In April 2013 the Office for National Statistics (ONS)’s Annual Population Survey adopted a new standardised question on individuals with health problems.
Ym mis Ebrill 2013 mabwysiadodd Arolwg Blynyddol y Swyddfa Ystadegau Gwladol o’r Boblogaeth gwestiwn safonol newydd am unigolion â phroblemau iechyd.