GPT Tries to Run the Stats – But Should It?

Artificial intelligence (AI) keeps inching its way into orthopedics — clinic notes, imaging reads, even patient communication. Now it’s coming for your meta-analyses.

A new study put GPT-5.1 to the test, asking a simple but high-stakes question: Can a large language model reproduce the kind of statistical outputs surgeons rely on from tools like R?

Short answer: sometimes. Long answer: proceed with caution.

Same Data, Different Brain

Researchers fed GPT-5.1 the raw data from two previously published orthopedic meta-analyses — no shortcuts, no summaries. The model was asked to calculate pooled effects, confidence intervals and heterogeneity metrics using standard frequentist approaches.

Its results were then compared head-to-head with outputs from established statistical packages in R.

This wasn’t about interpretation. It was about math.

Directionally Right — But Not Always Close

On the surface, GPT performed well. Across seven outcomes, it correctly identified the direction of effect every time.

That’s not trivial — especially for quick reads or exploratory work.

But dig deeper, and the cracks show:

• Minor deviations: 3 outcomes (43%)
• Moderate deviation: 1 outcome (14%)
• Major deviations: 3 outcomes (43%)

In nearly half the cases, the differences weren’t just rounding errors — they were meaningful.

Where It Breaks: Heterogeneity

The biggest issue? Between-study variability.

GPT-5.1 performed best when heterogeneity was low — clean datasets, consistent results, minimal noise.

But as soon as variability increased, especially under random-effects models, accuracy dropped off. The model tended to underestimate heterogeneity (τ²) and drift away from validated results.

That’s a problem. Because in orthopedics, heterogeneity isn’t the exception — it’s the rule.

Different implants. Different surgeons. Different rehab protocols. Different patients.

Helpful Assistant — Not Your Statistician

So where does this leave AI in the research workflow?

Right now, GPT looks more like a junior analyst than a replacement for statistical software. It can reproduce general trends, help sanity-check directionality and support early-stage or exploratory work.

But it struggles with complex modeling decisions, accurate variance estimation and high-heterogeneity datasets.

In other words, it can assist — but it doesn’t appear capable of critical thinking and shouldn’t sign off.

Where AI Fits — and Where It Falls Short

Large language models are getting closer to handling real statistical tasks. But “close” isn’t the same as “reliable.”

For now, if you’re running a meta-analysis that could influence clinical decision-making, stick with your trusted tools — and treat AI as a second set of eyes, not the final word.

Origin Study Title Link: Large language models are comparable with commonly used statistical software: A validation of GPT 5.1 for frequentist meta-analysis in orthopaedics

Authors: Mikhail Salzmann, Nikolai Ramadanov, Robert Prill, Robert Hable, Roland Becker