Background:
It is considered good practice to include the public in systematic reviews as team members or as part of an expert advisory group. We know little, however, about how to conduct involvement in search strategy development or what impact this may have. Our systematic review of parent-to-parent support for interventions for parents of babies cared for in a neonatal unit (PaReNt) includes a parent on the project team and a parent advisory group (PAG).

Objectives:
To engage with the PAG to help identify terms for the search strategy and consider the impact of this on the review.

Methods:
A draft search strategy was developed in MEDLINE, which captured all previously identified key papers. The project team (including researchers and healthcare professionals) suggested other terms. We discussed the search strategy at the inaugural PAG meeting using the search concepts: neonatal unit, parent and support. We discussed these with the PAG and captured all their suggestions. We then searched the additional terms suggested by both groups in the title field of MEDLINE Embase and PsycINFO in Ovid simultaneously and in CINAHL and BNI via HDAS. If the search term did not find any results or the first 50 hits contained no relevant references then it was not included. We added the remaining terms to the search strategy.

Results:
From the PAG suggestions, we added six additional terms to the neonatal, one to the parent and none to the support concept. From the project team we added no terms to the neonatal, four to the parent and two to the support concept. We developed two new search strategies: one for the project with all the relevant terms captured and one without the PAG terms, to enable us to document the impact of the additional PAG terms.

Conclusions:
We have shown that using patient and public involvement (PPI) in developing a search strategy is beneficial. This is an under-explored area for PPI and other projects may benefit from involvement at the search development stage. The activity was valued by the parents who welcomed the opportunity to contribute to the searching. The process also enabled the information specialist to engage directly with the PAG.

Patient or healthcare consumer involvement:
This project has had full public involvement from the beginning and this study demonstrates the benefits of this approach.