Many cross-sectional growth reference standards have been published, for both postnatal growth as well as at birth.
Flow charts of patients display how many patients were eligible for the study, how many were actually recruited, how many received the index test, how many received the reference standard, etc.
In addition, appropriate reference standards for many disorders are lacking.
These data, although they are infrequent, must be known and referred before to start an HPV primary screening of CIN2+ lesions especially with HCII methodology which is considered by many as a reference standard technology particularly in Belgium.
Of course, such work would also rely on reference standards of these metabolites, many of which are not currently obtainable.
A further improvement to be introduced is use of MS MS [ 17, 19, 34] and/or pseudo-MS MS (MS-All, MS-E, All Ions) [ 21] to obtain compseudo-MS MSic fragment ions for confirmation of reference standards, reducing the need to run many thousands of reference standards on a daily basis.
Many different populations were investigated, typically retrospectively, using various reference standards (e.g., clinical practice guidelines) and data sources (e.g., medical records).
The initiative has also allowed researchers to hurdle many of the barricades that have hindered accurate analysis such as the lack of reference standards and comparative data.
However, for many diseases it is impossible to determine the true disease status with certainty [ 6] and reference standards are imperfect.
Many studies evaluating filter paper do not include full details on the paper type or processing, key information regarding reference standards, and use of appropriate statistical tests.
