Physical
health assessments included self-reported problems with vision(two binary variableseyes/nofor ‘needglasses orcontact
lenses’and yes/no for ‘problems uncorrectable by glasses or contact lenses’) or hearing (responses collapsed to ‘good’ or
‘some trouble/deaf’). In addition, cohortmembers were asked if they had ever been diagnosed with ‘epilepsy’ or ‘depression/anxiety’ by a doctor. Self-assessed overall health was based on the first question of the Short Form 8 Medical Outcomes Instrument forwhich six response categories were collapsed to ‘poor/very poor’ and ‘not poor’ (i.e. fair/good/very good/excellent).BMI was calculated from reported height and weight, and
classified by Asian standards as underweight (