Baseline subject characteristics.

<p>Values are number (column-%) or means (SD). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099388#pone.0099388-Hemminki1" target="_blank">[1]</a> Lymphoproliferative cancer defined as Hodgkin's lymphoma, non-Hodgkin lymphoma and chronic lymphocytic leukemia, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099388#pone.0099388-Chakravarty1" target="_blank">[2]</a> Calculated on previous hospital contacts (<3 years), <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099388#pone.0099388-Khurana1" target="_blank">[3]</a>>10 mg/L, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099388#pone.0099388-Mercer1" target="_blank">[4]</a>>0.5•10<sup>9</sup>/L.</p>