serosv (version 1.1.0)

hcv_be_2006: Hepatitis C serological data from Belgium in 2006 (line listing)

Description

A study of HCV infection among injecting drug users. All injecting drug users were interviewed by means of a standardized face-to-face interview and information on their socio-demographic status, drug use history, drug use, and related risk behavior was recorded

Usage

hcv_be_2006

Format

A data frame with 3 variables:

dur

Duration of injection/Exposure time (years)

seropositive

If the individual is seropositive or not

Examples

# Reproduce Fig 4.3, p. 66
library(dplyr)
# snapping age to aggregated age group
# (credit: https://stackoverflow.com/a/12861810)
groups <- c(0.5:24.5)
range <- 0.5
low <- findInterval(hcv_be_2006$dur, groups)
high <- low + 1
low_diff <- hcv_be_2006$dur - groups[ifelse(low == 0, NA, low)]
high_diff <- groups[ifelse(high == 0, NA, high)] - hcv_be_2006$dur
mins <- pmin(low_diff, high_diff, na.rm = TRUE)
pick <- ifelse(!is.na(low_diff) & mins == low_diff, low, high)
hcv_be_2006$dur <- ifelse(
  mins <= range + .Machine$double.eps, groups[pick], hcv_be_2006$dur
)
hcv_be_2006 <- hcv_be_2006 %>%
  group_by(dur) %>%
  summarise(tot = n(), pos = sum(seropositive))

plot(
  hcv_be_2006$dur, hcv_be_2006$pos / hcv_be_2006$tot,
  cex = 0.1 * hcv_be_2006$tot, pch = 16,
  xlab = "duration of injection (years)",
  ylab = "seroprevalence", xlim = c(0, 25), ylim = c(0, 1)
)