Crude estimates of diagnostic accuracy were biased due to non-random exclusion of women who did not have the opportunity for full diagnostic verification (i.e., women who screened negative and were not randomized, or, referred women who refused colposcopy and/or biopsy) [13].
10, 22, 23 Recent studies on US trauma populations have demonstrated that patients excluded due to missing RTS data had more severe injuries and worse prognosis than patients with complete data and that such non-random exclusion will bias the conclusions drawn.
A limiting factor in analysis of random allelic exclusion has been the difficulty of detection in mixed populations in vivo.
Because random allelic exclusion results in two simultaneous patterns of expression in a mixture of cells, it has been difficult to detect in tissues.
The rationale for selection of OlfR genes was that they are the major gene family thus far known to undergo random allelic exclusion in CNS tissue [9], [25], [26].
Despite its potential importance, there have been few studies of autosomal genes that undergo random allelic exclusion (i.e., monoallelic expression that is not dependent upon parent-of-origin).
On the basis of registries, 80% of patients meeting inclusion criteria in the TTM trial would be eligible for random assignment after exclusion criteria were considered [ 16].
A different surveillance approach is needed to capture the heterogeneity of drug resistance at the local level and avoid over- or underestimating the magnitude of drug resistance by random inclusion or exclusion of outbreaks.
For those resulting from the CMiB pipeline, 96 of the 2,371 primer pairs that showed no similarity with previously-reported EST-SSR markers [ 24, 26] were selected at random after the exclusion of primer pairs that had already been selected for the read2Marker pipeline.
1 This principle is a key defence against bias, since participants who depart from randomised treatment are usually a non-random subset whose exclusion can lead to serious selection bias. 2 However, it is unclear how to apply the intention to treat principle when investigators are unable to follow up all randomised participants.
