Hysterectomy for postpartum hemorrhage in Japan: Diagnostic code validation and nationwide descriptive analysis

Hysterectomy is a life-saving procedure for severe postpartum hemorrhage (PPH), but reports on postoperative mortality are limited. This study aimed to describe the rates of hysterectomy and associated mortality in PPH patients using the Diagnosis Procedure Combination (DPC) database, Japan's largest inpatient database.

We first validated the accuracy of PPH diagnostic coding at a tertiary perinatal center, then conducted a nationwide descriptive analysis using DPC data from April 2018 to March 2023. The DPC database includes over half of all acute care hospital admissions in Japan. PPH cases were identified using International Statistical Classification of Diseases and Related Health Problems, 10th Revision codes and blood loss data. We examined hysterectomy rates and postoperative mortality, including a subgroup excluding cases with conditions requiring planned hysterectomy during cesarean section (e.g., placenta previa, accreta, uterine rupture, and cervical cancer).

The validation study showed high accuracy of PPH coding, with a sensitivity of 97.8% and specificity of 99.7%. Among 209 555 PPH cases, 1835 (0.88%) underwent hysterectomy, with a mortality rate of 0.87% (16 deaths). After excluding 23 039 cases with indications for planned hysterectomy, 681 of 186 516 cases (0.36%) required hysterectomy, with a higher mortality rate of 2.2%.

The DPC database reliably identifies PPH cases. Hysterectomy was performed in 0.88% of all PPH cases, with higher mortality in emergency cases after excluding planned procedures.