Study Directors field trials

Nonclinical Quality Assurance. Quality assurance unit means any person or organizational element, except the study director, designated by testing facility management to perform the duties relating to quality assurance of nonclinical laboratory studies. Nonclinical laboratory study means in vivo or in vitro experiments in which test articles are studied prospectively in test systems under laboratory conditions to determine their safety. The term does not include studies utilizing human subjects or clinical studies or field trials in animals. The term does not include basic exploratory studies carried out to determine whether a test article has any potential utility or to determine physical or chemical characteristics of a test article. 

Pesticides used on crops grown on the test site in previous seasons may also have an impact on the outcome of a field residue trial. Carryover of prior pesticide applications could contaminate samples in a new trial, complicate the growth of the crop in a trial, or cause interference with procedures in the analytical laboratory. For this reason, an accurate history of what has transpired at the potential test site must be obtained before the trial is actually installed. The protocol should identify any chemicals of concern. If questions arise when the history is obtained, they should be reviewed with the Study Director prior to proceeding with the test site. In most annual crop trials, this will not be a significant issue owing to crop rotations in the normal production practices, because the use of short residual pesticides and different chemical classes is often required for each respective crop in the rotation. However, in many perennial crops (tree, vines, alfalfa, etc.) and monoculture row crops (cotton, sugarcane, etc.), the crop pesticide history will play a significant role in trial site selection. 

Application of the test substance to the test system is without doubt the most critical step of the residue field trial. Under-application may be corrected, if possible and if approved by the Study Director, by making a follow-up application if the error becomes known shortly after the application has been made. Over-application errors can usually only be corrected by starting the trial again. The Study Director must be contacted as soon as an error of this nature is detected. Immediate communication allows for the most feasible options to be considered in resolving the error. If application errors are not detected at the time of the application, the samples from such a trial can easily become the source of undesirable variability when the final analysis results are known. Because the application is critical, the PI must calculate and verify the data that will constitute the application information for the trial. If the test substance weight, the spray volume, the delivery rate, the size of the plot, and the travel speed for the application are carefully determined and then validated prior to the application, problems will seldom arise. With the advent of new tools such as computers and hand-held calculators, the errors traditionally associated with applications to small plot trials should be minimized in the future. The following paragraphs outline some of the important considerations for each of the phases of the application. 

If the trial is planned through the services of a contract research company, their estimate should include a time and cost accounting which specifies the exact services they will perform for the trial. Services not included are the responsibility of the Study Director and sponsor. When contracting out a field residue study, the contractor s cost estimate will only be a part of the total cost to the sponsor. Make sure that costs... 

When a protocol is issued, the study is put on the Master Schedule. The Master Schedule is a computer-generated document that can be formatted and sorted to accommodate the needs of various participants in the study as well as the Quality Assurance Section. It contains the protocol number, the trial numbers, the study title, the proposed start and finish dates of field and analytical segments of the study, the proposed reporting date, the names of field participants, the name of the study director, and other information that may be useful to the users of the master schedule. As a study... 

Records are kept of when a sample was collected, the method of collection, who collected the sample, what the elapsed time was between harvest and freezing, the conditions under which it was stored, how it was shipped to the laboratory, and when it was shipped. When a sample arrives at the laboratory, the condition of the sample is checked and recorded. Then the information on the sample bag (sample number, application rate, preharvest interval, etc.) is compared to the trial information sheets which are submitted along with the samples. Any omissions or discrepancies are corrected at that time. If there is an omission or discrepancy that cannot be easily corrected by a telephone call from the sample processing laboratory to the field scientist, the study director is notified. The study director must make the decision about the validity of the sample and put a note in the data file explaining how the problem was corrected or that the problem could not be corrected and the trial is to be abandoned. If the trial is dropped, Quality Assurance is notified, the trial is deleted from the active Master Schedule, and an explanation is put in the study file. 

Proper organization of the study management is necessary for an effective quality assurance program. Each study is directed by the scientist who will write the final report but may be assisted by a coordinator. The coordinator also usually assists the study director in designing the study. All questions about the trial during its conduct in the field go to the study director or the coordinator. 

---