Gatekeeping and trailblazing: The role of biomarkers in novel guidelines for diagnosing Alzheimer’s disease

Digital phenotyping and the (data) shadow of Alzheimer's disease

In this paper, we examine the practice and promises of digital phenotyping. We build on work on the 'data self' to focus on a medical domain in which the value and nature of knowledge and relations with data have been played out with particular persistence, that of Alzheimer's disease research. Drawing on research with researchers and developers, we consider the intersection of hopes and concerns related to both digital tools and Alzheimer's disease using the metaphor of the 'data shadow'. We suggest that as a tool for engaging with the nature of the data self, the shadow is usefully able to capture both the dynamic and distorted nature of data representations, and the unease and concern associated with encounters between individuals or groups and data about them. We then consider what the data shadow 'is' in relation to ageing data subjects, and the nature of the representation of the individual's cognitive state and dementia risk that is produced by digital tools. Second, we consider what the data shadow 'does', through researchers and practitioners' discussions of digital phenotyping practices in the dementia field as alternately empowering, enabling and threatening.

The Framing of "Alzheimer's Disease": Differences Between Scientific and Lay Literature and Their Ethical Implications

Background and Objectives

The meaning of Alzheimer’s disease (AD) is changing in research. It now refers to a pathophysiological process, regardless of whether clinical symptoms are present. In the lay literature, on the other hand, AD is understood as a form of dementia. This raises the question of whether researchers and the lay audience are still talking about the same thing. If not, how will these different understandings of AD shape perspectives on (societal) needs for people with AD?

Research Design and Methods

We use framing analysis to retrieve the understandings of the term AD that are upheld in the research literature and in national Dutch newspaper articles. We make explicit how the framings of AD steer our normative attitudes toward the disease.

Results

In the analyzed research articles, AD is framed as a pathological cascade, reflected by biomarkers, starting in cognitively healthy people and ending, inevitably, in dementia. In the lay literature, AD is used as a synonym for dementia, and an AD diagnosis is understood as an incentive to enjoy “the time that is left.”

Discussion and Implications

The two different uses of the term AD in research and in the lay literature may result in misunderstandings, especially those research framings that falsely imply that people with AD biomarkers will inevitably develop dementia. Adoption of the research understanding of AD in clinical practice will have normative implications for our view on priority setting in health care. For example, it legitimizes biomarker testing in people without dementia as improving “diagnostic” certainty.

Ambivalent anticipation: How people with Alzheimer's disease value diagnosis in current and envisioned future practices

Emergent biomarkers for Alzheimer's disease (AD) are expected to provide earlier and more precise diagnoses. However, even if biomarkers live up to these expectations, it cannot be taken for granted that patients actually would value an earlier and more precise AD diagnosis. Based on an interview study, we aim to give more insight into the value of an AD diagnosis for patients, in existing as well as future practices, by describing how a diagnosis enables or may enable knowing, foreseeing, and acting in relation to one's illness. Our findings show that how people with AD value a diagnosis is not only characterised by great variety, as previous studies have shown, but also by profound ambivalence for the individual. With lack of treatment and poor prognostics as the status quo, this ambivalence and the way people deal with it are particularly linked to the far-from-straightforward capacity of an AD diagnosis to support anticipation of the future. We argue that in otherwise unchanged practices the envisioned future biomarker-based diagnostics are unlikely to reduce the ambivalence about receiving an AD diagnosis and, in particular, the challenges of anticipation that it entails. Rather, biomarker-based innovations may even reinforce some of the main issues involved.

An analytic framework for conceptualisations of disease: nine structuring questions and how some conceptualisations of Alzheimer's disease can lead to 'diseasisation'

According to the US National Institute on Aging and the Alzheimer's Association (NIA-AA), Alzheimer's disease (AD) should be understood as a biological construct. It can be diagnosed based on AD-characteristic biomarkers only, even if AD biomarkers can be present many years before a person experiences any symptoms of AD. The NIA-AA's conceptualisation of AD radically challenges past AD conceptualisations. This article offers an analytic framework for the clarification and analysis of meanings and effects of conceptualisations of diseases such as that of AD. This framework consists of nine questions that allows us to determine how the conceptualisations of diseases, such as that of AD, link or decouple the following terms to/from each other: screening, diagnosis, pathology, disease (along the lines of what have been labelled as "biological-physiological" or "normative" conceptions of disease in philosophy of medicine), symptoms, and illness. It also includes questions regarding how specific decouplings open up for new categories through which people can understand themselves in new ways, and what spaces of possibilities specific conceptualisations (and their decouplings and linkages) open to. The article shows how specific decouplings/linkages can open up not only for the phenomena of pathologisation but also for a distinct, but related phenomenon here termed as diseasisation.

Personalized Medicine, Disruptive Innovation, and "Trailblazer" Guidelines: Case Study and Theorization of an Unsuccessful Change Effort

Policy Points For complex reasons, the promise of "precision medicine" based on molecular pathways remains unrealized for many conditions. Clinical practice guidelines (theoretically, at least) can act as "trailblazers" to introduce tests and treatments that reflect precision medicine discoveries. We describe a detailed case study from the United Kingdom in which such an attempt was (so far) unsuccessful and show how this case provides generalizable lessons. Policymakers should be wary of using clinical practice guidelines as the sole, or even the primary, lever for introducing precision medicine.

CONTEXT

Precision medicine, which addresses underlying molecular mechanisms of disease, depends on new technologies that measure specific biomarkers, leading (it is anticipated) to more accurate diagnosis, patient stratification, and tailored treatment. These technologies can be disruptive-that is, they make possible, and often require, radical changes to clinical practice and service organization-thereby improving quality, safety, or efficiency of care. Clinical practice guidelines may act as "trailblazers," introducing and legitimizing novel technologies and practices.

METHODS

We describe a case study of an attempt by academic researchers to radically change asthma management in the United Kingdom using a precision medicine biomarker (fractional exhaled nitric oxide, FeNO), measured using a portable breath device. We collected a wide-ranging data set that included more than 100 documents, 61 interviews, and 150 hours of ethnographic observation, and we analyzed it using technology-enhanced strong structuration theory (TESST).

FINDINGS

Our study describes a so-far unsuccessful attempt by academic respiratory medicine researchers to pave the way for a precision medicine approach to asthma using a government-endorsed national guideline. These researchers considered asthma management, especially in primary care, to be characterized by overdiagnosis and poor tailoring of treatment; engaged a national guideline development body in an effort to fix this problem; and ensured that the guideline required primary care clinicians to use FeNO technology for diagnosis and monitoring. However, clinicians working outside the tertiary referral centers did not accept, or agree to enact, the vision of precision medicine inscribed in the guideline-for multiple professional, operational, and economic reasons.

CONCLUSIONS

"Trailblazer" guidelines, in which new technologies are recommended, may succeed as catalysts of change only in a limited way for interested individuals and groups. In the absence of a wider program of professionally led and adequately resourced change efforts, such guidelines will lack meaning, legitimacy, and authority among intended users and may be strongly resisted.

The rare and the common: scale and the genetic imaginary in Alzheimer's disease drug development

In this paper I examine how the promissory value of genetics is constituted through processes of scale and scaling, focussing on the relationship between "rare" and "common" forms of disease. I highlight the bodies and spaces involved in the production of post-genomic knowledge and technologies of Alzheimer's disease and the development of new disease-modifying drugs. I focus on the example of the development of a monoclonal antibody therapy for Alzheimer's disease. I argue that the process of therapeutic innovation, from genetic studies and animal models to phase III clinical trials, reflects the persistent importance of a genetic imaginary and a mutually constitutive relationship between the rare and the common in in shaping visions of Alzheimer's disease medicine. Approaching this relationship as a question of scale, I suggest the importance of attending to how and where genomic knowledge is "scaled" or proves resistant to scaling.

Somaticization, the making and unmaking of minded persons and the fabrication of dementia

This article examines the strategies by which the different and variable signs of failing mental powers become known sufficiently for 'dementia' to be made into a stable bio-clinical entity, that can be tested, diagnosed and perhaps one day even treated. Drawing on data from ethnographic observations in memory clinics, together with interviews with associated scientists and clinicians, we document the challenges that clinicians face across the clinical and research domain in making dementia a stable object of their investigation. We illustrate how the pressure for early diagnoses of dementia creates tensions between the scientific representations of early dementia and its diagnosis in the clinic. Our aim is to highlight the extent to which the work of diagnosing dementia involves an intricate process of smoothing out seemingly insurmountable problems, such as the notoriously elusive connections between brain/mind and body/person. Furthermore, we show that a part of this process involves enrolling patients as minded, agentic subjects, the very subjects who are excluded from dementia science research in pursuit of biomarkers for the pre-clinical detection of dementia.

Ethical and social implications of using predictive modeling for Alzheimer's disease prevention: a systematic literature review protocol

INTRODUCTION

The therapeutic paradigm in Alzheimer's disease (AD) has shifted towards secondary prevention, defined as an intervention aiming to prevent or delay disease onset in pre-symptomatic individuals at risk of developing dementia due to AD. The key feature of AD prevention is the need to treat years or even decades before the onset of cognitive, behavioural or functional decline. Prediction of AD risk and evaluation of long-term treatment outcomes in this setting requires predictive modelling and is associated with ethical concerns and social implications. The objective of this review is to identify and elucidate them, as presented in the literature.

METHODS AND ANALYSIS

A systematic literature review was conducted in Medline, Embase, PsycInfo and Scopus, and was complemented with a grey literature search. All searches were conducted between March and July 2018. Two reviewers independently assessed each study for inclusion and disagreements were adjudicated by a third reviewer. Data are now being extracted using an extraction sheet developed within the group of reviewers, based on an initial sample of three manuscripts, but allowing for inclusion of newly identified data items (ethical arguments). Data will be analysed qualitatively using a thematic analysis technique. Potential biases in selection and interpretation of extracted data are mitigated by the fact that reviewers come from a range of different scientific backgrounds and represent different types of stakeholders in this ethical discussion (academia, industry, patient advocacy groups).

ETHICS AND DISSEMINATION

The study does not require ethical approval. The findings of the review will be disseminated in a peer-reviewed journal and presented at conferences. They will also be reported through the Innovative Medicine Initiative project: Real World Outcomes Across the AD Spectrum for Better Care: Multi-modal Data Access Platform (IMI: ROADMAP).

TRIAL REGISTRATION NUMBER

CRD42018092205.