Table 1.

Ten ways to improve the validity of self-report measures

1. Do not reinvent the wheel; choose a self-report adherence measure with validation data for your target population whenever possible.

2. Define the adherence construct of interest (i.e., extent of adherence vs. reasons for nonadherence) and select a measure containing items matched to that need.

3. Administer adherence measures through computer surveys rather than face-to-face data collection to reduce social desirability concerns and improve data quality.

4. In research contexts, staff members who collect adherence data should be separate from staff members who deliver adherence support or adherence interventions.

5. Introduce the self-report adherence measure with a statement which normalizes nonadherence to help address social desirability concerns.

6. Use a question response format that asks respondents to estimate their overall adherence behavior. Response items that characterize adherence in ordinal terms (e.g., anchored Likert ratings scale) or quantitative continua (e.g., estimated percent of doses taken) may help reduce ceiling effects.

7. Use a self-report adherence measure that specifies a recall period for adherence behavior. A recall period of the last 30 days may reduce ceiling effects relative to shorter intervals. Populations characterized by cognitive impairment may require other approaches (e.g., daily text message or interactive voice response surveys).

8. Consider dichotomization of self-report adherence measures at the 100 % mark to recognize their tendency for over-reporting relative to other adherence measures.

9. Add a social desirability measure to complement analysis of self-report adherence data.

10. Research publications should include clear descriptions of any self-report adherence measure, its administration method, and descriptive data resulting from the measure (e.g., mean, median, standard deviation) to help further the science.