Table 1 Five stages of an integrative literature review (summarised from Whittemore and Knafl [11])

(1) Problem formulation

To clearly state topic of interest and purpose of review

• List variables of interest

• Set focus and boundaries

(2) Literature search

To make explicit and justify search strategy and sampling criteria

• Specify databases and other search methods

• State type of literature to be included (e.g. published/unpublished)

• Detail key words

• Acknowledge publication bias

(3) Data evaluation

To assess type, scope, diversity, and quality of accessed literature

• Specify different types of study found and classify into sub-groups

• Decide on quality criteria instruments for each type of study

(4) Data synthesis

To specify systematic analytical method

To create an innovative synthesis

To formulate a unified and integrated conclusion

• Data reduction: simplify sub-groups into a manageable framework according to the type (e.g. qualitative, comparative, experimental); create short summaries of each primary source

• Data display: create charts or visual network displays to show connection within each sub-group type

• Data comparison: identify patterns, themes, relationships, and major variables within and between sub-groups

• Conclusion drawing and verification: creative and critical analysis of data, acknowledging commonalities and differences, and including any justifiable generalisations

• Production of integrative summation

(5) Presentation

To capture the depth and breadth of the topic and produce a comprehensive understanding

• Summary should contribute to a new understanding

• Specify implications for practice, research, and policy

• Note limitations of the review as a whole