Limitations of record linkage studies using routinely collected administrative data are well known, and include the facts that the data are limited to hospitalised patients and that information about some variables of potential interest, such as social circumstances and ethnicity, are generally unavailable.
However, despite intense efforts, no linkage regions were unambiguously replicated, even after meta-analysis of 37 studies (including ~ 31,000 individuals) [ 28], demonstrating the limitations of the linkage approach.
To deal with the limitations of traditional linkage and association analysis methods in detecting susceptibility genes, alternative statistical and computational approaches must be explored.
A much more serious limitation of ASP linkage analysis is the implicit assumption that randomly sampled sib pairs share half their alleles identical by descent at any locus, whereas a critical assumption underlying Vieland and Huang's proof is that of joint Hardy-Weinberg equilibrium proportions at two trait loci.
A limitation of traditional linkage analysis, which is illustrated by the results of an 777 STRP marker screen and conventional multipoint analysis on the ALS-A family, is that there is a significant disparity between the theoretical portion of the genome that should be excluded from containing the ALS-A locus (>97%), and the portion of the genome actually excluded (67%).
This study shares the limitations of other data linkage studies, with reliability of study conclusions dependent on the accuracy of the record linkage, the study definitions used and the validity of the coding in the hospital records.
The goals, purposes, and limitations of any proposed linkage must be discussed and stated clearly.
An additional limitation of case-linkage is that data interpretation is restricted by the accuracy and completeness of data available.
Another limitation of all linkages of this type is that some individuals non-randomly chose Medicare Advantage plans, the results presented are subject to some selection bias, as, prior to the passage of the Affordable Care Act, these plans were not required to report health claims.
