Social Disparities and Mortality in a Large

Metropolitan HIV CohortPeter Messeri1

Mary Ann Chiasson2

1Columbia University, Mailman School of Public Health• 2Public Health Solutions

XIX International AIDS Conference July 23, 2012, Washington, D.C.

Background• Consistent with Fundamental Cause Theory (Link and

Phelan, 1995) it appears that social disparities in health outcomes have accompanied the rapid decline in HIV mortality following the 1996 introduction of HAART.– Some studies, but not all, find that mortality risk has

declined more rapidly among whites than blacks, – Evidence is mixed for presence and direction of gender

differences.– There is minimal evidence regarding more direct measures

of SES, such as income and education.• Firm conclusions about the size and source of disparities

in mortality are difficult to draw because of differences in sample design and statistical methods.

Study Questions

• Now well into the HAART era, how far have we come in reducing excess mortality among HIV infected populations?

• Have social disparities in mortality with respect to gender, race/ethnicity and education emerged during the HAART era?

• Does education mediate possible gender and race/ethnic disparities?

Study Sample• Study data come from three cohorts recruited for the

CHAIN Project. • NYC 1994 cohort

– 700 PLWHA recruited in 1994/1995 from 43 NYC medical care and AIDS Service Organizations.

– I268 additional members recruited in 1998.– Active through 2001

• Tri-County Cohort– 398 PLWHA recruited in 2001/2002 from 28 agencies located in

Westchester, Rockland and Putnam counties .– Active through 2007

• NYC 2002 cohort– 693 PLWHA recruited in 2002/2003 from 34 NYC agencies – Cohort remains active

Data

• Deaths were discovered through routine follow-up and confirmed through periodic check of the SSA online death registry.

• Cause of death for the two NYC cohorts was ascertained through a search of NYC death certificates conducted most recently in October, 2009

• Age, gender race/ethnicity, education and year of initial HIV diagnosis were obtained from baseline interviews.

Statistical Methods1. Estimate trends in annual mortality rate, 1995-20092. Fit hazard model to NYC 1994 cohort to test for

presence of emerging disparities in mortality following introduction of HAART in 1996

3. Combine three CHAIN cohorts to estimate social disparities in mortality during period of well established HAART use (2003 to 2008)

• Estimate excess mortality risk for CHAIN cohort based upon death rates for general NYC population matched on age, gender and race/ethnicity.

• Fit Poisson model to excess mortality to estimate mortality risk ratios attributable to HIV.

CHAIN ParticipantsCohort members alive as of 1/1/2003

1,827

Mean Age 39.4

% Male 63%

Race/Ethnicity Non-Hispanic Blacks Hispanic Non-Hispanic White

53%32%15%

Education Less than H.S. H.S. Beyond H.S.

47%24%29%

Median Year of Initial HIV diagnosis

1993

Reported an MD in charge of HIV medical care

97%

CHAIN participants are predominantly from populations of color, have low educational attainment, but are connected to medical care.

CHAIN Participants

Consistent with education as a potential mediator--minority cohort members completed fewer years of school than whites; males had more schooling than females.

Mortality TrendsAs of 12/31/2009 there were 674 confirmed deaths or 41.6 deaths per 1,000 person years(p.y.),Mortality risk declined sharply between 1995 and 1998 and remained at historical low levels through 2009.

0tan9a56609

0tan29a566029

0tan19a566019

0tan9a56609

0tan29a566029

0tan20a566020

0tan10a566010

Annual Deaths per 1000 Person-Years

NYC 1994 NYC 2002

Tri County

deat

hs/1

000

P.Y.

Cause of DeathDeclining death rates were accompanied by an increasing proportion of non-HIV-related causes of death. For 220 deaths between 2003 and 2008 for which cause could be ascertained , 41% were due to non-HIV causes.

'95-'96 '97-'98 '99-'00 '01-'02 '03-'04 '05-'06 '07-'080tan9a56609

0tan19a566019

0tan29a566029

0tan9a56609

0tan19a566019

0tan29a566029

0tan10a566010

Percent of NYC Deaths Due to HIV-Related Causes

% o

f dea

ths

Excess MortalityDespite the dramatic decline in mortality risk between 2003 and 2008, the CHAIN cohort continued to experience substantial excess mortality relative to the NYC general population. Of 318 deaths for this period, we estimated 249 excess deaths attributable directly or indirectly to HIV disease.

Trends in Social Disparities in Mortality, NYC 1994 Cohort,

Haz

ard

Rat

io

H.R.s adjusted for age and year of HIV diagnosis

Period of Risk:

Excess Mortality Hazard Ratios for Social Disparity Variables, CHAIN Cohort 2003-2008

Haz

ard

Rat

io

HRs adjusted for age , year of HIV diagnosis & cohort

Summary of Findings

• Despite sharp reduction in mortality, substantial excess mortality remains.

• Education was found to be the most robust dimension for social disparities.

• Possible excess mortality greater among males than females

• Education partially mediates race/ethnicity disparities, but not gender differences.

Discussion

• Interpretation of education requires further research– A proxy for SES?– A measure of human capital?

• Excess mortality requires further refinement to better disentangle mortality effects specific to HIV.

• Local demographics of epidemiology and context of health care system matter for nature and size of social disparities.

• Are findings an epitaph for the past or prologue to the future?

Concluding Observation

Further reductions in excess mortality and social disparities must build on existing, and often beleaguered, federal and state programs that ensure access to HIV medications regardless of ability to pay and enhanced with targeted interventions that help the disadvantaged individuals to engage and then stay connected to quality HIV medical care.

Acknowledgements• We thank Alexa Yim for her programming skills, members of the

CHAIN team for their diligence in data collection, and the CHAIN Technical Review Team for helpful comments on earlier versions of this presentation. A special thanks to Bureau of Vital Statistics, NYCDOHMH for their gracious assistance in facilitating timely access to NYC’s death certificate records.

• This research was supported by a grant from the NYC DOHMH as part of its Ryan White CARE Act grant, H89 HA00015, from the Department of Health and Human Services, Health Resources, HIV/AIDS Bureau (HRSA). Conference related expenses were supported by a travel grant from Bristol-Myers Squibb to the AIDS United Positive Charge program.