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
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 |