Global burden of disease due to smokeless tobacco consumption in adults: analysis of data from 113 countries.
BACKGROUND
Smokeless tobacco is consumed in most countries in the world. In view of its widespread use and increasing awareness of the associated risks, there is a need for a detailed assessment of its impact on health. We present the first global estimates of the burden of disease due to consumption of smokeless tobacco by adults.


METHODS
The burden attributable to smokeless tobacco use in adults was estimated as a proportion of the disability-adjusted life-years (DALYs) lost and deaths reported in the 2010 Global Burden of Disease study. We used the comparative risk assessment method, which evaluates changes in population health that result from modifying a population's exposure to a risk factor. Population exposure was extrapolated from country-specific prevalence of smokeless tobacco consumption, and changes in population health were estimated using disease-specific risk estimates (relative risks/odds ratios) associated with it. Country-specific prevalence estimates were obtained through systematically searching for all relevant studies. Disease-specific risks were estimated by conducting systematic reviews and meta-analyses based on epidemiological studies.


RESULTS
We found adult smokeless tobacco consumption figures for 115 countries and estimated burden of disease figures for 113 of these countries. Our estimates indicate that in 2010, smokeless tobacco use led to 1.7 million DALYs lost and 62,283 deaths due to cancers of mouth, pharynx and oesophagus and, based on data from the benchmark 52 country INTERHEART study, 4.7 million DALYs lost and 204,309 deaths from ischaemic heart disease. Over 85 % of this burden was in South-East Asia.


CONCLUSIONS
Smokeless tobacco results in considerable, potentially preventable, global morbidity and mortality from cancer; estimates in relation to ischaemic heart disease need to be interpreted with more caution, but nonetheless suggest that the likely burden of disease is also substantial. The World Health Organization needs to consider incorporating regulation of smokeless tobacco into its Framework Convention for Tobacco Control.
Department of Health Sciences, Hull York Medical School, University of York, Room 105a, First floor, ARRC Building, Heslington, York, YO10 5DD, UK. Kamran.siddiqi@york.ac.uk.
Kamran
K
Siddiqi
Department of Health Sciences, Hull York Medical School, University of York, Room 105a, First floor, ARRC Building, Heslington, York, YO10 5DD, UK. Sarwat.shah@york.ac.uk.
Sarwat
S
Shah
Fatima Memorial Hospital College of Medicine and Dentistry, Fatima Memorial System, Shadman, Lahore, 48000, Pakistan. taureanvibes@hotmail.com.
Syed Muslim
SM
Abbas
Department of Health Sciences, Hull York Medical School, University of York, Room 105a, First floor, ARRC Building, Heslington, York, YO10 5DD, UK. av661@york.ac.uk.
Aishwarya
A
Vidyasagaran
Department of Primary Care and Public Health, Imperial College London, Charing Cross Campus, Reynold's Building, Hammersmith, W6 8RP, UK. mohammed.jawad06@imperial.ac.uk.
Mohammed
M
Jawad
Department of Health Sciences, Hull York Medical School, University of York, Room 105a, First floor, ARRC Building, Heslington, York, YO10 5DD, UK. Omara.dogar@york.ac.uk.
Omara
O
Dogar
Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Medical School Doorway 3, Teviot Place, Edinburgh, EH8 9AG, UK. Aziz.sheikh@ed.ac.uk.
Aziz
A
Sheikh
D000328:Adult; D004938:Esophageal Neoplasms / Q000209:etiology / Q000401:mortality; D005260:Female; D014943:Global Health / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009062:Mouth Neoplasms / Q000209:etiology / Q000401:mortality; D017202:Myocardial Ischemia / Q000209:etiology / Q000401:mortality; D010610:Pharyngeal Neoplasms / Q000209:etiology / Q000401:mortality; D015995:Prevalence; D019057:Quality-Adjusted Life Years; D018570:Risk Assessment; D012307:Risk Factors; D064424:Tobacco Use / Q000009:adverse effects / Q000453:epidemiology; D014030:Tobacco, Smokeless / Q000009:adverse effects*