Administrative Database In Japan Research Articles

Factors affecting the occurrence of pulmonary embolism after spinal surgery: data from the national administrative database in Japan

Despite potentially devastating consequences, pulmonary embolism (PE) in patients undergoing spinal surgery remains poorly understood. To the best of our knowledge, few large studies have examined the prevalence and risk factors of PE after spinal surgery. To investigate the prevalence of symptomatic PE in patients undergoing elective spinal surgery and to identify clinical variables associated with the occurrence of postoperative PE. A retrospective analysis of data abstracted from the diagnosis procedure combination (DPC) database, a nationally representative database in Japan. We included all patients with a diagnosis of spinal canal stenosis, disc herniation, spondylosis, spondylolisthesis, trauma, metastatic tumor, or infection who underwent spinal surgery between July 1 and December 31 of 2007 and 2008, respectively. The primary end point was defined as the occurrence of postoperative PE during hospitalization. The secondary end point was in-hospital death after postoperative PE. We analyzed the association between the occurrence of postoperative PE and clinical variables recorded in the DPC database, including age, sex, comorbidities, location of surgery, primary diagnosis, anterior/posterior approach, use of instrumentation, and duration of anesthesia. A total of 47,743 patients were identified. Of these, 50 (0.10%) developed PE and four died as a result of PE. Logistic regression analyses revealed that occurrence of PE was associated with older age (70 years or older; odds ratio [OR], 3.15; 95% confidence interval [CI], 1.15-8.69; p=.026) and longer anesthesia time (more than 360 minutes; OR, 2.19; 95% CI, 0.88-5.44; p=.092). Patients with trauma were significantly more likely to have a PE than those with spinal canal stenosis (0.27% vs. 0.09%; OR, 2.86; 95% CI, 1.14-7.18; p=.026). This retrospective analysis of a nationally representative database identified older age, longer anesthesia time, and spinal trauma as risk factors for increased incidence of postoperative PE. Surgeons should be aware of the increased risk of postoperative PE in these subgroups of patients.

Assessment of hospital performance with a case-mix standardized mortality model using an existing administrative database in Japan

BackgroundFew studies have examined whether risk adjustment is evenly applicable to hospitals with various characteristics and case-mix. In this study, we applied a generic prediction model to nationwide discharge data from hospitals with various characteristics.MethodWe used standardized data of 1,878,767 discharged patients provided by 469 hospitals from July 1 to October 31, 2006. We generated and validated a case-mix in-hospital mortality prediction model using 50/50 split sample validation. We classified hospitals into two groups based on c-index value (hospitals with c-index ≥ 0.8; hospitals with c-index < 0.8) and examined differences in their characteristics.ResultsThe model demonstrated excellent discrimination as indicated by the high average c-index and small standard deviation (c-index = 0.88 ± 0.04). Expected mortality rate of each hospital was highly correlated with observed mortality rate (r = 0.693, p < 0.001). Among the studied hospitals, 446 (95%) had a c-index of ≥0.8 and were classified as the higher c-index group. A significantly higher proportion of hospitals in the lower c-index group were specialized hospitals and hospitals with convalescent wards.ConclusionThe model fits well to a group of hospitals with a wide variety of acute care events, though model fit is less satisfactory for specialized hospitals and those with convalescent wards. Further sophistication of the generic prediction model would be recommended to obtain optimal indices to region specific conditions.