Impact of Previous Genetic Counseling and Objective Numeracy on Accurate Interpretation of a Pharmacogenetics Test Report

Variability in conceptualizations and measurement of genetic literacy

Objective

To examine definitions and measures for genetic literacy in the published literature, and the associations between commonly utilized measures.

Methods

We completed a systematic review searching eight databases for empirical articles containing quantitative measures of genetic literacy. Articles were assessed for study properties, definitions, and measure characteristics. An online survey was then completed by 531 U.S. adults to examine correlations between frequently used genetic literacy measures.

Results

92 articles met inclusion criteria for the systematic review. Articles rarely defined genetic literacy, and existing definitions showed inconsistencies in the knowledge and cognitive domains that comprise genetic literacy. Definitions frequently included objective conceptual knowledge, comprehension, and applied knowledge, however most measures only assessed objective or subjective knowledge. Genetic literacy measures were infrequently assessed for psychometric properties and the content domains assessed by measures varied considerably. Correlation analyses showed weak to moderate relationships between genetic literacy measures.

Conclusion

A comprehensive and consistent definition of genetic literacy and its cognitive and conceptual domains should be implemented to inform the development of concordant measurement tools and improve research and clinical care in genetics.

Innovation

We examine and compare definitions and measures of genetic literacy, suggest a more comprehensive definition, and recommendations for research development.

Pharmacogenomic Clinical Decision Support: A Scoping Review

Clinical decision support (CDS) is often cited as an essential part of pharmacogenomics (PGx) implementations. A multitude of strategies are available; however, it is unclear which strategies are effective and which metrics are used to quantify clinical utility. The objective of this scoping review was to aggregate previous studies into a cohesive depiction of the current state of PGx CDS implementations and identify areas for future research on PGx CDS. Articles were included if they (i) described electronic CDS tools for PGx and (ii) reported metrics related to PGx CDS. Twenty of 3,449 articles were included and provided data on PGx CDS metrics from 15 institutions, with 93% of programs located at academic medical centers. The most common tools in CDS implementations were interruptive post-test alerts. Metrics for clinical response and alert response ranged from 12-73% and 21-98%, respectively. Few data were found on changes in metrics over time and measures that drove the evolution of CDS systems. Relatively few data were available regarding support of optimal approaches for PGx CDS. Post-test alerts were the most widely studied approach, and their effectiveness varied greatly. Further research on the usability, effectiveness, and optimization of CDS tools is needed.

Development and Validation of the Minnesota Assessment of Pharmacogenomic Literacy (MAPL)

Ensuring that patients have an adequate understanding of pharmacogenomic (PGx) test results is a critical component of implementing precision medicine into clinical care. However, no PGx-specific validated literacy assessment has yet been developed. To address this need, we developed and validated the Minnesota Assessment of Pharmacogenomic Literacy (MAPLTM). Foundational work included a scoping review of patient and general public attitudes and experiences with pharmacogenomic testing, three focus groups, readability assessments, and review by experts and members of the general public. This resulted in a 15-item assessment designed to assess knowledge in four domains: underlying concepts, limitations, benefits, and privacy. For validation, 646 participants completed the MAPL as a part of a larger survey about pharmacogenomic research and statewide PGx implementation. Two items were deemed to be “too easy” and dropped. The remaining 13 items were retained in the final MAPL with good internal reliability (Cronbach’s alpha = 0.75). Confirmatory factor analysis validated the four-domain construct of MAPL and suggested good model performance and high internal validity. The estimated coefficient loadings across 13 questions on the corresponding domains are all positive and statistically significant (p < 0.05). The MAPL covers multiple knowledge domains of specific relevance to PGx and is a useful tool for clinical and research settings where quantitative assessment of PGx literacy is of value.

The role of emotional sensitivity to probability in the decision to choose genetic testing

While the availability of genetic testing is rapidly increasing, many opt out of testing. The decision to test or not is emotionally charged, and both clinical research and theoretical work in psychology show that in emotional decisions, people often struggle to interpret and utilize risk information. Clinical research on genetic testing uptake also shows that feeling overwhelmed by numeric information may be a deterrent to testing. However, recent psychological research indicates that some portion of the population has greater emotional sensitivity to probability, (i.e., the extent to which emotional reactions to risk depend on probabilities) than others. We hypothesize that participants high in emotional sensitivity to probability will be more interested in genetic testing as an opportunity to seek greater precision in risk estimates and that this relationship is moderated by the testing context itself. In an online survey of a nationally representative sample (not recruited as patients), participants were presented with a hypothetical scenario describing a suspected diagnosis with an option for genetic testing. The scenario experimentally varied the pre-test probability estimate of the diagnosis (low or high) and whether the test results would result in certainty (ruling in or ruling out the diagnosis), or reduced uncertainty (providing a more precise individual risk estimate). Results indicated that emotional sensitivity to probability was a strong predictor of intention to test, particularly when the test allowed participants to rule out a diagnosis, reducing an already low probability to zero. These results highlight the way patients' individual characteristics interact with the testing context to guide decision-making and provide important insight into the way patients integrate risk probability information into intensely emotional decisions.

A Scoping Review of Attitudes and Experiences with Pharmacogenomic Testing among Patients and the General Public: Implications for Patient Counseling

The use of pharmacogenomic (PGx) tests is increasing, but there are not standard approaches to counseling patients on their implications or results. To inform approaches for patient counseling, we conducted a scoping review of published literature on patient experiences with PGx testing and performed a thematic analysis of qualitative and quantitative reports. A structured scoping review was conducted using Joanna Briggs Institute guidance. The search identified 37 articles (involving n = 6252 participants) published between 2010 and 2021 from a diverse range of populations and using a variety of study methodologies. Thematic analysis identified five themes (reasons for testing/perceived benefit, understanding of results, psychological response, impact of testing on patient/provider relationship, concerns about testing/perceived harm) and 22 subthemes. These results provide valuable context and potential areas of focus during patient counseling on PGx. Many of the knowledge gaps, misunderstandings, and concerns that participants identified could be mitigated by pre- and post-test counseling. More research is needed on patients’ PGx literacy needs, along with the development of a standardized, open-source patient education curriculum and the development of validated PGx literacy assessment tools.