a repository for the Newborn screening study
# Newborn Screening Study Code: HPLC and POCT
This repository contains R code for performing analyses related to the SickleInAfrica **Newborn Screening Study**. The study evaluates the accuracy of POCT (Point-of-Care Testing) compared to the gold standard HPLC/IEF method across different sites. The code calculates key performance metrics, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).
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## Repository Structure
- **`HPLC/`**: Contains code for performance calculations, with HPLC/IEF as the gold standard.
- **`POCT/`**: Contains code for performance calculations, with POCT as the gold standard.
- **`Quantitative/`**: Contains scripts and outputs for the quantitative analysis phase, focusing on large-scale data integration and statistical modeling.
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## Purpose
This repository supports the full lifecycle of newborn screening data analysis:
- Ensuring **data integrity and completeness**
- Performing **imputation for missing values**
- Conducting **quality control and diagnostics**
- Enabling **statistical analysis by genotype**
- Producing **reproducible outputs and reports**
- Extending into a **quantitative phase** for pooled, multi-country analyses
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## Key Metrics
The following performance metrics are calculated as part of the study:
1. **Sensitivity**: Proportion of true positives correctly identified by DBS/POCT.
2. **Specificity**: Proportion of true negatives correctly identified by DBS/POCT.
3. **Positive Predictive Value (PPV)**: Proportion of positive results by DBS/POCT that are true positives.
4. **Negative Predictive Value (NPV)**: Proportion of negative results by DBS/POCT that are true negatives.
5. **Quantitative Measures** (new phase): Cross-site pooled performance estimates, confidence intervals, heterogeneity tests, and regression-based modeling.
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## Data Requirements
- **Input Data**:
- Screening results for both HPLC and POCT.
- Quantitative data aggregated across site …