Using database linkage to estimate Using database linkage to estimate the incidence of the incidence of

new onset adult asthma new onset adult asthma in Alberta and British Columbiain Alberta and British Columbia

Jeremy Beach, Igor Burstyn, Nicola CherryJeremy Beach, Igor Burstyn, Nicola CherryOccupational Medicine ProgramOccupational Medicine Program

University of AlbertaUniversity of Alberta

OEMAC,OEMAC, October 2010October 2010

Occupational asthmaOccupational asthma Common; costly; preventableCommon; costly; preventable

If not recognised then may be poorly managedIf not recognised then may be poorly managed Probably under-diagnosedProbably under-diagnosed

Alberta WCB 131 cases 1995 – 2004Alberta WCB 131 cases 1995 – 2004 WorkSafe BC mean 59 cases/year 1995 - 2004WorkSafe BC mean 59 cases/year 1995 - 2004

SurveillanceSurveillance increase local intelligence (where, who, how much?)increase local intelligence (where, who, how much?) focus interventionfocus intervention demonstrate effectiveness of control measuresdemonstrate effectiveness of control measures

Use new onset adult asthma (NOAA) – but no single Use new onset adult asthma (NOAA) – but no single data source data source

OccupationOccupation ExposureExposure DiagnosisDiagnosis

Objectives Already used data linkage with Alberta

data1. To extend the same data linkage

technique used in Alberta (AB) to British Columbia (BC).

To compare results for the two provinces.

11Cherry et al, AJIM 2009;52:831Cherry et al, AJIM 2009;52:831

Source of dataSource of data Identify all WCB claims in 1995-2004Identify all WCB claims in 1995-2004

Source of Source of occupation and industryoccupation and industry data (reason for claim data (reason for claim irrelevant)irrelevant)

Identify all claims with unique identifier allowing linkage Identify all claims with unique identifier allowing linkage to health data (Personal Health Number (PHN) or to health data (Personal Health Number (PHN) or similar) similar)

Link to administrative database of Physician billing using Link to administrative database of Physician billing using PHNPHN

Source of Source of diagnostic data - NOAAdiagnostic data - NOAA Need to ensure person residentNeed to ensure person resident

Definition of NOAADefinition of NOAA Resident in province for four years prior to WCB Resident in province for four years prior to WCB

claimclaim

Physician Physician billing for asthma (ICD9 493) in 12 billing for asthma (ICD9 493) in 12 months prior to WCB claimmonths prior to WCB claim

No physician billing for asthma in preceding three No physician billing for asthma in preceding three years – prevalent casesyears – prevalent cases

Restricted to non-prevalent subjects - if prevalent Restricted to non-prevalent subjects - if prevalent not at risk of NOAAnot at risk of NOAA

AlbertaAlberta

1,320,792 WCB claims 1995-20041,320,792 WCB claims 1995-2004 782,908 eligible for matching782,908 eligible for matching 561,951 with occupation recorded.561,951 with occupation recorded. 349,999 with industry recorded.349,999 with industry recorded.

Collapse to groups with >250Collapse to groups with >250

British ColumbiaBritish Columbia

Approx 240 million physician billing episodes Approx 240 million physician billing episodes 1991-20041991-2004

3,268,114 WCB claims 1995-2004, 3,268,114 WCB claims 1995-2004, 1,118,239 WCB claims eligible for matching1,118,239 WCB claims eligible for matching Two different occupation codes usedTwo different occupation codes used

333,132 with valid SOC91 code333,132 with valid SOC91 code Industry coded using CU numberIndustry coded using CU number

Comparison of AB and BC claims

ABAB BCBC

782,908 eligible claims782,908 eligible claims 1,118,239 eligible claims1,118,239 eligible claims

Incidence 1.6%Incidence 1.6%(12,554 cases)(12,554 cases)

Incidence 1.4%Incidence 1.4%(15,520 cases)(15,520 cases)

Males 1.3%, Males 1.3%, Females 2.5%Females 2.5%

Males 1.1%, Males 1.1%, Females 2.0%Females 2.0%

Decrease with ageDecrease with ageMales <30 1.5%, Males <30 1.5%, ≥≥30 1.3%30 1.3%Females <30 3.0%, Females <30 3.0%, ≥≥ 30 2.3% 30 2.3%

Decrease with ageDecrease with ageMales <30 1.2%, Males <30 1.2%, ≥≥ 30 1.1% 30 1.1%Females <30 2.3%, Females <30 2.3%, ≥≥ 30 1.9% 30 1.9%

Similar occupations with increased risk in AB and BC (adjusted for age and sex)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)Gen office clerksGen office clerks 1.55 (1.17-2.05)1.55 (1.17-2.05) Clerical/gen office skillsClerical/gen office skills 2.06 (1.11-3.85)2.06 (1.11-3.85)

Receptionists/info clerkReceptionists/info clerk 1.60 (1.13-2.27)1.60 (1.13-2.27)

Bookkeepers acc clerksBookkeepers acc clerks 1.44 (1.02-2.02)1.44 (1.02-2.02)

Teaching/related fields necTeaching/related fields nec 1.74 (1.23-2.46)1.74 (1.23-2.46) Secondary school teachersSecondary school teachers 1.60 (1.04-2.47)1.60 (1.04-2.47)

School teacher asstsSchool teacher assts 1.76 (1.22-2.53)1.76 (1.22-2.53)

Early childhood educ/asstsEarly childhood educ/assts 1.64 (1.03-2.60)1.64 (1.03-2.60)

Waiters/hostesses/stewardsWaiters/hostesses/stewards 1.22 (1.01-1.47)1.22 (1.01-1.47) Bartenders Bartenders 1.69 (1.00-2.85)1.69 (1.00-2.85)

Bus driversBus drivers 1.26 (1.02-1.55)1.26 (1.02-1.55) Trades, transport equip opTrades, transport equip op 1.92 (1.17-3.14)1.92 (1.17-3.14)

Motor transport operators necMotor transport operators nec 1.73 (1.01-2.96)1.73 (1.01-2.96) Bus drivers, transit operatorsBus drivers, transit operators 1.47 (1.03-2.10)1.47 (1.03-2.10)

Stationary engine/equip opStationary engine/equip op 1.70 (1.06-2.72)1.70 (1.06-2.72) Taxi, limo drivers, chauffeursTaxi, limo drivers, chauffeurs 2.23 (1.41-3.51)2.23 (1.41-3.51)

Wood processors (not pulp)Wood processors (not pulp) 1.94 (1.08-3.46)1.94 (1.08-3.46) Sawmill machine operatorsSawmill machine operators

Furniture/fixture assemblersFurniture/fixture assemblers

Guards/watchmenGuards/watchmen 1.42 (1.19-1.71)1.42 (1.19-1.71) Other occ protective servicesOther occ protective services 2.62 (1.47-4.69)2.62 (1.47-4.69)

Protective services necProtective services nec 1.80 (1.29-2.53)1.80 (1.29-2.53)

Similar occupations with increased risk in AB and BC (adjusted for age and sex)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)Gen office clerksGen office clerks 1.55 (1.17-2.05)1.55 (1.17-2.05) Clerical/gen office skillsClerical/gen office skills 2.06 (1.11-3.85)2.06 (1.11-3.85)

Receptionists/info clerkReceptionists/info clerk 1.60 (1.13-2.27)1.60 (1.13-2.27)

Bookkeepers acc clerksBookkeepers acc clerks 1.44 (1.02-2.02)1.44 (1.02-2.02)

Teaching/related fields necTeaching/related fields nec 1.74 (1.23-2.46)1.74 (1.23-2.46) Secondary school teachersSecondary school teachers 1.60 (1.04-2.47)1.60 (1.04-2.47)

School teacher asstsSchool teacher assts 1.76 (1.22-2.53)1.76 (1.22-2.53)

Early childhood educ/asstsEarly childhood educ/assts 1.64 (1.03-2.60)1.64 (1.03-2.60)

Waiters/hostesses/stewardsWaiters/hostesses/stewards 1.22 (1.01-1.47)1.22 (1.01-1.47) Bartenders Bartenders 1.69 (1.00-2.85)1.69 (1.00-2.85)

Bus driversBus drivers 1.26 (1.02-1.55)1.26 (1.02-1.55) Bus drivers, transit operatorsBus drivers, transit operators 1.47 (1.03-2.10)1.47 (1.03-2.10)

Motor transport operators necMotor transport operators nec 1.73 (1.01-2.96)1.73 (1.01-2.96) Taxi, limo drivers, chauffeursTaxi, limo drivers, chauffeurs 2.23 (1.41-3.51)2.23 (1.41-3.51)

Stationary engine/equip opStationary engine/equip op 1.70 (1.06-2.72)1.70 (1.06-2.72) Trades, transport equip opTrades, transport equip op 1.92 (1.17-3.14)1.92 (1.17-3.14)

Wood processors (not pulp)Wood processors (not pulp) 1.94 (1.08-3.46)1.94 (1.08-3.46) Sawmill machine operatorsSawmill machine operators

Furniture/fixture assemblersFurniture/fixture assemblers

Guards/watchmenGuards/watchmen 1.42 (1.19-1.71)1.42 (1.19-1.71) Other occ protective servicesOther occ protective services 2.62 (1.47-4.69)2.62 (1.47-4.69)

Protective services necProtective services nec 1.80 (1.29-2.53)1.80 (1.29-2.53)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)Community welfare occupCommunity welfare occup 1.75 (1.35-2.26)1.75 (1.35-2.26)

Social work/related fieldsSocial work/related fields 2.13 (1.54-2.94)2.13 (1.54-2.94)

Tellers/cashiersTellers/cashiers 1.38 (1.19-1.60)1.38 (1.19-1.60)

Electronic data proc equip opElectronic data proc equip op 1.92 (1.22-3.02)1.92 (1.22-3.02)

Firefighters Firefighters 1.37 (1.08-1.74)1.37 (1.08-1.74) Firefighters – except forestFirefighters – except forest 0.71 (0.43-1.18)0.71 (0.43-1.18)

Firefighters -forestFirefighters -forest 1.58 (0.95-2.63)1.58 (0.95-2.63)

Launderers/dry cleanersLaunderers/dry cleaners 1.96 (1.28-2.98)1.96 (1.28-2.98)

Bakers/confectionary makersBakers/confectionary makers 1.41 (1.14-1.74)1.41 (1.14-1.74)

Painters/paper hangersPainters/paper hangers 1.33 (1.01-1.75)1.33 (1.01-1.75)

Insulators/constructionInsulators/construction 1.71 (1.19-2.48)1.71 (1.19-2.48)

Aides/assts health servicesAides/assts health services 2.58 (1.44-4.63)2.58 (1.44-4.63)

Med Lab TechMed Lab Tech 1.94 (1.12-3.37)1.94 (1.12-3.37)

Gas fittersGas fitters 2.25 (1.15-4.40)2.25 (1.15-4.40)

Indust butchers,meat cuttersIndust butchers,meat cutters 1.72 (1.16-2.561.72 (1.16-2.56

Machinists/metal formingMachinists/metal forming 2.35 (1.12-4.94)2.35 (1.12-4.94)

Occupations with increased risk in either AB or BC (adjusted for age and sex)

Similar industries with increased risk in AB and BC (adjusted for age and sex)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)

Saw mills, planing millsSaw mills, planing mills 1.31 (1.04-1.64)1.31 (1.04-1.64) Wood and paper productsWood and paper products 1.92 (1.22-3.02)1.92 (1.22-3.02)

OSB manufOSB manuf 2.39 (1.26-4.52)2.39 (1.26-4.52)

Chemical pulp and paper millChemical pulp and paper mill 1.17 (1.02-1.34)1.17 (1.02-1.34)

Shake or shingle millShake or shingle mill 2.61 (2.01-3.39)2.61 (2.01-3.39)

Wood preservingWood preserving 2.27 (1.07-4.84)2.27 (1.07-4.84)

Wooden component manuf Wooden component manuf 1.42 (1.14-1.76)1.42 (1.14-1.76)

Woodworking/carpentry shopWoodworking/carpentry shop 1.38 (1.09-1.74)1.38 (1.09-1.74)

Food processing miscFood processing misc 1.61 (1.02-2.54)1.61 (1.02-2.54) Food product manufacturingFood product manufacturing 1.56 (1.07-2.29)1.56 (1.07-2.29)

Restaurant/take out servicesRestaurant/take out services 1.18 (1.03-1.35)1.18 (1.03-1.35) Poultry processingPoultry processing 1.60 (1.21-2.11)1.60 (1.21-2.11)

Catering-industrial campsCatering-industrial camps 1.63 (1.03-2.56)1.63 (1.03-2.56) Sugar refining and packagingSugar refining and packaging 2.52 (1.18-5.38)2.52 (1.18-5.38)

Flour millsFlour mills 2.17 (1.14-4.13)2.17 (1.14-4.13) Grain elevatorGrain elevator 1.52 (1.03-2.24)1.52 (1.03-2.24)

Agriculture Agriculture 1.51 (1.07-2.13)1.51 (1.07-2.13)

Auto body repairAuto body repair 1.51 (1.01-2.27)1.51 (1.01-2.27) Truck body, trailer manufTruck body, trailer manuf 1.46 (1.03-2.06)1.46 (1.03-2.06)

Metal pipe, fitting manufMetal pipe, fitting manuf 2.14 (1.00-4.55)2.14 (1.00-4.55)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)Petrochem manufPetrochem manuf 1.72 (1.10-2.68)1.72 (1.10-2.68) Petroleum,coal,rubber,plastic Petroleum,coal,rubber,plastic 1.62 (1.15-2.29)1.62 (1.15-2.29)

Mech insulation install servMech insulation install serv 1.64 (1.01-2.661.64 (1.01-2.66 Paper recyc, cellulose insulPaper recyc, cellulose insul 1.29 (1,02-1.63)1.29 (1,02-1.63)

Fiber glass insulation manufFiber glass insulation manuf 2.06 (1.08-3.90)2.06 (1.08-3.90)

Fiber glass reinf prod manufFiber glass reinf prod manuf 2.54 (1.55-4.16)2.54 (1.55-4.16)

School boardsSchool boards 1.37 (1.15-1.62)1.37 (1.15-1.62) Public school districtPublic school district 1.28 (1.11-1.46)1.28 (1.11-1.46)

TownsTowns 1.48 (1.05-2.09)1.48 (1.05-2.09) Govt of BCGovt of BC 1.31 (1.10-1.56)1.31 (1.10-1.56)

CitiesCities 1.29 (1.14-1.46)1.29 (1.14-1.46) Local Govt and relatedLocal Govt and related 1.16 (1.01-1.33)1.16 (1.01-1.33)

Auto towingAuto towing 1.80 (1.05-3.08)1.80 (1.05-3.08) Traffic control - road construcTraffic control - road construc 2.45 (1.51-3.96)2.45 (1.51-3.96)

Gas bar – no servicesGas bar – no services 2.16 (1.29-3.60)2.16 (1.29-3.60) Bus line, chartered bus toursBus line, chartered bus tours 1.36 (1.08-1.70)1.36 (1.08-1.70)

Courier servicesCourier services 1.29 (1.01-1.65)1.29 (1.01-1.65)

Limousine, chauffeurLimousine, chauffeur 2.22 (1.14-4.34)2.22 (1.14-4.34)

Taxi serviceTaxi service 2.00 (1.42-2.83)2.00 (1.42-2.83)

Social Comm Supp ServicesSocial Comm Supp Services 1.87 (1.45-2.41)1.87 (1.45-2.41) Acute care – hlth soc assistAcute care – hlth soc assist 1.13 (1.01-1.27)1.13 (1.01-1.27)

Health/social field servicesHealth/social field services 1.29 (1.04-1.60)1.29 (1.04-1.60) Residential Soc servicesResidential Soc services 1.34 (1.04-1.73)1.34 (1.04-1.73)

Day homes/day care centresDay homes/day care centres 1.62 (1.11-2.35)1.62 (1.11-2.35) Counselling/Soc services necCounselling/Soc services nec 1.30 (1.03-1.65)1.30 (1.03-1.65)

Day care, preschoolDay care, preschool 1.96 (1.43-2.69)1.96 (1.43-2.69)

Security servicesSecurity services 1.70 (1.18-2.43)1.70 (1.18-2.43) Security /patrol servicesSecurity /patrol services 1.82 (1.30-2.55)1.82 (1.30-2.55)

Occupations and Industries with decreased risk in either AB or BC (adjusted for age and sex)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)Foremen, mine, quarry, oilForemen, mine, quarry, oil 0.11 (0.02-0.78)0.11 (0.02-0.78)

Rotary well drillersRotary well drillers 0.52 (0.39-0.70)0.52 (0.39-0.70)

Welders, flame cuttersWelders, flame cutters 0.88 (0.78-0.98)0.88 (0.78-0.98)

GlaziersGlaziers 0.36 (0.15-0.85)0.36 (0.15-0.85)

Truck driversTruck drivers 0.89 (0.89 (

Drilling of oil and gas wellsDrilling of oil and gas wells 0.45 (0.30-0.66)0.45 (0.30-0.66)

Construction trades and svceConstruction trades and svce 0.55 (0.37-0.83)0.55 (0.37-0.83)

Underground miningUnderground mining 0.43 (0.19-0.97)0.43 (0.19-0.97)

Liquid dairy prod manufLiquid dairy prod manuf 0.53 (0.31-0.89)0.53 (0.31-0.89)

Distribution centresDistribution centres 0.54 (0.29-0.98)0.54 (0.29-0.98)

Integrated loggingIntegrated logging 0.80 (0.65-0.97)0.80 (0.65-0.97)

Discussion Discussion This data linkage technique worked in BC as well as AB despite differences

in data formats.

Need to be some caution when interpreting these data: Relatively sensitive case definition – possibility of diagnostic errors. Errors in identifying occupation – ? job change possible if work-related. Only a sample of population – WCB claimants – possible bias. Ease of access to physician/availability of sickness absence

Overall incidence levels appear similar in the two provinces: if 5-25% of NOAA is occupational asthma suggests WCB claims may be a

significant underestimate (average 13-14 per year in Alberta, 59 per year in BC).

Occupations at risk show some similarities and differences between provinces - may reflect differences in exposures. Linkage to JEM.

Some unanticipated occupations appear at risk – raises possibility of heightened surveillance.

Acknowledgements Acknowledgements

Alberta WCBAlberta WCB Alberta Health and WellnessAlberta Health and Wellness BC Linked Health DatabaseBC Linked Health Database Allergen NCEAllergen NCE

Similar occupations with increased risk in AB and BC (adjusted for age and sex)

AlbertaAlberta OR (95% CI)OR (95% CI) BCBC OR (95% CI)OR (95% CI)Gen office clerksGen office clerks 1.55 (1.17-2.05)1.55 (1.17-2.05) Clerical/gen office skillsClerical/gen office skills 2.06 (1.11-3.85)2.06 (1.11-3.85)

Receptionists/info clerkReceptionists/info clerk 1.60 (1.13-2.27)1.60 (1.13-2.27)

Bookkeepers acc clerksBookkeepers acc clerks 1.44 (1.02-2.02)1.44 (1.02-2.02)

Teaching/related fields necTeaching/related fields nec 1.74 (1.23-2.46)1.74 (1.23-2.46) Secondary school teachersSecondary school teachers 1.60 (1.04-2.47)1.60 (1.04-2.47)

School teacher asstsSchool teacher assts 1.76 (1.22-2.53)1.76 (1.22-2.53)

Early childhood educ/asstsEarly childhood educ/assts 1.64 (1.03-2.60)1.64 (1.03-2.60)

Waiters/hostesses/stewardsWaiters/hostesses/stewards 1.22 (1.01-1.47)1.22 (1.01-1.47) Bartenders Bartenders 1.69 (1.00-2.85)1.69 (1.00-2.85)

Bus driversBus drivers 1.26 (1.02-1.55)1.26 (1.02-1.55) Trades, transport equip opTrades, transport equip op 1.92 (1.17-3.14)1.92 (1.17-3.14)

Motor transport operators necMotor transport operators nec 1.73 (1.01-2.96)1.73 (1.01-2.96) Bus drivers, transit operatorsBus drivers, transit operators 1.47 (1.03-2.10)1.47 (1.03-2.10)

Stationary engine/equip opStationary engine/equip op 1.70 (1.06-2.72)1.70 (1.06-2.72) Taxi, limo drivers, chauffeursTaxi, limo drivers, chauffeurs 2.23 (1.41-3.51)2.23 (1.41-3.51)

Wood processors (not pulp)Wood processors (not pulp) 1.94 (1.08-3.46)1.94 (1.08-3.46) Sawmill machine operatorsSawmill machine operators

Furniture/fixture assemblersFurniture/fixture assemblers

Guards/watchmenGuards/watchmen 1.42 (1.19-1.71)1.42 (1.19-1.71) Other occ protective servicesOther occ protective services 2.62 (1.47-4.69)2.62 (1.47-4.69)

Protective services necProtective services nec 1.80 (1.29-2.53)1.80 (1.29-2.53)