[Therapeutic inertia: physician, patient, and system-related factors and possible intervention strategies]

Therapeutic inertia is the result of a complex interaction between multiple factors. In the recent years, some authors suggested that the burden of responsibility for therapeutic inertia is shared, with 50% due to physician-related factors, 30% to patient-related factors, and the remaining 20% to healthcare system barriers. This view is misleading because it fails to capture the deep interconnection between the various elements and how they feed into each other in a vicious circle that influences therapeutic action. The physician's decision-making is influenced by cognitive biases, mental shortcuts, and contextual pressures that can lead to systematic errors. Within the different care settings, the patient is never a passive actor; their fears, perceptions and behaviors play a crucial role in factors that influence clinical reasoning and give rise to interactions in which avoiding conflict leads to a loss of therapeutic opportunities. At least four recurring clinical profiles can be identified, which can be defined as "phenotypes of therapeutic inertia": uninformed, hesitant, rigid, overwhelmed. Each phenotype is characterized by a different level of self-awareness and is supported by cognitive biases as well as specific relational difficulties with different types of patients. Identifying the phenotypes of inertia is only the first step: the crucial question for clinical practice is whether and how they can be modified. There are no single solutions: it is therefore a matter of developing an interpretative grid to recognize recurring patterns of inertia in clinical practice and identify the most effective corrective strategies.