epi

This example calculates mortalities caused by ambient PM2.5 concentrations.

var (
	// I represents currently observed deaths per 100,000
	// people in this region.
	I = 800.0

	// p represents number of people in different locations
	// in the region.
	p = []float64{100000, 80000, 700000, 90000}

	// z represents PM2.5 concentrations in μg/m³ in locations
	// corresponding to p.
	z = []float64{12, 26, 11, 2, 9}
)

// This is how we can calculate total deaths caused by air pollution
// using a regional underlying incidence rate.
io := IoRegional(p, z, NasariACS, I/100000)
var totalDeaths float64
for i, pi := range p {
	totalDeaths += Outcome(pi, z[i], io, NasariACS)
}
fmt.Printf("total deaths using regional underlying incidence: %.0f\n", totalDeaths)

// This is how we can calculate additional deaths caused by doubling
// air pollution:
var doubleDeaths float64
for i, pi := range p {
	doubleDeaths += Outcome(pi, z[i]*2, io, NasariACS) - Outcome(pi, z[i], io, NasariACS)
}
fmt.Printf("additional deaths caused by doubling air pollution: %.0f\n", doubleDeaths)

// This is how we can calculate lives saved by halving air pollution:
var halfDeaths float64
for i, pi := range p {
	halfDeaths += Outcome(pi, z[i]/2, io, NasariACS) - Outcome(pi, z[i], io, NasariACS)
}
fmt.Printf("lives saved by halving air pollution: %.0f\n", -1*halfDeaths)

// Sometimes it is not practical to calculate regional underlying
// incidence. This is how we can calculate total deaths caused by air pollution
// using a location-specific underlying incidence rate.
totalDeaths = 0
for i, pi := range p {
	totalDeaths += Outcome(pi, z[i], Io(z[i], NasariACS, I/100000), NasariACS)
}
fmt.Printf("total deaths using local underlying incidence: %.0f\n", totalDeaths)

// This is how we can calculate additional deaths caused by doubling
// air pollution using a local underlying incidence rate:
doubleDeaths = 0
for i, pi := range p {
	io := Io(z[i], NasariACS, I/100000)
	doubleDeaths += Outcome(pi, z[i]*2, io, NasariACS) - Outcome(pi, z[i], io, NasariACS)
}
fmt.Printf("additional deaths caused by doubling air pollution (local underlying incidence): %.0f\n", doubleDeaths)

Output:

total deaths using regional underlying incidence: 672
additional deaths caused by doubling air pollution: 403
lives saved by halving air pollution: 389
total deaths using local underlying incidence: 665
additional deaths caused by doubling air pollution (local underlying incidence): 401