Undefined and Unmeasured: How Conceptual Ambiguity Around the Informal Carer and Carer Burden May Undermine Public Support Policies

Background: Informal carers provide most long-term care in Europe, and supporting them recently became a political topic. Yet two foundations policy remain unstable: knowing who is considered a carer and what support they need. Objective: To examine how the absence of a consensual definition of the informal carer and the limited operational value of burden measurement hinder designing, targeting and evaluating public support policies. Methods: A critical review of the concepts of burden and informal carers, primary conceptual, psychometric and empirical studies, and policy documents. Results: Definitions of the informal carer converge on non-professional help to a person with long-term needs within a personal relationship, but diverge on several aspects. Prevalence estimates consequently vary across surveys and are partly artefacts of definition. Burden is alternately treated as a stressor, an appraisal or an outcome, and is conflated with stress, strain and burnout. Instruments are numerous, capture mainly subjective strain, have rarely been developed with carers, and seldom demonstrate content validity or responsiveness; none offers thresholds anchored to specific support needs. Policies therefore rely on proxies, typically the care recipient’s dependency level. The French daily carer allowance illustrates this mismatch: nearly 270,000 private-sector employees were eligible, whereas 6,626 entitlements had been opened after 18 months. Conclusions: Conceptual ambiguity is not merely an academic concern: it propagates into identification, targeting and evaluation failures. We propose a definition with explicit reporting of boundaries, separation of objective load, subjective strain and consequences, and the development of COSMIN-compliant, context-specific instruments.