Table 1.
Data extracted.
| Data | Source | Definition |
|---|---|---|
| ASA grade | Anesthetists' operative report | As decided by anesthetist at the time of surgery |
| Weight (kg) | Anesthetists' operative report | Measured day of surgery |
| Height (m) | Anesthetists' operative report | Measured day of surgery |
| Preoperative Hb (g/L) | Computerized laboratory results | 77% within 24 hours before surgery; 100% within 3 mo before surgery |
| Preoperative Hct | Computerized laboratory results | 77% within 24 hours before surgery; 100% within 3 mo before surgery |
| Intraoperative blood loss (mL) | Anesthetists' operative report | Total from suction and weighing swabs. Measured only for THR because TKR and UKR performed with tourniquet inflated |
| POD1 Hb (g/L) | Computerized laboratory results | Collected between 7 am and 9 am on the day after surgery |
| POD1 Hct | Computerized laboratory results | Collected between 7 am and 9 am on the day after surgery |
| POD2 Hb (g/L) | Computerized laboratory results | Collected between 7 am and 9 am on day 2 after surgery |
| POD2 Hct | Computerized laboratory results | Collected between 7 am and 9 am on day 2 after surgery |
| Volume and timing of postoperative transfusions | Medical and nursing notes | Any blood transfusion administered during hospital admission |
| Chemical thromboprophylaxis | Postoperative medical Kardex | Decided by surgeon according to risk stratification protocol (see text in Materials and methods) |
Hct, hematocrit.