Enter the total number of screening colonoscopies performed.
Enter the number of procedures where at least one adenoma was found.
Calculated Adenoma Detection Rate
0.00%
function calculateADR() {
var totalInput = document.getElementById('totalProcedures');
var adenomaInput = document.getElementById('adenomaProcedures');
var resultBox = document.getElementById('resultBox');
var adrResult = document.getElementById('adrResult');
var benchmarkMessage = document.getElementById('benchmarkMessage');
var total = parseInt(totalInput.value);
var positive = parseInt(adenomaInput.value);
// Validation
if (isNaN(total) || isNaN(positive)) {
alert("Please enter valid numbers for both fields.");
return;
}
if (total <= 0) {
alert("Total screening colonoscopies must be greater than zero.");
return;
}
if (positive total) {
alert("The number of procedures with adenomas cannot exceed the total number of procedures.");
return;
}
// Calculation
var adr = (positive / total) * 100;
var formattedADR = adr.toFixed(2);
// Display Result
resultBox.style.display = "block";
adrResult.innerHTML = formattedADR + "%";
// Interpretation based on general benchmarks (Source: ASGE/ACG)
// Standard benchmark is often cited as >= 25% overall
if (adr >= 25) {
benchmarkMessage.className = "benchmark-info benchmark-success";
benchmarkMessage.innerHTML = "Above Benchmark: This ADR meets or exceeds the recommended overall target of 25%.";
} else {
benchmarkMessage.className = "benchmark-info benchmark-warning";
benchmarkMessage.innerHTML = "Below Benchmark: This ADR is below the recommended overall target of 25%. Review detection techniques and withdrawal times.";
}
}
How to Calculate Adenoma Detection Rate (ADR)
The Adenoma Detection Rate (ADR) is widely considered the most important quality metric for screening colonoscopies. It measures the proportion of screening colonoscopies performed by an endoscopist in which at least one adenoma (precancerous polyp) is detected. A higher ADR is strongly correlated with a reduced risk of interval colorectal cancer for patients.
The Formula
The calculation for ADR is a simple percentage based on procedure data over a specific time period.
ADR = (Procedures with ≥1 Adenoma Detected / Total Screening Colonoscopies) × 100
Variables defined:
Total Screening Colonoscopies: The count of colonoscopies performed specifically for screening purposes (excluding diagnostic or therapeutic procedures for symptoms) on patients aged 50 and older.
Procedures with ≥1 Adenoma Detected: The count of those screening procedures where the pathology report confirmed at least one adenoma or adenocarcinoma.
Example Calculation
Dr. Smith performed 200 screening colonoscopies in the last quarter.
Total Screening Colonoscopies = 200
Procedures where adenomas were found = 65
Calculation: (65 ÷ 200) × 100 = 32.5%
In this example, Dr. Smith has an ADR of 32.5%, which is well above the standard quality benchmark.
Why ADR Matters
ADR serves as a direct proxy for the thoroughness of the mucosal inspection during a colonoscopy. Studies have demonstrated an inverse relationship between an endoscopist's ADR and the risk of post-colonoscopy colorectal cancer (PCCRC). Specifically, for every 1% increase in ADR, there is a measurable decrease in the risk of interval cancer.
Current Quality Benchmarks
The American Society for Gastrointestinal Endoscopy (ASGE) and the American College of Gastroenterology (ACG) have established minimum targets for ADR to ensure patient safety and effective screening:
Overall Target: ≥ 25%
Male Patients: ≥ 30%
Female Patients: ≥ 20%
It is important to note that these are minimum thresholds. Many high-performing endoscopists achieve ADRs significantly higher (40-50%).
Strategies to Improve ADR
If the calculated rate falls below the recommended benchmarks, several techniques can be employed to improve detection:
Increase Withdrawal Time: Ensure a minimum of 6 minutes is spent inspecting the mucosa during withdrawal.