bio-clinical-biostatistics-categorical-tests

bio-clinical-biostatistics-categorical-tests is a skill for Claude Code, Codex from GPTomics/bioSkills. It costs 86 tokens per session (6,352 once invoked), scanned A, original, MIT.

A guide to statistical tests for relationships between categorical variables, such as treatment group and whether a clinical outcome occurred. It includes tests for both independent groups and paired binary results.

In plain words
What is it for?
Use it to apply chi-square, Fisher’s exact, Boschloo, Cochran–Mantel–Haenszel, or McNemar tests and calculate confidence intervals for clinical outcomes.
Why use it?
It helps choose a suitable test when data are counts or categories, especially when sample sizes are small or results are paired.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to apply chi-square, Fisher’s exact, Boschloo, Cochran–Mantel–Haenszel, or McNemar tests and calculate confidence intervals for clinical outcomes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gptomics/bioskills/categorical-tests
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add GPTomics/bioSkills --skill categorical-tests
Clone the repo
git clone --depth 1 https://github.com/GPTomics/bioSkills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for bio-clinical-biostatistics-categorical-tests

README.md
[![agentmods](https://agentmods.dev/badge/skills/gptomics/bioskills/categorical-tests/github.svg)](https://agentmods.dev/skills/gptomics/bioskills/categorical-tests)
Your own site
<a href="https://agentmods.dev/skills/gptomics/bioskills/categorical-tests"><img src="https://agentmods.dev/badge/skills/gptomics/bioskills/categorical-tests/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for bio-clinical-biostatistics-categorical-tests

Your own site · 80×15
<a href="https://agentmods.dev/skills/gptomics/bioskills/categorical-tests"><img src="https://agentmods.dev/badge/skills/gptomics/bioskills/categorical-tests.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 86 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,352 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00086 $0.06352
Opus 5 $0.00043 $0.03176
Sonnet 5 $0.00017 $0.01270
Haiku 4.5 $0.00009 $0.00635

Measured 6d ago against content hash cdedea6bcd95, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

bio-clinical-biostatistics-categorical-tests scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (examples/categorical_tests_clinical.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

clinical-biostatistics/categorical-tests/SKILL.md · 311 lines

How it starts

The opening of the file, as written. The whole thing — 311 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Version Compatibility

Reference examples tested with: scipy 1.12+ (Boschloo and Barnard added in 1.7), statsmodels 0.14+, pingouin 0.5+, exact2x2 (R) 1.6+, pandas 2.1+, numpy 1.26+.

Before using code patterns, verify installed versions match. If versions differ:

  • Python: pip show <package> then help(module.function) to check signatures
  • R packages cited for reference (exact2x2, Exact, ratesci): use packageVersion() then ?function_name to verify parameters

If code throws ImportError, AttributeError, or TypeError, introspect the installed package and adapt the example to match the actual API rather than retrying.

Categorical Association Tests for Clinical Data

"Test association between categorical variables" -> Determine whether treatment and a categorical clinical outcome are statistically independent (or that marginal proportions agree, for paired data) using a test calibrated to the design, the sample size, and the regulatory question.

Algorithmic Taxonomy

Test Design Asymptotic / exact Conditioning Strength Fails when
Pearson chi-square (no continuity correction) Independent groups, any RxC Asymptotic None Standard for n>=40 with all expected counts >=5; matches Miettinen-Nurminen score CI Any expected cell <1; >20% of cells with expected <5 (Cochran 1954)
Fisher's exact (conditional) Independent 2x2 Exact Conditions on BOTH margins Exact small-sample guarantee on level Conservative (true alpha << nominal); discards information by double conditioning (Mehta-Senchaudhuri 2003)
Boschloo's exact Independent 2x2 Exact unconditional Conditions on ONE margin only Uniformly more powerful than Fisher (Boschloo 1970; Mehta-Senchaudhuri 2003); preserves nominal alpha exactly Computationally heavier; RxC extensions limited
Barnard's exact Independent 2x2 Exact unconditional Conditions on ONE margin only Maximises nuisance parameter; well-calibrated Slightly less powerful than Boschloo on average; compute scales O(n^2)
CMH (Mantel-Haenszel) Stratified independent groups Asymptotic Conditions within strata Tests common-OR null across strata; pooled OR estimator Assumes no qualitative interaction; misleading when ORs reverse direction across strata
Breslow-Day Stratified independent groups Asymptotic Within strata Tests homogeneity of stratum ORs Underpowered with few strata or sparse strata; non-significance does NOT prove homogeneity
McNemar (asymptotic, no continuity correction) Paired binary Asymptotic Conditions on discordant pairs Fagerland 2013 default; outperforms exact conditional Discordant pair count b+c < 25 (chi-square approximation breaks)
Mid-p McNemar Paired binary Quasi-exact Discordant pairs Fagerland-Lydersen-Laake 2013 recommended default; less conservative than exact conditional Slight under-coverage tolerable at small b+c
Exact conditional McNemar (Liddell 1983) Paired binary Exact Discordant pairs only Guaranteed coverage Over-conservative; loses power vs mid-p or unconditional
Suissa-Shuster exact unconditional Paired binary Exact unconditional All N pairs Uniformly more powerful than exact conditional McNemar; 20-40% smaller n for same power Implementation only in R exact2x2::mcnemarExactDP and SAS macros

Read the full file on GitHub · 311 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 311 lines · 86 tokens per session scan A cdedea6bcd95

Subscribe to this mod's changes

bio-clinical-biostatistics-categorical-tests is a skill published in the GitHub repository GPTomics/bioSkills (1,199 stars, last pushed 25d ago), licensed MIT. It adds 86 tokens to every session and 6,352 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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