Models for Diagnosing Covid Diagnosis

Was wondering if validated ML models existed, had not heard of any.  What is missing?   The article suggests lack of data, can that be?    Yes, if the needed validated supporting metadata was not gathered systematically.   Passed this piece on to some people with clinical diagnosis experience. 

ML Models for Diagnosing Covid-19 Not Yet Suitable for Clinical Use

University of Cambridge (U.K.),  March 15, 2021

A review of studies containing descriptions of machine learning (ML) models for diagnosing Covid-19 by researchers at the U.K.'s University of Cambridge concluded that none are yet suitable for detecting or diagnosing the virus from standard medical imaging. The team ultimately reviewed 62 studies, and invalidated each model's suitability due to biases in study design, methodological flaws, lack of reproducibility, and publicly available "Frankenstein datasets." Many ML models were trained on sample datasets that were too small to be effective, failed to specify their data's origins, were trained and tested on the same data, or lacked involvement from radiologists and clinicians. Cambridge's James Rudd said, "These early studies show promise, but they suffer from a high prevalence of deficiencies in methodology and reporting, with none of the literature we reviewed reaching the threshold of robustness and reproducibility essential to support use in clinical practice."