Why and How Epidemiologists Should Use Mixed Methods

Abstract

The field of epidemiology's current focus on causal inference follows a quantitative approach and limits research questions to those that are strictly quantifiable. How can epidemiologists study biosociocultural public health problems that they cannot easily quantify? The mixed-methods approach offers a possible solution by incorporating qualitative sociocultural factors as well as the perspective and context from the population under study into quantitative studies. After a pluralist perspective of causal inference, this article provides a guide for epidemiologists interested in applying mixed methods to their observational studies of causal identification and explanation. We begin by reviewing the current paradigms guiding quantitative, qualitative, and mixed methodologies. We then describe applications of convergent and sequential mixed-methods designs to epidemiologic concepts including confounding, mediation, effect modification, measurement, and selection bias. We provide concrete examples of how epidemiologists can use mixed methods to answer research questions of complex bio-socio-cultural health outcomes. We also include a case study of using mixed methods in an observational study design. We describe how mixed methods can enhance how epidemiologists define underlying causal structures. Our alignment of mixed-methods study designs with epidemiologic concepts addresses a major gap in current epidemiology education-how do epidemiologists systematically determine what goes into causal structures?

The EMICS Tool to Design Mixed-methods Studies in Epidemiology

“…We have previously discussed why it is worth taking a mixed-methods approach and explained how mixed methods can help strengthen various aspects of epidemiologic studies. 2 To complement this publication, we created EMICS (Epidemiology and Mixed Methods Informing Causal Studies), an online tool ( https://cumc.co1.qualtrics.com/jfe/form/SV_578kLV1tRlkxfTw ) to assist epidemiologists in designing mixed-methods observational studies. The web tool is hosted on our website, https://www.irvinginstitute.columbia.edu/mixed-methods , which has accompanying information.…”

“…Integrating qualitative methods into quantitative epidemiologic studies helps balance the etic and emic view, ultimately strengthening causal inference. 2 …”

“…The EMICS tool prompts responses that follow an underlying algorithm (Figure 1 ) to recommend the best-fitting mixed-methods design based on our prior framework. 2 The tool uses existing questionnaire-based software to create a user-friendly point-and-click interface; thus, no programming is necessary. The questions fall into three sections:…”

A guide for a student-led doctoral-level qualitative methods short course in epidemiology: faculty and student perspectives

“…5 Considering the importance of qualitative research and MM in the field, we argue that early-career training in these methods is essential. 6 …”