1. Data Entry:

   The user enters relevant information such as the analyst's name, control name, and the date/month of analysis. Additionally, the user inputs a series of control values obtained from quality control samples.
2. Calculation:

   Upon clicking the "Calculate" button, the application computes statistical parameters such as the mean, standard deviation (SD), and coefficient of variation (CV) of the input values.
3. Quality Control Rules Check:

   The application applies Westgard rules to the entered data to identify any out-of-control conditions.
4. Chart Generation:

   A Levey-Jennings chart is produced, displaying control values against time or sample number, with lines representing the mean and control limits based on standard deviations.
5. Violation Reporting:

   If any quality control rules are violated, the specific instances are reported to the user, allowing for investigation and corrective action.
6. Print and Show Violations:

   Users can print the generated chart and view detailed violations.

1. 1 3s Rule:

   A single control measurement exceeds 3 standard deviations from the mean (3s). This is a warning of a possible random error or shift in the process.
2. 2 2s Rule:

   Two consecutive control measurements exceed 2 standard deviations from the mean on the same side (2s). This rule suggests a systematic error is likely.
3. R 4s Rule:

   One control measurement exceeds 2 standard deviations from the mean (2s), and the next exceeds 2 standard deviations in the opposite direction. This indicates a random error.
4. 4 1s Rule:

   Four consecutive control measurements exceed 1 standard deviation from the mean on the same side. This implies a trend or systematic error.
5. 10x Rule:

   Ten consecutive control measurements fall on one side of the mean. This indicates a consistent bias in the process.

Understanding the Output

Once you input the data and press "Calculate," the calculator will output:

• Mean: The average of your control values, representing the expected value in a stable process.
• SD (Standard Deviation): A measure of the variability or dispersion of the control values. A higher SD indicates greater variation in the results.
• CV (Coefficient of Variation): Expressed as a percentage, the CV represents the ratio of the standard deviation to the mean, providing a scaled measure of variability relative to the size of the mean.

Chart Interpretation

The Levey-Jennings chart plots individual control values against time or sample number. The mean value is marked as a central line, with additional lines representing the mean ±1 SD, ±2 SD, and ±3 SD. Points outside these lines indicate potential violations of Westgard rules and warrant investigation.

Troubleshooting

Common issues include:

• Input Errors: Ensure all values are numerical and separated by commas. Check for extra spaces or characters.
• Misalignment: If elements on the page are misaligned, especially on different screen sizes, verify the CSS and Bootstrap grid classes for consistent styling.

Compliance Standards

The calculator adheres to standards set by CLIA, CAP, and ISO, which require rigorous QC to ensure laboratory test accuracy. Compliance with these standards is critical to meet regulatory requirements and maintain the quality of laboratory testing.