An Evidence Integration Lab Initiative

BIOSTATISTICS-DEMYSTIFIED

The companion app to Medical Biostatistics, published by Paras Medical Publishers — interactive calculators, one chapter, one concept, one clinical analogy at a time.

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Disclaimer: This calculator is intended for educational purposes only. Results are provided to support statistical learning and should not be used as the sole basis for clinical decision-making. Always interpret statistical outputs in the context of study design, clinical relevance, and professional judgement. An Evidence Integration Lab Initiative.

Chapter Calculators

2

Central Tendency & Dispersion

Mean · Median · Mode · Range · IQR · SD · SE

Enter any numerical dataset and instantly calculate all measures of central tendency and dispersion. Each result includes a plain-language explanation and a clinical nephrology example. Detects skewness and tells you what to report.

Analogy: eGFR in a CKD clinicNow you'll notice.
3

P-value & Confidence Intervals

One-sample t-test · Two-sample comparison · Proportion CI

Calculate p-values and 95% confidence intervals from your data. The app explains what the p-value actually measures, what the CI tells you that the p-value does not, and how to distinguish statistical from clinical significance.

Analogy: Renal biopsy — absence of evidenceNow you'll question.
4

Effect Size, Power & NNT

ARR · RRR · NNT · Cohen's d · Power · Sample Size

From statistical significance to clinical meaning. Calculate ARR, RRR, NNT, and NNH for binary outcomes; Cohen's d for continuous outcomes; and statistical power and required sample size for study planning.

Analogy: DAPA-CKD journal club — how many patients do I treat?Now you'll choose.
5

Composite Outcome Dissector

ARR per component · Dominance · Red flags · Direction consistency

Enter each component of a composite endpoint, label it hard or soft, and see exactly what drove the trial result. Flags direction inconsistency, soft-endpoint dominance, and hard endpoints trending the wrong way.

Analogy: The trial was positive — but which component moved?Now you'll dissect.
6

HR Plain Language Converter

HR interpreter · Absolute risk · NNT · RMST · Survival curve · KM guide

Enter a hazard ratio and CI for plain-English interpretation. Add baseline risk and follow-up time to compute absolute risk, ARR, NNT, RMST, and an estimated survival curve. Includes a 7-step guide to reading any Kaplan-Meier figure.

Analogy: HR 0.56 — but what does that mean for my patient?Now you'll read the curve.
7

OR · RR · and What Adjusted Means

OR vs RR · 10% flag · Zhang-Yu conversion · Adjustment explorer · Regression table guide

Same data, same patients, different number. Calculate OR and RR side by side with a flag that fires automatically when the outcome exceeds 10%. Then trace how a result changes across adjustment models and learn to read a logistic regression table column by column.

Analogy: Diabetic CKD: OR 2.67, RR 2.0 — why the difference mattersNow you'll question.
8

Diagnostic Test Statistics

Sensitivity · Specificity · PPV · NPV · LR+ · LR− · Prevalence · Post-test probability

Enter a 2×2 table and calculate all six diagnostic statistics. A live prevalence slider shows how PPV and NPV shift across populations. Enter a pre-test probability to get post-test probability via Bayes — with the full arithmetic shown.

Analogy: NGAL predicts AKI — but PPV 61% at 35% prevalence, 28% at 12%Now you'll question.
9

Sample Size Calculator

Two means · Two proportions · Survival (Schoenfeld) · Attrition · Bonferroni · Retrospective power

Calculate required sample size for your study design — continuous outcomes, binary events, or time-to-event endpoints. Includes attrition inflation, multiple comparisons correction, sensitivity analysis, and retrospective power calculation for any n already in hand.

Analogy: The IgAN trial that was underpowered before it startedNow you'll plan.
10

Statistical Test Selector

Four triage questions · One correct test · Assumptions · Pitfalls · Nephrology examples

Answer four sequential questions about your outcome, groups, design, and distribution — and land on the correct statistical test. Each result includes when to use it, key assumptions, the formula, a clinical nephrology example, common pitfalls, and what to do when assumptions are violated.

Analogy: Triage before you treat — choose before you calculateNow you'll choose wisely.
11

Test Runner — All 5 Tests

One-sample t · Independent t · Paired t · Chi-squared · Correlation

Run any of the five core statistical tests on your own data. Enter raw numbers or summary statistics, load a preset from the chapter worked examples, and get a fully formatted result: test statistic, degrees of freedom, p-value, effect size, 95% CI, and a copy-paste report sentence.

Analogy: Order the investigation — read the result — write the reportNow you'll know what to report.
12

Reporting Template Generator

Descriptive · t-tests · Binary · Correlation · Survival · Sample size

Fill in your numbers and get a pre-formatted Methods sentence, Results sentence, and table or figure caption — ready to paste into your manuscript. Every template includes all five non-negotiables: test statistic, degrees of freedom, exact p-value, 95% CI, and effect size.

Analogy: No analogy. Just templates.Now you'll know what to write.

Using this app with the book

This is the companion app to Medical Biostatistics (Paras Medical Publishers). Each calculator here maps to one chapter of the book. The book builds the understanding; the app lets you put your own numbers through the same calculation and see the result explained. Read first, then calculate — they are designed to be used side by side.

  1. Read the chapter first. Start with the clinical scene and the concept, so you know what the numbers mean before you compute them.
  2. Open the matching calculator. The chapter number on each card above matches the chapter in the book.
  3. Reproduce the worked example. Use the one-click preset to load the chapter's worked example, confirm you get the same answer, then change the inputs to your own data.
  4. Do the DIY exercises. The practice datasets at the end of each chapter load directly into the calculator, so you can check your answers against the book's answer key.
  5. Tap Explain on any result for the plain-language definition, a nephrology example, and guidance on when that measure should and should not be used.
  6. Use Download Report to export a formatted summary you can keep or paste into your own notes.

The app reproduces the book's calculations exactly — same methods, same rounding — so the two never disagree.