Table 2.

Primary indicators and study findings in this quantitative assessment of HTE evaluation.

Question	Rationale for Assessment	Results
(1) How often were HTEs assessed?	Assessing HTEs is important for several reasons. For instance, for understanding potential inequities in social policies. HTEs may also provide an explanation for the magnitude of an effect size.	24 of 54 (44%) of studies assessed HTEs.
(2) How often was the intent to assess HTEs specified a priori?	A priori specification is evidence of some plan for assessing HTEs.	15 of 24 (63%) specified their intent to assess HTEs a priori.
(3) What methods for assessing HTEs were used?	The type of method used to assess an HTE has implications for what inferences can be made regarding an HTE (e.g., confirmatory, descriptive, or exploratory).	17 of 24 (71%) studies used descriptive methods based on stratification to evaluate HTEs. 5 of 24 (21%) studies used statistical inference methods to evaluate HTEs (e.g., an interaction term between the social policy and the subgroup for HTE). 2 of 24 (8%) studies used a combination of descriptive and inferential methods to evaluate HTEs.
(4) For what subgroups were HTEs assessed?	The subgroups provide a sense of what types of factors are being considered as potential sources of treatment effect heterogeneity.	Diverse subgroups were tested to explore HTEs. See Fig. 1 where 17 different subgroups were identified to evaluate HTEs.

Note. THE = heterogeneous treatment effect.