The SPIDER Tool for Qualitative Evidence Synthesis

Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: The SPIDER Tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435–1443.

Journal article Evaluated/validated


Developing a question is a critical step to effectively searching for research evidence. While the PICO (Population, Intervention, Comparison, Outcome) tool has been a fundamental tool for evidence-based practice and systematic reviews, searching qualitative research is more problematic. The SPIDER tool, designed using the PICO tool as a starting point, has been created to develop effective search strategies of qualitative and mixed-methods research.

Effectively searching for research evidence is a key prerequisite for synthesizing evidence to answer practice-based questions. NCCMT's Search Pyramids have been designed to help public health professionals quickly and efficiently search for research evidence (click here for more information). The Search Pyramids focus primarily on synthesized forms of quantitative research evidence, such as systematic reviews, although they could also be used to search for qualitative research. To practise searching, see NCCMT's Searching for Research Evidence in Public Health online module.

The systematic review process in qualitative research is known as meta-synthesis, which uses an explicit and systematic method to find, interpret and analyze data from many qualitative studies (Rice, 2008). To learn more about synthesizing qualitative research to increase understanding on a health issue, and how this synthesis can be used with quantitative research, see Noyes and colleagues (2011).

Steps for Using Method/Tool

The SPIDER tool was developed by adapting the PICO tool as follows:

  • (S) Sample: smaller samples are used in qualitative research, where findings are not intended to be generalized to the general population.
  • (PI) Phenonemon of Interest: qualitative research examines how and why certain experiences, behaviours and decisions are occurring (in contrast to effectiveness of an intervention).
  • (D) Design: the study design influences the robustness of the study analysis and findings.
  • (E) Evaluation: evaluation outcomes may include more subjective outcomes (such as views, attitudes, etc.).
  • (R) Research type: qualitative, quantitative and mixed-methods research could be searched for.


Methley, A.M., Campbell, S., Chew-Graham, C. et al. PICO, PICOS and SPIDER: A comparison study of specificity and sensitivity in three search tools for qualitative systematic reviews. BMC Health Services Research, 14, 579.

Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: The SPIDER tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435–1443.

These summaries are written by the NCCMT to condense and to provide an overview of the resources listed in the Registry of Methods and Tools and to give suggestions for their use in a public health context. For more information on individual methods and tools included in the review, please consult the authors/developers of the original resources.

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