caa a22 4500 388059001 CHVBK 20180307125115.0 cr unu---uuuuu 161130e19980601xx s 000 0 eng 10.1375/twin.1.3.150 doi S1369052300000349 pii (NATIONALLICENCE)cambridge-10.1375/twin.1.3.150 Similarity of social security numbers among twins: data from the Virginia Twin Registry [Elektronische Daten] At least two twin registries in the United States have been or are being assembled using the similarity of Social Security Numbers in computerized records to help identify possible twin pairs. While the success of such enterprises depends directly on a high probability of twinness given Social Security Numbers, there are theoretical and practical reasons to study the probability of Social Security Number similarity given twinness. For example, the number of twin pairs with similar Social Security Numbers obviously determines the maximum number of twin pairs that can be discovered by similarity algorithms. To study this issue, we examined the similarity of known Social Security Numbers in twin pairs from the Virginia Twin Registry by age, sex, race, and zygosity of the pair. We found that similarity between the Social Security Numbers of twin pairs varies markedly by age, and MZ twin pairs have significantly more similar Social Security Numbers than DZ pairs at all ages. Among older twins, there are also significant differences by sex and race. For younger twins, algorithms that identify putative twin pairs on the basis of the similarity of their Social Security Numbers hold the promise of being able to identify a large proportion of all true twin pairs. Such algorithms will be substantially less successful, however, in identifying a large proportion of older twin pairs. Copyright © Cambridge University Press 1998 twins nationallicence epidemiologic methods nationallicence ascertainment bias nationallicence medical records linkage nationallicence United States Social Security Administration nationallicence Page William F. Medical Follow-up Agency, Institute of Medicine, National Academy of Sciences, Washington, DC, USA. wpage@nas.edu Corey Linda Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA. Twin Research Cambridge University Press 1/3(1998-06-01), 150-153 1369-0523 1:3<150 1998 1 THG https://doi.org/10.1375/twin.1.3.150 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1375/twin.1.3.150 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Page William F. Medical Follow-up Agency, Institute of Medicine, National Academy of Sciences, Washington, DC, USA. wpage@nas.edu NATIONALLICENCE 700 1- Corey Linda Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA NATIONALLICENCE 773 0- Twin Research Cambridge University Press 1/3(1998-06-01), 150-153 1369-0523 1:3<150 1998 1 THG CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge