Are we entering a new era for qualitative research? Using qualitative evidence to support guidance and guideline development by the World Health Organization.

Qualitative approaches are one of several methodologies utilised within the social sciences. New developments within qualitative methods are widening the opportunities for using qualitative evidence to inform health policy and systems decisions. In this commentary, we discuss how, in our work with the World Health Organization (WHO), we have explored ways of broadening the types of evidence used to develop evidence-informed guidance for health systems.Health systems decisions are commonly informed by evidence on the effectiveness of health system interventions. However, decision makers and other stakeholders also typically have additional questions, including how different stakeholders value different outcomes, the acceptability and feasibility of different interventions and the impacts of these interventions on equity and human rights. Evidence from qualitative research can help address these questions, and a number of WHO guidelines are now using qualitative evidence in this way. This growing use of qualitative evidence to inform decision making has been facilitated by recent methodological developments, including robust methods for qualitative evidence syntheses and approaches for assessing how much confidence to place in findings from such syntheses. For research evidence to contribute optimally to improving and sustaining the performance of health systems, it needs to be transferred easily between different elements of what has been termed the 'evidence ecosystem'. This ecosystem includes primary and secondary evidence producers, guidance developers and those implementing and evaluating interventions to strengthen health systems. We argue that most of the elements of an ecosystem for qualitative evidence are now in place - an important milestone that suggests that we are entering a new era for qualitative research. However, a number of challenges and constraints remain. These include how to build stronger links between the communities involved in the different parts of the qualitative evidence ecosystem and the need to strengthen capacity, particularly in low and middle income countries, to produce and utilise qualitative evidence and decision products informed by such evidence. We invite others who want to support the wider use of qualitative evidence in decision processes to look for opportunities in their settings to put this into practice.