To identify studies of the expected beneficial effects of interventions search strategies should include search strings for the intervention and the population and health problem of interest. Currently, there are no recommended methods for restricting search strategies by study design;
Review authors searching for evidence relating to ‘suspected’ adverse effects may want to consider searching for specific outcomes (i.e. adverse effects) of interest. This approach obviously cannot be used for more general searches of possible adverse effects of an (see Chapter 14, Section 14.5);
Exhaustive searching, which is recommended for randomized trials, may not be justified when reviewing NRS. However, there is no research at present to guide authors about this important issue.