Informed consent is a complex principle but one that affects all health professionals and service users across all domains of healthcare worldwide. Informed consent is a legal requirement prior to proceeding with patient investigation or treatment. Despite consent being carried out every day in clinical practice, research in this field has yielded significant disparity in approach and heterogeneity in results making meaningful comparison or synthesis of results challenging
To standardise measurement of the process, a core outcome set (COS) has been developed identifying nine key outcomes to be measured. A consensus within the available evidence to date has not demonstrated informed consent as a unified measure.
This research study aims to understand which core outcomes are most important to patients undergoing non-emergency surgery, and how can these be prioritised to develop a measurement tool to improve the informed consent process for surgery that could be used in clinical practice. The research study will compromise of three fundamental components: a systematic review of the published literature using COSMIN methodology, a ranking survey of the nine core outcomes for informed consent and semi-structured interviews and consensus meeting.
Research Question: Which core outcomes are most important to patients undergoing non-emergency surgery, and how can these be prioritised to develop a measurement tool for improving the informed consent process?
Objectives
I. To identify if there is a ranking within the core outcome set
II. To identify any currently validated measurement tools to measure the core outcome set available in the published literature
III. To identify and adapt/develop a measurement tool for the highest ranking outcomes that could be used in clinical practice to standardise measurement and qualitatively assess the consent process
Outcome:
The outcome of the study is to identify a validated instrument or tool for measuring the most important core outcomes in the informed consent process for surgery that could be used in clinical practice.
Ethical approval from Office of Research Ethics Northern Ireland Committee (ORECNI) is in progress.
A Systematic Review to Evaluate Patient-Reported Outcome Measures (PROMs) for Informed Consent for Intervention in Adults According to the COnsensus-Based Standard for the Selection of Health Measurement INstruments (COSMIN) Methodology
Aim: To identify any validated measurement tools to measure the core outcomes in the core outcome set for informed consent for intervention available in the published literature.
The systematic review will be conducted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations for outcome measurement instruments. The COSMIN methodology developed specifically for reporting outcome measurement instruments will also be used.
Several measurement properties will be considered to evaluate the quality of measurement instruments. These will include content validity, criterion validity, construct validity, reliability and responsiveness.
Criteria for included studies
Validation studies reporting the development, validation or evaluation of the measurement properties of patient reported outcome measurement instruments for the established informed consent COS will be included. To be eligible, the instrument must be self-report; evaluate one of the core outcome domains identified in the informed consent for therapy COS and have been specifically developed for or adult patients aged 18 or over. Full-text original papers of human studies published in English will be included.
Invasive intervention is defined as any invasive surgical, anaesthetic, radiological, dental, oncological, screening or endoscopic procedure under local, regional blockade or general anaesthetic.
Exclusion criteria
Studies evaluating consent in patients without capacity, children (under 18 years) or patients requiring consent by proxy will be excluded. Studies involving interventions other than surgery or invasive procedures will be excluded. Studies investigating ways to improve drug therapy trials or randomised clinical trials will be excluded. Dissertations, editorials, conference proceedings and reports will be excluded. Studies using the patient reported outcome measurement to validate another instrument. Studies published in a language other than English will be excluded.
Search strategy for identification of studies
A systematic review will be conducted in accordance with the PRISMA-COSMIN for outcome measurement instruments 2024 guidelines. These recommendations consist of two checklists which aim to improve the reporting of systematic reviews of outcome measurement instruments.
A search strategy has been designed in collaboration with a senior medical librarian (RF) and the principal investigator (RC).
Searches will be applied to the electronic databases MEDLINE (from 1990 to October 2024), EMBASE (from 1990 to October 2024), PsycINFO (from 1806 to October 2024), CINHAHL (from 1990 to October 2024), Web of Science (as of October 2024) and Cochrane Library (as of October 2024).
Eligibility of studies for inclusion
Study titles and abstracts will be screened by two independent reviewers to identify potentially eligible studies. Full text articles will be retrieved if a title is ambiguous or appears to meet the inclusion criteria. A third senior reviewer will be sought to resolve any differences. All studies not meeting inclusion criteria will be excluded.
Data Extraction
A pre-defined standardised data extraction template will be used by two independent reviewers to extract data from the included studies. Data extracted will include primary and secondary outcomes, lead author, title of study, type of study, year of publication, duration of study, location of study, number of study sites, number of participants, consent intervention, conflicts of interest, funding sources, invasive intervention, type of outcome measurement instrument and validity of outcome measurement instrument.
Data Analysis
Data will be summarised in tabular form outlining the primary and secondary outcomes. The outcomes with a reported measurement tool will be recorded. Measurement properties including content validity, criterion validity, construct validity, reliability and responsiveness will be used for analysis in each validated measurement outcome instrument. We will summarise outcomes using standardised estimated mean differences and relative risk, respectively.
Measures of variance will be calculated as 95% confidence intervals. Non-parametric data will be included in the narrative description only. If required, assessment of heterogeneity will be performed using meta- analyses. If there is missing data or the available data is not eligible for inclusion in the meta-analysis, the study will be considered individually, and the effects of the missing data discussed.
The COSMIN Risk of Bias checklist manual for systematic reviews of patient reported outcome measurements will be followed throughout.
Principal Investigator:
Professor S J Kirk
Consultant Surgeon
Ulster Hospital
Supervisor: Professor Mike Clarke
Professor/Director of MRC Methodology Hub
School of Medicine, Dentistry and Biomedical Sciences Centre for public health
Study Group: Rachael Coulson, Joshua Clements, Liam Convie, Mike Clarke
Disease Category: Other
Disease Name: Informed Consent for Surgery
Age Range: 18 - 99
Sex: Either
Nature of Intervention:
- Clinical experts
- Consumers (patients)
- Researchers
- Patient/ support group representatives
- Service users
- Statisticians
- Recommendations for outcome measures (measurement/how)
- Consensus meeting
- Interview
- Systematic review
- Survey
The research study will compromise of three fundamental components.
1. Systematic review of the published literature
2. Ranking survey of the nine core outcomes for informed consent
3. Semi-structured interviews and consensus meeting
This research project will comprise several elements. Firstly, a systematic review will be performed utilising COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology. This will identify existing outcome measurement instruments for each of the outcomes generated from an established core outcome set. A steering group, comprising all potential informed consent stakeholders (clinicians and patients and public involvement) will be generated and will be involved at all stages of development and validation. A survey and semi-structured interview will follow to identify if there is a ranking within the core outcomes and to focus efforts on potential measurement tool identification and development.
Electronic Survey
Identified participants will consent to completion of an electronic survey to rank the importance of the nine core outcomes. Following completion of the survey participants will be asked if they would like to be involved in the next phase of the research, semi structured interviews. Results from the survey will be analysed by the research group. A ranking of the core outcomes will be finalised. The three top ranking core outcomes will be considered in greater detail in the next phase of the project.
Semi-structured interview and Consensus Meeting
Participants will be invited to complete a 30-minute interview, either by telephone or in person. During the interview, they will be asked to reflect on survey findings and to share their personal views on the measurement of informed consent. Data analysis will use the framework approach, an established qualitative analysis method employing constant comparison techniques and grounded theory.
A web-based consensus meeting, including PPI representative, will be conducted to discuss equivocal findings in the survey or semi-structured interviews, aiming to resolve any points of conflict identified during the study.