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Co nstruc ting I nve rse Pro b a b ility We ig hts fo r Sta tic I nte rve ntio ns K unja l Pa te l, DSc MPH Se nio r Re se a rc h Sc ie ntist Ha rva rd T .H. Cha n Sc ho o l o f Pub lic He a lth Ac kno wle dg e me nt Slide s c o


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SLIDE 1

Co nstruc ting I nve rse Pro b a b ility We ig hts fo r Sta tic I nte rve ntio ns

K unja l Pa te l, DSc MPH Se nio r Re se a rc h Sc ie ntist Ha rva rd T .H. Cha n Sc ho o l o f Pub lic He a lth

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SLIDE 2

Ac kno wle dg e me nt

 Slide s c o ntrib ute d b y Mig ue l He rná n o r a da pte d fro m

Causal I nfe re nc e (Cha pma n & Ha ll/ CRC, 2017) b y Mig ue l He rná n a nd Ja mie Ro b ins

 Any mista ke s a re my o wn  Cha pte rs o f b o o k a nd SAS, ST

AT A, a nd R c o de fre e ly a va ila b le a t http:/ / www.hsph.ha rva rd.e d u/ mig ue l- he rna n/ c a usa l-infe re nc e -b o o k/

 Yo u c a n “like ” Ca usa l I

nfe re nc e a t https:/ / www.fa c e b o o k.c o m/ c a usa linfe re nc e

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SLIDE 3

Ca se Study

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SLIDE 4

I ntro duc tio n/ Ba c kg ro und

Ra ndo mize d c o ntro lle d tria ls (RCT s) in HI V-infe c te d a dults ha ve sho wn HAART to b e hig hly e ffe c tive in re duc ing the risk o f mo rta lity

Na tura l pro g re ssio n o f HI V infe c tio n in c hildre n is diffe re nt fro m a dults:

HI V RNA le ve ls re ma in pe rsiste ntly hig he r tha n a dults fo r first 2-3 ye a rs o f life , de c re a sing to ste a dy sta te le ve ls in a dults a fte r a ppro xima te ly five -ye a rs

Ge ne ra liza b ility o f a dult tria l re sults?

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SLIDE 5

Studie s o f HAART in Childre n

RCT s o f HAART in c hildre n ha ve fo c use d o n inte rme dia te immuno lo g ic a nd viro lo g ic e ndpo ints

L

  • ng -te rm studie s o f HAART
  • n mo rta lity re lia nt o n
  • b se rva tio na l studie s:

I ta lia n c o ho rt study: triple c o mb ina tio n the ra py vs. no the ra py – HR=0.29 (0.13-0.67) (De Martino e t al. 2000)

PACT G 219 study: c o mb ina tio n the ra py with PI vs. the ra py witho ut PI – HR=0.33 (0.19-0.58) (Go rtmake r e t al. 2000)

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SLIDE 6

Ne e d to Re -E va lua te E ffe c t o f HAART

  • n Mo rta lity

Pre vio us studie s e nde d fo llo w-up in 1999:

Use o f ne w a ntire tro vira l drug s ha s inc re a se d

Cha ng e s in initia l HAART re g ime ns o ve r time

Va n Dyke e t a l. JAIDS 2011; 57:165-173

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SLIDE 7

Study q ue stio n

 Wha t is the e ffe c t o f HAART

  • n mo rtality a mo ng

pe rina ta lly HI V-infe c te d c hildre n?

 I

s this a g o o d study q ue stio n?

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SLIDE 8

F

  • rmula tio n o f a we ll-de fine d study q ue stio n

 We ll-de fine d c a usa l infe re nc e q ue stio ns c a n b e ma ppe d

into a ta rg e t tria l

 Ca se e xa mple : Wha t is the e ffe c t o f initiating HAART

  • n

mo rta lity a mo ng pe rina ta lly HI V-infe c te d c hildre n?

 Spe c ify the pro to c o l o f the ta rg e t tria l inc luding :  E

lig ib ility c rite ria

 T

re a tme nt stra te g ie s

 Ra ndo mize d tre a tme nt a ssig nme nt  F

  • llo w-up pe rio d

 Outc o me  Ca usa l c o ntra st o f inte re st  Ana lysis Pla n

He rna n, Ro b ins Am J E pid e mio l. 2016;183(8):758–764

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SLIDE 9

Pe dia tric AI DS Clinic a l T ria ls Gro up (PACT G) Pro to c o ls 219 & 219C

 Pro spe c tive c o ho rt studie s o f HI

V-e xpo se d c hildre n (infe c te d a nd uninfe c te d) fro m mo re tha n 80 study site s in the US

 Asse ss the lo ng -te rm e ffe c ts o f HI

V infe c tio n a nd in- ute ro a nd po stna ta l e xpo sure to a ntire tro vira l the ra py

 PACT

G 219: April 1993-Se pte mb e r 2000

 PACT

G 219C: Se pte mb e r 2000-2006

 E

xte nsive c linic a l, ne uro psyc ho lo g ic a l, a nd la b o ra to ry e va lua tio ns

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SLIDE 10

Study Po pula tio n, E xpo sure , F

  • llo w-up

 1,236 pe rina ta lly HI

V-infe c te d c hildre n e nro lle d in PACT G 219 a nd 219C b e twe e n Ja nua ry 1, 1996 a nd June 30, 2006

 E

xc lude s tho se with pre vio us o r c urre nt use o f HAART a t time o f study e ntry

 HAART

de fine d a s the use o f a t le a st 3 drug s fro m a t le a st 2 diffe re nt c la sse s o f HI V the ra py (NRT I s, NNRT I s, o r PI s)

 Onc e sub je c ts initia te d HAART

the y we re a ssume d to re ma in o n HAART fo r the dura tio n o f the ir fo llo w-up

 F

  • llo w-up fo r a ma ximum o f te n ye a rs to the la st visit a t

whic h sub je c t wa s se e n a live o r the la st visit b e fo re June 30, 2006 (i.e . “c o mple tio n o f study”)

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SLIDE 11

Cla ssific a tio n o f tre a tme nt stra te g ie s a c c o rding to the ir time c o urse

 Point inte rve ntio ns

 I

nte rve ntio n o c c urs a t a sing le time

 E

xa mple s: o ne -do se va c c ina tio n, sho rt-live d tra uma tic e ve nt, surg e ry…

 I

nte ntio n-to -tre a t e ffe c ts in RCT s a re a b o ut po int inte rve ntio ns

 Sustaine d stra te g ie s

 I

nte rve ntio ns o c c ur a t se ve ra l time s

 E

xa mple s: me dic a l tre a tme nts, life style , e nviro nme nta l e xpo sure s…

 Ma ny (mo st? ) q ue stio ns a re a b o ut susta ine d e xpo sure s

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SLIDE 12

Cla ssific a tio n o f susta ine d tre a tme nt stra te g ie s

 Static  a fixe d str

ate gy for e ve r yone

 E

xample : tr e at with 150mg of daily aspir in dur ing 5 ye ar s

 Case e xample : initiate HAART  Dyna mic  a stra te g y tha t a ssig ns diffe re nt va lue s to diffe re nt

individua ls a s a func tio n o f the ir e vo lving c ha ra c te ristic s

 E

xa mple : sta rt a spirin tre a tme nt if c o ro na ry he a rt dise a se , sto p if stro ke

 Ca se e xa mple : initia te HAART

if CD4 dro ps b e lo w 500 c e lls/ mm3

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SLIDE 13

Ra ndo mize d tre a tme nt a ssig nme nt

 Ca usa l infe re nc e me tho ds a re me tho ds tha t e mula te

ra ndo miza tio n

 Why is ra ndo miza tio n impo rta nt?

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SLIDE 14

De finitio n o f a n a ve ra g e c a usa l e ffe c t

l

 E

a c h pe rso n ha s two c o unte rfa c tua l o utc o me s:

 Outc o me Y if tre a te d - Yi, a=1  Outc o me Y if untre a te d – Yi, a=0

 I

ndividua l c a usa l e ffe c t:

 Yi, a=1 ≠ Yi, a=0  Ca nno t b e de te rmine d e xc e pt unde r e xtre me ly stro ng

a ssumptio ns

 Ave ra g e (po pula tio n) c a usa l e ffe c t:

 E

[Ya=1 = 1] ≠ E [Ya=0 = 1]

 Ca n b e e stima te d unde r:  No a ssumptio ns (ide a l ra ndo mize d e xpe rime nts)  Stro ng a ssumptio ns (o b se rva tio na l studie s)

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SLIDE 15

Ca usa tio n ve rsus Asso c ia tio n

Pr[Ya=0=1] Pr[Ya=1=1] Pr[Y=1|A=0] Pr[Y=1|A=1]

l

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SLIDE 16

Ca usa tio n ve rsus Asso c ia tio n

 Pr[Ya=1]

 pro po rtio n o f sub je c ts tha t wo uld ha ve de ve lo pe d the

  • utc o me Y ha d a ll sub je c ts in the po pula tio n re c e ive d

e xpo sure va lue a

 (Co unte rfa c tua l) risk o f Ya  Unc o nditio na l o f ma rg ina l pro b a b ility – “c a lc ula te d” using

da ta fro m the who le po pula tio n

 Ca usa tio n: Pr[Ya=1=1] ≠ Pr[Ya=0 = 1]

 Pr[Y=1|A=a]

 Pro po rtio n o f sub je c ts tha t de ve lo pe d o utc o me Y a mo ng

tho se tha t re c e ive d e xpo sure va lue a in the po pula tio n

 Risk o f Y a mo ng tho se e xpo se d/ une xpo se d  Co nditio na l pro b a b ility – c a lc ula te d b y using da ta fro m a

sub se t o f the po pula tio n

 Asso c ia tio n: Pr[Y=1|A=1] ≠ Pr[Y=1|A=0]

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SLIDE 17

I de a l Ra ndo mize d E xpe rime nt

 L

a rg e (ne a r-infinite ) po pula tio n

 No lo ss to fo llo w-up  F

ull c o mplia nc e (a dhe re nc e ) to a ssig ne d e xpo sure o r tre a tme nt

 Do ub le b lind a ssig nme nt

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SLIDE 18

Ra ndo miza tio n (I )

 Assume two e xpo sure g ro ups (tre a te d a nd untre a te d)  Me mb e rship in e a c h g ro up is ra ndo mly a ssig ne d

 e .g ., b y a flip o f a c o in

 F

irst o ptio n:

 T

re a t sub je c ts in g ro up 1, do n’ t tre a t sub je c ts in g ro up 2

 Pr[Y=1|A=1] is, sa y, 0.57

 Se c o nd o ptio n:

 T

re a t sub je c ts in g ro up 2, do n’ t tre a t sub je c ts in g ro up 1

 Wha t is the risk? Pr[Y=1|A=1] is ?

0.57

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SLIDE 19

Ra ndo miza tio n (I I )

 Whe n g ro up me mb e rship is ra ndo mly a ssig ne d, risks a re

the sa me

 Bo th g ro ups a re c o mpa ra b le o r e xc hange able  E

xc ha ng e a b ility is the c o nse q ue nc e o f ra ndo miza tio n

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SLIDE 20

E xc ha ng e a b ility

 Sub je c ts in g ro up 1 wo uld ha ve ha d the sa me risk a s

tho se in g ro up 2 ha d the y re c e ive d the tre a tme nt o f tho se in g ro up 2

 T

he c o unte rfa c tua l risk a mo ng the tre a te d e q ua ls the c o unte rfa c tua l risk a mo ng the untre a te d unde r the sa me e xpo sure le ve l

 Pr[Ya=1|A=1] = Pr[Ya=1|A=0] A Ya Ya A  I

mplie s la c k o f c o nfo unding

 

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SLIDE 21

I n ide a l ra ndo mize d e xpe rime nts

 Pr[Y=1|A=1] is e q ua l to Pr[Ya=1=1]  Pr[Y=1|A=0] is e q ua l to Pr[Ya=0=1]

 T

he re fo re the a sso c ia tio na l risk ra tio

 Pr[Y=1|A=1]/ Pr[Y=1|A=0]

is e q ua l to the c a usa l risk ra tio

 Pr[Ya=1=1]/ Pr[Ya=0=1]

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SLIDE 22

Why is Pr[Y=1/ A=1] is e q ua l to Pr[Ya=1=1]

 A two ste p pro o f:

1. Pr[Y=1|A=1] = Pr[Ya=1=1|A=1]

b y de finitio n o f a c o unte rfa c tua l va ria b le (i.e ., c o nsiste nc y)

2. Pr[Ya=1=1|A=1] = Pr[Ya=1=1|A=0] = Pr[Ya=1=1]

b y ra ndo miza tio n – (i.e ., e xc ha ng e a b ility)

Ste p 2 no t g e ne ra lly true in the a b se nc e o f ra ndo miza tio n

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SLIDE 23

I n a n ide a l ra ndo mize d e xpe rime nt

 Asso c ia tio n is c a usa tio n

 Be c a use ra ndo miza tio n pro duc e d e xc ha ng e a b ility

 We ha ve a me tho d fo r c a usa l infe re nc e !

 No ne e d fo r a djustme nts o f a ny so rt  Assumptio n-fre e !

….Ho we ve r, re a l ra ndo mize d e xpe rime nts a re no t ide a l ra ndo mize d e xpe rime nts….No c le a r-c ut se pa ra tio n b e twe e n re a l ra ndo mize d e xpe rime nts a nd

  • b se rva tio na l studie s…
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SLIDE 24

De a d e nd?

 E

xc ha ng e a b ility (a c o nse q ue nc e o f ra ndo miza tio n) is a c o nditio n fo r c a usa l infe re nc e

 E

xc ha ng e a b ility is no t g e ne ra lly a n a c c e pta b le a ssumptio n in o b se rva tio na l studie s

 E

xpo se d a nd une xpo se d g e ne ra lly no t c o mpa ra b le

 I

ndividua ls who re c e ive a he a rt tra nspla nt ma y ha ve mo re se ve re dise a se

 Ca se e xa mple : c hildre n who initia te HAART

ma y ha ve mo re se ve re dise a se tha n tho se who do n’ t (i.e ., c o nfo unding b y indic a tio n)

 A c o nditio n we a ke r tha n e xc ha ng e a b ility is ne e de d fo r

c a usa l infe re nc e fro m o b se rva tio na l da ta

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SLIDE 25

Ho pe

 Co nside r o nly individua ls with the sa me pre -e xpo sure

pro g no stic fa c to rs

 T

he n the e xpo se d a nd une xpo se d ma y b e e xc ha ng e a b le

 e .g ., a mo ng individua ls with a n e je c tio n fra c tio n o f 10%,

tho se who do a nd do no t re c e ive a he a rt tra nspla nt ma y b e c o mpa ra b le

 e .g ., a mo ng individua ls with CD4 c o unt <100, tho se who do

a nd do no t re c e ive a ntire tro vira l the ra py ma y b e c o mpa ra b le

 T

his is o fte n re a so na b le

 E

spe c ia lly if c o nditio ning o n ma ny pre -e xpo sure c o va ria te s L

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SLIDE 26

Co nditio na l E xc ha ng e a b ility

 Within le ve ls o f the c o va ria te s, L

, e xpo se d sub je c ts wo uld ha ve ha d the sa me risk a s une xpo se d sub je c ts ha d the y b e e n une xpo se d, a nd vic e ve rsa

 Co unte rfa c tua l risk is the sa me in the e xpo se d a nd the

une xpo se d with the sa me le ve l o f L

 Pr[Ya=1|A=1, L

=l] = Pr[Ya=1|A=0, L =l] A Ya|L =l Ya A|L =l

 E

q uiva le nt to ra ndo miza tio n within le ve ls o f L

 I

mplie s no unme a sure d (re sidua l) c o nfo unding within le ve ls o f the me a sure d c o va ria te s L

 

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SLIDE 27

I n a n o b se rva tio na l study

 Asso c ia tio n is c a usa tio n within le ve ls o f the c o va ria te s

 Unde r the assumption o f c o nditio na l e xc ha ng e a b ility

 We ha ve a me tho d fo r c a usa l infe re nc e fro m

  • b se rva tio na l da ta tha t is no t a ssumptio n-fre e

 But the ne e d to re ly o n this a ssumptio n is no t T

HE pro b le m

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SLIDE 28

T HE pro b le m

 T

he a ssumptio n o f c o nditio na l e xc ha ng e a b ility is

unte stable

 E

ve n if the re is c o nditio na l e xc ha ng e a b ility, the re is no wa y we c a n kno w it with c e rta inty

 T

his is why c a usa l infe re nc e fro m o b se rva tio na l da ta is c o ntro ve rsia l

 We c a n use e xpe rt kno wle dg e to e nha nc e pla usib ility o f the

a ssumptio n

 Me a sure a s ma ny re le va nt pre -e xpo sure c o va ria te s a s

po ssib le

 Ca n o nly ho pe tha t the a ssumptio n is a ppro xima te ly true

(i.e ., the re ma y b e c o nfo unding due to unme a sure d fa c to rs)

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SLIDE 29

Me tho ds to c o mpute c a usa l e ffe c ts

 Stra tific a tio n  Re g re ssio n  Ma tc hing  Sta nda rdiza tio n  I

nve rse pro b a b ility we ig hting AL L a ssuming c o nditio na l e xc ha ng e a b ility

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SLIDE 30

Cho ic e o f me tho d de pe nds o n type o f stra te g ie s

 Co mpa riso n o f stra te g ie s invo lving po int inte rve ntio ns

  • nly

 All me tho ds wo rk  if a ll b a se line c o nfo unde rs a re me a sure d  Co mpa riso n o f susta ine d stra te g ie s  Ge ne ra lly o nly c a usa l infe re nc e me tho ds wo rk  T

ime -va rying tre a tme nts imply time -va rying c o nfo unde rs

 po ssib le tre a tme nt-c o nfo unde r fe e db a c k  Co nve ntio na l me tho ds ma y intro duc e b ia s e ve n whe n

suffic ie nt da ta a re a va ila b le o n time -va rying tre a tme nts a nd time -va rying c o nfo unde rs

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SLIDE 31

Ca se e xa mple : HAART initia tio n o ve r time

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SLIDE 32

Ca se E xa mple : Dire c te d Ac yc lic Gra ph

Whe re L i = c o nfo und e r (CD4, vira l lo a d , e tc ) info rma tio n a t time i, Ai = tre a tme nt (HAART ) info rma tio n a t time i, a nd Y = o utc o me (mo rta lity) info rma tio n a t time i. U = unme a sure d c o va ria te

L0 A0 L1 A1 Y U

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SLIDE 33

Pro b le m with Stra tifie d Ana lytic Appro a c h

L A0 L

1

A1 Y1

U

 Inte re ste d in the c umula tive e ffe c t o f tre a tme nt.  L 1 is a c o nfo unde r fo r the tre a tme nt A1 – if do n’ t a djust fo r it the n tre a tme nt

e ffe c t is c o nfo unde d.

 Also c o uld induc e se le c tio n b ia s (c o llide r).  L 1 is a ffe c te d b y A0 – if a djust fo r L 1 the n lo sing so me o f the e ffe c t o f A0.

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SLIDE 34

I nve rse pro b a b ility we ig hting

 YOU will c o mpute the c a usa l risk ra tio using

inve rse pro b a b ility we ig hting (I PW) in a n

  • b se rva tio na l study

 i.e ., yo u will c o mpute Pr[Ya=1=1]/ Pr[Ya=0=1]

unde r c o nditio na l e xc ha ng e a b ility

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SLIDE 35

A simplifie d o b se rva tio na l study

 500 HI

V-infe c te d a dults

 Va ria b le s:

 L

=1: CD4 c e ll c o unt <200 c e lls/ mm 3

 A=1: o n hig hly a c tive a ntire tro vira l the ra py (HAART

)

 Y=1: AI

DS

 T

re a tme nt sta tus is de c ide d a fte r lo o king a t CD4 c e ll c o unt

 No lo ss to fo llo w-up

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SLIDE 36

T he da ta summa rize d in a ta b le

L =0 L =1 Y=1 Y=0 Y=1 Y=0 A=1 15 35 144 216 A=0 30 20 32 8

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SLIDE 37

T he da ta summa rize d in a tre e

32 30 35 15 8 20 216 144 50

L =1: CD4 c e ll c o unt <200 c e lls/ mm3

A=1: o n HAART

Y=1: AI DS

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SLIDE 38

Yo ur g o a l

 T

  • c o mpute the e ffe c t o f HAART
  • n the risk o f AI

DS o n the c a usa l risk ra tio sc a le

 Pr[Ya=1=1]/ Pr[Ya=0=1]  Assuming c o nditio na l e xc ha ng e a b ility within le ve ls o f L

 F

irst, c o mpute Pr[Ya=0=1]

 Se c o nd, c o mpute Pr[Ya=1=1]

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SLIDE 39

Orig ina l da ta

32 30 35 15 8 20 216 144 50

L =1: CD4 c e ll c o unt <200 c e lls/ mm3

A=1: o n HAART

Y=1: AI DS

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SLIDE 40

Da ta ha d e ve ryo ne b e e n untre a te d

320 60 80 40

L =1: CD4 c e ll c o unt <200 c e lls/ mm3

A=1: o n HAART

Y=1: AI DS

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SLIDE 41

Da ta ha d e ve ryo ne b e e n tre a te d

70 30 240 160 100

L =1: CD4 c e ll c o unt <200 c e lls/ mm3

A=1: o n HAART

Y=1: AI DS

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SLIDE 42

320 60 70 30 80 40 240 160 100

W=1/f[A|L]

1/.5=2 1/.5=2 1/.5=2 1/.5=2 1/.1=10 1/.1=10 1/.9=1.11 1/.9=1.11

Da ta ha d e ve ryo ne b e e n tre a te d a nd untre a te d

Pseudopopulation

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SLIDE 43

Pse udo po pula tio n da ta a na lysis

Ya=1 Ya=0 a =1 a =0 190 380 310 120

 Pr[Ya=1=1] = 190/ (190+310) = 0.38  Pr[Ya=0=1] = 380/ (380+120) = 0.76  Ca usa l risk ra tio = 0.38/ 0.76 = 0.5  YOU DI

D I T ! Co mpute d the c a usa l risk ra tio using I PW

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SLIDE 44

Whic h a ssumptio n a re yo u ma king ?

Ya A|L =l

 Co nditio na l e xc ha ng e a b ility in the po pula tio n

 E

xpo sure is ra ndo mize d within le ve ls o f L

 No unme a sure d c o nfo unding within le ve ls o f the me a sure d

va ria b le L

 Within le ve ls o f L

, the risk a mo ng the e xpo se d if the y we re une xpo se d is the sa me a s the risk a mo ng the une xpo se d in the po pula tio n

 a nd vic e ve rsa

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SLIDE 45

Unde r c o nditio na l e xc ha ng e a b ility

 T

he o b se rva tio na l study in the o rig ina l po pula tio n is a ra ndo mize d e xpe rime nt within le ve ls o f L

 T

he study in the pse udo po pula tio n c re a te d b y I PW is a ra ndo mize d e xpe rime nt

 E

xpo se d a nd une xpo se d sub je c ts a re (unc o nditio na lly) e xc ha ng e a b le b e c a use the y a re the sa me individua ls

 E

xpo sure is ra ndo mize d (i.e . e q ua lly pro b a b le a c ro ss le ve ls o f the c o va ria te L )

 T

he re is no c o nfo unding

 I

n the pse udo po pula tio n, c a usa l e ffe c ts c a n b e e stima te d a s in a ra ndo mize d e xpe rime nt

 No ne e d fo r a djustme nt o f a ny so rt

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SLIDE 46

Dire c te d Ac yc lic Gra ph in Pse udo po pula tio n

L0 A0 L1 A1 Y U

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SLIDE 47

Use o f mo de ls fo r I PW

 Re a lity is we de a l with hig h-dime nsio na l da ta with

multiple c o va ria te s (L s), so me with multiple le ve ls

 Ca nno t o b ta in me a ning ful no n-pa ra me tric e stima te s o f the

we ig hts

 Mo de l the pro b a b ility o f e xpo sure with L

s a s the c o va ria te s

 So me individua ls ma y c o ntrib ute a re a lly hig h we ig ht due

to the ir a re la tive ly sma ll pro b a b ility o f ha ving the e xpo sure the y ha d g ive n the ir c o va ria te histo ry

 Sta b ilize the we ig hts b y using the pro b a b ility o f tre a tme nt in

the nume ra to r

 Apply sta b ilize d we ig hts (SW) to e stima te the pa ra me te rs o f

a ma rg ina l struc tura l mo de l

 re duc e va ria nc e in mo de l fo r the o utc o me

slide-48
SLIDE 48

Sta b ilize d I nve rse Pro b a b ility o f T re a tme nt We ig hts

 Nume ra to r: T

he pro b a b ility tha t the sub je c t re c e ive d his/ he r o b se rve d tre a tme nt a t we e k k, c o nditio na l o n pa st tre a tme nt histo ry a nd b a se line c o va ria te s.

 De no mina to r: T

he pro b a b ility tha t the sub je c t re c e ive d his/ he r o wn o b se rve d tre a tme nt a t we e k k, g ive n pa st tre a tme nt histo ry a nd c o va ria te histo ry (b a se line a nd time -de pe nde nt).

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SLIDE 49

Dire c te d Ac yc lic Gra ph in Pse udo po pula tio n with SW

V A0 L1 A1 Y U

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SLIDE 50

E stima ting I PW a nd fitting the MSM

 E

stima te SW fo r b o th tre a tme nt a nd c e nso ring :

 F

it lo g istic re g re ssio n mo de ls fo r tre a tme nt a nd c e nso ring

 Use pre dic te d va lue s fro m the mo de ls to c a lc ula te sta b ilize d

we ig hts

 E

stima te the I PW e stima te o f HAART

  • n mo rta lity:

 F

it we ig hte d po o le d lo g istic mo de l using the e stima te d sta b ilize d we ig hts.

 Use “ro b ust” va ria nc e e stima to rs (GE

E ) to a llo w fo r c o rre la te d o b se rva tio ns c re a te d b y we ig hting – c o nse rva tive 95% CI .

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SLIDE 51

Ca se E xa mple : Co nfo unde rs

  • Ag e
  • Se x
  • Ra c e / E

thnic ity

  • We e k o f F
  • llo w-up
  • Ca le nda r Ye a r
  • CDC Clinic a l Ca te g o ry
  • CD4%
  • T
  • ta l lympho c yte c o unt
  • White b lo o d c e ll c o unt
  • He ma to c rit
  • Alb umin
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SLIDE 52

SAS Co de fo r E stima ting Nume ra to r a nd De no mina to r fo r T re a tme nt I PW

slide-53
SLIDE 53

SAS Co de fo r E stima ting Nume ra to r a nd De no mina to r fo r Ce nso ring I PW

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SLIDE 54

SAS Co de fo r Ca lc ula ting I PW a nd sta b ilize d I PW (1)

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SLIDE 55

E xa mple Da ta

k1_0 phrt_0 k1_w phrt_w k2_0 punc_0 k2_w punc_w IPTWnum TrtPredictNum IPTWden TrtPredictDen IPCWnum CensPredictNum IPCWden CensPredictDen 49360 0.96375 0.96375 0.9658 0.9658 0.98868 0.98868 0.97466 0.97466 49360 13 0.92911 0.96406 0.93651 0.96967 0.97643 0.98761 0.95619 0.98105 49360 26 0.89599 0.96436 0.90843 0.97002 0.96318 0.98643 0.93807 0.98105 49360 39 0.86433 0.96466 0.8815 0.97036 0.94888 0.98515 0.9203 0.98105 49360 52 0.83404 0.96496 0.85273 0.96735 0.93346 0.98375 0.89698 0.97466 49360 65 1 0.02898 0.96525 0.03368 0.96051 0.92481 0.99074 0.87097 0.97101 49360 78 1 0.02898 . 0.03368 . 0.91543 0.98986 0.84129 0.96592 49360 91 1 0.02898 . 0.03368 . 0.90526 0.98889 0.81261 0.96592 49360 104 1 0.02898 . 0.03368 . 0.89426 0.98784 0.77494 0.95364 49360 117 1 0.02898 . 0.03368 . 0.88235 0.98669 0.73902 0.95364 49360 130 1 0.02898 . 0.03368 . 0.8695 0.98543 0.71683 0.96997 49360 143 1 0.02898 . 0.03368 . 0.85564 0.98406 0.6836 0.95364 49360 156 1 0.02898 . 0.03368 . 0.84071 0.98255 0.65191 0.95364 49360 169 1 0.02898 . 0.03368 . 0.82466 0.98091 0.62169 0.95364 49360 182 1 0.02898 . 0.03368 . 0.80743 0.97912 0.59287 0.95364 49360 195 1 0.02898 . 0.03368 . 0.78899 0.97716 0.56539 0.95364 49360 208 1 0.02898 . 0.03368 . 0.76928 0.97502 0.53918 0.95364 49360 221 1 0.02898 . 0.03368 . 0.74827 0.97269 0.48733 0.90384 49360 234 1 0.02898 . 0.03368 . 0.72593 0.97015 0.45571 0.93512 49360 247 1 0.02898 . 0.03368 . 0.70225 0.96737 0.43398 0.95232 49360 260 1 0.02898 . 0.03368 . 0.67722 0.96436 0.41329 0.95232 49360 273 1 0.02898 . 0.03368 . 0.65085 0.96107 0.3863 0.93471 49360 286 1 0.02898 . 0.03368 . 0.62318 0.95749 0.35013 0.90637 49360 299 1 0.02898 . 0.03368 . 0.59427 0.9536 0.32502 0.92826 49360 312 1 0.02898 . 0.03368 . 0.56418 0.94937 0.3017 0.92826 49360 325 1 0.02898 . 0.03368 . 0.53303 0.94478 0.28005 0.92826 49360 338 1 1 0.02898 . 0.03368 . 0.50095 0.9398 0.26063 0.93063 Patid Week HAART Censored

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SLIDE 56

E xa mple da ta wo rkshe e t

k1_0 phrt_0 k1_w phrt_w k2_0 punc_0 k2_w punc_w IPTWnum TrtPredictNum IPTWden TrtPredictDen IPCWnum CensPredictNum IPCWden CensPredictDen 49488 0.96972 0.96972 0.97553 0.97553 0.98239 0.98239 0.94649 0.94649 49488 13 0.9406 0.96998 0.9557 0.97967 0.96347 0.98074 0.9094 0.96081 49488 26 1 0.028 0.97023 0.02285 0.97609 0.95287 0.989 0.85239 0.93731 49488 39 1 0.028 . 0.02285 . 0.9414 0.98796 0.79402 0.93153 49488 52 1 0.028 . 0.02285 . 0.92899 0.98682 0.74591 0.93941 49488 65 1 0.028 . 0.02285 . 0.91559 0.98557 0.69915 0.93731 49488 78 1 0.028 . 0.02285 . 0.90113 0.98421 0.65532 0.93731 49488 91 1 1 0.028 . 0.02285 . 0.88556 0.98272 0.6145 0.93771 Patid Week HAART Censored

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SLIDE 57

E xa mple da ta wo rkshe e t – c a lc ula te SW

k1_0 k1_w k2_0 k2_w Stabilized IPTWnum IPTWden IPCWnum IPCWden Weight 49488 0.96972 0.97553 0.98239 0.94649 1.03175 49488 13 0.9406 0.9557 0.96347 0.9094 1.04272 49488 26 0.028 0.02285 0.95287 0.85239 1.37007 49488 39 0.028 0.02285 0.9414 0.79402 1.45308 49488 52 0.028 0.02285 0.92899 0.74591 1.52641 49488 65 0.028 0.02285 0.91559 0.69915 1.605 49488 78 0.028 0.02285 0.90113 0.65532 1.68531 49488 91 0.028 0.02285 0.88556 0.6145 1.76621 Patid Week

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SLIDE 58

SAS Co de fo r F ina l MSM

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SLIDE 59

E stima te d E ffe c t o f HAART

  • n Mo rta lity fro m

Unwe ig hte d (Sta nda rd) a nd We ig hte d Mo de ls

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Unweighted model, no covariates Unweighted model, baseline covariates Weighted model, baseline covariates Unweighted model, baseline and time-dependent covariates Hazard ratio (95% CI)

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SLIDE 60

Assumptio ns fo r I PW e stima tio n o f a MSM

 Co nditio na l e xc ha ng e a b ility within le ve ls o f me a sure d

c o va ria te s

 Una b le to a djust fo r HI

V-1 vira l lo a d

 Use d to g uide de c isio ns a b o ut whe n to initia te HAART

in re c e nt ye a rs a nd is a sso c ia te d with mo rta lity

 Re po rte d HR like ly to b e unde re stima te d

 Co rre c t mo de l spe c ific a tio n fo r a ll mo de ls to e stima te

we ig hts a nd fina l MSM

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SLIDE 61

Co nc lusio ns

 L

  • ng -te rm HAART

use (> 5 ye a rs) is a sso c ia te d with sig nific a ntly lo we r mo rta lity a mo ng c hildre n a nd a do le sc e nts infe c te d with HI V-1 c o mpa re d to no n-HAART use .

 Suppo rt c urre nt US pe dia tric g uide line s  Re sults c o mpa ra b le to a dult RCT

a nd pre vio us pe dia tric

  • b se rva tio na l studie s

 Suppo rt e xpa nde d de live ry o f c a re to HI

V-infe c te d c hildre n g lo b a lly

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SLIDE 62

Co nc lusio ns

 Co ntinue d fo llo w-up is ne e de d a s this po pula tio n a g e s

a nd ma ture s with the use o f HAART

 Ne e d to e stima te the e ffe c ts o f pro lo ng e d use o f HAART

  • n

immune func tio n, g ro wth, se xua l ma tura tio n, a nd q ua lity o f life pa ra me te rs

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SLIDE 63

Ac kno wle dg e me nts

 Childre n a nd F

a milie s o f PACT G 219/ 219C

 PACT

G 219/ 219C T e a m a nd Pa rtic ipa ting I nstitutio ns

 F

unde d b y NI AI D, NI CHD

 Suppo rte d b y the Sta tistic a l a nd Da ta Ana lysis Ce nte r

(SDAC) o f the PACT G unde r the NI AI D c o o pe ra tive a g re e me nt No . 5 U01 AI 141110

 T

32 HI V/ AI DS T ra ining Gra nt