Dose Response Modeling: An Example Using Ozone and Mortality. Statistical Methods and Analysis of Health Data Workshop. Mumbai, India May 30, 2016

Transcription

1 Dose Response Modeing: An Eampe Using Ozone and Moraiy Saisia Mehods and Anaysis of Heah Daa Workshop Mumbai, India May 30, 2016 Mihee Be, Yae Universiy Ouine Bakground on dose response (onenraionresponse) Differen ypes of urves and approahes Eampe of modeing eposure response urve for risk of moraiy from ozone in 98 US iies Conuding houghs 1

2 Dose Response Curve (Eposure Response Curve) Shows he reaionship beween differen eves of eposure and differen eves of risk Response Conenraion Curves an be a wide variey of shapes Curves an ross: Subsane A may be more oi a ow doses, Subsane B more oi a high doses May have some daa poins, bu no he whoe urve (may no know he rue shape) Heah Response? One approah: Saisia modeing hrough ses of poins Dose (or pouan onenraion) 2

3 May have daa a high eposures, bu no ower eposures (or vie versa) Heah Response? Unknown One approah: Erapoaion Known Dose (or pouan onenraion) Ofen Summary Measures are Repored Peren Response moraiy % response D 50 D 50 = Dose One approah: Summarize one poin of he urve dose a whih 50% of subjes respond 3

4 Eampe of a urve wih ie onenraion-dependene Heah Risk Shows ie dose-response Si here is an effe Conenraion Resisan and Sensiive Popuaions Resisan Popuaions Heah Response Hypersensiive Popuaions Conenraion 4

5 Does he effe persis a very ow onenraions? Eposure response urve sudy How does risk hange wih eve of eposure? Are here safe eves? If so, are hey a or beow urren reguaions? Moraiy Risk? O 3 Conenraion Threshod? Bakground Here, we fous on shor erm eposure (a day or a few days) Epidemioogia sudies: Esimae assoiaion beween eposure and risk of heah ouome Eg, A 10 ppb inrease in daiy 8 hour maimum O 3 is assoiaed wih a 052% inrease in risk of daiy moraiy 5

6 n Origina Mode (iy speifi) number of ag days onsidered E y DOW ns( ime,7 / year) moraiy in iy on day 0 ns( T,6) ns( T, 3,6) ns( D,3) ns( D, 3,3) non inear funions for emperaure onenraion in iy on day a ag regression oeffiien for iy and ag day of he week for day regression oeffiien for iy for day of he week ineraion erms for age and ime variabes represening empora rends non inear funions for dew poin emperaure Epidemioogia Mode Time series mode (iy speifi) n Eμ β 0 = Epeed moraiy in iy on day = Pouion eve in iy on day a ag = Regression oeffiien for iy and pouion a ag = maimum number of days onsidered for ags 6

7 Eposure response urve modes 1 Origina mode neμ β 0 Eposure response urve modes 1 Origina mode neμ β 0 2 Subse approah neμ β 0, s s = speified subse vaue Generaes effe esimaes ony for onenraions beow s Vary eve of s 7

8 Resus Subse Approah % Inrease in Moraiy Risk s: for daiy ag 01 O 3 (ppb) Threshod: eve beow whih no adverse heah effe ours (safe eve) 100 Heah Risk 50? 0 Threshod Conenraion 8

9 Eposure response urve modes 1 Origina mode neμ β 0 2 Subse approah neμ β 3 Threshod mode n Eμ β - h) ( 0 where 0, s ( h) ( h) if h, 0 o/w h = speified hreshod vaue Assumes no heah effe for onenraions <h, effe for >h Eposure response urve modes 1 Origina mode neμ β 0 2 Subse approah neμ β 3 Threshod mode n Eμ β - h) ( 0 where 0, s ( h) ( h) if h, 0 o/w 4 Spine mode neμ ns( ) 0 9

10 Eposure Response Curve Sudy Conusions Consisen evidene ha if a hreshod eiss, i is a very ow eves Consisen resus under muipe mehods Any safe eve woud be beow urren reguaions a he ime of he sudy Srong effes under ompiane wih US EPA, WHO, CA, Canada, and European Commission Heah benefi from redued O 3, even in areas meeing urren reguaions 10

11 Conuding Thoughs No a air pouion heah reaionships may foow he radiiona eposure response mode form This eampe: O 3 and moraiy effes and ow eves (see referene) Simiar approahes appiaions for oher air pouans, oher heah effes, oher aspes of he eposure response urve (eg, high pouion eves) Mihee Be, Roger D Peng, and Franesa Dominii The eposure response urve for ozone and risk of moraiy and he adequay of urren ozone reguaions Environmena Heah Perspeives , p