Challenges and solutions for N-of-1 design studies in health psychology

Challenges and solutions for N-of-1 design studies in health psychology

Kwasnicka, Dominika (Curtin University; SWPS University of Social Sciences and Humanities)
Inauen, Jennifer (Swiss Federal Institute of Aquatic Science and Technology)
Nieuwenboom, Wim (University of Applied Sciences Northwestern Switzeland)
Nurmi, Johanna (University of Helsinki; University of Cambridge)
Schneider, A. (University College London (UCL))
Short, Camille E. (University of Adelaide)
Dekkers, T. (TU Delft Applied Ergonomics and Design)
Jess Williams, A. (University of Birmingham)
Bierbauer, Walter (University of Zürich)
Haukkala, Ari (University of Helsinki)
Picariello, Federica (King’s College London)
Naughton, Felix (University of East Anglia)

2019

Theories of behaviour change and health behaviour change interventions are most often evaluated in between-person designs. However, behaviour change theories apply to individuals not groups and behavioural interventions ultimately aim to achieve within-person rather than between-group change. Within-person methodology, such as N-of-1 (also known as single case design), can circumvent this issue, though has multiple design-specific challenges. This paper provides a conceptual review of the challenges and potential solutions for undertaking N-of-1 studies in health psychology. Key challenges identified include participant adherence to within-person protocols, carry-over and slow onset effects, suitability of behaviour change techniques for evaluation in N-of-1 experimental studies, optimal allocation sequencing and blinding, calculating power/sample size, and choosing the most suitable analysis approach. Key solutions include involving users in study design, employing recent technologies for unobtrusive data collection and problem solving by design. Within-person designs share common methodological requirements with conventional between-person designs but require specific methodological considerations. N-of-1 evaluation designs are appropriate for many though not all types of interventions. A greater understanding of patterns of behaviours and factors influencing behaviour change at the within-person level is required to progress health psychology into a precision science. Video abstract: Supplementary Material 1.

idiographic design
N-of-1
single case study
within-person design

http://resolver.tudelft.nl/uuid:0581e7b0-f286-40a9-b89c-11c66cba00a1

https://doi.org/10.1080/17437199.2018.1564627

2020-01-23

1743-7199

Health Psychology Review, 13 (2), 163-178

Accepted author manuscript

Institutional Repository

journal article

© 2019 Dominika Kwasnicka, Jennifer Inauen, Wim Nieuwenboom, Johanna Nurmi, A. Schneider, Camille E. Short, T. Dekkers, A. Jess Williams, Walter Bierbauer, Ari Haukkala, Federica Picariello, Felix Naughton