not take any of your medicine over the past weekend?” (4)
3-day adherence	Question about adherence to medication over the previous three days	“How many pills did you take over the past 3 days?” (1)
7-day (week) adherence	Question about adherence to medication over the previous week	“How many pills did you take over the past 7 days?” (1)
7-day (week) non-adherence	Question about non-adherence to medication over the previous week	“Thinking about the last week, how often have you not taken your medicine?” (4)

Longer Recall Timeframe

Longer recall periods may be more susceptible to recall bias, but they are also better able to capture variation in adherence behaviors, which may be more clinically relevant. (2)
One study found that participants reported more accurate adherence behavior when recalled item was less specific (days vs doses) and the adherence criterion was stricter (perfect adherence vs imperfect adherence). (1)
Longer recall periods may be less susceptible to a ceiling effect. (1)

Recall Times	Explanation	Example
2 week non-adherence	Question about non-adherence to medication over the previous two weeks	“Thinking over the past 2 weeks, were there any days when you did not take your medicine?” (3)
1-month adherence	Question about adherence to medication over the previous month	Over the past month, how many days did you take all doses of your HIV medication? (1)
1-month non-adherence	Question about non-adherence to medication over the previous month	Over the past month, how many days did you not take any dose of your HIV medication? (1)
3-month non-adherence	Question about non-adherence to medication over the previous three months	“Over the past three months, how many days have you not taken any medicine at all?” (4)

References

Da et al. (2018). Evaluation of self-report adherence measures and their associations with detectable viral load among people living with HIV (PLHIV) in China. PloS one, 13(8).
Lu et al. (2007). Optimal Recall Period and Response Task for Self-Reported HIV Medication Adherence. AIDS and Behavior, 12(1), 86-94.
Zongo et al. (2016). SAGE Open Medicine.
Agala et al. (2020). Reliability, validity and measurement invariance of the Simplified Medication Adherence Questionnaire (SMAQ) among HIV-positive women in Ethiopia: a quasi-experimental study. BMC public health, 20(1), 567.