Skip to main content

Table 1 Definitions of variables in a nation-wide cohort study of surgical site infection rates and associated factors in 31,807 adult patients undergoing surgery of a distal radius fracture in Sweden between November 1st 2006 and October 31st 2013

From: Surgical site infections after distal radius fracture surgery: a nation-wide cohort study of 31,807 adult patients

Variable Data source Definition
Inclusion criteria NPR Patients ≥18 years with a surgically treated DRF registered in the NPR between Nov 1st 2006 and Oct 31st 2013
 DRF NPR ICD-10-SE codes S525 and/or S526 as primary and/or secondary diagnosis
 Surgical methods NPR NCSP-S codes: NCJ29, NDJ29 = external fixation. NCJ49, NDJ49 = percutaneous pinning.
NCJ69, NDJ69 = plate fixation
 Index date NPR First concomitant registration of a code for a relevant surgical procedure (NCJ29, NDJ29, NCJ49, NDJ49, NCJ69 or NDJ69) and a DRF code (S525 or S526), occurring within 28 days from the first DRF registration (S525, S526). If several index dates, only first index date included
 First DRF registration NPR First registration of a DRF code (S525 or S526) preceded by a period ≥18 months without any registration of a DRF code. NPR was screened from May 1st 2005 with regard to the 18-month period
Exclusion criteria
 Time periods NPR Index date occurring between Jan 1st 2001 - Oct 31st 2006 and Nov 1st 2013 - Dec 31st 2013
 Forearm fractures other than DRFs NPR ICD-SE-10 codes beginning with S52, other than S525 and S526
 Non-surgically treated DRFs   Registrations of a DRF code (S525, S526) without a concomitant surgical procedure code
 DRFs treated with other surgical methods NPR NCSP-S codes: NCJ89, NDJ89 = combinations. NCJ59, NDJ59, NCJ99, NDJ99 = other methods
 Non-adults NPR Age < 18 years
Primary outcome SPDR Yes/No. Yes = a registration of the ATC codes J01CF05 (Flucloxacillin) and/or J01FF01 (Clindamycin) in the SPDR within the first 8 weeks following the index date. The date of primary outcome = date of prescription
Potential confounders   Factors used to adjust the association between surgical method and the primary outcome
 Age NPR At the time of index date. Categorized into 18–49 years, 50–74 years, and ≥ 75 years
 Sex NPR Women/Men
 Fracture type NPR Closed/open. Fifth position in ICD-SE-10 code. Closed = 0, Open = 1. If missing defined as closed (0)
 Antibiotics treatment due to other reasons at the time of DRF surgery SPDR Yes/No. Yes = registration of the ATC codes J01CF05 (Flucloxacillin) and/or J01FF01 (Clindamycin) in the SPDR during the 8 weeks preceding the index date
  1. DRF distal radius fracture, NPR Swedish national patient register, SPDR Swedish prescribed drug register, NCSP-S NOMESCO classification of surgical procedures, Swedish version, ATC anatomical therapeutic chemical classification code