|
|
|
|
|
|
|
received and analyzed on the day of sampling, preferably by early afternoon. The laboratory then endeavors to ensure that the results are transmitted overnight to the investigator for his consideration the next morning. |
|
|
|
|
|
|
|
|
VI. Clinical Pathology Support of Phase II and Phase III Trials |
|
|
|
|
|
|
|
|
A. Views of Investigators on the Use of Local Versus Central Laboratories |
|
|
|
|
|
|
|
|
Irrespective of the nature of the trial most investigators would prefer to use the center's local laboratory. The investigator would, therefore, have no concerns about sample preparation, transport delays, test values, units and ranges, or the turnaround time for the results. He might, however, have concerns about the local unavailability of special tests stipulated in the trial protocol, of having to conduct an audit of the local laboratory, or of having to ensure local archiving of laboratory data for a minimum of 15 years. These concerns do not exist when using a central laboratory but they may be replaced by doubts about the validity of the test results. Although investigators like the consistency of the data from a central laboratory there is usually an initial concern because of the difference in the results received from the central laboratory compared to those received from his/her local laboratory. In most cases this is due to methodology differences between the two laboratories but differences in the test results units (e.g., uKat/L or IU/L for serum enzyme activity) and the laboratory reference range may add to the investigator's doubt. Sample degradation during transport is often a concern of an investigator but in reality degradation is so small that it rarely presents a clinical problem (see Table 2). |
|
|
|
|
|
|
|
|
B. Views of Sponsors on the Use of Multiple Local Laboratories |
|
|
|
|
|
|
|
|
Provided that critical care of the patient is not an issue, the disadvantages for the sponsor of using several local laboratories for a multicenter trial far outweigh the advantages. The disadvantages of using multiple local laboratories can be categorized as being related to either methodology or logistics. Two examples illustrating the type of methodological problems that can arise have been presented by Bloom [4]. In a particular clinical trial the protocol required serologic testing to identify acute infection with certain micro-organisms known to be insensitive to the antibiotics being tested. Unfortunately it was not established before the start of the trial which method should be used by the laboratories to evaluate antibody production. Therefore, some laboratories used total immunoglobin, IgG or IgM, some used nephelometry, while others |
|
|
|
|
|