cfDNA PPV Calculator
Medical
Free · Designed for iPad. Not verified for macOS.
Estimate PPV and NPV for common cfDNA screening conditions using Bayesian probability. Editable test performance and prevalence inputs.
This Cell Free Fetal DNA PPV Calculator estimates positive predictive value (PPV) and negative predictive value (NPV) for prenatal cell-free DNA (cfDNA) screening using Bayesian probability.
Conditions supported:
• Trisomy 21
• Trisomy 18
• Trisomy 13
• Monosomy X (45,X)
• 47,XXY
• 47,XYY
• 47,XXX
For autosomal trisomies, pretest probability may be derived from maternal-age population risk tables (midtrimester risk by age at term). For sex chromosome aneuploidies, pretest probability can be entered as population prevalence (1 in N). Sensitivity and specificity are user-editable to reflect lab-specific performance.
This app is for screening support and educational use. It does not provide a diagnosis. Positive screening results should be confirmed with diagnostic testing and clinical correlation.
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The developer, David Deschamps, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- David Deschamps
- Size
- 678.9 KB
- Category
- Medical
- Compatibility
Requires iOS 18.4 or later.
- iPhone
Requires iOS 18.4 or later. - iPad
Requires iPadOS 18.4 or later. - Mac
Requires macOS 15.4 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.4 or later.
- iPhone
- Languages
- English
- Age Rating
16+
- 16+
- Frequent
Medical Treatment Information
- Copyright
- © 2026 David Deschamps