Choosing and Interpreting PROs and COAs – A Guide for Clinical Trial Statisticians

Episode Overview In this episode, I speak with Anna Mosikian, a physician by training and Global Clinical Program Lead working at the intersection of clinical development and strategic marketing. Anna brings a powerful perspective on how clinical data translates into real-world value—bridging evidence generation, regulatory expectations, and commercial impact. We dive into what clinical leaders truly expect from statisticians and how statisticians can move from technical contributors to strategic partners. We explore what “good collaboration” really looks like in practice, why understanding the purpose of a study is critical, and how statisticians can elevate their impact through communication, proactiveness, and cross-functional thinking.

Trust is one of the most fundamental elements of effective leadership—and yet, most organizations don’t measure it properly. In this episode, I speak again with my good friend Alun Bedding about how we can move from talking about trust to actually quantifying and improving it. We explore why trust is essential for collaboration, leadership, and performance, and what happens when it’s missing. We also dive into practical tools like the Leadership Trust Index, how to interpret trust as a lead measure, and how organizations can systematically improve trust over time. If you want to become a more effective leader and create real impact, this episode gives you both the mindset and the tools to do it.

In this episode, I sit down with Rachael Lawrance to dive into a topic that has become absolutely central to clinical research: patient-centered outcomes. When I first started as a statistician, I knew these measures existed—but I didn’t really understand how they were developed, analyzed, or used in decision-making. That has changed dramatically over the years. Today, patient-reported outcomes (PROs) and the broader framework of clinical outcome assessments (COAs) play a key role in regulatory approvals, payer decisions, and how we demonstrate treatment value. Rachael brings deep expertise from her work at Adelphi Values and shares how these endpoints are developed, validated, and applied in practice. We also discuss how statisticians can contribute more effectively by understanding the science behind these measures—not just treating them as “just another scale.”

pisode Summary In this episode of The Effective Statistician, Alun Bedding speaks with Emma May about the skills that truly differentiate effective statisticians from great leaders. While technical expertise remains essential, success in today’s environment increasingly depends on the ability to build trust, communicate effectively, and lead with emotional intelligence. Drawing from their joint leadership workshops, Alun and Emma explore how statisticians can develop these capabilities and apply them in real-world settings. They discuss practical approaches to creating psychological safety, shifting from a “telling” to a coaching mindset, and fostering a growth mindset within teams. The conversation highlights why leadership is not about having all the answers—but about enabling others to contribute, grow, and succeed.

Generative AI is moving fast—and in pharma, it’s no longer just a buzzword. In this episode of The Effective Statistician Podcast, I speak with Manuel Cossio about how Generative AI is already being applied in real-world pharma settings, where it’s delivering value today, and what still needs careful consideration in regulated environments. Manuel brings a unique hybrid background, combining molecular biology, genetics, pharma experience, and deep AI engineering expertise. He works at the cutting edge of AI in clinical development, including agentic systems, human-in-the-loop approaches, and large-scale document automation. This conversation goes well beyond theory. We focus on practical use cases, real limitations, and how statisticians, programmers, and data scientists can responsibly use GenAI to become more effective.

As we start 2026, I want to take a moment to express my sincere gratitude to everyone who has been part of The Effective Statistician podcast. This episode features my co-host, Alun Bedding, reflecting on the past year and sharing thanks on behalf of both of us. From our listeners who tune in, share episodes, and engage with the content, to our guests who generously share their expertise and real-world experiences — your participation makes this podcast both insightful and practical for statisticians worldwide. I also want to recognize Reine and her production team. So much of the work that brings each episode to life happens behind the scenes, and we are deeply grateful for their professionalism and dedication. We’re excited about what 2026 has in store. I look forward to continuing this journey with all of you and bringing even more valuable conversations to our community.

In this episode, I talk with my long-time friend and frequent guest, Kaspar Rufibach, about a skill that quietly determines how much impact we really have: presenting and communicating our work. We walk through how Kaspar prepares his talks (including why he starts months in advance), how he structures messages so stakeholders actually remember and act on them, and why overcrowded slides are often just a sign that we haven’t done the hard thinking yet. We also get honest about something many statisticians feel but rarely discuss: the fear of public speaking, the frustration of bad meetings, and the “personal brand” you build every time you present—whether you intend to or not. If you’ve ever walked out of a meeting thinking “I don’t think they really understood what I meant,” this episode is for you.

In this episode, I’m joined by Deepa Jahagirdar, Associate Research Principal at Cytel, to explore what it really takes to build a good external control arm (ECA). Deepa brings a fascinating background from social epidemiology, where causal questions often need to be answered without running randomized trials. That experience translates directly into today’s growing need for ECAs, especially when we rely on real-world data to support single-arm trials, extension phases, or situations where randomization simply isn’t possible. Together, we discuss how to choose the right data source, how target trial emulation works in practice, what to do about confounding, and how to judge whether an ECA is truly robust. If you’re working with real-world evidence, complex study designs, or causal inference, this episode will give you clarity and confidence in approaching ECAs the right way.

Why this episode made our all-time Top 9: If you’ve ever thought “non-parametric = Wilcoxon/Mann-Whitney and that’s it,” this conversation will happily destroy that myth. Frank shows how rank-based methods unlock rigorous analyses for skewed data, outliers, ordinal endpoints, small samples, composites/estimands—and how to communicate effects without relying on means.

Adaptive designs let us learn earlier, stop smarter, and protect patients—but they also make communication tricky. In this episode, Kaspar Rufibach and I dig into what “still correct” looks like when you try to explain results from group-sequential and other adaptive trials to regulators, clinicians, and scientific audiences. We unpack conditional vs. unconditional bias, median-unbiased estimation, stage-wise ordering for p-values, confidence intervals in multi-stage settings, and what to do with secondary endpoints and multiplicity. We also touch on ICHE20 (Adaptive Clinical Trials) and why pre-specification isn’t just a box-tick—it’s what builds trust.