The Costs and The Costs and Consequences of HIV/AIDS Consequences of HIV/AIDS

InterventionsInterventions

Damien de WalqueDamien de Walque

Development Research Group Development Research Group (DECRG)(DECRG)

The World BankThe World Bank

December 1December 1stst, 2005, 2005

Cost-benefit analysis?Cost-benefit analysis?

Yes, but…Yes, but… What do we mean by costs?What do we mean by costs? What do we mean by benefits?What do we mean by benefits?

The value added of merging biomedical The value added of merging biomedical and socio-economic data…and socio-economic data…

Examples from HIV prevention and anti-Examples from HIV prevention and anti-retroviral treatment (ART)retroviral treatment (ART)

Prevention: Information campaignsPrevention: Information campaigns

HIV Prevalence for individuals aged 18 to 29: MRC General Population Cohort, Rounds 1 -12 (1990-2001). (Source: De Walque, 2004)

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

1 2 3 4 5 6 7 8 9 10 11 12

Rounds

HIV

pre

vale

nce

in %

HIV prevalence is declining in HIV prevalence is declining in UgandaUganda

Due to behavioral changes or Due to behavioral changes or mortality?mortality?

Due to information campaigns?Due to information campaigns?

Which segment of the population is Which segment of the population is driving it?driving it?

Looking at response by education Looking at response by education HIV prevalence by education category, MRC General Population Cohort, Rural Uganda,

1990-2001. Individuals aged 18-29

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

1 2 3 4 5 6 7 8 9 10 11 12

Rounds

HIV

pre

vale

nce

No education Primary Secondary

Source: De Walque, 2004Source: De Walque, 2004

What do we learn by looking at What do we learn by looking at socio-economic variables?socio-economic variables?

- behavioral changes- behavioral changes

- education facilitates response to - education facilitates response to informationinformation

- need other approaches to target - need other approaches to target less educated group.less educated group.

Anti-retroviral treatment (ART)Anti-retroviral treatment (ART)

What is the benefit of ART? Example in What is the benefit of ART? Example in Kenya. Kenya. (from Goldstein, (from Goldstein, Graff Zivin and Thirumurthy Graff Zivin and Thirumurthy 2005)2005)

- Life saved, quality of life. Fewer orphans.Life saved, quality of life. Fewer orphans.

- In addition: labor force participation, In addition: labor force participation, children going back to school, less child children going back to school, less child laborlabor

CD4 Counts before and after CD4 Counts before and after treatmenttreatment

50

10

01

50

20

02

50

30

0M

ed

ian

CD

4 c

ou

nt

-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90Weeks Before/After ARV Initiation

Source: Goldstein, Graff Zivin and Thirumurthy 2005

Body Mass Index before and after Body Mass Index before and after treatmenttreatment

19

20

21

22

Me

dia

n B

MI

-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90Weeks Before/After ARV Initiation

Source: Goldstein, Graff Zivin and Thirumurthy 2005

Labor force participation before and Labor force participation before and after treatmentafter treatment

.6.7

.8.9

Fra

ction p

art

icip

ating in labor

forc

e

-8 0 8 16 24 32 40 48 56Weeks on ARVs

Source: Goldstein, Graff Zivin and Thirumurthy 2005

What are the consequences of What are the consequences of anti-retroviral treatmentanti-retroviral treatment

individual benefits and costsindividual benefits and costs benefits and costs at the household benefits and costs at the household

and extended family leveland extended family level

Also look at the impact of treatment on Also look at the impact of treatment on the dynamics of the epidemicthe dynamics of the epidemic

( spillovers: social benefit and cost)( spillovers: social benefit and cost)

Possible effects of ART on HIV Possible effects of ART on HIV transmission transmission

From: M. Over, et al. (2004)From: M. Over, et al. (2004)

Direction of effect

Beneficial(Slow transmission)

Adverse(Speed transmission)

Type of effect

Biological

Reduce infectiousness Select for resistance.

Longer duration of infectivity

Behavioral

Encourage prevention,especially testing

Off-setting behavior

““Hypothetical AIDS Transition”Hypothetical AIDS Transition”

Rate per 1000 people

Time

New infections

AIDS Deaths

“Explosion of ART patients”

Rate of growth of people living with HIV/AIDS

Source: Over (2004)

Transition might fail either because Transition might fail either because treatment stops working …treatment stops working …

AIDS Deaths Rate of growth of people

living with HIV/AIDS

Rate per 1000 people

Time

New infections

“Boom” of ART patients

Source: Over (2004)

… … or because the rate of new infections or because the rate of new infections never declines.never declines.

Rate of growth of people living with HIV/AIDS

Rate per 1000 people

Time

New infections

AIDS Deaths

“Explosion of ART patients”

Source: Over (2004)

If ART engenders complacency, the number If ART engenders complacency, the number of new infections might increase.of new infections might increase.

“Explosion of ART patients”

Rate of growth of people living with HIV/AIDS

Rate per 1000 people

Time

New infections

AIDS Deaths

Source: Over (2004)

How to maximize benefits and How to maximize benefits and minimize adverse effects?minimize adverse effects?

Need to learn as we scale-up ART Need to learn as we scale-up ART (example TAP learning agenda)(example TAP learning agenda)

Measure:Measure:

- private benefits and costs- private benefits and costs

- biological effects, including - biological effects, including resistance. Role of quality of service resistance. Role of quality of service provision and adherence.provision and adherence.

-- behavioral effectsbehavioral effects

How to sustain ART in the long run?How to sustain ART in the long run?

Example: ThailandExample: Thailand Total Cost of Public ART (NAPHA)

$0

$50

$100

$150

$200

$250

$300

$350

$400

$450

$500

20

00

20

01

20

02

20

03

20

04

20

05

20

06

20

07

20

08

20

09

20

10

20

11

20

12

20

13

20

14

20

15

20

16

20

17

20

18

20

19

20

20

20

21

20

22

20

23

20

24

20

25

Millions

Cost of Public ART_1 line_asy Cost of Public ART_1 line_sym

Cost of Public ART_2 line_asy Cost of Public ART_2 line_sym

Source: Revenga et al, Forthcoming

Treatment in the long run?Treatment in the long run?

The greater the success of The greater the success of treatment, the more patients treatment, the more patients

Second line therapy is much more Second line therapy is much more expensive. expensive.

Adherence crucial: role of health Adherence crucial: role of health infrastructure and staffinfrastructure and staff

Still…Still… Prevention, prevention, prevention!Prevention, prevention, prevention!

Impact of condom use on the Impact of condom use on the number of new HIV infections in India number of new HIV infections in India

(Over et al. 2004)(Over et al. 2004)

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

1995 2000 2005 2010 2015 2020 2025 2030 2035

Year

Nu

mb

er

of

HIV

in

fecti

on

s p

er

ye

ar

40% condom 50% condom 70% condom 90% condom

ConclusionsConclusions

Socio-economic variables together Socio-economic variables together with biomedical datawith biomedical data

Treatment AND PreventionTreatment AND Prevention - Organize ART so that prevention is - Organize ART so that prevention is

reinforcedreinforced - Focus prevention efforts so that - Focus prevention efforts so that

ART is sustainableART is sustainable