Beyond the pyramid: Reconsidering evidence synthesis as distinct from original research

The evidence pyramid, originally intended to guide clinicians and students in understanding levels of clinical evidence. Over time, systematic reviews and meta-analyses were elevated to the apex of this hierarchy, often misconstrued as superior to primary research. Systematic reviews and meta-analyses, while powerful in integrating findings and invaluable for evidence-based practice, remain secondary analyses that depend on the quality of the included studies. Poorly designed or biased trials, coupled with publication bias and redundant syntheses, risk undermining the reliability of aggregated evidence. The current pyramid has inadvertently fostered a culture of desk-based evidence synthesis priority over original, data-generating studies, thereby discouraging innovation. To address these limitations, we propose a dual-framework model that distinguishes original research from evidence syntheses. This model positions randomised controlled trials, large multicentre studies, and qualitative designs within a hierarchy of evidence generation, while treating meta-analysis, realist reviews, and other qualitative syntheses as non-hierarchical but complementary. This effort is to restore balance, encourage methodological pluralism, and promotion of evidence use based on appropriateness and context rather than rigid ranking.