Dollars and diseaseMarrying social, economic and disease dynamic

perspectives for public health

Nim ArinaminpathyImperial College London

Roles of transmission models in public health

Supporting healthcare delivery

Informing decision-makingBasic science: contributing to evidence base for policy

Careseeking(unmeasured confounders)

Health systems

Macroeconomicshocks

National politics with borderless infections

(Klepac et al, PNAS 2011)

Why economics/sociological processes

Individual behaviour(Funk et al, PNAS 2009)

Decision-making under economic constraints

(Edmunds, 200x)

Implementationand

logistics

Marketdynamics

Careseeking(unmeasured confounders)

Health systems

Macroeconomicshocks

National politics with borderless infections

(Klepac et al, PNAS 2011)

Why economics/sociological processes

Individual behaviour(Funk et al, PNAS 2009)

Decision-making under economic constraints

(Edmunds, 200x)

Implementationand

logistics

Marketdynamics

Careseeking(unmeasured confounders)

Health systems

Macroeconomicshocks

National politics with borderless infections

(Klepac et al, PNAS 2011)

Why economics/sociological processes

Individual behaviour(Funk et al, PNAS 2009)

Decision-making under economic constraints

(Edmunds, 200x)

Implementationand

logistics

Marketdynamics

Implementation: logistical/resource factors

• Decision trees for clinical algorithms

• Operations research– E.g. diagnostic tests for TB control

Eg: Rao, Schellenberg & Ghani, 2013Dowdy, Cattamanchi et al, 2011

Central laboratory

Peripheral sites

Careseeking(unmeasured confounders)

Health systems

Macroeconomicshocks

National politics with borderless infections

(Klepac et al, PNAS 2011)

Why economics/sociological processes

Individual behaviour(Funk et al, PNAS 2009)

Decision-making under economic constraints

(Edmunds, 200x)

Implementationand

logistics

Marketdynamics

Diseases of poverty

• The ‘big three’: HIV, TB, Malaria• Poverty:

– Increases risk of acquiring infection– Reduces access to essential healthcare

• Economic factors loom large for dynamics of infection

0

50

100

150

200

250

300

1820 1840 1860 1880 1900 1920 1940 1960 1980 2000

TB d

eath

s/10

0,00

0/yr

Britain beat TB in the 19th and 20th centuries?Much of the (slow) decline preceded drugs

Keats1821

E Bronte1848

C Bronte1855

Mansfield1923

Lawrence1930

Orwell1953

Leigh1967

Russia Hungary

Health in financial crises: Soviet Union in the 1990s

Arinaminpathy, Dye (2010) J.R.Soc.Interface

Strong associations between economic changes and TB epidemiology

Process vs pattern?

Most recent financial crisis?

Tuberculosis today8.7M new TB cases,1.4M deaths in 2011 1.1M TB/HIV+ cases, 430k deaths

Global Tuberculosis Report, 2012

As yet no effective TB vaccine

But most TB cases are curable with 6-9 months of drug treatment.

Ecology of TB drug markets

Few manufacturersof TB drugs

Global demand for drugs fragmented amongst many high-burden, low-income countries

Irregular supply, with drugs of uncertain quality

Ecology of TB drug markets• Global Drug Facility (GDF):

• What impact has the GDF had, on the TB drug market?– Private-sector prices as well as in national TB programmes

• What might be the effects of GDF expansion?

Arinaminpathy, Cordier-Lassalle, Vijay, Dye (2013) Lancet

Health systems in infectious disease dynamics

Lin, Langley, Mwenda et al (2011) Int.J.Tuberc Lung Dis.

Photo credit: Peter Small

Patient trajectories and infectious periods

Kapoor, Raman, Sachdeva, Satyanarayana (2012) PLoS ONE

Driving questions

• What are the most effective levers, at the public/private interface?

• How might provider incentives be structured, to minimise diagnosis and treatment delays?

• What effects might such interventions have on TB transmission?

Conclusions

• Economic factors can be an important part of the interface between infectious disease modeling and public health

• Health-economic implications of given interventions have played an important role in decision-making

• Future directions: recognising economic/sociological processes as part of the disease-dynamical system, for public health