• What is the layout of the entire test starting from sample collection, sample
analysis to final results?
• What equipment (or instruments), reagents, and assistance are required to
perform the test?
• Is the diagnostic assay kit easily accessible in different geographies?
• In case of complex testing, what is the turnaround time from sample collection
to availability of results?
4. Interpretation of results: The results of a clinical test could be interpreted by
visual observation and manual calculation or could be determined through computer software. Regardless of how the results are obtained and reported, this key
feature should include how the results are calculated and interpreted. In order to
do so, the following questions must be answered and taken into consideration.
• How will the results be calculated?
• What are the acceptable criteria for a positive or negative/clinically insignificant test result?
• What format should be used for reporting the result?
• What factors can impact the test results? For example, improper handling of
samples or reagents, calibration of equipment, and storage of samples or
reagents.
5. Performance characteristics: The last key step to complete the TPP for a particular diagnostic assay would be to summarize the critical performance characteristics that would be used as a standard to build the road map of the studies
required to generate data to test and validate the specifications. A checklist of
performance characteristics for a diagnostic test is as follows.
• Robustness: Robustness is a measure of a diagnostic test capacity to remain
unaffected by small but deliberate variations in test parameters and, thus,
provides an indication of its reliability during normal usage.
• Specificity: Specificity is the ability of a diagnostic test to assess unequivocally
the analyte in the presence of components which may be expected to be
present such as impurities and degradants.
• Sensitivity: Sensitivity is the ability of a diagnostic test to detect the minimum
concentration of an analyte in a sample.
• Reproducibility: The reproducibility of a diagnostic test is the ability of the
diagnostic test to measure the sample and generate data within acceptable
range under the same operating conditions.
• Limit of quantification (LOQ) and limit of detection (LOD): The quantitation
limit of a diagnostic test is the lowest amount of analyte in a sample which can
be quantitatively determined with suitable precision and accuracy. The detection limit of a diagnostic test is the lowest amount of analyte in a sample which
can be detected but not necessarily quantitated as an exact value.
To understand TPPs better, consider this example. In 2017, the WHO outlined an
overarching TPP for developing a test for predicting the advancement of tuberculosis
200
H. Kaur et al.
analysis to final results?
• What equipment (or instruments), reagents, and assistance are required to
perform the test?
• Is the diagnostic assay kit easily accessible in different geographies?
• In case of complex testing, what is the turnaround time from sample collection
to availability of results?
4. Interpretation of results: The results of a clinical test could be interpreted by
visual observation and manual calculation or could be determined through computer software. Regardless of how the results are obtained and reported, this key
feature should include how the results are calculated and interpreted. In order to
do so, the following questions must be answered and taken into consideration.
• How will the results be calculated?
• What are the acceptable criteria for a positive or negative/clinically insignificant test result?
• What format should be used for reporting the result?
• What factors can impact the test results? For example, improper handling of
samples or reagents, calibration of equipment, and storage of samples or
reagents.
5. Performance characteristics: The last key step to complete the TPP for a particular diagnostic assay would be to summarize the critical performance characteristics that would be used as a standard to build the road map of the studies
required to generate data to test and validate the specifications. A checklist of
performance characteristics for a diagnostic test is as follows.
• Robustness: Robustness is a measure of a diagnostic test capacity to remain
unaffected by small but deliberate variations in test parameters and, thus,
provides an indication of its reliability during normal usage.
• Specificity: Specificity is the ability of a diagnostic test to assess unequivocally
the analyte in the presence of components which may be expected to be
present such as impurities and degradants.
• Sensitivity: Sensitivity is the ability of a diagnostic test to detect the minimum
concentration of an analyte in a sample.
• Reproducibility: The reproducibility of a diagnostic test is the ability of the
diagnostic test to measure the sample and generate data within acceptable
range under the same operating conditions.
• Limit of quantification (LOQ) and limit of detection (LOD): The quantitation
limit of a diagnostic test is the lowest amount of analyte in a sample which can
be quantitatively determined with suitable precision and accuracy. The detection limit of a diagnostic test is the lowest amount of analyte in a sample which
can be detected but not necessarily quantitated as an exact value.
To understand TPPs better, consider this example. In 2017, the WHO outlined an
overarching TPP for developing a test for predicting the advancement of tuberculosis
200
H. Kaur et al.