Hello Chioma! I'm assuming you're reviewing mostly qualitative studies (or mixed-method). So a more appropriate tool that the PICO in this case would be the SPIDER tool: Sample, Phenomenon of Interest, Design, Evaluation, Research type.
So your sample would be nurses (of a specific population group maybe), phenomenon of interest would be SIDS, design would be the theoretical framework used in the qualitative research or the research methods, evaluation would be the beliefs, knowledge and practices, and finally the research type that you selected for your literature review.
More details on the SPIDER tool here: Article Beyond PICO: the SPIDER tool for qualitative evidence synthesis
thank you Farah Nabil Abdelnaim Mohamed. I would look into that, but the studies am getting are quantitative studies. Do you think SPIDER would be the right tool?
Chioma Udeani The SPIDER tool could also be used for quantitative or mixed methods studies. You could specify so in the R (which stands for research type).
I'm not sure PICO/ PICOT/ PICOS are the right tools since you don't seem to have an intervention of interest.