Practical use of indicators: CSR, CSC & outcomes

Susan Lewallen, MD

A place to start

• CSC would probably be the most important indicator to tell us how well we’re serving people

• Ideally we’d have a CSC of 100% in every “district” and country (assuming all surgeries had a good outcome!)

Inconvenient reality…

• Measuring CSC requires a population based survey – Expensive – Difficult

• Most “VISION 2020 Districts” will never have such a survey

CSR is more practical to measure• Limitations:

– requires proper record keeping to know where patient resides

– requires cooperation and reporting from all providers

– still not measured properly in most districts – country level CSR hides inequalities among

districts– does not consider outcomes

• But it’s still the best we’ve got for planning and monitoring

So what CSR over time would lead to a 100% CSC?

Incident cataracts

Operated eyes

People (eyes) who die unoperated

Eyes with unop’d cataract

How many surgeries required to do all the cataracts?

How can we get incidence data in developing countries?

It can be modeled from age specific prevalence data obtained in population based surveys, such

as RAABs

Target CSR should equal annual incidence of cataract.

AFRICAVariation in target CSR needed for 100%

CSC (eyes at <6/18)

050010001500200025003000350040004500

Hypothesis: variation due to genetic differences?

Other factors that determine what target CSR should be

Population structure

LATIN AMERICAVariation in target CSR needed for 100%

CSC (eyes at <6/18)

0100020003000400050006000700080009000

Much of the variation due to age structure differences

Other factors that determine what target CSR should be

VA at which cataracts are operated

Better pre op VA requires higher CSR

Target CSR varies with VA

0

1000

2000

3000

4000

5000

6000

7000

6/18 6/60 3/60

Kili

Eritrea

Mali

Moz

Argent

Ecuador

Another inconvenient reality…

Not all surgeries result in sight restoration.

Some bad outcomes occur

Outcomes (RAAB)

Monitoring outcomes

• Some hospitals/programmes do it• Most do not. Why?

– Extra work for someone– Culture not established– Donors not demanding it – WHO guidelines designed for use at 6

weeks

• But it could be done at discharge, at the hospital. Much better than nothing.

Summary- use of indicators• CSC meaningful but not practical to

measure• Target CSR to achieve 100% CSC can be

modeled from RAAB data. Useful planning tool

• Actual CSR can be monitored annually– Requires reasonable records– Requires cooperation among all eye care

providers– Can be monitored by District or by country

• Outcomes -just as important as CSC– Most practical is to measure at hospital level

Thank you