© 2020 The Authors. The Milbank Quarterly published by Wiley Periodicals, Inc. on behalf of The Millbank Memorial Fund 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.
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