We will discuss different sources of bias in study design, handling of specimens, and statistical analysis to illustrate possible pitfalls associated with marker research, and present legal, ethical, and technical considerations associated with storage and handling of specimens.
The degree of syncytin immunostaining was visually graded using coded specimens and statistical analysis showed that it correlated positively with disease-free survival of the patients (Larsson et al. 2007b).
It will also use standardized and innovative laboratory, clinical, specimen collection, and statistical techniques and comprehensive laboratory testing of body fluid and tissue specimens.
In particular, the repeatability of each test was estimated as the percent mean standard error of the three acquisitions of the test on each specimen and a statistical descriptive analysis was made for all results, using the mean values of repeated tests for each specimen.
GC weighed and measured the specimens and ran the statistical analyses.
Protein expression of MET was evaluated in these 170 specimens and all further statistical analyses were performed on this patient population.
AW participated in developing the methodology of the research, assisting in preparing the specimens, drafting the manuscript and statistical analysis.
The design should incorporate appropriate control procedures for collecting and processing specimens, validated analytical methods, and statistical analyses that account for sampling issues such as urine dilution (Barr et al. 2005) and collection times (Calafat and Needham 2009).
As for the successful CONSORT initiative for randomised trials and for the STARD statement for diagnostic studies, we suggest guidelines to provide relevant information about the study design, pre-planned hypotheses, patient and specimen characteristics, assay methods, and statistical analysis methods.
Similar to the successful CONSORT initiative for randomised trials and the STARD statement for diagnostic studies, we suggest guidelines to provide relevant information about the study design, preplanned hypotheses, patient and specimen characteristics, assay methods, and statistical analysis methods.
Similar to the successful CONSORT initiative for randomised clinical trials (Moher et al, 2001), and the STARD statement for studies of diagnostic test accuracy (Bossuyt et al, 2003a), these guidelines suggest relevant information that should be provided about the study design, preplanned hypotheses, patient and specimen characteristics, assay methods, and statistical analysis methods.
