Dyad – what does this mean in the context of research?
Posted on 8th August 2019 by Dolly Sud
The technical definition of the term dyad is something that exists of two elements or parts. In mathematics it is defined as an operator which is a combination of two vectors. So how is this term applicable to research? In this blog, we will look at the meaning of the term dyad in the context of participant recruitment in qualitative research and outline some of the challenges that can arise.
What is a dyad within the context of healthcare research?
Within the context of healthcare research a dyad consists of the participant (a patient) and a person with whom they have a partnership or relationship with (their partner). This could be, for example, a patient and their informal carer or a patient and their clinician. The inclusion of patients and their partners in descriptive and intervention studies can allow researchers to explore more fully the factors that may be pertinent in health outcomes.
What is the value of including dyads in research?
Interviews with dyads have the potential to generate a more in-depth and thicker (richer) understanding of views, experiences and perspectives than a single perspective. It facilitates the exploration of complex perspectives whether those are complementary or contradictory .
Approach to recruitment
Dyads for research can be accessed from various healthcare settings: inpatient, outpatient, community, home or public. Well-thought-out recruitment strategies are required for each setting. Clinical staff may be useful here in helping determine if patients have a family member involved. With regards to recruitment of family and friends, Steinhauser et al  suggest asking the patient to identify the person spending the most time with them (because some patients are reluctant to acknowledge the need for a caregiver).
Whichever method is chosen the protocol should clearly explain how the dyad is selected and recruited. Permission must be sought from the patient. Patients may feel that their family members are under stress or already doing too much for them so may be reluctant to ask them to take part. The partner can still decline to participate, even when contacted, if they already have busy schedules or just don’t want to take part.
Protocols must also incorporate what to do if both the patient and their informal carer are eligible to take part, for example, both have been given a diagnosis of schizophrenia. Another important consideration is to decide how you will proceed if one of the pair in the dyad declines to take part.
How might you collect qualitative research data from a dyad?
Eisikovits and Koren (2010)  provide a comprehensive overview of different methods that can be employed – they outline 5 approaches as well as the advantages and disadvantages of each:
1. separate interviews
2. separate interviews performed simultaneously by different interviewers
3. joint interviews
4. both separate and joint interviews with the same participants
5. separate interviews with some informants and joint interviews with others
I would advise researchers to choose carefully which of these they use depending on the goals of their research.
My own experience
My own experience of dyad research relates to a research study I am conducting exploring the care and support of physical health for those with severe mental illness (e.g. bipolar disorder). During the initial process of thinking about the study design, I had already decided that I would like to recruit patients and their informal carers. I wasn’t aware of the term ‘dyad’ but later learned that this was what it was called! Individuals with severe mental illness suffer significantly with higher rates of morbidity and mortality, mainly due to physical health problems such as heart disease and diabetes. Part of what I am interested in finding out about is what the role and impact is of, and for, the informal carer. I am also interested in what can be found by comparing and contrasting responses between the individuals comprising the dyad.
The dyad in this study is patients with severe mental illness and an informal carer. The patient is asked to identify a person from whom they get the most support from, and this doesn’t necessarily have to be a family member (avoiding the use of the term ‘carer’ or ‘caregiver’). If they are able to identify someone and think this person might want to take part then an information pack (which includes an introductory letter and participant information sheet) is given to them to pass to that person. This is followed by instructions that if the informal carer is interested in taking part then they should contact the researcher directly themselves.
We looked at other research studies that have successfully recruited patients and their informal carers, mainly in advanced cancer care , to inform our own method of recruitment.
The semi-structured interviews have been conducted with each participant (the patient and their informal carer) separately. Using this particular approach allows for each participant to provide information from his or her own perspective without having this impacted upon by information provided by the other person.
Practical and ethical issues
1) recruitment can take time
2) participants consent to their own participation and then consent to providing information to the other member of the dyad
3) where interviews are conducted separately, the researcher must take time to reflect on the interplay between their standpoint and data interpretation
4) steps must be taken to ensure that confidentiality is maintained between dyads, particularly during the recruitment process, documentation of any background demographic information, and also in undertaking research itself
5) undertaking interviews separately and then analysing them dyadically might make it difficult to maintain confidentiality between the individuals in the dyad when information is compared and contrasted. Certainly, there will need to be balance between what needs to be kept and what needs to be left out to ensure preservation of meaning whilst safeguarding confidentiality.
Conclusion: The whole is greater than the sum of its parts
I would urge researchers to consider the value of undertaking research with dyads. Whilst there are practical and ethical challenges to consider, it has the potential to provide data which can be viewed on both an individual and dyadic level.