The Person-Based Approach to intervention planning

At the planning stage we find five activities useful for developing, describing and refining the ‘programme theory’ for the intervention – the description of how the intervention should work, for whom and in what circumstances. 

1. Reviewing/synthesising relevant literature

An initial theory of how the intervention should work can be created by learning from relevant theory and research (general guidance on literature review is available elsewhere). For the Person-Based Approach we find it particularly useful to learn from qualitative and mixed methods evaluations of similar interventions, to understand the barriers and facilitators influencing engagement with the intervention.

2. User needs studies

If review of the literature reveals evidence gaps then studies may need to be carried out to address unanswered questions – for example, if the intervention or the healthcare problem it addresses is novel so there is little relevant previous research. The choice of methods to address the evidence gap will depend on the research question. Qualitative studies (e.g. focus groups, interviews, ethnography) are often helpful to help intervention developers understand the users’ needs and perspectives and the contexts in which the intervention will be implemented.

3. Logic model /‘theory of change’

This is a diagram that summarises the cause-effect sequence describing how the key elements of the intervention should lead to positive behaviour change and better health. Creating a logic model is best practice common to most approaches to intervention development so there is already guidance elsewhere on how to do this.

4. Intervention planning table

This table brings together all the available evidence about exactly what elements are needed in the intervention and why, drawing on theory, research, and the expertise of all members of the intervention development team, including public contributors and other stakeholders (see below for details). The table helps by capturing key pieces of information and early decisions in one place so that it is easy for the whole team to see and discuss the evolving picture.

5. Guiding principles for intervention design

The guiding principles focus on what is needed to make the intervention acceptable, feasible and engaging for the users it is designed for. A few key guiding principles can help keep the development focused on what will be especially appealing and useful to the intended users.

Carrying out User Needs Studies

Research into user needs is a vital part of the Person-Based Approach if there are evidence. There is no single method we use since different methods are needed to investigate different aspects of user needs. Methods that can be useful include:

  • Surveys, focus groups or interviews to collect data on the needs, lifestyle and preferences of the target user population
  • Ethnography to obtain an in-depth understanding of user contexts
  • Participatory research to generate and prioritise ideas for useful interventions
  • Analysis of population data to identify the population groups with specific needs and their characteristics (e.g. underserved groups or communities)

Guidance on carrying out these different types of studies is given elsewhere.

Click here for examples of Person Based Approach User Needs Studies.


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The early stages of applying the Person-Based Approach involve seeking to gain an in-depth understanding of user perspectives and key context-specific behavioural issues around the target behaviour(s) and potential intervention elements. 

This may involve:

  • Discussions with PPI representatives who are members of the target user group, and with other stakeholders (e.g. practitioners, providers, policy-makers, community groups)
  • Exploring, reviewing or synthesising the relevant empirical literature (especially mixed methods and qualitative studies)
  • Identifying relevant theories and models
  • Primary qualitative research into user needs, views and experiences

An Intervention Planning Table (see example below) allows the development team to collate these sources of evidence and ideas. Benefits are that it can be used to:

  • Provide a structure to support co-creation with colleagues/PPI/stakeholders
  • Record the rationale and evidence-base for selecting or designing intervention elements
  • Capture any unresolved questions or issues to be followed up

The table is intended as a simple and flexible tool that can be adapted to the needs of a specific intervention. Some useful adaptations are:

  • Adding behavioural analysis columns to describe the behaviour change techniques that are included in the intervention
  • Adding ranking criteria for guiding decisions about whether and how to include intervention elements. A research team might agree to give highest priority to elements that are required for legal or clinical reasons, second priority to elements that are endorsed by stakeholders and central to the logic model, and lower priority to elements that do not meet these criteria.

The aim of guiding principles is to highlight how the intervention will address key issues crucial to engagement in the specific context of the target users.

To achieve this we:

  1. Identify the specific user characteristics likely to affect engagement, such as their views, needs and capabilities (see first column of table below).
  2. Identify key intervention design objectives to improve engagement – what the intervention design must achieve to meet these specific needs or overcome these specific barriers
  3. Identify key features of the intervention that will achieve those objectives. Key features can include behaviour change techniques (from intervention planning - e.g. goal setting), delivery characteristics (e.g. video format), implementation setting (e.g. schools), communication methods (e.g. framing), navigation methods (e.g. tunnelling, self-tailoring), or any other aspect of the intervention that could affect engagement.

The golden principles of Guiding Principles are:

  • They draw on an in-depth understanding of your target user group
  • They focus on making the intervention engaging – persuasive, meaningful, enjoyable
  • They can be revisited and refined throughout development
  • They provide a brief summary of what should be especially appealing and useful about this particular intervention for this particular group of users and their context

This example shows the guiding principles for designing a digital intervention to encourage older people to become more physically active.

User Context
Key Design Objective

In older people:

1. Levels of physical activity are low and often unchanged by interventions

2. Improving health not usually a strong motivation for physical activity

Encourage engagement with and intrinsic motivation for physical activity

Offer novel activities, ensure compatible with lifestyle and identity:

  • Lifestyle activity
  • Strength and balance training
  • Breaks from sitting

Rather than framing activities in terms of reducing risk of health conditions, highlight benefits that have immediately evident and noticeable outcomes and are known to be valued by the intended user group

e.g. keeping mobile, maintaining independence, enjoyment, reducing pain, social connection, enhancing mood, general quality of life

Key references

A new framework for developing and evaluating complex interventions: update of Medical Research Council guidance BMJ 2021; 374 doi: (Published 30 September 2021) Cite this as: BMJ 2021;374:n2061

O’Cathain, A., Croot, L., Sworn, K. et al. Taxonomy of approaches to developing interventions to improve health: a systematic methods overview. Pilot Feasibility Stud 5, 41 (2019).

INDEX Study (IdentifyiNg and assessing different approaches to DEveloping compleX interventions) [Available from:

Skivington K, Matthews L, Simpson SA, Craig P, Baird J, Blazeby JM, et al. Framework for the development and evaluation of complex interventions: gap analysis, workshop and consultation-informed update. Health Technol Assess 2021;25(57); Appendix 5: Approaching complexity in evidence synthesis

Intervention Planning Table examples

Guiding Principle examples

Active Lives

Essery, R., Pollet, S., Smith, K. A., et al. Planning and optimising a digital intervention to protect older adults' cognitive health. Pilot Feasibility Stud, 7(1), 158 (2021). 

Payne, L., Ghio, D., Grey, E. et al. Optimising an intervention to support home-living older adults at risk of malnutrition: a qualitative study. BMC Fam Pract 22, 219 (2021).

Reviewing/synthesising literature examples

Corbett, T., Singh, K., Payne, L., Bradbury, K., Foster, C., Watson, E., Richardson, A., Little, P., & Yardley, L. (2018). Understanding acceptability of and engagement with Web-based interventions aiming to improve quality of life in cancer survivors: A synthesis of current research. Psychooncology, 27(1), 22-33.

Guidance for creating logic models

General guidance for use of logic models in intervention development:

O'Cathain A, Croot L, Duncan E, et al Guidance on how to develop complex interventions to improve health and healthcare BMJ Open 2019;9:e029954. doi: 10.1136/bmjopen-2019-029954

Example of a complex logic model and a dark logic model from MRC guidance: 

Skivington K, Matthews L, Simpson SA, Craig P, Baird J, Blazeby JM, et al. Framework for the development and evaluation of complex interventions: gap analysis, workshop and consultation-informed update. Health Technol Assess 2021;25(57), p69-72.

Example of how a logic model and behavioural analysis table can be included in PBA intervention planning:

Bradbury, K., et al. (2019). Developing a digital intervention for cancer survivors: an evidence-, theory- and person-based approach. NPJ Digit Med, 2, 85.