Study on the Risk Factors for Postoperative Delirium Using the National Health Insurance Claims Database in Japan

Abstract

Although it is important to determine the risk factors for postoperative delirium (POD) to prevent the onset of POD, most previous studies that focused on risk factors for POD analyzed small cohort groups. Therefore, we aimed to explore the risk factors for the onset of POD by analyzing the National Health Insurance Claims Database (NDB) in Japan, which covers most Japanese residents.We compiled the clinical data of patients who emerged from POD after eight types of surgical procedures from August 2015 to August 2016 from the NDB. We subsequently developed a logistic regression model to determine the factors that affected the onset of POD.From the logistic regression analysis, we found that four factors (being over 75 years old, previous history of delirium, administration of a blood product during the operation, and emergency hospitalization) increased the odds ratio of POD. These factors may decrease physiological function, thereby leading to the onset of POD. We also clarified that the odds ratio of POD in patients administered inhalation anesthetic alone was lower than in patients administered combined inhalation and intravenous anesthetics for coronary artery bypass grafting. This finding was in line with the results of a previous small cohort study.These findings imply that, to prevent the onset of POD, appropriate precaution for and appropriate selection of anesthetic agents is necessary for patients with the four POD risk factors.

Demographic and clinical characteristics of patients with delirium: analysis of a nationwide Japanese medical database

“… 22 According to Sakakibara et al , delirium is recorded on the claims receipt only for patients with severe delirium requiring more medical resources, but not for those with mild-to-moderate delirium. 24 Our results confirm that the majority of Japanese patients with delirium can be identified from a Japanese claims database based on prescription of an antipsychotic during their hospital stay; 88.2% of patients with delirium were identified based on an antipsychotic prescription. A recent study employing a Japanese national inpatient database used the daily nursing necessity score (dangerous behaviour or misunderstanding of nursing instructions) as the criterion of delirium, but reported a prevalence of delirium of approximately 1% (n=21 182) among 2 070 000 postoperative patients.…”

“…17 18 A limited number of studies have examined the characteristics of patients experiencing delirium based on a medical database. [17][18][19][20][21][22][23][24][25] This is because identification of delirium through a medical database is quite challenging, given the inconsistent and poor documentation of records. 26 Moreover, the identification of delirium requires bedside cognitive assessments and application of validated diagnostic tools such as the Confusion Assessment Method 27 or the Diagnostic and Statistical Manual of Mental Disorders criteria.…”

“…A limited number of studies have examined the characteristics of patients experiencing delirium based on a medical database 17–25. This is because identification of delirium through a medical database is quite challenging, given the inconsistent and poor documentation of records 26.…”

“…Although several medical database studies in the USA19 and Japan24 have used International Classification of Diseases, 9th Revision (ICD-9) or ICD, 10th Revision (ICD-10) codes to identify patients with a diagnosis of delirium, only around 2% of patients with delirium (postoperative in Japan) could be identified. On the other hand, several medical database studies have employed antipsychotic use to identify patients with delirium 21 23 25.…”

Trends Associated with Hemorrhoids in Japan: Data Mining of Medical Information Datasets and the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open Data Japan

“…18) Various large-scale medical information databases have been used for clinical and epidemiological research in Japan. 19,20) In 2009, the MHLW developed the NDB, which covers over 95% of current insurance claim information provided by health insurance in Japan. 21,22) The NDB contains data that has been prepared to optimize medical expenses.…”