Table 1.

Summary of Research Designs Used in Studies Reviewed on Alcohol Consumption and ART Adherence.

Design	Description	Example	What It Can Yield	What It Cannot Yield
Longitudinal Event Level	Prospective assessment of the occurrence of a specific behavior on an occasion and whether alcohol was present during the behavior. Typically assess past 24-hour adherence, and number/timing of drinks consumed over the past 24 hours, every day for a period of weeks or months.	Daily Diary Study	Possible to obtain reliable/accurate information on precise temporal ordering of events with relatively little recall error. Also provides information on the relative likelihood of a behavior in the presence or absence of alcohol.	Despite good temporality, still correlational. Clear causal inferences based on data generated from it are not warranted.
Retrospective Event Level	Retrospective assessment of the occurrence of a specific behavior on an occasion and whether alcohol was present during the behavior. The occurrence of nonadherence and the presence of alcohol is assessed for each day over a specified past period of time. Variations include the last time 1–5 times the event occurred, or the occurrence of events over the last 30–90 days.	Critical Incident studies; Multiple event studies; Timeline Followback (TLFB)	Information on the co-occurrence of alcohol use and behavior of interest. Also provides information on the relative likelihood of a behavior in the presence or absence of alcohol.	Causal inferences between 2 or more variables; More subject to recall bias or memory failure than prospective event level studies.
Situational Associational	An assessment of whether some behavior has tended to occur or has ever occurred in conjunction with the behavior of interest. Typically use of single item to assess whether alcohol use tends to co-occur with ART non-adherence, whose outcome is used to predict an aggregate measure of frequency of ART adherence.	Endorsement of a single item such as “I tend skip taking my HIV medications if I will be drinking”	General information on whether the co-occurrence of two behaviors at one point in time predicts some outcome of interest.	Precise information on temporality.
Longitudinal Global Association	Correlation of an aggregate measure of one variable over some period of time with an aggregate measure of a second variable, measured at and over a second period of time.	Correlation of a measure of average frequency of alcohol use over the last 3 months at baseline, with self-report of ART adherence in the previous 30 days at 6-month follow-up.	In early stages of research on a phenomenon a “signal” that that two variables may co-occur and perhaps are causally connected. The signal is that follow-up research seems warranted.	Any information on temporality.
Cross-sectional Global Association	Correlation of an aggregate measure of one variable over some period of time with an aggregate measure of a second variable, measured at, and sometimes over, the same period of time.	Correlation of a measure of average frequency of alcohol use over the 30 days with self-report of ART adherence over the last 30 days.	In early stages of research on a phenomenon a “signal” that that two variables may co-occur. The signal is that follow-up research seems warranted.	Any information on temporality.