The total count of patients discharged alive who meet inclusion criteria.
The count of unplanned readmissions occurring within 30 days of discharge.
Readmission Rate:—
Ratio (1 in X patients):—
Status:—
How to Calculate 30-Day Readmission Rate
The 30-day readmission rate is a critical key performance indicator (KPI) for hospitals and healthcare facilities. It measures the percentage of patients who experience an unplanned readmission to an acute care hospital within 30 days of being discharged from an initial "index" admission.
This metric is widely used by organizations like the Centers for Medicare & Medicaid Services (CMS) to evaluate the quality of care, discharge planning effectiveness, and post-acute care coordination.
Readmission Rate = (Count of 30-Day Readmissions ÷ Total Index Admissions) × 100
Understanding the Variables
Total Index Admissions: This is the denominator. It represents the total number of eligible discharges during the measurement period. Not all patients are included; typically, patients who died during the initial stay, left against medical advice, or were transferred to another acute care facility are excluded from the denominator to ensure fair measurement.
Readmissions: This is the numerator. It counts the number of patients from the index group who returned to the hospital for an unplanned reason within the 30-day window following their discharge date.
Why is this Calculation Important?
Under programs like the Hospital Readmissions Reduction Program (HRRP) in the United States, high readmission rates can lead to significant financial penalties. Beyond finances, a high rate often indicates issues such as:
Premature discharge of unstable patients.
Poor communication of discharge instructions.
Lack of follow-up care or medication reconciliation errors.
Inadequate support systems at the patient's home.
Example Calculation
Let's say a hospital discharged 1,250 eligible patients in a specific quarter. Records show that 185 of those patients were readmitted within 30 days.
Step 1: Divide readmissions by total discharges: 185 / 1,250 = 0.148
Step 2: Multiply by 100 to get a percentage: 0.148 × 100 = 14.8%
The hospital's raw readmission rate is 14.8%.
Risk Adjustment
While the calculator above provides the "raw" or "observed" readmission rate, regulatory bodies often use "risk-adjusted" rates. This complex statistical method accounts for patient demographics, comorbidities (illness severity), and age. Risk adjustment ensures that hospitals treating sicker patients are not unfairly penalized compared to hospitals treating generally healthier populations.
function calculateReadmission() {
// Get input elements
var admissionsInput = document.getElementById('indexAdmissions');
var readmissionsInput = document.getElementById('readmissionCount');
var errorDisplay = document.getElementById('errorDisplay');
var resultBox = document.getElementById('resultBox');
// Get values
var totalAdmissions = parseFloat(admissionsInput.value);
var totalReadmissions = parseFloat(readmissionsInput.value);
// Reset display
errorDisplay.style.display = 'none';
resultBox.style.display = 'none';
errorDisplay.innerHTML = ";
// Validation logic
if (isNaN(totalAdmissions) || isNaN(totalReadmissions)) {
errorDisplay.innerHTML = "Please enter valid numbers for both fields.";
errorDisplay.style.display = 'block';
return;
}
if (totalAdmissions <= 0) {
errorDisplay.innerHTML = "Total Index Admissions must be greater than zero.";
errorDisplay.style.display = 'block';
return;
}
if (totalReadmissions totalAdmissions) {
errorDisplay.innerHTML = "Number of readmissions cannot exceed total admissions.";
errorDisplay.style.display = 'block';
return;
}
// Calculation
var rate = (totalReadmissions / totalAdmissions) * 100;
// Ratio calculation (1 in X patients)
var ratio = 0;
if (totalReadmissions > 0) {
ratio = totalAdmissions / totalReadmissions;
}
// Determine general status (These thresholds are illustrative/general estimates)
var statusText = "";
var statusColor = "";
if (rate = 10 && rate = 15 && rate 0) {
document.getElementById('ratioResult').innerHTML = "1 in approx " + Math.round(ratio) + " patients";
} else {
document.getElementById('ratioResult').innerHTML = "0 patients";
}
var statusEl = document.getElementById('statusResult');
statusEl.innerHTML = statusText;
statusEl.style.color = statusColor;
// Show results
resultBox.style.display = 'block';
}