Fig 1 Derivation of Scottish Mental Survey 1947 (SMS1947) analytic sample. Most of those with missing census dates had migrated or joined armed forces for whom records contained no last known GP registration date. *Analytic sample represents 92% of survey. †46.0% of those with vital status had died, which is approximate to Scottish population statistics for those aged 75-80. ‡Includes 5381 who emigrated abroad (2857 men); 3391 cancelled from GP registration (1383 men); 454 armed forces recruits (411 men); 96 residents of Northern Ireland or Isle of Man (52 men)