BALF analytes

For each analyte and each of the six batches of measurements, and in addition to the concentrations measured in the various supernatants, Myriad RBM provided the least detectable dose (LDD) and lower limit of quantification (LLOQ), which were not necessarily constant across the batches. The LDD was determined as the mean + 3 standard deviations of 20 blank readings, while the LLOQ was the lowest concentration of an analyte that could be reliably detected in a sample and at which the total error met the laboratory requirements for accuracy. In this case, LLOQ was the concentration of an analyte at which the coefficient of variation of replicate standard samples was 30%. Given that these definitions of LDD and LLOQ are independent, sometimes LDD > LLOQ and vice versa.
In the original data reporting from Myriad RBM, not all measurements were reported as values. Some were instead reported as ‘quantity not sufficient for testing’ (QNS). Additionally, some myoglobin (only) measurements were reported as ‘>xxx’, where xxx represented the upper limit of quantification. Finally, for the first four shipments, some values were indicated as ‘’, indicating that they could not be measured on the standard curve. Values below LDD or LLOQ were reported as values in these first four shipments. Myriad RBM reporting changed from shipment 5. ‘’ values and values below LLOQ were reported as ‘LLOQ, it was reported as a value.
To accommodate these variations in reporting between shipments, the following decisions were made for our internal data analysis:
QNS values were considered to be missing.
Values ‘>xxx’ were substituted by 1.1 * xxx.
or
Values
Other values were left unchanged for data analysis.