The Limits of Averages: A Framework for Contextual Effectiveness in Palliative Care Medicinal Cannabis Research

This article introduces a framework of contextual effectiveness to reconcile the persistent gap between patients' positive experiences with treatments and negative clinical trial outcomes in palliative care. Using medicinal cannabis as an illustrative example, we challenge the statistical assumption that averaging patient responses yields a reliable "true effect" for subjective outcomes like quality of life. We argue that treatment effects vary not only between patients but also within the same patient across contexts and time. While averaging approaches remain valid for discrete symptoms (e.g., pain), a patient's reported improvement in overall well-being in specific situations may reflect genuine contextual effectiveness rather than placebo or misattribution. Highly individualized findings complicate guideline and funding decisions; hence, we propose a dual-pathway model for evidence generation: traditional randomised controlled trials (RCTs) for population-level efficacy, followed by post-trial contextual surveillance studies (CSS) that empower individualized patient-clinician decisions. This framework maintains scientific rigor while enabling more person-centered care. By recognizing that a patient may be both a "responder" and "non-responder" depending on life context, we offer a paradigm shift in how subjective outcomes are understood, evaluated, and applied in palliative care practice.