Table I.
Criteria for quality assessment by De Graeff (12).
| Score | ||
|---|---|---|
|
|
||
| Criteria | Sub-criteria | Criteria |
| 1. Is the population under study defined with in and exclusion criteria? | 1 | |
| 2. Were patient data prospectively collected? | 1 | |
| 3. Are the main prognostic patient and tumor characteristics presented?a | 1 | |
| 4. Is the method used for determination of protein expression specified? | 2 | |
| Criteria for immunohistochemistry: | ||
| Is the immunohistochemical staining protocol specified?b | 1 | |
| Were stainings evaluated by >1 observer? | 1 | |
| Criteria for RT-PCR: | ||
| Is the RNA isolation method and cDNA synthesis specified? | 1 | |
| Is the PCR protocol specified?c | 1 | |
| 5. Is the study endpoint defined? | 1 | |
| 6. Is the time of follow up specified? | 1 | |
| 7. Is loss during analysis or follow up described? | 1 | |
| Total | 8 | |
a
At least four of the following characteristics: age at diagnosis, tumor stage, tumor location, differentiation grade and residual tumor after primary surgery.
b
At least four of the following criteria: antigen retrieval, primary antibody, dilution, detection method, cut-off value for positive expression:
c
At least the primers used and the annealing temperature or number of cycles.