basic_stats_calculator: Basic Statistics Calculator (Diagnostic Test Evaluation)

In cliot: Clinical Indices and Outcomes Tools

Basic Statistics Calculator (Diagnostic Test Evaluation)

Description

Calculates standard diagnostic statistics from a 2x2 contingency table (True Positives, False Positives, False Negatives, True Negatives). Metrics include Sensitivity, Specificity, Positive/Negative Predictive Values (PPV/NPV), Likelihood Ratios (LR+/LR-), Accuracy, and Disease Prevalence.

Usage

basic_stats_calculator(tp, fp, fn, tn)

Arguments

tp	Numeric. Count of True Positives (Disease Present, Test Positive).
fp	Numeric. Count of False Positives (Disease Absent, Test Positive).
fn	Numeric. Count of False Negatives (Disease Present, Test Negative).
tn	Numeric. Count of True Negatives (Disease Absent, Test Negative).

Value

A list containing:

Diagnostic_Accuracy	Sensitivity, Specificity, and Overall Accuracy.
Predictive_Values	PPV and NPV.
Likelihood_Ratios	LR+ (Sensitivity / (1-Specificity)) and LR- ((1-Sensitivity) / Specificity).
Population_Stats	Prevalence of disease in the sample and total sample size.

References

Altman DG, Bland JM. Diagnostic tests 1: Sensitivity and specificity. BMJ. 1994;308(6943):1552. Altman DG, Bland JM. Diagnostic tests 2: Predictive values. BMJ. 1994;309(6947):102.

Examples

# Example 1: Good Test
# TP=80, FP=10, FN=20, TN=90
basic_stats_calculator(80, 10, 20, 90)

# Example 2: Perfect Specificity
# TP=50, FP=0, FN=50, TN=100
# LR+ will be Inf
basic_stats_calculator(50, 0, 50, 100)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.