Estimates of item parameters.

<p>*: optional items.</p><p>**: p value from χ² test.</p

Test information functions for the VFQ25 and the VFQ-J11.

<p>Both functions reached their maxima at about the same value of the latent trait (a theta of approximately −0.8). For values of theta between approximately −2.0 and +0.8, the test information for the VFQ-J11 was greater than 9, which indicates that in that range (−2.0 to +0.8) the test's reliability is equivalent to or greater than a Cronbach's alpha of 0.9.</p

Candidate items, and the 11 items chosen (*) for the short version of the VFQ (the VFQ-J11).

a<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0073084#pone-0073084-t001" target="_blank">Table 1</a> for item numbers.</p><p>VFQ: The Visual Function Questionnaire originally developed by the National Eye Institute.</p><p>VFQ-J11: The short-form VFQ 11-item Japanese version.</p

Demographic and clinical characteristics of the participants in the Hisayama study and in the JDOPPS.

<p>Demographic and clinical characteristics of the participants in the Hisayama study and in the JDOPPS.</p

Micronutrient intake stratified by dietary pattern.

<p>Estimated micronutrient intake stratified by dietary pattern. Dotted lines show dietary standards according to Japan’s clinical guidelines (Dietary recommendations for chronic kidney disease, 2007, Japanese Society of Nephrology). </p