Knee Arthroplasty Infection
HAIBA case definition of deep infection after total knee arthroplasty
The HAIBA algorithm is based on operation and diagnosis codes from the National Patient Register (LPR) and microbiological sample responses from the Danish Microbiology Database (MiBa).
Primary knee arthroplasty (index surgery, see operation codes below) is divided into acute or planned, using diagnosis codes (see classification below).
The patient is followed for infections from 2 to 90 days after the index operation and up to 365 days. Patients with bilateral index surgery have two parallel follow-up periods.
An infection is recorded if a relevant re-operation has been recorded and at least two out of a minimum of three Kamme biopsy tests are positive for the same microorganism.
HAIBA case definition of knee arthroplasty (index operation)
Notes on surveillance data from HAIBA
Figures for infections occurring 2-90 days after the index surgery are shown online as the majority of infections occur in this period.
Figures on infections after acute index surgery are not presented online, but data on these infections and on infections occurring 91-365 days after the index surgery are made available to each of the Danish regions.
Data from HAIBA cover the past five full calendar years and the current year. Infections are calculated on a monthly basis in relation to the date of the index operation.
Which department/hospital are infections attributed to?
Infections are listed according to the date of the operation and the department where the operation was performed. As an example: An index operation was performed in Department X on January 2, 2016. Re-operation, during which an infection was found, was performed in Ward Y on February 10, 2016.
This infection is recorded in HAIBA as an infection in Department X on January 2, 2016.
How is incidence calculated?
The incidence of knee arthroplasty infections is calculated as a risk or cumulative incidence fraction, i.e. the number of infections per 100 index operations.