Table 2 Summary of key processes in critical interpretive synthesis

Reflexivity

Constant reflexivity on the part of the review authors is essential to the critical interpretive synthesis (CIS) process, to ensure thorough searching and selection processes and generation of theory which is critically informed and credible in light of the evidence available

Review question

A review question should be proposed but left open to adjustment over the course of the research

Literature searching

The initial search strategy should be broad to identify potentially relevant papers close to the topic of interest.

Searching, sampling, critique and analysis occur simultaneously

Purposive sampling

Purposive sampling of potentially relevant material is used to identify material which may fall outside of the initial search boundaries

Data extraction

Data extraction may be guided by formal data extraction procedures, but this is not essential for the CIS approach

Quality appraisal

Appraisal of the evidence aims to prioritise relevance and theoretical contribution to the review objectives, through critical interrogation of the evidence. Formal methodological quality appraisal of individual studies may be appropriate, but papers are not usually excluded on the basis of quality alone

Data analysis

Analysis aims to generate a synthesising argument or conceptual framework. This is developed through a critically informed synthesis of evidence included in the review. The framework should illustrate connections and relationships between new (synthetic) and existing constructs identified in the literature. The developing conceptual framework guides further selection of potentially relevant literature