Patient involvement in a meta-analysis of inter-arm blood pressure difference (INTERPRESS-IPD) – what’s the point?




Poster session 3


Tuesday 18 September 2018 - 12:30 to 14:00

All authors in correct order:

Boddy K1, Liabo K1, Reed N2, Turner M2, Goddard J2, Clark C1
1 University of Exeter Medical School, UK
2 Public Involvement Member, UK
Presenting author and contact person

Presenting author:

Kate Boddy

Contact person:

Abstract text
Inter-arm differences in blood pressure (IAD) are associated with increased cardiovascular and all-cause mortality in various cohort studies. INTERPRESS is an individual patient data (IPD) meta-analysis to address questions arising from previous work:

- What is the independent contribution of IAD to prognostic risk estimation for cardiovascular and all-cause mortality?
- What minimum cut-off value for IAD defines elevated risk?
- What is the incremental association between IAD and mortality risk?
- Do different IAD measurement techniques affect the prognostic value of IAD measurements?

An international collaboration, the INTERPRESS-IPD, was formed to address these questions by combining individual patient data from IAD cohort studies into a single large dataset for IPD meta-analysis. Three public advisors were involved in this collaboration to offer their perspective on the development and conduct of the research.

To give a brief outline of the meta-analysis then, in more detail, describe how three public advisors were involved in INTERPRESS and explore the impact of their involvement on the research process, on the researchers and on the public advisors. We will also explore what factors enabled the public advisors to express their views openly within the research process.

The participants in this study, on the impact of involvement in INTERPRESS, are the 11 members of the INTERPRESS international collaboration, the three public advisors and the three external members of the independent monitoring group. The presentation will draw on inductive and thematic analysis of transcribed audio recordings of the meetings (n = 12).

Findings and conclusions:
The qualitative research data collection completes in April 2018. We will present results from our full analysis, which will be conducted in May, June and July 2018. Ongoing feedback and reflections on the involvement has been gathered throughout the study's life-course, drawing on the PiiAF framework.

Patient or healthcare consumer involvement:
This research explores how public involvement impacted an IPD meta-analysis. This abstract has been co-produced with the INTERPRESS public advisors and and we will co-present the results.

Relevance to patients and consumers: 

When blood pressure is measured some people have different readings in their left and right arms. Studies which follow up people with such inter-arm differences over a number of years have shown increased rates of death in those with inter-arm differences compared to those without. There is uncertainty about how small an inter-arm difference has to be before it can be regarded as normal, in other words, when can people be reassured that such a finding is not a marker of increased risk for future mortality? This study aims to answer these questions.