Fragility Fractures in Older People in Japan Based on the National Health Insurance Claims Database

Abstract

Fragility fractures associated with age-related bone loss are of urgent concern worldwide because they reduce QOL and pose financial burdens for health care services. Currently, national data in Japan are limited. This study provides quantitative data for older patients throughout Japan who, although otherwise relatively healthy, sustained fragility fractures and were hospitalized for them. The National Database of Health Insurance Claims and Specific Health Checkups of Japan was accessed to target patients aged 65 years or older who sustained fractures between May 2013 and September 2014 and were not hospitalized for at least 13 months prior to fracture. We investigated whether the first fracture sustained was fragility related at any of four locations (proximal humerus, distal radius, vertebra, or femoral neck) and whether it necessitated hospitalization. Fragility fractures were identified in 490138 of 1188754 patients (41.2%, 345980 patients/ year; 1 : 4 male-to-female ratio). Regardless of gender, vertebral fractures were most common across the age cohorts studied (43286 males and 162767 females/year), and femoral neck fractures increased markedly with increased patient age. Approximately 80% of patients with femoral neck fractures were hospitalized (62.3% of males, 71.1% of females) compared with up to 10.4% of patients with other fragility fractures. Data provided in this study can be used as a baseline for evaluating the health economy and establishing health policy in Japan.

Central Nervous System Agent Classes and Fragility Fracture Risk among Elderly Japanese Individuals in a Nationwide Case-Crossover Design Study

“…The results of the present study showed that the risk of fragility fracture associated with the use of hypnotics and sedatives and anxiolytics was statistically nonsignificant for the analyses with a 3-d window, but marginally significant in analyses with longer windows. Results of previous studies are controversial; the association was nonsignificant in the metaanalysis by Takkouche et al 3) and in a case-crossover study by Leach et al, 4) and the RR was 1.5 14) and 1.2 15) in two other meta-analyses.…”

“…a The detailed flowchart to identify patients who incurred fragility fractures is illustrated elsewhere. 16) antiepileptic agents in the case window (i.e., immediately before incurring the fracture) but did not use them in the control windows was certainly higher than the opposite pattern, suggesting that the use of antiepileptic agents, not the occurrence of seizures, caused fragility fractures. This is because an antiepileptic agent would have been used after a fracture if a seizure caused the fracture.…”

“…There are also some limitations based on claims data, i.e., information bias such as inaccuracy of disease and medication use, which has been described in detail elsewhere. 16) It is difficult to carry out validation studies to confirm accuracy in Japan, where links between social security numbers and databases are not established. For this reason, we did not conduct validation studies, but we carefully identified fragility fractures by connecting diagnostic codes with modifier codes in addition to diagnostic codes, diagnosis date, and radiographic examination, as described in Materials and Methods.…”

“…The study design, data source, study population, and definition of fragility fracture used in the present study have been described elsewhere, 16,17) and are summarized briefly in the paragraphs below. Our previous reports did not focus on single classes of CNS agents, but instead focused on other topics; one revealed the number of elderly people who incurred fragility fractures according to sex, age, and received care, 16) and the other estimated fracture risk associated with statin use. 17) The case-crossover design, which is self-controlled, 18) compares medication use between case and control windows for patients who incurred any event.…”

“…6,7) Thus far, the association between the use of CNS agents and fracture risk has been investigated by focusing on each medication individually or by analyzing the risk with the use of some restricted classes of CNS agents, such as antiepileptic agents, antidepressants, antipsychotics, benzodiazepines, and opioids. [3][4][5][8][9][10][11][12][13][14][15] However, no study has estimated the fracture risk of a wide range of CNS agent classes to the best of our knowledge. A study among individuals in the same population using the same definitions of exposure and outcome makes fracture risk among CNS agent classes appropriate to compare and easy to interpret.…”