Health technology assessment (HTA) organizations generate guidelines to inform healthcare practices toward improved health outcomes. This review sought to identify and classify outcomes of guidelines from HTA organizations within published research.

We performed a systematic mixed studies review of empirical studies that (a) referred to a published guideline from an HTA organization and (b) reported an outcome resulting from a guideline. We searched the published literature in English or French within seven databases. Outcome types were classified within five dimensions of an existing framework for online health information (e.g., relevance, cognitive/affective impact, and use). Subdimensions were inductively developed. A two-phase sequential data synthesis was performed. Phase 1: a hybrid deductive–inductive thematic analysis identified the types of outcomes and displayed their relationships on a concept map. Phase 2: descriptive statistics were tabulated by the type of outcome.

A total of 6,719 records were retrieved through searches on 6 February 2023. After screening, we included 120 observational studies (twenty-one qualitative, ninety-four quantitative, and five mixed methods). Phase 1 identified twenty-nine types of outcomes. The most frequently reported outcomes were within the organizational dimension (reported in ninety-four studies). The most common subdimensions were “Referrals” (thirty-eight occurrences), the “Quality of Prescriptions” (fifteen occurrences), and the “Quality of Diagnosis” (eight occurrences). For Phase 2, we could only generate descriptive statistics on seventeen outcomes. These were almost equally distributed among positive, neutral, and negative effects. Our results contribute to knowledge about the outcomes of HTA guidelines and options for documenting and measuring them in future evaluations.