The identification of death is critical for epidemiological research. Despite recent developments in health insurance claims databases, the quality of death information in claims is not guaranteed because health insurance claims are collected primarily for reimbursement. We aimed to examine the usefulness and limitations of death information in claims data and to examine methods for improving the quality of death information for aged persons.We used health insurance claims data and enrollment data (as the gold standard) from September 2012 through August 2015 for nondependent persons aged 65–74 years enrolled in Japanese workplace health insurance. Overall, 3,710,538 insured persons were registered in the database during the study period. We analyzed 45,441 eligible persons. Inpatient and outpatient deaths were identified from the discharge/disease status in the claims, with sensitivities of 94.3% and 47.4%, specificities of 98.5% and 99.9%, and PPVs of 96.3% and 95.7%, respectively, using enrollment data as the gold standard. For outpatients, death defined as a combination of disease status and charge data for terminal care still indicated low sensitivity (54.7%).The validity of death information in inpatient claims was high, suggesting its potential usefulness for identifying death. However, given the low sensitivity for outpatient deaths, the use of death information obtained solely from records in outpatient claims is not recommended.

Aims/Introduction Although the epidemiological relationship between hypoglycemia and increased risk of acute coronary syndrome (ACS) has been well established, the time period for increased risk of ACS after a severe hypoglycemic episode remains unknown. The present study aimed to determine the ACS risk after a severe hypoglycemic episode. Materials and Methods We carried out a retrospective population‐based cohort study based on national claims data in Japan. We retrieved data of diabetes patients aged ≥35 years collected from April 2014 to March 2016. The absolute risk of ACS was defined as the occurrence of an emergency percutaneous coronary intervention after a severe hypoglycemic episode. Results In total, data of 7,909,626 patients were included in the analysis. The absolute risk of ACS was 2.9 out of 1,000 person‐years in all patients. ACS risk in patients with severe hypoglycemic episodes was 3.0 out of 1,000 person‐years. Severe hypoglycemic episodes increased the absolute risk of ACS in patients aged ≥70 years, but not in patients aged <70 years. The absolute risk of ACS was 10.6 out of 1,000 person‐years within 10 days of a severe hypoglycemic episode. There was a significant trend between shorter duration after an episode and higher ACS risk. Conclusions Severe hypoglycemia was associated with an increased risk of ACS in elderly diabetes patients. ACS risk increased with a shorter period after a severe hypoglycemic episode, suggesting that severe hypoglycemia leads to an increased risk of ACS in diabetes patients. These findings show that it is important to avoid severe hypoglycemia while treating diabetes, particularly in elderly patients.

ObjectivesQuality indicators are measurable elements widely used to assess the quality of care. They are often developed from the results of systematic reviews or clinical practice guidelines. These sources are regularly updated in line with new clinical evidence, but there are few articles on updating quality indicators based on clinical practice guidelines. This study aimed to update the quality indicators developed for low-risk labour care in Japan in 2012, mainly drawing on new or updated clinical practice guidelines, and making the process clearly visible and assessable.Design and settingWe used a modified Delphi method for the update. The procedure included four steps: (1) updating the definition of low-risk labour; (2) reviewing the literature published between June 2012 and December 2015 using five guidelines and two quality indicator databases to extract potential candidate indicators; (3) formation of a multidisciplinary panel including mothers and (4) panel ratings (two rounds between February and April 2016) on the validity of the candidate indicators, and judging the validity of the previous quality indicators drawing on the new evidence.ParticipantsA multidisciplinary panel of 13 clinicians, including obstetricians, paediatricians and midwives, plus 3 non-clinician mothers.ResultsThe literature review identified 276 new recommendations from 27 clinical practice guidelines including 2 published in Japan and 21 quality indicators. We developed 13 new candidate indicators from these sources and panel recommendations, 12 of which were approved by the multidisciplinary panel. The panel also accepted all 23 existing quality indicators as still valid, resulting in a total of 35 quality indicators for low-risk labour.ConclusionsWe successfully updated the quality indicators for low-risk labour care in Japan. The procedure developed may be useful for updating other quality indicators based on new clinical practice guidelines.

AimsThe aim of this study was to elucidate the epidemiological background of central serous chorioretinopathy (CSC), including its incidence and treatment pattern.MethodsThis was a population-based longitudinal cohort study using a nationwide health insurance claims database of the Japan Ministry of Health, Labour and Welfare (MHLW). As Japan employs universal health coverage, the database covers more than 95% of claims issued in Japan. We accessed all data stored in the database with permission from the MHLW. We traced all individuals aged 30 years or older and identified individuals with new onset of CSC between January 2011 and December 2018. CSC cases were categorised by age and sex for each year, and incidence rate was calculated. We also identified major treatments for CSC to elucidate the initial treatment pattern.ResultsDuring the 8-year period, 247 930 incidences of CSC were identified, among which 75.9% were men. The crude incidence rate (per 100 000 person-years) in the general population aged 30 years or older was 34.0 (95% CI 33.9 to 34.2), in men was 54.2 (95% CI 53.9 to 54.4) and in women was 15.7 (95% CI 15.5 to 15.8). The mean age of onset was lower in men than in women (50.5±12.5 years vs 54.7±13.5 years). Most of the patients with newly diagnosed CSC (86.8%) did not receive major treatment.ConclusionsThe current study provides the nationwide population-based evidence to clarify the detailed epidemiology of CSC. These results could help to understand the pathogenesis and mechanisms of CSC in the future.