trial_data <- data.frame(
id = 1:10,
age = c(45, 62, 38, NA, 55, 71, 29, 48, NA, 65),
group = c("Drug", "Control", "Drug", "Drug", "Control", "Control", "Drug", "Control", "Drug", "Control"),
bp_start = c(160, 155, 145, 170, 150, NA, 135, 148, 165, 158),
bp_end = c(120, 150, 130, 140, 145, 155, 125, 148, NA, 140),
adverse_event = c(FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, NA, TRUE, FALSE)
)