Beyond randomisation: Re-thinking evidence hierarchies in global surgery

The advent of evidence-based medicine (EBM) placed randomised controlled trials (RCTs) near the apex of evidence hierarchies, prompting a gradual but powerful shift in how surgical research is judged. In 1996, Richard Horton famously lamented that much of surgical research resembled a “comic opera,” raising many questions but offering few answers. ¹ Nearly three decades later, a more recent Lancet editorial celebrated the maturation of surgical research, noting with satisfaction that large RCTs have become increasingly common in surgery. ² While this progress deserves recognition, the implicit suggestion that RCTs alone confer legitimacy on surgical research merits careful reconsideration – particularly from the perspective of global surgery.

Global surgery is practiced largely in low- and middle-income countries (LMICs), where health systems operate under profound resource constraints, disease patterns differ from those in high-income countries, and social context decisively shapes both problems and solutions. In such environments, surgical progress has often depended on frugal surgical innovations (FSIs) – locally developed, contextually relevant, affordable, and scalable solutions created by grassroots surgeons responding to everyday realities. These solutions rarely emerge from large RCTs. Instead, they are most often evaluated through observational studies, which remain the dominant form of surgical research worldwide.

To privilege RCTs as the sole marker of ‘good’ science risks marginalising the very knowledge base on which global surgery depends. It also perpetuates epistemic inequities, whereby research questions relevant to well-resourced settings are rewarded, while context-specific solutions from LMICs struggle for visibility. Many FSIs fail to gain recognition not because they lack merit, but because their evaluation and reporting do not align with prevailing editorial expectations.^3–5 When viewed exclusively through an RCT-centric lens, such work is too often dismissed prematurely.

Yet, RCTs are not the only building blocks of EBM. Even its most committed advocates acknowledge that it is neither feasible nor ethical to randomise every surgical innovation. Carefully designed prospective observational studies with predefined outcomes can provide robust and actionable evidence. ⁶ Indeed, several transformative procedures – including laparoscopic cholecystectomy, joint replacement surgery, and organ transplantation – were widely adopted without prior RCT validation. Surgical science has historically advanced through observation, iteration, and refinement rather than through randomisation alone.

Importantly, observational studies occupy a formal and recognised position within the IDEAL framework for surgical innovation, representing the early stages of evaluation before progression to more definitive study designs. ⁷ To disparage observational research is therefore to undermine the very pathway through which surgical innovation – especially in resource-limited settings – can responsibly evolve. Calls to end the ‘witch-hunt’ against observational studies are not pleas for lowered standards, but for appropriate standards that reflect surgical realities. ⁶

Equally vital to global surgery is the growing role of qualitative research as applied social science. ⁸ Rudolf Ludwig Carl Virchow (1821–1902), widely regarded as the father of modern pathology and the founder of social medicine, reminded us that ‘medicine is a social science’. ⁹ Had this principle remained central to medical thinking, the legitimacy of qualitative inquiry in surgery would never have been questioned. Over the past two decades, applied social science in the form of qualitative studies has matured substantially within surgical research, and its rightful place is now axiomatic. Qualitative methods allow exploration of domains that quantitative metrics alone cannot capture – quality of life and well-being, gender and other forms of discrimination, surgical education and training, mental health challenges, burnout, and the lived experiences of both patients and surgeons. This dimension is particularly critical in global surgery, where social context – shaped by poverty, gender norms, geography, health system capacity, and cultural beliefs – often determines not only outcomes but the very type of treatment that is feasible, acceptable, or ethical. In such settings, understanding why an intervention succeeds or fails is as important as determining whether it does. Surgical researchers must use the wide array of rigorous qualitative techniques available to study these neglected social facets of surgery, thereby enriching the surgical literature with insights that are contextually grounded, methodologically sound, and globally relevant. ⁸

Scientific history reminds us that impact is not dictated by study design alone. The helical structure of DNA – one of the most influential discoveries in biomedical science – was first reported as a brief letter to the editor. ¹⁰ Albert Einstein's warning against a ‘confusion of goals and perfection of means’ remains strikingly relevant. When methodological purity becomes an end in itself, scientific inquiry risks drifting away from lived realities. ¹¹

Global surgery, therefore, demands methodological pluralism, contextual sensitivity, epistemic balance, and a more inclusive evidence paradigm. RCTs are invaluable and should be pursued wherever feasible. But they cannot – and should not – serve as the sole arbiters of scientific legitimacy. Observational and qualitative studies, when conducted and reported with rigour, are not second-tier science. They are indispensable to understanding, innovating, and improving surgical care for the majority of the world's population. To deny them their rightful place and respect in the hierarchy of evidence is a failure to engage seriously with how surgery is practiced across much of the world. A hierarchy of evidence that does not accommodate context, feasibility, and social reality risks mistaking methodological elegance for clinical relevance.