Recurrent infection of kidney catheters

Data on the recurrence times to infection, at the point of insertion of the catheter, for kidney patients using portable dialysis equipment. Catheters may be removed for reasons other than infection, in which case the observation is censored. Each patient has exactly 2 observations.

The data set has been used by several authors to illustrate random effects ("frailty") models for survival data. However, any non-zero estimate of the random effect is almost entirely due to one outlier, subject 21.

• patient id
• follow-up time
• status: 0 = censored, 1 = infection
• age
• sex (1 = male, 2 = female)
• disease type
  • 0 = Glomerulo Nephritis
  • 1 = Acute Nephritis
  • 2 = Polycystic Kidney Disease
  • 3 = Other
• estimate of the frailty, as listed in the reference below