Chris Anderson knows better than to screw around with MacArthur “genius grant” winner Sue Goldie – she’s a third degree blackbelt in Tae Kwon Do. She gives us some of her life story – the child of a young teen mother, a foster child, a medical student who studied public health by taking a train back and forth from New Haven to Boston while raising two children. “it reflects the tension in my life between caring for individual patients and working on the big problems through public health.”
Her talk focuses on the effectiveness of various public health strategies. She studies HIV, Hepatitis and HPV – Human papilomavirus – but focuses on HPV for the sake of this talk. All these diseases affect low, middle and high income countries, and all have long latency periods, which is a very serious challenge for epidemiologists to model.
Of the many strains of HPV, two have a high chance of causing cervical cancer through persistent infection. As a decision scientist, she’s interested in figuring out what interventions are most appropriate and cost effective around the world. Right now, the US tests for HPV and cervical cancer via annual pap smears – this is very effective, but very expensive. She’s interested in three other interventions:
– a low tech visual inspection screening that costs $2
– a higher tech test that requires $4.50
– a vaccine against two types of HPV that costs $120
To decide between these interventions, you need to build and test models that “simulate the natural history of the disease.” These models need to match the real world. In Kenya, for instance, the cost of administrating tests for HPV is hugely affected by the travel time and costs for the women affected. If you don’t go into the field and test these models, you simply get them wrong. She and colleagues test their models against real-world data, like cancer incidence by age.
The goal of these models is to test cost effectiveness of these interventions. The ratio considered is the gain in health over the cost od intervention. She looks at the difference of these interventions in different environments. “$50,000 would buy a total of 23 weeks of life expectancy in the US, but would buy 1000 years of life expectancy in Kenya” by buying new interventions.
These sorts of models are useful in negotiating with drug companies. She’s been able to discover that bringing the HPV vaccine down to $12.25 a dose is quite unhelpful in the developing world – at $0.55, it’s quite realistic. This allows negotiators to set intelligent targets for drug prices.
She reminds us that, as a decision scientist, waiting has a cost – HPV will kill thousands of women and cost years of productivity. With a little work, she can tell you precisely how many lives lost and how little money we’d need to screen for HPV around the world.