3.2.1 Qualitative evidence and evidence-based healthcare

This section provides an introductory perspective on the synthesis of qualitative research, as well as the relationship between qualitative evidence and evidence-based healthcare. These foundational understandings establish a framework for considering the philosophic traditions associated with the synthesis of qualitative research. A brief outline of some of the debates regarding qualitative synthesis is presented, although not with the intent of comprehensively addressing the significant variety of positions, but rather, to situate meta-aggregation as a methodology and method of analysis within the broader debate.

What is qualitative research?

Qualitative research is a type of research that aims to explore and provide a deeper understanding of human experiences, behaviours, social norms, processes and phenomena (Jordan 2006). Qualitative research methods are rooted in the humanities and social sciences, with the primary aim of analysing the intricate nature of human phenomena within naturalistic settings and adopting a holistic perspective (Aspers & Corte 2019).

The term ‘qualitative’ encompasses various research methodologies, such as action research, content analysis, discourse analysis, ethnography, grounded theory, phenomenology and qualitative description. Common methods include interviews, either individual or in groups (also called focus groups) and observation, whether direct or indirect. Arts-based and other creative methods are also becoming increasingly common (Majid & Kandasamy 2021; Woodgate et al. 2020). Researchers who use qualitative methodologies seek a deeper understanding of phenomena by studying them in their natural setting and interpreting them through the lens of the meanings assigned to them (Aspers & Corte 2019).

Qualitative evidence and healthcare

In healthcare, qualitative research ‘seeks to, in its nature, explore and/or explain the phenomena in the real world, which shape or are shaped by human perspectives, experiences and wider political, social and cultural contexts‘ (Long & Jiang 2023 p. 1). Over the past two decades, the value of qualitative inquiry in healthcare research, policy and practice has increased (Long & Jiang 2023; Williams, Boylan & Nunan 2019). In healthcare, qualitative research plays a particular role in understanding patterns of health behaviours, exploring healthcare needs, describing and understanding lived experiences, developing behavioural theories and designing interventions (Renjith et al. 2021).

The strength of qualitative research lies in examining the ‘how‘ and ‘why’ of decision-making, rather than the ‘when’ and ‘what’ (Renjith et al. 2021). Using qualitative methods aimed at exploring, describing and explaining a phenomenon, qualitative inquiry attempts to understand the complexity of human behaviour (Renjith et al. 2021). As an example, the question ‘What proportion of smokers have tried to stop?’ leads to statistical answers, while the question ‘Why do people continue to smoke?’ leads the researcher to explore the ideas and concerns that people who smoke tobacco may have about their smoking habits (Greenhalgh & Taylor 1997).

Qualitative research plays an important role in understanding how individuals and communities perceive health, manage their own health and make decisions related to health behaviour or health service usage. It can help to understand the culture of communities with regard to implementing changes and overcoming barriers. It can also inform planners and policy makers about the manner in which service users experience health as well as illness and can be used to evaluate the activities of health services such as health promotion and community development.

Philosophical perspectives, research methodologies and methods

A philosophical perspective encompasses our assumptions about reality (ontology) and how we come to understand it (epistemology). This perspective shapes our beliefs about the nature of existence, knowledge and truth, guiding our approach to understanding the world (methodology) and how we conduct research (methods). Collectively, these elements form a paradigm, which is the overarching framework that influences how we perceive and investigate the world within a particular field of study. This overview simplifies complex paradigms and interested readers are encouraged to explore further for a more detailed understanding.

Qualitative research is distinguished by unique philosophical perspectives, methodologies and methods that set it apart from quantitative approaches. In health-related research, three primary paradigms are commonly used:

• Positivist (or empirico-analytical) paradigm: This paradigm is often associated with quantitative evidence and emphasises objective reality, measurement and the use of scientific methods to discover generalisable truths.

• Interpretive paradigm: This paradigm is largely associated with qualitative evidence and focuses on understanding the meaning and experiences of individuals within their social contexts. It values subjective reality and the importance of context in shaping human behaviour and knowledge.

• Critical paradigm: Also linked to qualitative evidence, this paradigm aims to identify and challenge power structures and inequalities in society. It seeks not only to understand but also to transform social conditions by addressing issues of power, inequality and social justice.

At its core, the interpretive paradigm emphasises the subjective and socially constructed nature of reality. It asserts that human experiences, behaviours and phenomena cannot be understood without considering the context in which they occur. Researchers who embrace this perspective believe that individuals and social groups create meaning through their interactions and interpretations of the world. As a result, the focus is on understanding these meanings and interpretations, often through the eyes of the participants themselves. Researchers using this paradigm employ a variety of methodologies, such as content analysis, ethnography, grounded theory or phenomenology. In health services research, it is also common to use ‘descriptive qualitative research’ where the aim is to describe and characterise an experience or a phenomenon (rather than to generate deeper, more theoretical understandings of it). These methodologies are chosen based on the research questions and the nature of the phenomenon under investigation.

Interpretive research uses a range of data collection methods, including interviews, participant observation, focus groups, diaries, document analysis and sometimes visual data (such as photographs or video). These methods allow researchers to gather rich, context-specific data that capture the nuances and complexities of the phenomenon being studied. Data analysis in the interpretive paradigm often involves processes such as thematic analysis, constant comparative analysis, content analysis or narrative analysis. These processes aim to identify and interpret patterns in the data expressed as themes, concepts or metaphors, which are sometimes developed further into conceptual models or mid-range theories. It is an iterative process and the researcher’s subjectivity is acknowledged and integrated into the analysis.

The critical paradigm incorporates a distinct philosophical perspective, methodology and methods, emphasising social justice, power relations and a commitment to transformative change (Paradis-Gagné & Pariseau-Legault 2022). At its core, the critical paradigm is grounded in a philosophy that challenges the status quo and questions the power structures and social inequalities that exist in societies. Researchers who adopt this perspective view knowledge as a socially constructed phenomenon, reflecting the dominant power structures in society, and influenced by the political, economic and cultural contexts in which this knowledge is situated. The critical paradigm seeks to uncover hidden power dynamics, expose social injustices and promote emancipation and social change. It is often associated with an orientation towards social critique and advocacy for marginalised groups.

Data collection methods in the critical paradigm often include participant observation, interviews, and focus groups, among others. These methods are used to investigate and document the experiences of marginalised and oppressed groups, as well as to analyse the ways in which power and inequality manifest in different contexts. The goal is to provide a platform for the voices of those who have been traditionally marginalised or silenced and to raise awareness about social injustices. Data analysis within the critical paradigm focuses on identifying and exposing oppressive structures and systems, as well as proposing strategies for change and empowerment.

The following table summarises the core paradigms, methodologies, and methods commonly used in qualitative research.

Table 1: A summary of qualitative philosophy, methodologies and methods.