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. Author manuscript; available in PMC: 2015 Sep 7.
Published in final edited form as: Lancet. 2015 Jun 7;386(9995):743–800. doi: 10.1016/S0140-6736(15)60692-4

Table 8. Prevalence and YLDs, with percentage of total, for intellectual disability by cause in 1990 and 2013, and prevalence by severity in 2013.

Total prevalence (× 1000) Total YLDs (× 1000) Prevalence by severity in 2013 (× 1000)
1990 2013 1990 2013 Borderline Mild Moderate Severe Profound
Idiopathic intellectual
disability
77 102.5 (65·24%) 94 680·0 (61·47%) 3822·3 (38·30%) 4666·7 (31·46%) 32 937·9 (21·38%) 38 873·1 (25·24%) 14 804·3 (9·61%) 5946·2 (3·86%) 2118·5 (1·38%)
Preterm birth
complications
5913·0 (5·00%) 13 576·3 (8·81%) 558·1 (5·59%) 1450·4 (9·78%) .. 11 480·7 (7·45%) 1277·6 (0·83%) 535·2 (0·35%) 282·8 (0·18%)
Chromosomal
unbalanced
rearrangements
6398·2 (5·41%) 11 171·7 (7·25%) 859·1 (8·61%) 1590·4 (10·72%) 1411·6 (0·92%) 3733·1 (2·42%) 3038·7 (1·97%) 1953·8 (1·27%) 1034·5 (0·67%)
Neonatal
encephalopathy due to
birth asphyxia and
trauma
9520·3 (8·06%) 8947·4 (5·81%) 892·5 (8·94%) 1228·3 (8·28%) .. 7128·4 (4·63%) 833·1 (0·54%) 645·2 (0·42%) 340·8 (0·22%)
Down’s syndrome 4546·4 (3·85%) 8184·4 (5·31%) 605·6 (6·07%) 1157·9 (7·81%) 1034·0 (0·67%) 2735·1 (1·78%) 2226·2 (1·45%) 1431·3 (0·93%) 757·8 (0·49%)
Ischaemic stroke 2686·4 (2·27%) 4887·1 (3·17%) 967·9 (9·70%) 1764·2 (11·89%) .. .. 2978·2 (1·93%) 1248·5 (0·81%) 660·3 (0·43%)
Pneumococcal meningitis 3132·6 (2·65%) 2803·2 (1·82%) 382·2 (3·83%) 344·8 (2·32%) 751·6 (0·49%) 1213·6 (0·79%) 420·8 (0·27%) 272·9 (0·18%) 144·2 (0·09%)
Haemorrhagic stroke 1040·8 (0·88%) 1966·8 (1·28%) 386·6 (3·87%) 728·8 (4·91%) .. .. 1197·3 (0·78%) 503·4 (0·33%) 266·1 (0·17%)
Haemolytic disease and
other neonatal jaundice
768·3 (0·65%) 1400·5 (0·91%) 425·5 (4·26%) 781·8 (5·27%) .. .. 641·8 (0·42%) 496·4 (0·32%) 262·2 (0·17%)
Alcohol use disorders 1000·8 (0·85%) 1382·2 (0·90%) 62·3 (0·62%) 85·8 (0·58%) 383·1 (0·25%) 791·2 (0·51%) 126·6 (0·08%) 81·3 (0·05%) ..
Haemophilus influenzae
type B meningitis
1654·4 (1·40%) 1309·6 (0·85%) 244·5 (2·45%) 206·7 (1·39%) 443·4 (0·29%) 329·0 (0·21%) 270·5 (0·18%) 174·5 (0·11%) 92·2 (0·06%)
Other meningitis 1406·9 (1·19%) 1050·2 (0·68%) 220·9 (2·21%) 172·3 (1·16%) 340·7 (0·22%) 265·1 (0·17%) 222·5 (0·14%) 145·2 (0·09%) 76·7 (0·05%)
Encephalitis 873·4 (0·74%) 886·6 (0·58%) 120·7 (1·21%) 131·3 (0·88%) 337·7 (0·22%) 223·7 (0·15%) 162·7 (0·11%) 106·3 (0·07%) 56·1 (0·04%)
Neural tube defects 293·7 (0·25%) 477·9 (0·31%) 151·8 (1·52%) 246·1 (1·66%) .. .. .. 312·6 (0·20%) 165·3 (0·11%)
Meningococcal
meningitis
538·7 (0·46%) 429·2 (0·28%) 90·4 (0·91%) 75·3 (0·51%) 128·2 (0·08%) 107·7 (0·07%) 96·5 (0·06%) 63·3 (0·04%) 33·5 (0·02%)
Syphilis 310·2 (0·26%) 315·2 (0·20%) 57·5 (0·58%) 58·4 (0·39%) .. .. 315·2 (0·20%) .. ..
Sickle cell disorders 96·3 (0·08%) 197·0 (0·13%) 39·4 (0·39%) 79·9 (0·54%) .. .. 197·0 (0·13%) .. ..
Maternal hypertensive
disorders
140·9 (0·12%) 128·9 (0·08%) 9·5 (0·10%) 8·8 (0·06%) .. 128·9 (0·08%) .. .. ..
Tetanus 580·2 (0·49%) 71·6 (0·05%) 30·7 (0·31%) 5·9 (0·04%) .. 64·9 (0·04%) 3·1 (0·00%) 2·4 (0·00%) 1·2 (0·00%)
Malaria 45·5 (0·04%) 66·7 (0·04%) 25·4 (0·25%) 37·7 (0·25%) .. .. 30·6 (0·02%) 23·6 (0·02%) 12·5 (0·01%)
Klinefelter’s syndrome 31·3 (0·03%) 44·5 (0·03%) 0·5 (0·01%) 0·7 (0·00%) 41·0 (0·03%) 3·5 (0·00%) .. .. ..
Iodine deficiency 60·0 (0·05%) 38·3 (0·02%) 10·0 (0·10%) 6·4 (0·04%) .. .. .. 28·5 (0·02%) 9·8 (0·01%)
African
trypanosomiasis
33·8 (0·03%) 9·4 (0·01%) 16·5 (0·17%) 4·7 (0·03%) .. .. .. 6·1 (0·00%) 3·2 (0·00%)
Total prevalence 118 174·6 (100·00%) 154 024·7 (100·00%) .. .. 37 809·3 (24·55%) 67 077·9 (43·55%) 28 842·6 (18·73%) 13 977·0 (9·07%) 6317·9 (4·10%)
Total YLDs .. .. 9979·7 (100·00%) 14 833·4 (100·00%) 722·4 (4·87%) 3209·3 (21·64%) 4925·1 (33·20%) 3963·3 (26·72%) 2013·3 (13·57%)

Data are number (%). YLDs=years lived with disability.