2. 2
IInn tthhiiss pprreesseennttaattiioonn……
• Recognition of sources and authors
• Description of WHO Global Burden of Disease
Comparative Risk Assessment Study
– Contribution of Selected Occupational Risks to the GBD
• Discussion of the magnitude of occupational contribution
to GBD
– Context with ILO
• Next steps
3. American J. Industrial Medicine 48 ((66)):: 338855 –– 554411 ((22000055))
SSppeecciiaall IIssssuuee:: CCoonnttrriibbuuttiioonn ooff OOccccuuppaattiioonnaall RRiisskkss
ttoo tthhee GGlloobbaall BBuurrddeenn ooff DDiisseeaassee
Marilyn Fingerhut, Deborah Imel Nelson, Timothy Driscoll, Marisol
Concha-Barrientos, Kyle Steenland, Laura Punnett, Annette Prüss-Üstün,
James Leigh, Carlos Corvalan, Gerry Eijkemans, Jukka Takala,
Supriya Lahiri, Charles Levenstein, Pia Markinen, Beth Rosenberg,
Judith Gold, Sang Woo Tak, Robert Nelson
3
Eleven articles and an editorial
• WHO GBD Comparative Risk Assessment
– WHO 2002 World Health Report
– WHO 2005 Comparative Quantification of Health Risks
Chapter 15
4. BBaacckkggrroouunndd aabboouutt GGlloobbaall BBuurrddeenn ooff DDiisseeaassee
WHO Global Burden of Disease (GBD) Project focuses on
4
outcomes (death and disability)
– First estimates based on 1990
– Recent estimates based on 2000
– GBD database of 135 disease and injury outcomes
Outcome Measures in GBD Project and in the WHO Database
1. Death
2. (Death plus Disability ) DALY (Disability Adjusted Life Year)
DALY = Σ (YLL + YLD)
• YLL = years of life lost due to premature mortality
• YLD = the (weighted) years lived with a disability
5. BBaacckkggrroouunndd aabboouutt CCoommppaarraattiivvee RRiisskk AAsssseessssmmeenntt ((GGBBDD))
WHO Comparative Risk Assessment (CRA) project is
part of the broad Global Burden of Disease effort.
– Begins with risks (26 risk factors)
– Estimates the fraction of an outcome attributable to the risk factor
– Burden is estimated as
5
• Deaths
• DALYs (death plus disability)
– Has stringent requirements for data entry
– Uses a single model for analysis
6. 6
TThhee GGlloobbaall BBuurrddeenn ooff DDiisseeaassee
WWHHOO CCoommppaarraattiivvee RRiisskk AAsssseessssmmeenntt
• What is it?
– An analysis of the contribution of 26 risk factors to the global
burden of disease
• What is special about it?
– Similar exposure and risk information for all 26 risk factors was put
into a single model to make comparisons possible
• Why was it done?
– To provide decision makers with an understanding of the relative
contributions of the risk factors to disease and injury outcomes
• For example, x% of lung cancer is due to smoking, y% to air
pollution, z% to work exposures, etc
7. HHooww wwaass iitt ddoonnee?? SSuummmmaarryy ooff CCRRAA mmeetthhoodd::
7
Exposure distribution
in the population
Exposure-response
relationship
Impact fraction
Disease burden estimates
per disease
Disease burden
attributable to risk
factor
RReellaattiivvee rriisskk
((oorr aabbssoolluuttee rriisskk))
S(Pex • RRx) - 1
S (Pex • RRx)
IF =
DDeeaatthhss
DDAALLYYss
AAttttrriibbuuttaabbllee DDeeaatthhss
DDAALLYYss
PP==PPrrooppoorrttiioonn ooff
ppooppuullaattiioonn eexxppoosseedd
RRRR== RReellaattiivvee rriisskk
8. TThhee GGlloobbaall BBuurrddeenn ooff DDiisseeaassee::
WWHHOO CCoommppaarraattiivvee RRiisskk AAsssseessssmmeenntt
8
• What are its limitations?
1. Lack of data in developing nations
• Few estimates of exposure levels
• Incomplete counts of outcomes (mortality and morbidity)
• Incomplete reporting systems
2. Extrapolations made from one region to another
• Adds uncertainty
3. Stringent requirements for global data
– 224 age, sex, regional groupings
• Eliminated many occupational risk factors
9. 9
Legend:
Afr D
Afr E
Amr A
Amr B
Amr D
14 WHO Regions serving as basis for calculations
Eur A
Eur B
Eur C
Emr B
Emr D
Sear B
Sear D
Wpr A
Wpr B
10. The 26 WHO Global BBuurrddeenn RRiisskk FFaaccttoorrss
10
• Childhood and maternal under-nutrition
– Underweight, iron deficiency, Vitamin A deficiency
• Adult nutritional factors and physical inactivity
– High blood pressure, high cholesterol, high BMI, low fruit and vegetable
intake, physical inactivity
• Sexual and reproductive health
– Unsafe sex, lack of contraception, childhood sexual abuse, usafe health-care
injections
• Addictive substances
– Tobacco, alcohol, illicit drugs
• Environmental and occupational risks
– Unsafe water, sanitation and hygiene, urban outdoor air pollution, indoor
smoke from solid fuels, lead, global climate change…AND…
11. TThhee OOccccuuppaattiioonnaall RRiisskk FFaaccttoorrss
11
• Occupational Risk Factors
– Carcinogens
– Particulate
– Hazards for Injuries
– Ergonomic Stressors for
Back Pain
– Noise
– Needlesticks in Health Care
Workers
• Outcomes
– Cancer (lung, leukemia)
– Asthma, COPD, Silicosis,
Asbestosis, Mesothelioma
– Injuries
– Back Pain
– Hearing Loss
– HIV/AIDS, Hepatitis B and C
Infections
12. EExxcclluuddeedd OOccccuuppaattiioonnaall RRiisskk FFaaccttoorrss,,
12
OOuuttccoommeess aanndd WWoorrkkeerrss
• Excluded Occupational Risk Factors for Outcomes
– Reproductive disorders
– Coronary heart disease
– Musculoskeletal disorders of upper extremities
– Infectious disease
– Dermatitis
– Some cancers
• Excluded All Child Labor (under 15 years of age)
13. Environmental and occupational risk factors
Water resources
13
Carcinogens
Air pollution
Occupational
environment
Airborne particulates
Microbiological
hazards
Chemical hazards
Injury
hazards
Noise
Ergonomic stressors
Physical and
psychological
hazards
Sress.
Bacteria,Vruses
Vectors
•Occupational
risks in CRA
Agricultural
environments
Injury
hazards
General environment
•Type of hazard
Pesticides
Food safety
Lead
Water supply,
sanitation
& hygiene
High-risk natural
environments,
such as wetlands
15. R Exposure, Riisskk EEssttiimmaattee,, aanndd BBuurrddeenn
MMeeaassuurreess ffoorr OOccccuuppaattiioonnaall RRiisskk FFaaccttoorrss
• Exposed worker population and exposure levels
- computed by economic sector or occupation
• Risk Estimates - taken from literature
----------------------------------------------------------------
• Burden Measures: Deaths and DALYs – in WHO GBD Database
15
DALY (Disability Adjusted Life Year) =
Mortality + Disability
• Attributable fraction = % of Burden due to particular risk factor
16. 16
Population in each region (World Bank)
Economically active population (≥15
years) (ILO)
Economic sector
(agriculture, industry,
services)
Percentage of
exposed workers
Occupation category
Level: background
Level: low
Level: high
Percentage of
exposed workers
Level: background
Level: low
Level: high
17. Exposure bbaasseedd oonn EEccoonnoommiicc SSeeccttoorr aanndd
17
OOccccuuppaattiioonn**
• Economic sectors (Agriculture, Industry, Services) and
subsectors (Mining, Manufacturing, Electrical, Construction, Trade,
Transport, Finance, Services)
– Used for carcinogens, most particulates, and injuries
• Occupational categories (Professional, Administration, Clerical,
Sales, Service, Production)
– Used for noise, ergonomic stressors, and asthmagens
• *International Standard Industrial Classification of All Economic
Activities (ISIC )
18. Sources for Occupational Exposure Levels aanndd ffoorr RReellaattiivvee
RRiisskkss oorr MMoorrttaalliittyy bbyy EEccoonnoommiicc SSeeccttoorr oorr OOccccuuppaattiioonn
18
• Carcinogens
– CAREX database (FIOH 1999); Kauppinen et al. 2000, Nurminen and
Karjalainen 2001; Steenland 2002, etc
• Particulates
– Silica, asbestos, coal dust Kauppinen et al. 2000; Korn et al. 1987;
USEPA 2001
– Asthmagens Karjalainen et al, 2002; Kogevinas et al 1999
– COPD Kauppinen et al. 2000; Korn et al. 1987; USEIA 2001
• Noise
– NIOSH 1998
• Ergonomic Stressors for Back Pain
– Leigh and Sheetz 1989
• Injury Risks
– ILO 2002, mortality rates in Regions
19. EExxaammppllee –– LLuunngg ccaarrcciinnooggeennss ((11))
((aarrsseenniicc,, aassbbeessttooss,, bbeerryylllliiuumm,, ccaaddmmiiuumm,, cchhrroommiiuumm,,
19
ddiieesseell eexxhhaauusstt,, nniicckkeell,, ssiilliiccaa))
• Exposure: CAREX (Carcinogen Exposure database)
– FIOH 1999; Kauppinen et al. 2000
– Survey providing proportion of the working population with
occupational exposure to carcinogens in the European Union, by
economic sector and subsector, at the 3-digit classification level
– Applicable to A subregions, extrapolated to B, C, D and E subregions
• Levels of exposure
– A regions: 10% high; 90% low
– BCDE regions: 50% high; 50% low
20. EExxaammppllee –– LLuunngg ccaarrcciinnooggeennss ((22))
((aarrsseenniicc,, aassbbeessttooss,, bbeerryylllliiuumm,, ccaaddmmiiuumm,, cchhrroommiiuumm,,
20
ddiieesseell eexxhhaauusstt,, nniicckkeell,, ssiilliiccaa))
• Relative risk: Lung carcinogens
– A summary relative risk of 1.6 for occupational exposure
to the set of lung carcinogens considered here was taken
from review paper by Steenland et al 1996
– Partitioned into risks for low and high exposure of 1.3 and
1.9 and in regions weighted by population exposed to
each carcinogen
27. SSppeecciiaall aannaallyyssiiss:: EEssttiimmaattiioonn ooff iinnffeeccttiioonnss aattttrriibbuuttaabbllee ttoo
ccoonnttaammiinnaatteedd sshhaarrppss iinnjjuurriieess aammoonngg hheeaalltthhccaarree wwoorrkkeerrss
– About 35 million health care workers worldwide
– About 3 million percutaneous exposures to bloodborne pathogens in
2000
– Analysis carried out because of the critical role of healthcare workers
everywhere
27
Question: What fractions of Hepatitis B, Hepatitis C,
and HIV/AIDS infections in healthcare workers are
due to contaminated sharps?
28. Overall, about 40% HBV, 40% of HCV aanndd 44..44%% HHIIVV//AAIIDDss iinn
HHeeaalltthhccaarree WWoorrkkeerrss aarree dduuee ttoo ccoonnttaammiinnaatteedd nneeeeddlleessttiicckkss
Attributable fraction of HCV, HBV and HIV infections in healthcare w orkers due to injuries
Wpr B
28
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Percentage
Afr D
Afr E
w ith contaminated sharps, ages 20-65
Amr B
Amr D
Amr A
Emr B
Emr D
Eur B
Eur C
Eur A
Sear B
Sear D
Wpr A
Regions
HCV
HBV
HIV
30. 30
CCoonncclluussiioonnss aanndd DDiissccuussssiioonn (11))
• Overall - the leading causes of global burden of disease
(DALYs) in the WHO Comparative Risk Assessment
– Childhood and maternal underweight (9.5%)
– Unsafe sex (6.3%),
– High blood pressure (4.4%)
– Tobacco (4.1%)
– Alcohol (4.0%)
• Main impact is on developing nations
31. 31
CCoonncclluussiioonnss aanndd DDiissccuussssiioonn ((22))
• Five selected occupational risk factors in this study
– Responsible for 1.7% of Global Burden (23.7 million DALYs)
– Responsible for about 850,000 deaths
• Analysis greatly underestimates occupational burden
– Many occupational risk factors could not be included due to lack of
global data
– Even where data are present, under-reporting is grave
– All child labor was excluded
32. 32
CCoonncclluussiioonnss aanndd DDiissccuussssiioonn ((33))
• ILO Methodology to estimate global occupational fatalities
– For injuries: National fatality rates applied to employed labor force
– For diseases: Attributable fractions applied to deaths for outcomes
in the WHO Global Burden of Disease database
• ILO Results*
– 2.2 million occupational disease and injury deaths occurred in 2000
• Underestimation of WHO: The five WHO selected risk
factors constitute only about 40% of the occupational
deaths.
**DDeecceenntt WWoorrkk –– SSaaffee WWoorrkk XXVVIIII WWoorrlldd CCoonnggrreessss, MMiiaammii, SSeepptteemmbbeerr 22000055
33. CCoonncclluussiioonnss aanndd DDiissccuussssiioonn ((44))
• Benefit of studying global occupational risks
(despite the limitations)
– Demonstrate major contribution to global burden of disease
33
– Encourage steps to reduce risks
– Stimulate improved surveillance systems and data collection
– Motivate improved future analyses of occupational risks
34. NNeexxtt SStteeppss ((11)):: AAcctt nnooww! IInnttrroodduuccee wwoorrkkppllaaccee
34
iinntteerrvveennttiioonnss ttoo rreedduuccee rriisskkss
• Employ hierarchy of controls: substitution, engineering
controls, administrative controls, personal protective
equipment
• Use and evaluate simplified guidance: E.g. WHO/ILO
International Chemical Control Toolbox
http://www.ilo.org/public/english/protection/safework/ctrl_banding/• For healthcare workers: Use sharps substitutions, proper
needle handling and waste management; vaccinate health
care workers for Hepatitis B; provide post-exposure
prophylaxis
35. NNeexxtt SStteeppss ((22)):: CCaallccuullaattee nnaattiioonnaall aanndd llooccaall bbuurrddeenn ooff
ddiisseeaassee ccaauusseedd bbyy ooccccuuppaattiioonnaall rriisskk ffaaccttoorrss
35
• Available from WHO (free)
– Occupational Noise
– Occupational Carcinogens
– Occupational Particulates
– Needlesticks among Health
Care Workers
– Occupational Injuries (in
preparation)
hhttttpp::////wwwwww..wwhhoo..iinntt//qquuaannttiiffyyiinngg__eehhiimmppaaccttss//ppuubblliiccaattiioonnss//eenn//
36. 36
NNeexxtt SStteeppss ((33))
• Improve data collection in countries
– Caution: Balance between ‘perfect’ data and ‘enough data to act’
• Improve methodologies to estimate exposed populations,
exposure levels, risk levels, burden of disease
• Evaluate cost-effectiveness of preventive interventions
– Use studies and tools for company level analysis of
the net-costs of interventions in workplaces
• AJIM Special Issue 48 (6) 2005: 503–541
• J. Safety Research 36 (3) 2005: 207-308
37. NNeexxtt SStteeppss ((44)):: PPaarrttnneerrsshhiippss ttoo rreedduuccee GGBBDD dduuee
ttoo ooccccuuppaattiioonnaall rriisskkss
• Integrated, coordinated, strategic response needed
– Health and Labor Ministries
– Employers and Workers
– Non-governmental OSH organizations (ICOH, IOHA, IEA)
– National OSH organizations
– Training institutions
– National and local governments
– International Networks (WHO Global Network, ILO)
• Share information, new analyses, successful interventions,
useful legislation
37
