Development of the Knowledge of Genome Sequencing (KOGS) questionnaire

https://doi.org/10.1016/j.pec.2018.07.011Get rights and content

Highlights

  • The Knowledge of Genome Sequencing (KOGS) scale is a robust new 9-item measure.

  • The KOGS was developed using a rigorous psychometric development approach.

  • The KOGS can be administered to patients, research participants and public.

  • The KOGS can also be administered to non-genetics clinicians.

  • The KOGS may be useful to researchers and clinicians using genome sequencing.

Abstract

Objective

Whole-genome sequencing is being implemented in research and clinical care, yet tools to assess patients’ knowledge are lacking. Our aim was to develop a robust measure of whole-genome sequencing knowledge suitable for patients and other stakeholders including research participants, public, students, and healthcare professionals.

Methods

An initial set of 17 items was developed via an iterative process including literature review, expert consultation, focus groups, and cognitive interviews with patients, and then administered to 243 individuals. We used exploratory factor analysis and item-response theory to confirm the psychometric suitability of the candidate items for assessing whole-genome sequencing knowledge.

Results

There was a strong main component after removing 5 items with low factor loadings. Item and scale homogeneity was achieved using Mokken scale analysis. Three further items were removed because they were misfits, inverse duplicates or resulted in local dependency. The remaining nine items fitted the two-parameter logistic IRT model which achieved excellent fit to the observed data. Cronbach’s alpha was 0.79 indicating acceptable reliability.

Conclusion

The KOGS, developed using a rigorous psychometric approach, is a brief and reliable tool.

Practice implications

The KOGS may prove useful for researchers and healthcare professionals using whole-genome sequencing with patients and other stakeholders.

Introduction

Whole-genome sequencing is gradually being incorporated widely into research and clinical care. For whole-genome sequencing to be integrated effectively and safely it is important that individuals make informed choices before consenting. For informed decision-making there are several patient-reported factors [1], of which knowledge is a central component [2]. It is important that measures of knowledge about whole-genome sequencing are available so that healthcare providers can evaluate whether patients are making informed choices about having whole-genome sequencing done. Such measures would also be useful in many other contexts, including evaluation of the effectiveness of interventions designed to improve informed decision-making among patients and research participants, assessment of non-genetics healthcare providers’ understanding of whole-genome sequencing and to track public understanding over time. As genomics is introduced into mainstream clinical practice it will be increasingly important to track knowledge in all these contexts.

One current measure of knowledge of whole-genome sequencing was developed by investigators in the US and administered to 311 patients participating in the ClinSeq project [3]. This 11-item knowledge measure has been used in several studies with patients and research participants since its development [4]. However, a different factor structure and low scale-reliability was found for the scale when it was administered to 862 online survey respondents, raising questions about the measure’s validity and reliability in different populations and methods of administration [5]. Recently one additional measure of genomic sequencing knowledge has been developed: the University of North Carolina Genomic Knowledge Scale (UNC-GKS) [6], but 19 of the 25 items in this measure assess general genetics concepts (e.g. how genes are inherited in families) that have been included in many previous measures of genetics knowledge [[7], [8], [9]]. The other six items relate to exome sequencing rather than whole-genome sequencing, and so do not assess respondents’ understanding of what a ‘genome’ is (the complete set of DNA, as against the 1% that comprises the exome), or specifically what whole-genome sequencing is (e.g. that it looks at almost all, rather than only a small subset, of a person’s DNA). Thus there remains a need for a valid, reliable measure of knowledge specifically of whole-genome sequencing that can be used with individuals in a range of settings.

As part of a study (NIHR PG-PB-1014-350160) to measure and examine informed choice among patients being offered whole-genome sequencing via the 100,000 Genomes Project [10], we are developing a new measure of informed choice for individuals making decisions about whole-genome sequencing in the context of rare disease diagnosis. During development of the informed choice measure, it became apparent that the majority of the items (questions) being developed were ‘context-specific,’ i.e. were relevant primarily to the specific context of whole-genome sequencing for the purposes of diagnosing a rare disease. A subset of the items, however, was ‘context-neutral’, i.e. the items could be administered to patients or other stakeholders (e.g. health care providers, students, general public) regardless of the clinical or other context. We therefore expanded our work with patients to develop a new measure of whole-genome sequencing knowledge that could be administered to a range of stakeholders including public, students, and health professionals as well as patients, their relatives and research participants.

Section snippets

Selection of knowledge domains

In order to identify the domains to include in the knowledge measure overall, and the specific sub-domains (concepts) to cover we reviewed selected professional guidelines and recommendations, patient information materials, and an existing measure [3]. For the professional guidelines and recommendations we drew on a 2013 systematic review of papers on genomic sequencing informed consent recommendations by either experts or societies, the latter of which included international guidelines such as

Sample characteristics

Of 267 individuals invited to complete the KOGS at T1, a total of 24 participants had incomplete data and were excluded, leaving a final sample size of 243 for the main psychometric and T1 analyses. This comprised 189 students/staff, and 54 patients who completed the survey after they had given informed consent to take part in the 100,000 Genomes Project.

Of the 189 students/trainees, 131 had complete data for the pre- vs post-lecture (T1 vs T2) comparison analyses.

Psychometrics

Psychometric analyses were

Discussion

We have developed a robust 9-item Knowledge of Genome Sequencing (KOGS) questionnaire using a rigorous psychometric measure development approach. This is very timely as there are several large genomic studies involving patients and the public ongoing in the UK [29,30], the USA [31,32] and elsewhere [33] and patient-reported measures regarding whole-genome sequencing are urgently needed [1]. Our knowledge measure is an advance on previous measures because it includes both true and false

Acknowledgements

The work presented in this manuscript represents independent research funded by the National Institute for Health Research (NIHR) under the Research for Patient Benefit funding stream (PB-PG-1014-35016: A study to define patient priorities and preferences when consenting to whole genome sequencing to ensure informed choice). All research at Great Ormond Street Hospital NHS Foundation Trust and UCL Great Ormond Street Institute of Child Health is made possible by the NIHR Great Ormond Street

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