Microbiological findings in patients with community-acquired pneumonia: An analysis using the National Hospital Organization Clinical Data Archives

Although large-scale administrative databases may be useful for studies of infectious diseases, conventional databases lack microbiological data. To illustrate the applicability of the National Hospital Organization Clinical Data Archives, a novel database of electronic medical records in Japan, we conducted a descriptive study of the microbiological findings in patients with community-acquired pneumonia using the database. We identified patients aged ≥18 years who were hospitalized for community-acquired bacterial pneumonia between April 2016 and March 2019. We evaluated the results of bacterial culture and antibacterial susceptibility of specimens obtained on the first day of hospitalization, in addition to patient characteristics, diagnosis codes, and intravenous antibiotics administered. The analysis identified 2200 eligible patients from 15 hospitals. Sulbactam-ampicillin was the most frequently used initial antibiotic (32 %), followed by ceftriaxone (22 %) and tazobactam-piperacillin (19 %). Overall, 56 %, 95 %, 56 %, and 73 % of patients with pathogen-specific diagnosis codes in the database for Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa, respectively, also tested positive for the corresponding pathogen in their sputum or blood cultures. Antibacterial susceptibilities were consistent with a previous report from Japan; 81 % of S. pneumoniae cases were resistant to azithromycin, and 48 % of H. influenzae cases were resistant to ampicillin. These microbiological characteristics warrant the future use of this database for detailed real-world research on infectious diseases.

Weight loss and functional decline in older Japanese people: A cohort study using large-scale claims data

BACKGROUND

The association between weight loss and subsequent functional decline is uncertain. The study aims to elucidate the association between weight loss over a year and subsequent functional decline requiring assistance in performing their activities of daily living in older individuals.

METHODS

The study used data from the publicly funded Long-Term Care Insurance service in Japan, which provides coverage for long-term care services for individuals unable to perform activities of daily living due to physical or cognitive impairment. The study enrolled people born in or before 1949, who underwent health checkups in both 2014 and 2015. The participants were followed from 2015 to the worsening of functional decline requiring long-term care services, death, or February 28, 2019, whichever occurred first. The risk of subsequent functional decline in each weight loss category was estimated using a Cox regression model adjusted for age, sex, baseline body mass index, smoking, and Charlson comorbidity index.

RESULTS

We identified 67,452 eligible individuals from the database. The median follow-up period was 1,284 days. The hazard ratios (95 % confidence interval) of functional decline for -1 %, -2 %, -3 %, -4 %, and ≤-5% weight change compared to 0 % weight change were 1.17 (1.03-1.32), 1.26 (1.11-1.43), 1.29 (1.12-1.49), 1.61 (1.39-1.87), and 1.79 (1.58-1.99), respectively.

CONCLUSIONS AND IMPLICATIONS

Older people with weight loss of 1 % or more were at risk of functional decline. Close weight monitoring may serve as an easy and inexpensive means of identifying older individuals at risk of functional decline.

Treatment strategies for pelvic organ prolapse and postoperative outcomes in older women with long-term care needs: A population-based retrospective cohort study

OBJECTIVE

The study aimed to investigate treatment options for older women with pelvic organ prolapse (POP) and postoperative outcomes based on their long-term care (LTC) status.

METHODS

We used the medical and LTC insurance claims databases of Tochigi Prefecture in Japan, covering 2014 to 2019. We included women 65 years and older with POP and evaluated their care status and treatment, excluding women with an observation period <6 months. Among women with a postsurgical interval ≥6 months, we compared care level changes and deaths within 6 months and complications within 1 month postoperatively between those with and without LTC using Fisher exact test.

RESULTS

We identified 3406 eligible women. Of the 447 women with LTC and 2959 women without LTC, 16 (3.6%) and 415 (14.0%), respectively, underwent surgery. Among 393 women with a postsurgical interval ≥6 months, 19 (4.8%) required LTC at surgery. Two of the 19 women with LTC (10.5%) and eight of 374 women without LTC (2.1%) experienced worsening care-needs level. No deaths were recorded. Urinary tract infection (UTI) was significantly more frequent in women with LTC than in women without LTC (36.8% vs 8.6%). Other complications were rare in both groups.

CONCLUSION

The proportion of patients who underwent surgery for POP was lower in women with LTC than in women without LTC. Postoperative UTI was common and 11% had a worsening care-needs level postoperatively, whereas other complications were infrequent. Further detailed studies would contribute to providing optimal treatment to enhance patients' quality of life.

"Association between perinatal mood disorders of parents and child health outcomes"

PURPOSE

Perinatal mood disorders affect both parents, impacting their children negatively. Little is known on the association between parental perinatal mood disorders and pediatric outcomes in Japan considering relevant covariates. Our objective was to investigate the association between paternal and maternal perinatal mood disorders and adverse physical and psychological child outcomes by the age of 36 months, adjusting for covariates such as the child's sex, age of parent at child's birth, perinatal mood disorders of the other parent, and perinatal antidepressant use.

METHODS

We identified parents in the JMDC Claims Database in Japan from 2012 to 2020. Perinatal mood disorders were defined using International Classification of Diseases, 10th codes for mood disorders during the perinatal period combined with psychiatric treatment codes. We evaluated the association between parental perinatal mood disorders and pediatric adverse outcomes by the age of 36 months using Cox proportional hazard models adjusted for the covariates.

RESULTS

Of the 116,423 father-mother-child triads, 2.8% of fathers and 2.3% of mothers had perinatal mood disorders. Paternal perinatal mood disorders were not significantly associated with adverse child outcomes. After adjusting for paternal perinatal mood disorders and antidepressant use, maternal perinatal mood disorders were associated with delayed motor development, language development disorders, autism spectrum disorders, and behavioral and emotional disorders (adjusted hazard ratio [95% confidence interval]: 1.65 [1.01-2.69], 2.26 [1.36-3.75], 4.16 [2.64-6.55], and 6.12 [1.35-27.81], respectively).

CONCLUSIONS

Paternal perinatal mood disorders were not associated with adverse child outcomes in this population. Maternal perinatal mood disorders were associated with multiple child outcomes.

Effect of periodontal therapy on glycaemic control in type 2 diabetes

AIM

This study aimed to elucidate the impact of periodontal therapy on glycaemic control in individuals with type 2 diabetes and various baseline blood glucose levels using a large-scale claims database from Japan.

MATERIALS AND METHODS

Using the JMDC Claims Database, we identified individuals with type 2 diabetes who underwent health check-ups in the fiscal years 2018 or 2019 and were followed up until the next year's health check-up. We conducted a weighted cohort analysis using stabilized inverse probability weights for treatment and censoring to estimate the effect of periodontal therapy on changes in haemoglobin A1c levels within a year. Analysis was done for different baseline haemoglobin A1c categories: 6.5%-6.9%, 7.0%-7.9% and ≥8.0%.

RESULTS

Of the 4279 insured persons included in the study, 957 received periodontal therapy. Overall, there was a tendency towards improved glycaemic control among those who received periodontal therapy. Participants with baseline haemoglobin A1c levels of 7.0%-7.9% who received periodontal therapy exhibited significantly better glycaemic control compared with those without dental visits (difference; -0.094 [95% confidence interval: -0.181 to -0.007]).

CONCLUSIONS

Periodontal therapy may improve glycaemic control in individuals with diabetes, especially in those with haemoglobin A1c levels ≥7.0%.

Antiemetic Effect of Rikkunshito, a Japanese Kampo Herbal Medicine, on Cisplatin-induced Nausea and Vomiting: A Nationwide Database Study in Japan

Objective The effect of Rikkunshito, a Japanese herbal Kampo medicine, on chemotherapy-induced nausea and vomiting (CINV) has been evaluated in several small prospective studies, with mixed results. We retrospectively evaluated the antiemetic effects of Rikkunshito in patients undergoing cisplatin-based chemotherapy using a large-scale database in Japan. Methods The Diagnosis Procedure Combination inpatient database from July 2010 to March 2019 was used to compare adult patients with malignant tumors who had received Rikkunshito on or before the day of cisplatin administration (Rikkunshito group) and those who had not (control group). Antiemetics on days 2 and 3 and days 4 and beyond following cisplatin administration were used as surrogate outcomes for CINV. Patient backgrounds were adjusted using the stabilized inverse probability of treatment weighting, and outcomes were compared using univariable regression models. Results We identified 669 and 123,378 patients in the Rikkunshito and control groups, respectively. There were significantly fewer patients using intravenous 5-HT3-receptor antagonists in the Rikkunshito group (odds ratio, 0.38; 95% confidence interval, 0.16-0.87; p=0.023) on days 2 and 3 of cisplatin-based chemotherapy. Conclusion The reduced use of antiemetics on day 2 and beyond of cisplatin administration suggested a beneficial effect of Rikkunshito in palliating the symptoms of CINV.

Amoxicillin vs third-generation cephalosporin for infection prophylaxis after third molar extraction

OBJECTIVES

Although amoxicillin is the first-line prophylactic drug for impacted mandibular third molar extraction, third-generation cephalosporins are widely prescribed in Japan. The lack of real-world evidence may be one reason for this inappropriate use. We evaluated differences in the incidence of surgical site infection between amoxicillin and third-generation cephalosporins for impacted mandibular third molar extraction.

METHODS

Using the JMDC Claims Database, we identified dental visits with fully or horizontally impacted mandibular third molar extraction from April 2015 to March 2020. One-to-one propensity-score matching was conducted between amoxicillin and third-generation cephalosporin groups. The incidence of surgical site infection following extraction was compared in the matched pairs using McNemar's test.

RESULTS

We identified 109,266 dental visits, including 39,514 (36.2%) patients who received amoxicillin and 69,752 (63.8%) patients who received third-generation cephalosporins. In the 39,514 matched pairs, the incidence of surgical site infection was 3.5% (n = 1399) for amoxicillin group and 3.7% (n = 1467) for third-generation cephalosporin group (p = 0.003).

CONCLUSIONS

Amoxicillin was associated with a lower incidence of surgical site infection after impacted mandibular third molar extraction compared with third-generation cephalosporins. This result supports current guidelines and strengthens the importance of disseminating and implementing antimicrobial resistance control in dentistry.

Machine Learning-based Models for Outpatient Prescription of Kampo Formulations: An Analysis of a Health Insurance Claims Database

BACKGROUND

Despite the widespread practice of Japanese traditional Kampo medicine, the characteristics of patients receiving various Kampo formulations have not been documented in detail. We applied a machine learning model to a health insurance claims database to identify the factors associated with the use of Kampo formulations.

METHODS

A 10% sample of enrollees of the JMDC Claims Database in 2018 and 2019 was used to create the training and testing sets, respectively. Logistic regression analyses with lasso regularization were performed in the training set to construct models with prescriptions of 10 commonly used Kampo formulations in 1 year as the dependent variable and data of the preceding year as independent variables. Models were applied to the testing set to calculate the C-statistics. Additionally, the performance of simplified scores using 10 or 5 variables were evaluated.

RESULTS

There were 338,924 and 399,174 enrollees in the training and testing sets, respectively. The commonly prescribed Kampo formulations included kakkonto, bakumondoto, and shoseityuto. Based on the lasso models, the C-statistics ranged from 0.643 (maoto) to 0.888 (tokishakuyakusan). The models identified both the common determinants of different Kampo formulations and the specific characteristics associated with particular Kampo formulations. The simplified scores were slightly inferior to full models.

CONCLUSION

Lasso regression models showed good performance for explaining various Kampo prescriptions from claims data. The models identified the characteristics associated with Kampo formulation use.

Association of the Japanese herbal kampo medicine kakkonto with antibiotic use and surgical drainage for noninfectious mastitis: A nationwide database study

AIM

Kakkonto, a Japanese herbal kampo medicine, is empirically prescribed to improve milk stasis and ameliorate breast inflammation in patients with noninfectious mastitis. We investigated whether early use of kakkonto is associated with a reduction in antibiotic use and surgical drainage in patients with noninfectious mastitis.

METHODS

We identified 34 074 patients with an initial diagnosis of noninfectious mastitis within 1 year of childbirth between April 2012 and December 2022 using the nationwide administrative JMDC Claims Database. Patients were divided into the kakkonto (n = 9593) and control (n = 9648) groups if they received and did not receive kakkonto on the day of the initial diagnosis of noninfectious mastitis, respectively. Antibiotic administration and surgical drainage within 30 days after the initial diagnosis of noninfectious mastitis in the two groups were compared using propensity score-stabilized inverse probability of treatment weighting analysis.

RESULTS

The frequency of antibiotic administration within 30 days after the initial diagnosis of noninfectious mastitis was significantly lower in the kakkonto group than in the control group (10% vs. 12%; odds ratio, 0.88 [95% confidence interval, 0.80-0.96]). The frequency of antibiotic administration during 1-3 and 4-7 days after the initial diagnosis were also significantly lower in the kakkonto group than in the control group. The frequency of surgical drainage did not differ significantly between the two groups.

CONCLUSIONS

Kakkonto was associated with reduced administration of antibiotics for noninfectious mastitis, making it a potential treatment option for relieving breast inflammation and promoting antimicrobial stewardship.

Therapeutic plasma exchange for anti-glomerular basement membrane disease with dialysis-dependent kidney failure without diffuse alveolar hemorrhage

BACKGROUND

Anti-glomerular basement membrane (anti-GBM) disease is treated with immunosuppressive medications and plasma exchange. However, whether plasma exchange, in addition to pulse glucocorticoid therapy, would benefit patients with anti-GBM disease with dialysis-dependent kidney failure without diffuse alveolar hemorrhage remains unclear.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients diagnosed with anti-GBM disease with dialysis-dependent kidney failure and without diffuse alveolar hemorrhage from July 2010 to March 2020. We compared in-hospital mortality within 10 days of hospitalization between patients who received therapeutic plasma exchange in addition to pulse glucocorticoid therapy and those who received pulse glucocorticoid therapy alone. Overlap weighting based on propensity score was performed to adjust for potential confounders.

RESULTS

We identified 207 eligible patients; 168 patients received therapeutic plasma exchange plus pulse glucocorticoid therapy, while 39 patients received pulse glucocorticoid therapy alone. The mean dose of therapeutic plasma exchange was 52.2 ml/kg/day of albumin and/or fresh frozen plasma. Therapeutic plasma exchange in addition to pulse glucocorticoid therapy was associated with a lower in-hospital mortality risk in the unweighted (10.7% versus 28.2%; risk difference, 17.5%; 95% confidence interval, 2.6-32.4%; P = 0.02) and weighted analyses (11.5% versus 28.4%; risk difference, 17.0%; 95% confidence interval, 1.5-32.5%; P = 0.03) than pulse glucocorticoid therapy alone.

CONCLUSIONS

This retrospective cohort study using a national database suggests that therapeutic plasma exchange may improve the in-hospital prognosis of anti-GBM disease with dialysis-dependent kidney failure and without diffuse alveolar hemorrhage.

Cilostazol versus Aspirin or Clopidogrel for Reducing Post-Stroke Aspiration Pneumonia: A Nationwide Retrospective Cohort Study

INTRODUCTION

The association between the use of cilostazol as a post-stroke antiplatelet medication and a reduction in post-stroke pneumonia has been suggested. However, whether cilostazol has a greater preventive effect against post-stroke aspiration pneumonia (AP) than other antiplatelet medications remains unclear. Thus, this study aimed to evaluate whether cilostazol has a greater preventive effect against post-stroke AP than aspirin or clopidogrel.

METHODS

Through the Japanese Diagnosis Procedure Combination database, we identified patients who were hospitalized for ischemic stroke between April 2012 and September 2019. We performed 1:1 propensity score matching between patients who received cilostazol alone at discharge and those who received aspirin or clopidogrel alone at discharge. The primary outcome was the 90-day readmission for post-stroke AP. The occurrence of recurrent ischemic stroke within 90 days was also evaluated.

RESULTS

Among the 305,543 eligible patients with ischemic stroke, 65,141 (21%), 104,157 (34%), and 136,245 (45%) received cilostazol, aspirin, and clopidogrel, respectively. Propensity score matching generated 65,125 pairs. The cilostazol group had a higher proportion of 90-day post-stroke readmissions with AP than the aspirin or clopidogrel groups (1.5% vs. 1.2%, p < 0.001). The proportion of patients with recurrent ischemic stroke within 90 days was also higher in the cilostazol group (2.4% vs. 2.2%, p = 0.017).

CONCLUSION

The present study suggests that cilostazol may not have a greater effect on preventing post-stroke AP within 90 days than other antiplatelet medications. Nevertheless, further randomized controlled trials with longer follow-up periods are warranted.

Bevacizumab-induced proteinuria and its association with antihypertensive drugs: A retrospective cohort study using a Japanese administrative database

Proteinuria is a major side-effect of the anti-tumor drug bevacizumab, although its incidence and risk factors in the real world are still unclear. Although renin-angiotensin-aldosterone system inhibitors are used clinically to prevent proteinuria, their efficacy remains unclear. The aim of the present study was to reveal the incidence and risk factors of bevacizumab-induced proteinuria and examine the effectiveness of antihypertensive drugs in preventing proteinuria. We conducted a retrospective cohort study using the National Hospital Organization Clinical Data Archives and Medical Information Analysis Databank. Hospitalized patients who received bevacizumab between January 1, 2016, and June 30, 2019, were included. The study outcome was proteinuria within 12 months of bevacizumab administration. Patient characteristics, laboratory tests, and medications were compared between patients with and without proteinuria using multivariable logistic regression analysis. Among the 2,458 patients, 27% developed proteinuria after bevacizumab administration. Nursing dependence (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.89-3.05; P<0.001) and systolic blood pressure ≥140 mmHg (OR, 1.44; 95% CI, 1.17-1.79; P<0.001) were identified as risk factors. Patients with an estimated glomerular filtration rate (eGFR) of 60-89, 45-59, and <45 mL/min/1.73 m2 had 29.7%, 76.8%, and 66.0% higher odds of proteinuria, respectively, than those with an eGFR ≥90 mL/min/1.73 m2. No significant relationship was observed between antihypertensive drugs and the occurrence of proteinuria. More patients may suffer from proteinuria after bevacizumab administration than previously reported. Nursing dependence and systolic blood pressure are predictive risk factors for bevacizumab-induced proteinuria. Patients at risk of proteinuria should be closely monitored.

Effect modification of the association between temperature variability and hospitalization for cardiovascular disease by comorbid diabetes mellitus: A nationwide time-stratified case-crossover analysis

AIMS

We aimed to explore the association between short-term exposure to temperature variability (TV), and cardiovascular hospitalization stratified by the presence of comorbid diabetes.

METHODS

We collected data on nationwide hospitalization for cardiovascular diseases and daily weather conditions during 2011-2018 in Japan. TV was calculated as the standard deviation of daily minimum and maximum temperatures within 0-7 lag days. We applied a two-stage time-stratified case-crossover design to estimate the association between TV and cardiovascular hospitalization with and without comorbid diabetes, adjusting for temperature and relative humidity. Furthermore, specific cardiovascular disease causes, demographic characteristics, and seasons were used for stratification.

RESULTS

In 3,844,910 hospitalizations for cardiovascular disease, each 1 °C increase in TV was associated with a 0.44% (95% CI: 0.22%, 0.65%) increase in the risk of cardiovascular admission. We observed a 2.07% (95% CI: 1.16%, 2.99%) and 0.61% (95% CI: -0.02%, 1.23%) increase per 1 °C in risk of heart failure admission in individuals with and those without diabetes, respectively. The higher risk among individuals with diabetes was mostly consistent in the analyses stratified by age, sex, body mass index, smoking status, and season.

CONCLUSION

Comorbid diabetes may increase susceptibility to TV in relation to acute cardiovascular disease hospitalization.

Treatment and outcome of hepatorenal syndrome in Japan: a retrospective cohort study using a national inpatient database

BACKGROUND

Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease. This study aimed to clarify the status of HRS in Japan by analyzing the Japanese Diagnosis Procedure Combination database.

METHODS

Patients hospitalized for cirrhosis and HRS from July 2010 to March 2019 were sampled. They were divided into two groups according to their prognosis upon discharge: the transplant-free survival group and the death or liver transplantation group. The two groups' baseline patient characteristics and treatments were compared.

RESULTS

The mean age of the 1,412 participants was 67.3 years (standard deviation: 12.3 years), and 65.4% were male. The Child-Pugh grades was B and C in 18.8% and 81.2%, respectively. Hepatocellular carcinoma was present in 27.1% of the patients, and the proportion of spontaneous bacterial peritonitis was 2.3%. Albumin, noradrenaline, and dopamine were administered to 57.9%, 8.0%, and 14.9% of the patients, respectively; 7.0% of the patients underwent renal replacement therapy; and 5.0% were admitted to the intensive care unit. Intravenous antibiotics were administered to 30.8% of the patients. A total of 925 patients (65.5%) died or underwent liver transplantation. In addition to a higher proportion of patients with poor baseline liver function, the death or liver transplantation group included more males, patients with hepatocellular carcinoma, and those with spontaneous bacterial peritonitis.

CONCLUSIONS

HRS in Japan has a high mortality rate. Albumin was administered to over 50% of participants. Although noradrenaline is recommended in Japanese clinical guidelines, dopamine was more frequently used as a vasoconstrictor in clinical practice.

Association between the type of hypnotic drug and in-hospital fractures in older patients with neurocognitive disorders: A case-control study using a nationwide database

AIM

Hypnotics might increase the risk of falls and fractures in older patients with neurocognitive disorders. Orexin receptor antagonists have recently been approved, but the relationship between the new drugs and fractures remains unclarified. This study aimed to evaluate the association between the type of hypnotic and in-hospital fractures in older patients with neurocognitive disorders using a nationwide inpatient database.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we collected information on inpatients aged ≥65 years with neurocognitive disorders between April 2014 and March 2021. We examined trends in the prescription patterns of benzodiazepine drugs, Z-drugs, orexin receptor antagonists and melatonin receptor agonists. We also carried out a 1:4 matched case-control analysis of in-hospital fractures. The odds ratio of each hypnotic drug was estimated using a generalized estimating equation with adjustment for walking ability, comorbidities, osteoporosis, dialysis, selective serotonin reuptake inhibitor use and anti-dementia drug use.

RESULTS

The prescription of benzodiazepine hypnotics decreased and that of orexin receptor antagonists increased. This case-control analysis included 6832 patients with fractures and 23 463 controls. Ultrashort-acting benzodiazepines, short-acting benzodiazepines and Z-drugs were associated with an increased risk of bone fracture (odds ratio [95% confidence interval] 1.38 [1.08-1.77], 1.38 [1.27-1.50], 1.49 [1.37-1.61], respectively). Orexin receptor antagonists were not associated with an increased risk of bone fracture (1.07 [0.95-1.19]).

CONCLUSIONS

In contrast to other types of hypnotics, orexin receptor antagonists were not associated with in-hospital fractures in older patients with neurocognitive disorders. Geriatr Gerontol Int 2023; ••: ••-••.

Association between ambient temperature and cause-specific cardiovascular disease admissions in Japan: A nationwide study

BACKGROUND

Substantial evidence suggests that non-optimal temperatures can increase the risk of cardiovascular disease (CVD) mortality and morbidity; however, limited studies have reported inconsistent results for hospital admissions depending on study locations, which also lack national-level investigations on cause-specific CVDs.

METHODS

We performed a two-stage meta-regression analysis to examine the short-term associations between temperature and acute CVD hospital admissions by specific categories [i.e., ischemic heart disease (IHD), heart failure (HF), and stroke] in 47 prefectures of Japan from 2011 to 2018. First, we estimated the prefecture-specific associations using a time-stratified case-crossover design with a distributed lag nonlinear model. We then used a multivariate meta-regression model to obtain national average associations.

RESULTS

During the study period, a total of 4,611,984 CVD admissions were reported. We found cold temperatures significantly increased the risk of total CVD admissions and cause-specific categories. Compared with the minimum hospitalization temperature (MHT) at the 98^th percentile of temperature (29.9 °C), the cumulative relative risks (RRs) for cold (5^th percentile, 1.7 °C) and heat (99^th percentile, 30.5 °C) on total CVD were 1.226 [95% confidence interval (CI): 1.195, 1.258] and 1.000 (95% CI: 0.998, 1.002), respectively. The RR for cold on HF [RR = 1.571 (95% CI: 1.487, 1.660)] was higher than those of IHD [RR = 1.119 (95% CI: 1.040, 1.204)] and stroke [RR = 1.107 (95% CI: 1.062, 1.155)], comparing to their cause-specific MHTs. We also observed that extreme heat increased the risk of HF with RR of 1.030 (95% CI: 1.007, 1.054). Subgroup analysis showed that the age group ≥85 years was more vulnerable to these non-optimal temperature risks.

CONCLUSIONS

This study indicated that cold and heat exposure could increase the risk of hospital admissions for CVD, varying depending on the cause-specific categories, which may provide new evidence to reduce the burden of CVD.

Validation studies of Japanese administrative health care data: A scoping review

Large-scale administrative health care databases are increasingly being utilized for research. However, there has not been much literature that validated administrative data in Japan; a previous review identified six validation studies published between 2011 and 2017. We conducted a literature review of studies that assessed the validity of Japanese administrative health care data. We searched for studies published by March 2022 that compared individual-level administrative data with a reference standard from another data source, as well as studies that validated administrative data using other data within the same database. The eligible studies were also summarized based on characteristics which included data types, settings, reference standard used, numbers of patients, and conditions validated. There were 36 eligible studies, including 29 that used external reference standard and seven that validated administrative data using other data within the same database. Chart review was the reference standard in 21 studies (range of the numbers of patients, 72 to 1,674; 11 studies conducted in single institutions and nine studies in 2-5 institutions). Five studies used a disease registry as the reference standard. Diagnoses of cardiovascular diseases, cancer, and diabetes were frequently evaluated. Validation studies are being conducted at an increasing rate in Japan, although most of them are small scale. Further large-scale comprehensive validation studies are necessary to effectively utilize the databases for research. This article is protected by copyright. All rights reserved.

Factors Associated With the Development of Bacterial Pneumonia Related to Seasonal Influenza Virus Infection: A Study Using a Large-scale Health Insurance Claim Database

Background

Influenza-related bacterial pneumonia is a leading complication of influenza infection. However, the differences in the incidence rates and risk factors associated with concomitant viral/bacterial pneumonia (CP) and secondary bacterial pneumonia following influenza (SP) remain unclear. This study aimed to clarify the incidence rates of CP and SP following seasonal influenza and identify factors associated with their development.

Methods

This retrospective cohort study was conducted using the JMDC Claims Database, a health insurance claims database in Japan. All patients aged <75 years who developed influenza during 2 consecutive epidemic seasons, 2017/2018 and 2018/2019, were analyzed. CP was defined as bacterial pneumonia diagnosed between 3 days before and 6 days after the date of influenza diagnosis, and SP was defined as pneumonia diagnosed 7-30 days after the date of diagnosis. Multivariable logistic regression analyses were performed to identify factors associated with the development of CP and SP.

Results

Among the 10 473 014 individuals registered in the database, 1 341 355 patients with influenza were analyzed. The average age at diagnosis (SD) was 26.6 (18.6) years. There were 2901 (0.22%) and 1262 (0.09%) patients who developed CP and SP, respectively. Age 65-74 years, asthma, chronic bronchitis/emphysema, cardiovascular disease, renal disease, malignant tumor, and immunosuppression were significant risk factors for both CP and SP, whereas cerebrovascular disease, neurological disease, liver disease, and diabetes were risk factors specific to CP development.

Conclusions

The results determined the incidence rates of CP and SP and identified their risk factors, such as older age and comorbidities.

Duration of influenza vaccine effectiveness in the elderly in Japan: A retrospective cohort study using large-scale population-based registry data

BACKGROUND

The immune response to influenza vaccination in the elderly is likely to be lower than that in young adults. Clinical protection may not persist year-round in the elderly. However, the effectiveness of influenza vaccine in the elderly has not been adequately studied, especially in terms of the duration of effectiveness.

METHODS

We used a linked database of healthcare administrative claims data and vaccination records maintained by the municipality of a city in Kanto region of Japan. We studied individuals who were aged 65 years or older at baseline and were followed up between April 1, 2014 to March 31, 2020. The duration of influenza vaccine effectiveness by age category was analyzed using a time-dependent piecewise Cox proportional hazard model with time-dependent vaccine status, prior season vaccination and covariates confirmed in the baseline period (age, sex, cancer, diabetes, chronic obstructive pulmonary diseases, asthma, chronic kidney diseases, and cardiovascular diseases).

RESULTS

We identified an analysis population of 83,146 individuals, of which 7,401 (8.9%) had experienced influenza and 270 (0.32%) underwent influenza-related hospitalization. Individuals who were vaccinated during the first season (n = 47,338) were older than non-vaccinated individuals (n = 35,808) (average age, 75.8 vs. 74.1 years, respectively). The multivariable analysis showed a lower incidence of influenza in vaccinated individuals (hazard ratio [HR], 0.47; 95% confidence interval [CI], 0.43-0.51; P < 0.001), while the incidence of hospitalization for influenza did not differ significantly by vaccination status (HR, 0.79; 95% CI, 0.53-1.18; P = 0.249). Protective effectiveness against incidence was maintained for 4 or 5 months after vaccination in those aged 65-69 and 80-years, 5 months in 70-79 years.

CONCLUSIONS

Our study identified moderate vaccine effectiveness in preventing the incidence of influenza in the Japanese elderly. Vaccine effectiveness showed a trend of gradual attenuation. Clinicians should suspect influenza infection even in those vaccinated, especially in elderly individuals who had received vaccination more than 4 or 5 months previously.

Effect of the 23-valent pneumococcal polysaccharide vaccine on the incidence of hospitalisation with pneumonia in adults aged ≥65 years: retrospective cohort study using a population-based database in Japan

OBJECTIVES

The effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in preventing pneumonia in older adults remains controversial. Some studies have suggested differences in the effectiveness according to age or sex.

METHODS

We conducted an observational study using the database of vaccine subsidisation data and health insurance claims data for a city in Japan. Participants were residents from 2014 to 2018 turning 65, 70, 75, 80, 85, 90 or 95 years during a given fiscal year, and PPV23 during the first year of observation were identified. We matched vaccinated and non-vaccinated individuals of the same age using propensity scores for vaccination. Incidence of hospitalisation with pneumonia was compared using Fine-Gray regression model. We summarised the results for each age using random-effects meta-analysis and conducted a subgroup analysis by sex.

RESULTS

A total of 102,136 participants were included, of whom 35% received PPV23. Propensity score matching selected 32,510 pairs of vaccinated and non-vaccinated individuals. Overall, PPV23 administration was associated with a decreased incidence of hospitalisation with pneumonia (17.2 vs. 20.4 per 1,000 person-years, sub-distribution hazard ratio: 0.84, 95% confidence interval: 0.77 to 0.91). Vaccine effectiveness was highest among those aged 70 years and decreased with increasing age. No statistically significant effect was observed in those aged 90 or 95 years. Vaccine effectiveness was observed in both males and females.

CONCLUSIONS

PPV23 was associated with an overall decrease in hospitalisation with pneumonia in older adults. However, vaccine effectiveness was significant in those aged 65 to 85 years but not in older population.

Institutional Variance in Mortality after Percutaneous Coronary Intervention for Acute Myocardial Infarction in Korea, Japan, and Taiwan

BACKGROUND

Although there have been studies that compared outcomes of patients with acute myocardial infarction (AMI) across countries, little focus has been placed on institutional variance of outcomes. The aim of the present study was to compare institutional variance in mortality following percutaneous coronary intervention (PCI) for AMI and factors explaining this variance across different health systems.

METHODS

Data on inpatients who underwent PCI for AMI in 2016 were obtained from the National Health Insurance Data Sharing Service in Korea, the Diagnosis Procedure Combination (DPC) Study Group Database in Japan, and the National Health Insurance Research Database (NHIRD) in Taiwan. Multilevel analyses with inpatient mortality as the outcome and the hierarchical structure of patients nested within hospitals were conducted, adjusting for common patient-level and hospital-level variables. We compared the intraclass correlation coefficient (ICC) and the proportion of variance explained by hospital-level characteristics across the three health systems.

RESULTS

There were 17 351 patients from 160 Korean hospitals, 29 804 patients from 660 Japanese hospitals, and 10 863 patients from 104 Taiwanese hospitals included in the analysis. Inpatient mortality rates were 6.3%, 7.3%, and 6.0% in Korea, Japan, and Taiwan, respectively. After adjusting for patient and hospital characteristics, Taiwan had the lowest variation in mortality (ICC, 1.8%), followed by Korea (2.2%) and then Japan (4.5%). The measured hospital characteristics explained 38%, 19%, and 9% of the institutional variance in Korea, Taiwan, and Japan, respectively.

CONCLUSION

Korea, Japan, and Taiwan had similarly uniform outcomes across hospitals for patients undergoing PCI for AMI. However, Japan had a relatively large institutional variance in mortality and a lower proportion of variation explainable by hospital characteristics, compared with Korea and Taiwan.

Validity of Algorithms to Identify Patients With Glaucoma Using the Japanese Claims Data

PRCIS

Diagnostic or antiglaucoma drug records in the Japanese claims data showed a high validity in identifying glaucoma patients. Specific subtypes were identified with high specificity and negative predictive values but low sensitivity and positive predictive values.

PURPOSE

Despite the widespread use of administrative claims data in epidemiological research on glaucoma, only a few studies have investigated the validity of the methods in defining patients with glaucoma using diagnoses and drug records. We aimed to evaluate the validity of these algorithms in identifying patients with glaucoma using the Japanese claims data.

METHODS

Two ophthalmologists independently reviewed the medical charts and administrative claims data of 500 randomly selected patients who visited the Department of Ophthalmology of an academic hospital in 2019. We constructed 12 algorithms to identify patients with any type and specific subtypes of glaucoma using the claims records of diagnosis, antiglaucoma drugs, and visual field tests. We regarded the diagnosis of glaucoma based on the medical charts as the reference standard and calculated the sensitivity, specificity, and positive and negative predictive values of each algorithm based on the claims data.

RESULTS

The algorithms of ≥1 diagnostic record per year and ≥1 antiglaucoma drug record per year exhibited sensitivities of 94.6% and 89.2%, respectively, and specificities of 88.9% and 98.3%, respectively. An increase in the frequency of records resulted in a decreased sensitivity and slightly increased specificity. The addition of visual field tests did not improve the validity. The algorithms for specific subtypes of glaucoma exhibited high specificity and relatively low sensitivity.

CONCLUSION

Diagnostic or antiglaucoma drug records in the Japanese claims data were useful for identifying patients with glaucoma. Researchers should select identification algorithms based on the study design.

Ocular Adverse Events after Coronavirus Disease 2019 mRNA Vaccination: Matched Cohort and Self-Controlled Case Series Studies Using a Large Database

PURPOSE

To investigate the risk of ocular adverse events after Coronavirus Disease 2019 (COVID-19) mRNA vaccination.

DESIGN

Matched cohort and self-controlled case series (SCCS) studies.

PARTICIPANTS

We used a population-based database of medical claims and vaccination records in a large Japanese city. In the matched cohort study, we identified individuals who received COVID-19 vaccination (BNT162b2) from February 2021 to September 2021. One control was selected from nonvaccinated individuals by matching time, date of birth, sex, Charlson comorbidity index, and the enrollment period for health insurance. In the SCCS study, we analyzed individuals who developed ocular adverse events.

METHODS

In the matched cohort study, we applied the Kaplan-Meier estimator to estimate the cumulative incidence of ocular adverse events over 21 days after the first dose and 84 days after the second dose. In the SCCS method, we used conditional Poisson regression to estimate the incidence rate ratio (IRR) of ocular adverse events during the risk periods (0-21 days after the first dose and 0-84 days after the second dose) compared with the remaining periods.

MAIN OUTCOME MEASURES

Composite outcome of uveitis, scleritis, retinal vein occlusion (RVO), and optic neuritis.

RESULTS

There were 99 718 pairs eligible for the matched cohort study after the first dose (mean age, 69.3 years; male, 44%). The vaccinated and control groups developed 29 and 21 events, respectively, over 21 days after the first dose, and 79 and 28 events, respectively, over 84 days after the second dose. The differences in cumulative incidence (reference, the control group) were 2.9 (95% confidence interval, -14.5 to 19.1) events/100 000 persons and 51.3 (16.2-84.3) events/100 000 persons, respectively, for the first and second doses. The SCCS study showed the IRRs of 0.89 (0.62-1.28) and 0.89 (0.71-1.11) for the first and second doses, respectively.

CONCLUSIONS

The matched cohort analysis found an increased risk for the composite outcome after the second dose; however, the SCCS analysis showed no increased risk. Considering that the SCCS can cancel out time-invariant confounders, the current results suggest that COVID-19 vaccination is unlikely to causally increase the risk of ocular adverse events.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Validity of diagnoses of respiratory diseases recorded in a Japanese administrative database

BACKGROUND

Validating the information recorded in administrative databases is essential. However, no study has comprehensively validated the accuracy of Japanese Diagnosis Procedure Combination (DPC) data on various respiratory diseases. Therefore, this study aimed to evaluate the validity of diagnoses of respiratory diseases in the DPC database.

METHODS

We conducted chart reviews of 400 patients hospitalized in the departments of respiratory medicine in two acute-care hospitals in Tokyo, between April 1, 2019 and March 31, 2021, and used them as reference standards. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DPC data on 25 respiratory diseases were determined.

RESULTS

Sensitivity ranged from 22.2% (aspiration pneumonia) to 100% (chronic eosinophilic pneumonia and malignant pleural mesothelioma) and was <50% for eight diseases, while specificity was >90% for all diseases. PPV ranged from 40.0% (aspiration pneumonia) to 100% (coronavirus disease 2019, bronchiectasis, chronic eosinophilic pneumonia, pulmonary hypertension, squamous cell carcinoma, small cell carcinoma, lung cancer of other histological types, and malignant pleural mesothelioma) and was >80% for 16 diseases. Except for chronic obstructive pulmonary disease (82.9%) and interstitial pneumonia (other than idiopathic pulmonary fibrosis) (85.4%), NPV was >90% for all diseases. These validity indices were similar in both hospitals.

CONCLUSIONS

The validity of diagnoses of respiratory diseases in the DPC database was high in general, thereby providing an important basis for future studies.

Prednisolone versus cyclosporine as initial treatment for Kawasaki disease

BACKGROUND

Several studies have demonstrated the efficacy of prednisolone and cyclosporine as initial combination treatments for the prevention of coronary artery abnormalities (CAA) in patients with Kawasaki disease. However, whether prednisolone or cyclosporine results in superior clinical outcomes is unknown. Thus, this study aimed to compare the outcomes of these two treatments.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients with Kawasaki disease who had received prednisolone or cyclosporine in addition to initial intravenous immunoglobulin treatment between April 2014 and March 2021. The primary outcome was the proportion of CAA; secondary outcomes included intravenous immunoglobulin resistance, medical costs, and length of hospital stay. Propensity score matching was conducted to compare outcomes between the two groups.

RESULTS

We identified 6288 patients with Kawasaki disease who had received prednisolone (n = 6147) or cyclosporine (n = 141) as an initial treatment in combination with intravenous immunoglobulin. Four-to-one propensity score-matched analysis demonstrated no significant difference in the proportion of CAA (0.7% vs. 2.8%; p = 0.098), intravenous immunoglobulin resistance, or medical costs between the treatment groups. The length of hospital stay was significantly longer in the prednisolone group (14 vs. 11 days, p < 0.001).

CONCLUSIONS

Prednisolone and cyclosporine used in the initial combination treatment for Kawasaki disease showed similar clinical outcomes regarding the risk of CAA, intravenous immunoglobulin resistance, and medical costs, whereas the length of hospital stay was longer in the prednisolone group than in the cyclosporine group.

Predictive Factors for Oral Intake Recovery After Acute Stroke: Analysis of a Japanese Nationwide Inpatient Database

OBJECTIVE

It remains unclear which factors contribute to dysphagia recovery after an acute stroke. This study aimed to identify factors associated with complete oral intake recovery in patients with post-stroke dysphagia.

METHODS

Data were obtained from the Diagnosis Procedure Combination database, which is a nationwide database of administrative claims and discharge abstracts in Japan. We selected patients admitted within 3 days of stroke onset and conducted multivariable logistic regression analysis. Total oral intake within 30 days of admission was the primary outcome measure.

RESULTS

A total of 151,302 patients were included, and total oral intake was observed in 48% of them within 30 days of admission. Total oral intake was significantly associated with age, sex, stroke subtype, consciousness disturbance, low body mass index, multiple comorbidities, and the modified Rankin Scale before stroke onset. In addition, males had worse outcomes than females (odds ratio, 0.75; 95% confidence interval, 0.73-0.77, p < 0.001), and intracerebral and subarachnoid hemorrhagic stroke subtypes were associated with non-recovery.

CONCLUSION

This study identified several prognostic factors for total oral intake in patients with acute stroke. These results may be useful for predicting a patient's dysphagia prognosis at the time of admission and designing a nutritional management plan for patients with acute stroke.

Comparative Effectiveness of BNT162b2 and mRNA-1273 Booster Dose After BNT162b2 Primary Vaccination Against the Omicron Variants: A Retrospective Cohort Study Using Large-Scale Population-Based Registries in Japan

BACKGROUND

Direct comparative effectiveness of booster doses of BNT162b2 and mRNA-1273 after BNT162b2 primary vaccination is unknown.

METHODS

We investigated comparative effectiveness of BNT162b2 and mRNA-1273 booster dose using data from registry systems for vaccination and coronavirus disease 2019 (COVID-19) infection in a local city in Japan. We followed participants aged ≥16 years who completed the BNT162b2 primary vaccination between 22 November 2021, and 15 April 2022. We collected information on age, sex, vaccination status, vaccine type, and infection status. Age was categorized as 16-44, 45-64, 65-84, and ≥85 years. Vaccine effectiveness for mRNA-1273 and no booster vaccination against BNT162b2 was estimated using age-stratified Cox regression adjusted for age, sex, and days since the second vaccination. The estimated hazard ratios for mRNA-1273 and no booster vaccinations were integrated separately using random effects meta-analyses.

RESULTS

During the study period, we identified 62 586 (40.4%), 51 490 (33.2%), and 40 849 (26.4%) participants who received BNT162b2, mRNA-1273, and no booster dose, respectively. The median age was 69, 71, and 47 years for BNT162b2, mRNA-1273, and no booster dose, respectively. The integrated hazard ratio with reference to BNT162b2 was 1.72 for no booster vaccination and 0.62 for mRNA-1273. The comparative effectiveness of mRNA-1273 was similar across age categories.

CONCLUSIONS

Both homologous and heterologous vaccinations are effective against Omicron variants. In the head-to-head comparison, the effect was stronger in people who received heterologous vaccination than in those who received homologous vaccination. These findings may help improve logistics and decision making in future vaccination programs.

Association between comprehensive geriatric assessment and polypharmacy at discharge in patients with ischaemic stroke: A nationwide, retrospective, cohort study

BACKGROUND

Polypharmacy and its adverse drug events are a major healthcare challenge related to falls, hospitalisations and mortality. Comprehensive geriatric assessment (CGA) may contribute to polypharmacy improvement, however, there is no clear evidence so far.

METHODS

Using a national inpatient database in Japan from April 1, 2014 to March 31, 2018, we investigated the association between CGA and polypharmacy. We identified patients aged ≥65 years admitted for ischaemic stroke who could receive oral medications. Propensity score matching was conducted for patients with and without CGA during hospitalisation. The outcomes were polypharmacy (defined as use of five or more types of oral medications) at discharge, the number of medication types prescribed at discharge, and the difference between the numbers of medication types prescribed on admission and at discharge.

FINDINGS

A total of 162,443 patients were analysed, of whom 39,356 (24·2%) received CGA, and propensity score matching identified 39,349 pairs. Compared with non-CGA group, the CGA group had a significantly lower proportion of polypharmacy at discharge (34·3% vs. 32·9%, p < 0·001) and a smaller number of medication types prescribed at discharge (3·84 vs. 3·76, p < 0·001).

INTERPRETATION

This study shows the clear evidence that there is a positive relationship between CGA and a reduction in the number of medications in older inpatients with ischaemic stroke.

FUNDING

The Ministry of Health, Labour and Welfare, Japan and the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Maoto plus neuraminidase inhibitor versus neuraminidase inhibitor alone for reducing hospitalization in older adults with seasonal influenza

BACKGROUND

Maoto is a Japanese Kampo formula used for treating febrile illnesses. However, researchers have not yet clarified its effect in preventing severe influenza among older adults. We evaluated the association between the addition of maoto to a neuraminidase inhibitor in older adults and reduced hospitalization following influenza.

METHODS

Using a prefecture-wide health insurance claims database, we identified outpatients aged ≥60 years who were diagnosed with influenza between September 2012 and August 2017. We performed one-to-one propensity score matching between patients who received maoto in addition to a neuraminidase inhibitor and those who received a neuraminidase inhibitor alone. Hospitalization within 7 days of influenza diagnosis was compared using the McNemar's test. We performed subgroup analyses based on sex, age, and other characteristics.

RESULTS

We identified 57,366 eligible patients with influenza. Maoto was used in 8.1% of these patients. In 4,630 matched pairs, the 7-day hospitalization rate was 1.77% (n = 82) and 1.62% (n = 75) for patients with and without maoto, respectively; the difference between the groups was insignificant (P = 0.569). Subgroup analysis showed a tendency toward more hospitalizations within 7 days among patients aged 90 years or older who were prescribed maoto than those who were not (9.7% vs. 6.6%, P = 0.257).

CONCLUSIONS

Maoto use was not associated with decreased hospitalization rates in older adults with influenza. This warrants further research to evaluate the safety and effectiveness of maoto in different patient groups, particularly the oldest-old population.

Safety of topical ophthalmic antibiotics in pregnant women with hordeola, chalazia, blepharitis, or bacterial conjunctivitis: propensity score analyses

OBJECTIVE

To investigate the association between exposure to topical ophthalmic antibiotics during pregnancy and adverse neonatal outcomes.

METHODS

In this retrospective cohort study, we identified pregnant women with hordeola, chalazia, blepharitis, or bacterial conjunctivitis from 2005 to 2018 using the Japanese Medical Data Centre Claims Database. From the eligible women, we extracted women who were dispensed no topical antibiotics during the first trimester (non-antibiotic group), women who were dispensed topical fluoroquinolones alone at least once (fluoroquinolone alone group), and women who were dispensed any single type of antibiotic (single-antibiotic group). We compared the frequency of congenital anomalies (CA), preterm birth (PB), low birth weight (LBW), and the composite outcome of these three between the fluoroquinolone and non-antibiotic groups and between the single-antibiotic and non-antibiotic groups, using propensity score adjustment.

RESULTS

A total of 891 eligible women were identified. In the fluoroquinolone (n = 409) and non-antibiotic (n = 309) groups, CA occurred in 6.8% and 6.8%, PB in 2.4% and 3.2%, LBW in 2.9% and 3.2%, and the composite outcome in 10.5% and 11.3%, respectively. Analysis using propensity score adjustment showed no significant difference between the groups in the frequency of CA (adjusted odds ratio, 1.15; 95% confidence interval, 0.61-2.18), PB (0.80; 0.30-2.17), LBW (1.08; 0.45-2.63), or the composite outcome (1.12; 0.67-1.87). Comparison of the single-antibiotic and non-antibiotic groups showed similar results.

CONCLUSIONS

Topical ophthalmic antibiotics for hordeola, chalazia, blepharitis, or bacterial conjunctivitis during the first trimester were not associated with increased adverse neonatal outcomes.

Safety of Japanese herbal Kampo medicines for the treatment of depression during pregnancy

OBJECTIVE

To clarify the fetal safety of herbal Kampo medicines, including Hange-koboku-to, Koso-san, Nyoshin-san, Yokukansan, Yokukansan-kachinpi-hange, Saiko-keishikankyo-to, Keishi-karyukotu-borei-to, and Kanbaku-taisou-to, when administered to pregnant women with depression using a large healthcare administrative database.

METHODS

We extracted data from the JMDC Claims Database (2005-2018) for this retrospective cohort study of pregnant women aged 19 years or older admitted to obstetric clinics or hospitals for delivery. Participants were classified into four groups: those without depression, those diagnosed with depression without medication, those given Kampo medicines for depression, and those given western medicines for depression. Neonatal outcomes (congenital anomalies, low birth weight, and preterm birth) were considered as the safety outcome measures.

RESULTS

We identified 179 707 eligible mothers. The adverse outcomes did not differ significantly between participants receiving Kampo medicine and those not diagnosed with depression during pregnancy. The proportion of low-birth-weight neonates did not differ significantly between the Kampo medicine and non-depression groups (adjusted odds ratio [aOR] 1.28; 95% confidence interval [CI] 0.86-1.91), but was significantly higher in the unmedicated depression group (aOR 1.31; 95% CI 1.07-1.61) and western medicine group (aOR 1.47; 95% CI 1.18-1.83).

CONCLUSION

Kampo medicines are safe for treating depression during pregnancy without increasing the incidence of congenital anomalies, low birth weight, or preterm birth.

Factors Associated with Surgical Treatment in Postpartum Women with Mastitis or Breast Abscess: A Retrospective Cohort Study

Objective: The aim of this study was to identify factors associated with requiring surgical treatment for mastitis or breast abscess in postpartum mothers. Materials and Methods: This was a retrospective cohort study using the Japan Medical Data Center Claims Database. Information on pairs of infants born between April 2012 and December 2016 and their mothers were extracted. Data regarding the baseline characteristics, medical history, medical practice, and prescription drugs of mothers and their infants were collected. Multivariable logistic regression analysis was used to examine factors associated with undergoing surgical treatment. Results: The data of 69,363 eligible mothers were analyzed. The proportion of mothers who were diagnosed with mastitis or breast abscess within 1 year after childbirth was 10.8% (7,516/69,363). There were 114 mothers who underwent surgical treatment within 1 year after childbirth. This was 0.2% of all mothers and 1.5% of those diagnosed with mastitis or breast abscess. Surgical treatment was significantly associated with mothers having their first child (adjusted odds ratio [AOR], 2.58; 95% confidence interval [CI], 1.63-4.07) compared to those with a second or later child; it was also significantly associated with the diagnosis of breast abscess (AOR, 10.38; 95% CI, 5.28-20.40). Conclusions: This was the first report of the prevalence of mastitis or breast abscess and the requirement for surgical treatment among postpartum mothers in Japan. A first diagnosis of breast abscess and having a first child were associated with requiring surgical treatment. Health care professionals providing postpartum care should be aware of these factors.

Development of Deep Learning Models for Predicting In-Hospital Mortality Using an Administrative Claims Database: Retrospective Cohort Study

BACKGROUND

Administrative claims databases have been used widely in studies because they have large sample sizes and are easily available. However, studies using administrative databases lack information on disease severity, so a risk adjustment method needs to be developed.

OBJECTIVE

We aimed to develop and validate deep learning-based prediction models for in-hospital mortality of acute care patients.

METHODS

The main model was developed using only administrative claims data (age, sex, diagnoses, and procedures on the day of admission). We also constructed disease-specific models for acute myocardial infarction, heart failure, stroke, and pneumonia using common severity indices for these diseases. Using the Japanese Diagnosis Procedure Combination data from July 2010 to March 2017, we identified 46,665,933 inpatients and divided them into derivation and validation cohorts in a ratio of 95:5. The main model was developed using a 9-layer deep neural network with 4 hidden dense layers that had 1000 nodes and were fully connected to adjacent layers. We evaluated model discrimination ability by an area under the receiver operating characteristic curve (AUC) and calibration ability by calibration plot.

RESULTS

Among the eligible patients, 2,005,035 (4.3%) died. Discrimination and calibration of the models were satisfactory. The AUC of the main model in the validation cohort was 0.954 (95% CI 0.954-0.955). The main model had higher discrimination ability than the disease-specific models.

CONCLUSIONS

Our deep learning-based model using diagnoses and procedures produced valid predictions of in-hospital mortality.

Trends in prophylactic antibiotic use for tooth extraction from 2015 to 2018 in Japan: An analysis using a health insurance claims database

INTRODUCTION

To describe patterns in antibiotic prophylaxis for tooth extraction following the 2016 Japanese National Action Plan on Antimicrobial Resistance.

METHODS

Using a health insurance claims database, we retrospectively identified tooth extraction visits by patients aged ≥18 years from September 2015 to August 2018 and classified patients as undergoing extraction of a fully impacted or horizontally impacted mandibular wisdom tooth, being at risk of infective endocarditis or surgical site infection, or being at low risk. Antibiotic use and type of antibiotics prescribed on the day of tooth extraction were evaluated across the study period, with stratification by tooth extraction category and facility type (hospital or dental clinic).

RESULTS

We identified 662,435 patients with tooth extraction. The mean age was 42.7 years, and 57% were male. Twelve percent underwent wisdom tooth extraction, 32% were high risk, and 10% visited hospitals. The proportion of antibiotic use was 83% overall and 82% among low-risk patients. This proportion remained similar throughout the study period. A shift from third-generation cephalosporins to amoxicillin was observed from 2015 to 2018: the proportion prescribed third-generation cephalosporins decreased from 58% to 34% in hospitals and from 57% to 56% in clinics, and the proportion prescribed amoxicillin increased from 16% to 37% in hospitals and from 6% to 10% in clinics.

CONCLUSIONS

The pattern of prophylactic antibiotic use for tooth extraction gradually changed after the initiation of the National Action Plan. Further efforts are required to reduce potentially inappropriate prescriptions for low-risk patients, especially in dental clinics.

Prognosis of patients with liver cirrhosis: A multi-center retrospective observational study

AIM

Despite advances in the management of liver diseases and changes in the etiology of cirrhosis, few studies have updated the prognosis of cirrhosis. This study aimed to clarify the recent prognosis of cirrhosis and identify risk factors for death.

METHODS

In this retrospective observational study by the Hepatic Disease Network of the National Hospital Organization in Japan, chart reviews were performed to follow patients with cirrhosis beginning in 2011. We conducted Kaplan-Meier survival time analyses stratified by Child-Pugh classification and albumin-bilirubin grade. Cox regression analysis was used to identify risk factors for death.

RESULTS

We identified 444 eligible patients from 25 hospitals, including 303 (68%), 110 (25%), and 31 (7%) patients with Child-Pugh classes A, B, and C, respectively. Hepatitis C virus infection was the cause of cirrhosis for 63% of the patients. The 1-year and 5-year cumulative survival rates of patients with Child-Pugh classes A, B, and C were 90% and 61%, 78% and 42%, and 65% and 25%, respectively. The 1-year and 5-year cumulative survival rates of patients with albumin-bilirubin grades 1, 2, and 3 were 98% and 80%, 91% and 56%, and 58% and 23%, respectively. Cirrhosis classification (Child-Pugh and albumin-bilirubin), age, liver cancer, and untreated esophageal varices were associated with increased hazard of death.

CONCLUSIONS

Little improvement was observed in the prognosis of cirrhosis compared with previous reports, and the prognosis of Child-Pugh class C cirrhosis remained poor. Untreated esophageal varices were identified as a risk factor for death.

Outpatient treatment following alcohol screening at health checkups and change in drinking patterns among excessive drinkers with lifestyle-related diseases

•

General outpatient care following alcohol screening at health checkups was evaluated.

•

Database of claims data and health checkups was used for propensity score matching.

•

Outpatient care was associated with reduced drinking frequency in risky drinkers.

•

Outpatient care was not associated with improved drinking behavior in heavy drinkers.

Screening and brief interventions have been implemented in primary care settings to reduce excessive drinking. However, the effectiveness of screening and brief interventions within a health checkup setting is unclear. We assessed the effectiveness of general treatment for lifestyle-related diseases following screening for alcohol consumption at health checkups, using data on medical claims and health checkups. Participants were people with excessive drinking who met the threshold of recommendation to receive treatment for lifestyle-related diseases. We analyzed risky drinkers (drinking every day, 40–60 g/day for male and 20–60 g/day for female) and heavy drinkers (drinking every day, >60 g/day) separately. We performed one-to-one propensity score matching between people who received general outpatient treatment for lifestyle-related diseases and those who did not. Outcomes were drinking patterns (frequency and amount) and liver function at the next year's health checkup. Middle-aged males accounted for about 94% of the 23,347 participants. Eleven percent of the participants received treatment after the health checkup. After propensity score matching, among 1990 pairs of risky drinkers, those with treatment were significantly more likely to reduce their frequency of drinking (11.7% vs. 8.7%, p = 0.002) and showed lower transaminase values than those without treatment. In 575 pairs of heavy drinkers, there was no significant change in drinking patterns or liver function. Treatment in primary care after screening at health checkups was associated with the change in drinking behavior and improvement in liver condition among risky drinkers. More intensive intervention may be needed to reduce drinking in heavy drinkers.

Association between protein intake and mortality in older patients receiving parenteral nutrition: a retrospective observational study

BACKGROUND

Malnutrition of inpatients is often overlooked and remains a serious concern. However, there are few studies on the relations between infused energy and amino acid intakes and clinical outcomes in older patients on parenteral nutrition.

OBJECTIVES

We aimed to determine the short-term outcomes of infused energy and amino acid intakes in older patients receiving parenteral nutrition.

METHODS

We conducted a retrospective observational study using a national inpatient database covering >1000 hospitals in Japan. Participants were those who underwent central venous (CV) port insertion between 2011 and 2016, were aged ≥65 y, and did not have cancer. Based on the types and amounts of products used for enteral feeding and intravenous feeding on postoperative day (POD) 7 after CV port insertion, the infused energy and amino acid intakes were estimated. The primary end point was mortality on POD 90. Multivariable logistic regression was performed to investigate the relations of infused energy and amino acid intakes with mortality on POD 90.

RESULTS

A total of 10,153 patients aged ≥65 y who underwent CV port insertion were included. The mortality rates at 90 d after central venous port insertion were 14.9% and 14.0% (risk difference, 0.9%; 95% CI: -0.5%, 2.3%; P = 0.216) with infused energy intakes <20 and ≥20 kcal/kg, respectively, and 15.4% and 13.2% (risk difference, 2.2%; 95% CI: 0.9%, 3.6%; P = 0.001) with infused amino acid intakes <0.8 and ≥0.8 g/kg, respectively. The differences were retained after adjustment for multiple variables including hospital, age, sex, BMI, emergency admission, and 27 major underlying diseases. The OR for the ≥0.8-g/kg group compared with the <0.8-g/kg group was 0.87 (95% CI: 0.77, 0.99; P = 0.028).

CONCLUSIONS

A positive relation between infused amino acid intake and mortality was found in older patients receiving parenteral nutrition.

Validity of a model using routinely collected data for identifying infections following gastric, colorectal, and liver cancer surgeries

PURPOSE

Validating outcome measures is a prerequisite for using administrative databases for comparative effectiveness research. Although the Japanese Diagnosis Procedure Combination database is widely used in surgical studies, the outcome measure for postsurgical infection has not been validated. We developed a model to identify postsurgical infections using the routinely-collected Diagnosis Procedure Combination data.

METHODS

We retrospectively identified inpatients who underwent surgery for gastric, colorectal, or liver cancer between April 2016 and March 2018 at four hospitals. Chart reviews were conducted to identify postsurgical infections. We used bootstrap analysis with backwards variable elimination to select independent variables from routinely-collected diagnosis and procedure data. Selected variables were used to create a score predicting the chart review-identified infections, and the performance of the score was tested.

RESULTS

Among the 756 eligible patients, 102 patients (13%) had postoperative infections. Three variables were identified as predictors: diagnosis of infectious disease recorded as a complication arising after admission, addition of an intravenous antibiotic, and bacterial microscopy or culture. The prediction model had a C-statistic of 0.891 and pseudo-R² of 0.380. A cut-off of 1 point of the score showed a sensitivity of 92% and specificity of 71%, and a cut-off of 2 points showed a sensitivity of 77% and specificity of 91%.

CONCLUSIONS

Our model using routinely-collected administrative data accurately identified postoperative infections. Further external validation would lead to the application of the model for research using administrative databases. This article is protected by copyright. All rights reserved.

Validity of diagnoses and procedures in Japanese dental claims data

BACKGROUND

Dental claims data have been used for epidemiological studies without establishing the validity of the recorded diagnoses or procedures. The present study aimed to examine the accuracy of diagnoses, procedures, operation time, and the number of teeth recorded in dental claims data.

METHODS

We reviewed the charts of 200 patients who visited and 100 patients who were hospitalized in the Department of General Dentistry, Orthodontics, and Oral and Maxillofacial Surgery in an academic hospital between August 2012 and December 2017. The sensitivity and specificity of the dental claims data for five diseases and 15 procedures were evaluated. We assessed the difference in the number of teeth and duration of general anesthesia between claims data and chart reviews.

RESULTS

Sensitivity was more than 86% for six out of seven diagnoses except for pericoronitis (67%). Specificity ranged from 72% (periodontal disease) to 100% (oral cancer for inpatient). The sensitivity of procedures ranged from 10% (scaling for inpatient) to 100%, and the specificity ranged from 6% (food intake on the day of the surgery) to 100%. The mean (standard deviation [SD]) number of teeth in the chart review was 22.6 (6.8), and in the dental claims was 21.6 (8.6). The mean (SD) operation time was 171.2 (120.3) minutes, while the duration of general anesthesia was 270.9 (171.3) minutes.

CONCLUSIONS

The present study is the first study to validate dental claims data, and indicates the extent of usefulness of each diagnosis and procedure for future dental research using administrative data.

Infant Injury Prevention Education for Pregnant Women Attending Antenatal Class: A Quasi-Experimental Study

It is important to educate caregivers in order to prevent infant injuries. However, there have been few studies on the effects of education on pregnant women. This study aimed to evaluate the effects of injury prevention group education on this group. Study participants were recruited from a group of pregnant mothers attending an antenatal class in Tokyo. Participants were assigned to either the intervention or control group based on the month in which they attended the existing antenatal class. Both groups received a leaflet on injury prevention, but only the intervention group received an additional short one-shot lecture. The implementation of each of the nine safety practices was assessed during home visits after childbirth. Of the 131 study participants (56 in the control group and 75 in the intervention group), 106 (80.9%) received home visits after birth. Mothers in the intervention group implemented three practices significantly more than those in the control group: Keep soft objects away from the baby's head (38.3% vs. 13.0%), Do not place your baby on a high surface (74.6% vs. 52.2%), and Use the baby carrier correctly (93.3% vs. 76.1%). In the future, we plan to follow up the participants to evaluate the program's long-term effects, and to continue to improve the program.

Association between nutritional guidance or ophthalmological examination and discontinuation of physician visits in patients with newly diagnosed diabetes: A retrospective cohort study using a nationwide database

AIMS/INTRODUCTION

Discontinuation of diabetes care has been studied mostly in patients with prevalent diabetes and not in patients with newly diagnosed diabetes, whose dropout risk is highest. Because enrolling patients in a prospective study will influence adherence, we retrospectively examined whether guideline-recommended practices, defined as nutritional guidance or ophthalmological examination, can prevent patient discontinuation of diabetes care after its initiation.

MATERIALS AND METHODS

We retrospectively identified adults with newly screened diabetes during checkups using a large Japanese administrative claims database (JMDC, Tokyo, Japan) that contains laboratory data and lifestyle questionnaires. We defined discontinuation of physician visits as a follow-up interval exceeding 6 months. We divided the patients into those who received guideline-recommended practices (nutritional guidance or ophthalmology consultation) within the same month as the first visit and those who did not. We calculated propensity scores and carried out inverse probability of treatment weighting analyses to compare discontinuation between the two groups.

RESULTS

We identified 6,508 patients with at least one physician consultation for diabetes care within 3 months after their checkup, including 4,574 patients without and 1,934 with guideline-recommended practices. After inverse probability of treatment weighting, patients with guideline-recommended practices had a significantly lower proportion of discontinuation than those without (17.2% vs 21.8%; relative risk 0.79, 95% confidence interval 0.69-0.91).

CONCLUSIONS

This study is the first to show that after adjustment for both patient and healthcare provider factors, guideline-recommended practices within the first month of physician consultation for diabetes care can decrease subsequent discontinuation of physician visits in patients with newly diagnosed diabetes.

Oral corticosteroid dosage and clinical presentation of psychiatric conditions after steroid use: A consultation-liaison psychiatry service's experience

Aim

Psychiatric disturbances are the major adverse effects of corticosteroids. There are no consistent conclusions regarding changes in steroid dosage and the incidence of psychiatric conditions, due in part to the lack of consistent evaluation criteria. The purpose of this research was to determine the incidence and dose‐dependency of psychiatric conditions as assessed by trained psychiatrists.

Methods

A retrospective chart review was conducted at a university hospital in Japan. We identified inpatients receiving oral prednisolone treatment, who were referred to the consultation‐liaison psychiatry team from April 2015 to March 2018. Patients were divided into high‐dose (≥0.5 mg/kg/day) and low‐dose (<0.5 mg/kg/day) groups. We investigated the associations between steroid dosage and incidence of psychiatric conditions.

Results

A total of 93 patients (35 in the high‐dose group, 58 in the low‐dose group) were included. Various psychiatric conditions, such as insomnia, delirium, depression, and psychosis, occurred during steroid therapy. The most common condition was insomnia (72%). We observed no significant differences in the patient background characteristics and the incidence of most psychiatric conditions between the high‐dose and low‐dose groups. However, there were more patients with delirium in the low‐dose group than in the high‐dose group.

Conclusions

Based on the accurate assessment of psychiatric conditions by psychiatrists, our analysis suggests that, among inpatients referred to a consultation‐liaison psychiatry team, the incidence of psychiatric conditions, with the exception of delirium, is independent of the dose of oral prednisolone.

We investigated the differences in psychiatric symptoms and clinical features according to the dose of oral prednisolone by conducting a retrospective chart review of the 93 patients referred to our consultation‐liaison psychiatry team. The results showed that psychiatric symptoms, except for delirium, were not dose‐related.

Eye drops for dry eye disease during pregnancy and adverse neonatal outcomes: high-dimensional propensity score analyses

We investigated the association between exposure to eye drops prescribed for dry eye disease (DED) during pregnancy and adverse neonatal outcomes. Pregnant women with DED in the JMDC Claims Database (JMDC Inc., Tokyo, Japan) between 2005 and 2020 were included. According to their prescriptions during the first trimester, the women were classified into three exposed groups (hyaluronate 0.1% alone, hyaluronate 0.3% alone, and diquafosol alone) and an unexposed group (no eye drops for DED). We compared adverse neonatal outcomes (congenital anomalies, preterm birth, low birthweight, and composite outcome of these three) between the exposed and unexposed groups. We conducted a high-dimensional propensity score analysis using many variables in the database together with known potential confounders such as chronic comorbidities. We identified 4,808 eligible women, of whom 936 (19.5%) received eye drops for DED. Congenital anomalies occurred in 7.2% and 6.0%, preterm birth in 3.1% and 4.0%, low birthweight in 7.9% and 6.0%, and composite outcome in 14.9% and 12.3% of women in the hyaluronate 0.1% alone and unexposed groups, respectively. The high-dimensional propensity score analysis showed that hyaluronate 0.1% alone was not significantly associated with increases in congenital anomalies (risk difference, 0.4% [95% confidence interval, -1.9% to 2.7%]), preterm birth (-0.6% [-2.2% to 0.9%]), low birthweight (1.8% [-0.6% to 4.1%]), or composite outcome (1.9% [-1.3% to 5.1%]). Similar results were obtained in the hyaluronate 0.3% alone and diquafosol alone groups. Use of eye drops for DED in pregnant women was not associated with adverse neonatal outcomes.

Validity of initial cancer diagnoses in the Diagnosis Procedure Combination data in Japan

BACKGROUND

In Japan, the Diagnosis Procedure Combination (DPC) data have been used as a nationwide administrative hospital discharge database for clinical studies. However, few studies have evaluated the validity of recorded diagnoses of cancer in the database.

METHODS

We compared the DPC data with hospital-based cancer registries in Osaka Prefecture, Japan to assess the validity of the recorded cancer diagnoses in the DPC data. Fifteen types of cancer were included in the analysis. Cancer stage with tumor-node-metastasis (TNM) classification was assessed for eight cancer types with >400 patients. We evaluated concordance and positive predictive value of cancer diagnosis, and concordance of cancer stage between the DPC data and the hospital-based cancer registry.

RESULTS

In total, we identified 29,180 eligible patients. The five types of cancer with the highest number of patients were as follows: 6,765 (23.2 %) colorectal, 6,476 (22.2 %) stomach, 4,862 (16.7 %) breast, 4,445 (15.2 %) lung, and 2,257 (7.7 %) liver. Concordance of diagnosis ranged from 63.9 %-99.5 %, and twelve of the fifteen types of cancers had concordance of over 90 %. Positive predictive values of diagnosis ranged from 86.8 %-100 %. Regarding cancer stage, the overall degree of concordance was 67.2 % in all patients and the concordance was over 70 % in four types of cancers.

CONCLUSIONS

The DPC data had high validity of cancer diagnosis. However, the potential impact of the misclassifications and low concordance in cancer stage among specific type of cancers in the DPC data should be considered.

Effect of Branched-Chain Amino Acid Infusion on In-Hospital Mortality of Patients With Hepatic Encephalopathy and End-Stage Kidney Disease: A Retrospective Cohort Study Using a National Inpatient Database

OBJECTIVES

Renal failure and hepatic cirrhosis are mutually aggravating factors. However, no specific therapeutic strategies for hepatic encephalopathy (HE) and end-stage kidney disease have been established. The coexistence, with an extremely poor prognosis, makes randomized controlled trials unfeasible. We evaluated whether an infusion of branched-chain amino acids was associated with mortality in patients hospitalized for HE and end-stage kidney disease.

DESIGN AND METHODS

Using the Japanese Diagnosis Procedure Combination database, we retrospectively identified patients with HE and end-stage kidney disease who received hemodialysis within 2 days of admission from July 2011 to March 2017. We divided the patients into those who received branched-chain amino acid infusion within 2 days of admission and those who did not. We conducted analyses using overlap weights based on propensity scores to compare in-hospital mortality between the groups. Sub-group analysis was conducted by stratifying patients by Child-Pugh class.

RESULTS

We identified 553 eligible patients, including 503 patients who received branched-chain amino acid infusion and 50 who did not. The patients who received branched-chain amino acid infusion had lower mortality than those who did not (10.2% vs. 20.1%, relative risk 0.51, 95% confidence interval 0.27-0.95). Sub-group analysis showed that branched-chain amino acid infusion was associated with decreased in-hospital mortality in patients with Child-Pugh class C (16.2% vs. 39.0%, relative risk 0.41, 95% confidence interval 0.23-0.76).

CONCLUSIONS

Branched-chain amino acid infusion may improve the prognosis of HE in patients with end-stage kidney disease, particularly those with lower liver function. Further research is necessary to provide a suitable treatment for HE in patients with end-stage kidney disease.

Association between allergic or autoimmune diseases and incidence of endometriosis: A nested case-control study using a health insurance claims database

PROBLEM

Immune responses were reported to be associated with the pathogenesis of endometriosis. However, previous studies of an association between allergic or autoimmune diseases and endometriosis have reported inconsistent results. We investigated the association between allergic or autoimmune diseases and the incidence of endometriosis.

METHOD OF STUDY

Using a large-scale health insurance claims database in Japan, we identified patients with endometriosis diagnosed between April 2011 and August 2018. For each case, we identified up to four controls with the same age and registration month. Conditional logistic regression analyses were conducted to evaluate the incidence rate ratio (IRR) of endometriosis in women with allergic diseases (asthma, allergic rhinitis, urticaria, atopic dermatitis, allergic conjunctivitis, and type 1 allergies combined), systemic lupus erythematosus, and rheumatoid arthritis compared with women without these diseases.

RESULTS

We identified 30 516 cases with endometriosis and 120 976 control participants. Mean age at registration was 30 years. There were significant positive associations between type 1 allergy and endometriosis (IRR, 1.10; 95% confidence interval, 1.06-1.13) and between rheumatoid arthritis and endometriosis (IRR, 1.31; 95% confidence interval, 1.05-1.64). Diagnosis of systemic lupus erythematosus was not associated with increased incidence of endometriosis. Among the different allergic diseases, allergic rhinitis, urticaria, and allergic conjunctivitis were associated with the increased incidence.

CONCLUSION

Several allergic diseases were associated with an increased incidence of endometriosis. A higher incidence was also observed in patients with rheumatoid arthritis. Further studies are warranted to elucidate the influence of immune responses on the development of endometriosis.