Another caveat is that the sources that were observed to be associated with mortality may be proxy markers of exposure for unmeasured elements or sources that are the underlying causes of the associations.
If our assumption is correct that the discharge medication represents individuals' optimum prescribing, these combinations would be a proxy marker for efficacy and were likely to be associated with positive clinical benefit.
This would suggest the possibility that α-tryptase copy number variation alleles are acting as proxy markers for variation at or near the β-tryptase locus, through linkage disequilibrium.
The ibuprofen use in the latter studies, however, could equally have been a proxy marker for more severe illness.
Other factors such as family size and education level of participants' families were assessed, as possible proxy markers for crowding or socio-economic status, both identified in the past as possible risk factors for M. tuberculosis infection.
However, we could confirm that physiological EEG rhythms, especially power in the gamma band, which was shown in the feline model to be an indirect proxy marker for the 'up' and 'down' state (Mukovski et al., 2007), appeared predominantly during the positive half-wave representing the presumed 'up' state.
Crystallised intelligence may be considered a proxy marker for exposure to intellectual activity, and determining whether this may have been confounded by association with higher physical activity might have been useful.
It is, therefore, important to identify affordable proxy markers for response to therapy in RLS.
Second, haplotypes may be proxies for untyped causal markers [ 35].
