caveat

The distribution is named clinical-insight-caveat; its Python import remains caveat.

Research prototype: Use only non-sensitive data. Do not use it for patient care, clinical decisions, or regulated submissions. Checks can miss errors and can flag valid results; they do not establish that an analysis is valid. Independent statistical review is required.

Statistical caveats for analysis results. Give it a result table and the question that produced it; it reports selected checks and reasons when checks are skipped.

The checks do not call a language model. Their findings depend on the supplied data, inferred column roles, configuration, and supported checks.

import pandas as pd, caveat

df = pd.DataFrame({"arm": ["a", "b"], "cases": [8, 4], "n": [20, 900]})
print(caveat.render(caveat.analyze(df, "which arm has the higher rate?")))

!! [small_sample] 1 group(s) have n < 30 in `n` — estimates unstable. e.g. a (n=20).
!  [contrasts] 1/1 pairwise contrasts survive BH-FDR (q<0.05). Largest: a vs b,
   risk difference +39.6pp (95% CI [18.1, 61.4], q=0.000). Report differences with CIs, not raw ranks.
!  [confounding] This compares `cases` across `arm` **unadjusted** ...

Why this exists

Text-to-SQL and analytics agents got good at producing correct queries and stayed bad at knowing when the answer means nothing. A query over eight rows returns a number, an agent reports it as a finding, and nothing in the stack says the top group is also the smallest, and no pairwise difference survives correction.

Adjacent tools solve adjacent problems. Data-quality frameworks (Great Expectations, pandera) validate inputs against expectations. Profilers (ydata-profiling) describe datasets. Statistics libraries (statsmodels, pingouin) supply the tests but not the decision about which caveat applies here. guardrails-ai validates the shape and safety of LLM output, not the soundness of a conclusion. This library occupies the gap: given a result, which caveats apply.

What it checks

When nothing survives correction, contrasts reports the minimum detectable effect — because "no difference" only means something next to what the data could have detected.

When a supplied rate does not match the counts as a fraction or percentage within 0.5 percentage points, count-based contrasts and related checks are withheld. The rate may be adjusted, use other units, or describe a different population; the check does not determine which value is correct. Likewise, agreement cannot establish that the denominator represents the intended population. Missing or invalid inputs also withhold those checks. Review column roles and the rate definition.

Column roles

Roles are resolved in three layers. Explicit always wins, and naming an absent column raises rather than falling back silently.

caveat.analyze(df, numerator="cases", denominator="n", group="arm")

Left to itself it infers, first from column names and then from the shape of the numbers — a count column bounded elementwise by a larger count column is a numerator inside a denominator whatever the two are called. That structural layer is what keeps the library useful on columns named a, b, cnt.

report = caveat.analyze(df)
print(report.roles)
# Roles(numerator='a'[structural], denominator='b'[structural], group='grp'[structural])

It tells you what it could not do

A report with no findings is ambiguous: clean data, or a tool that identified nothing? caveat never leaves you guessing.

for s in report.skipped:
    print(s)
# contrasts: needs both a numerator and a denominator column (pass numerator='<col>', denominator='<col>')

Multiplicity across a session

Each analyze() corrects within its own family, which is right and is not enough. An agent that answers twenty questions against one dataset has run twenty families and corrected none against each other — the garden of forking paths, arrived at by conversation rather than intent.

session = caveat.Session()
for question, df in conversation:
    report = session.analyze(df, question)

After enough looking, every report carries a session_multiplicity warning. The warning is about interpretation rather than a corrected q-value: for an exploratory sequence there is no honest family-wide correction to apply after the fact, only the obligation to say how much looking was done.

Configuration

caveat.analyze(df, config=caveat.Config(
    min_n=100,                                    # a web funnel is not a clinical trial
    alpha=0.01,
    confounders=("age", "sex", "comorbidity burden"),   # named in the confounding message
))

Install

python -m pip install ./packages/caveat

Run from the repository root. The PyPI name and ownership have not been verified for this project. Requires numpy and pandas. No scipy — the normal CDF comes from math.erf and Wilson, Newcombe, Benjamini-Hochberg and the bootstraps are implemented in-package, so this stays installable inside someone else's agent without dragging in a research stack.

License

MIT