Detection Algorithms for Gastrointestinal Perforation Cases in the Medical Information Database Network (MID-NET®) in Japan

BACKGROUND

The Medical Information Database Network (MID-NET®) in Japan is a vast repository providing an essential pharmacovigilance tool. Gastrointestinal perforation (GIP) is a critical adverse drug event, yet no well-established GIP identification algorithm exists in MID-NET®.

METHODS

This study evaluated 12 identification algorithms by combining ICD-10 codes with GIP therapeutic procedures. Two sites contributed 200 inpatients with GIP-suggestive ICD-10 codes (100 inpatients each), while a third site contributed 165 inpatients with GIP-suggestive ICD-10 codes and antimicrobial prescriptions. The positive predictive values (PPVs) of the algorithms were determined, and the relative sensitivity (rSn) among the 165 inpatients at the third institution was evaluated.

RESULTS

A trade-off between PPV and rSn was observed. For instance, ICD-10 code-based definitions yielded PPVs of 59.5%, whereas ICD-10 codes with CT scan and antimicrobial information gave PPVs of 56.0% and an rSn of 97.0%, and ICD-10 codes with CT scan and antimicrobial information as well as three types of operation codes produced PPVs of 84.2% and an rSn of 24.2%. The same algorithms produced statistically significant differences in PPVs among the three institutions. Combining diagnostic and procedure codes improved the PPVs. The algorithm combining ICD-10 codes with CT scan and antimicrobial information and 80 different operation codes offered the optimal balance (PPV: 61.6%, rSn: 92.4%).

CONCLUSION

This study developed valuable GIP identification algorithms for MID-NET®, revealing the trade-offs between accuracy and sensitivity. The algorithm with the most reasonable balance was determined. These findings enhance pharmacovigilance efforts and facilitate further research to optimize adverse event detection algorithms.

Information heterogeneity between progress notes by physicians and nurses for inpatients with digestive system diseases

This study focused on the heterogeneity in progress notes written by physicians or nurses. A total of 806 days of progress notes written by physicians or nurses from 83 randomly selected patients hospitalized in the Gastroenterology Department at Kagawa University Hospital from January to December 2021 were analyzed. We extracted symptoms as the International Classification of Diseases (ICD) Chapter 18 (R00-R99, hereinafter R codes) from each progress note using MedNER-J natural language processing software and counted the days one or more symptoms were extracted to calculate the extraction rate. The R-code extraction rate was significantly higher from progress notes by nurses than by physicians (physicians 68.5% vs. nurses 75.2%; p = 0.00112), regardless of specialty. By contrast, the R-code subcategory R10-R19 for digestive system symptoms (44.2 vs. 37.5%, respectively; p = 0.00299) and many chapters of ICD codes for disease names, as represented by Chapter 11 K00-K93 (68.4 vs. 30.9%, respectively; p < 0.001), were frequently extracted from the progress notes by physicians, reflecting their specialty. We believe that understanding the information heterogeneity of medical documents, which can be the basis of medical artificial intelligence, is crucial, and this study is a pioneering step in that direction.

Evaluation of Machine Translation Accuracy Focused on the Adverse Event Terminology for Medical Devices

The purpose of this study was to evaluate the accuracy of deep neural machine translation focused on medical device adverse event terminology. 10 models were obtained, and their English-to-Japanese translation accuracy was evaluated using quantitative and qualitative measures. No significant difference was found in the quantitative index except for a few pairs. In the qualitative evaluation, there was a significant difference and googletrans and GPT-3 were regarded as useful models.

Allulose for the attenuation of postprandial blood glucose levels in healthy humans: A systematic review and meta-analysis

D-Allulose is a rare sugar that exists in nature. It is a food ingredient with nearly zero calories (<0.4 kcal/g) and has many physiological functionalities such as attenuation of postprandial blood glucose levels, attenuation of postprandial fat mass accumulation, and anti-aging property. This study focused on the postprandial blood glucose changes in healthy humans by a systematic review and meta-analysis. They were chosen because of its importance to a prevention from diabetes. The study objective was to examine acute blood glucose concentrations of healthy humans after the meal with and without allulose. The study collected all D-allulose related studies from various databases. A forest plot of the comparison between an allulose intake group and the control group showed both 5g and 10g intake groups have the significantly smaller area under the curve of postprandial blood glucose levels. It means that D-Allulose attenuates postprandial blood glucose concentrations in healthy humans. As the result, D-Allulose is a valuable blood glucose management tool for healthy humans and diabetes patients. Allulose Diet enables reduction of sucrose intake through Sugar Reformulation in the future diet.

COVID-19 outbreak trends in South Africa: A comparison of Omicron (B.1.1.529), Delta (B.1.617.2), and Beta (B.1.351) variants outbreak periods

Objectives

We provided COVID-19 outbreak trends in South Africa during the Omicron (B.1.1.529), Delta (B.1.617.2), and Beta (B.1.351) variants outbreak periods from November 2020 to March 2022.

Methods

We used the time series summary data of the COVID-19 outbreak for South Africa available in the COVID-19 data repository created by the Center for System and Science and Engineering at Johns Hopkins University and the Our World in Data database by the University of Oxford from January 2020 to March 2022. We used the joinpoint regression model with a data-driven Bayesian information criterion method for analyzing the outbreak trends. In addition, we used density ellipses and partition modeling on the outbreak data.

Results

During the Omicron outbreak period, COVID-19 cases in South Africa significantly jumped by 4.7 times from December 01 to December 08, 2021. The average daily growth rate of incidence peaked at 23,000 cases/day until December 16, 2021, which was 18.6 % higher than the peak growth during the Delta outbreak period. South Africa experienced peak growth in COVID-19 cases with 18,611 cases/day (January 04 to January 14, 2021) during the Beta outbreak period and with 19,395 cases/day (July 01 to July 11, 2021) during the Delta outbreak period. Density ellipsoid showed a significant correlation between daily cases and daily death count during the Beta and Delta outbreak period which was not prominent in the Omicron outbreak period. Comparatively higher daily death tolls were reported in days with a recovery rate of less than 89.1 % and 91.9 % in the Beta and Delta outbreak period respectively. The backlog counts may be one of the reasons for the significant increase in daily death tolls during the Omicron period.

Conclusions

During the Omicron period, COVID-19 cases peaked growth was 18.6 % higher than the peak growth during the Delta outbreak period. Despite that fact, growth in death trends in the Omicron outbreak period was found low which might be due to the low mortality rate and case fatality proportion. The emergence of the Omicron variant once again reminds us that- “no one is safe until everyone is safe”.

t-SNE Visualization of Vector Pairs of Similar and Dissimilar Definition Sentences Created by Word2vec and Doc2vec in Japanese Medical Device Adverse Event Terminology

The purpose of our study is to identify the patterns of vectors in similar/dissimilar pairs of definition sentence created by Word2vec and doec2vec for elaboration of the terminology for Japanese Medical Device Adverse Events. 2-dimension vector space created by t-SNE showed that the pair with true positive located closer in a vector space, especially Doc2vec had a strong tendency. Comparing with Word2vec, Similar vectors in Doc2vec were close and tended to form clusters.

Extracorporeal cardiopulmonary resuscitation in adult patients with out-of-hospital cardiac arrest: a retrospective large cohort multicenter study in Japan

BACKGROUND

The prevalence of extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA) has been increasing rapidly worldwide. However, guidelines or clinical studies do not provide sufficient data on ECPR practice. The aim of this study was to provide real-world data on ECPR for patients with OHCA, including details of complications.

METHODS

We did a retrospective database analysis of observational multicenter cohort study in Japan. Adult patients with OHCA of presumed cardiac etiology who received ECPR between 2013 and 2018 were included. The primary outcome was favorable neurological outcome at hospital discharge, defined as a cerebral performance category of 1 or 2.

RESULTS

A total of 1644 patients with OHCA were included in this study. The patient age was 18-93 years (median: 60 years). Shockable rhythm in the initial cardiac rhythm at the scene was 69.4%. The median estimated low flow time was 55 min (interquartile range: 45-66 min). Favorable neurological outcome at hospital discharge was observed in 14.1% of patients, and the rate of survival to hospital discharge was 27.2%. The proportions of favorable neurological outcome at hospital discharge in terms of shockable rhythm, pulseless electrical activity, and asystole were 16.7%, 9.2%, and 3.9%, respectively. Complications were observed during ECPR in 32.7% of patients, and the most common complication was bleeding, with the rates of cannulation site bleeding and other types of hemorrhage at 16.4% and 8.5%, respectively.

CONCLUSIONS

In this large cohort, data on the ECPR of 1644 patients with OHCA show that the proportion of favorable neurological outcomes at hospital discharge was 14.1%, survival rate at hospital discharge was 27.2%, and complications were observed during ECPR in 32.7%.

Using Natural Language Processing Techniques to Detect Adverse Events From Progress Notes Due to Chemotherapy

Objective:

In recent years, natural language processing (NLP) techniques have progressed, and their application in the medical field has been tested. However, the use of NLP to detect symptoms from medical progress notes written in Japanese, remains limited. We aimed to detect 2 gastrointestinal symptoms that interfere with the continuation of chemotherapy—nausea/vomiting and diarrhea—from progress notes using NLP, and then to analyze factors affecting NLP.

Materials and methods:

In this study, 200 patients were randomly selected from 5277 patients who received intravenous injections of cytotoxic anticancer drugs at Kagawa University Hospital, Japan, between January 2011 and December 2018. We aimed to detect the first occurrence of nausea/vomiting (Group A) and diarrhea (Group B) using NLP. The NLP performance was evaluated by the concordance with a review of the physicians’ progress notes used as the gold standard.

Results:

Both groups showed high concordance: 83.5% (95% confidence interval [CI] 74.1-90.1) in Group A and 97.7% (95% CI 91.3-99.9) in Group B. However, the concordance was significantly better in Group B ( P = .0027). There were significantly more misdetection cases in Group A than in Group B (15.3% in Group A; 1.2% in Group B, P = .0012) due to negative findings or past history.

Conclusion:

We detected occurrences of nausea/vomiting and diarrhea accurately using NLP. However, there were more misdetection cases in Group A due to negative findings or past history, which may have been influenced by the physicians’ more frequent documentation of nausea/vomiting.

Terminology integration and inconsistency identification of adverse event terminology for Japanese medical devices using SPARQL

Background

For standardization of terms in the reports of medical device adverse events, 89 Japanese medical device adverse event terminologies were published in March 2015. The 89 terminologies were developed independently by 13 industry associations, suggesting that there may be inconsistencies among the terms proposed. The purpose of this study was to integrate the 89 sets of terminologies and evaluate inconsistencies among them using SPARQL.

Methods

In order to evaluate the inconsistencies among the integrated terminology, the following six items were evaluated: (1) whether the two-layer structure between category term and preferred term is consistent, (2) whether synonyms of a preferred term are involved. Reversing the layer-category order of matching was also performed, (3) whether each preferred term is subordinate to only one category term, (4) whether the definitions of terms are uniquely determined, (5) whether CDRH-NCIt terms corresponding to preferred terms are uniquely determined, (6) whether a term in a medical device problem is used for patient problems.

Results

About 60% of the total number of duplicated terms were found. This is because industry associations that created multiple terminologies adopted the same terms in terminologies of similar medical device groups. In the case that all terms with the same spelling have the same concept, efficient integration can be achieved automatically using RDF. Furthermore, we evaluated six matters of inconsistency in this study, terms that need to be reviewed accounted for about 10% or less than 10% in each item.

Conclusions

The RDF and SPARQL were useful tools to explore inconsistencies of hierarchies, definition statements, and synonyms when integrating terminolgy by term notation, and these had the advantage of reducing the physical and time burden.

Evaluation of a Treatment Algorithm for Tsushima Mamushi (Gloydius tsushimaensis) Snakebites, after Its Introduction to Tsushima Island, Nagasaki, Japan

Objective Tsushima mamushi (Gloydius tsushimaensis) is an endemic species of snake inhabiting only Tsushima Island, a remote Japanese island. We conducted a multicenter, retrospective study of G. tsushimaensis bites for the first time and developed a treatment algorithm that unified treatment on the island and is still in use today. Methods This is a multicenter, retrospective study comparing 72 cases from January 2005 to December 2018, before the introduction of the algorithm, and 12 cases from January 2019 to December 2020, after its introduction. Results There was no significant decrease in the maximum grade of symptoms after the introduction of the algorithm, but there was a decreasing trend (p=0.057). Conversely, the median of the maximum creatinine kinase levels was 343.5 IU/L (interquartile range: 115.5-4,745.5) before the algorithm's introduction and significantly lower (142.5; interquartile range: 111.3-163) after the algorithm's introduction (p=0.042). After the algorithm's introduction, the disseminated intravascular coagulation merger rate and the acute kidney injury incidence both dropped to 0%, from 9.7% and 6.9%, respectively, before the algorithm's introduction. There was no significant difference in the length of hospital stay before versus after the algorithm's introduction. Conclusion This study showed that the treatment algorithm can be safely and quickly applied. The algorithm's effectiveness is expected to be strengthened by the accumulation of more cases in the future.

Diagnostic Accuracy of Diastolic Fractional Flow Reserve for Functional Evaluation of Coronary Stenosis

Background

In the resting conditions, narrowing the window of coronary pressure measurements from the whole cardiac cycle to diastole improves diagnostic performance of coronary pressure–derived physiological index. However, whether this also applies to the hyperemic conditions has not yet been thoroughly evaluated.

Objectives

The purpose of this study was to assess whether diastolic fractional flow reserve (diastolic FFR) has better diagnostic performance in identifying ischemia-causing coronary lesions than conventional FFR in a prospective, multicenter, and independent core laboratory–based environment.

Methods

In this prospective multicenter registry at 29 Japanese centers, we compared the diagnostic performance of FFR, diastolic FFR, resting distal to aortic coronary pressure (Pd/Pa), and diastolic pressure ratio (dPR) using myocardial perfusion scintigraphy (MPS) as the reference standard in 378 patients with single-vessel coronary disease.

Results

Inducible myocardial ischemia was found on MPS in the relevant myocardial territory of the target vessel in 85 patients (22%). In the receiver-operating curve analyses, diastolic FFR had comparable area under the curve (AUC) compared with FFR (AUC_{diastolic FFR}: 0.66; 95% confidence interval [CI]: 0.58-0.73, vs AUC_FFR: 0.66; 95% CI: 0.58-0.74, P = 0.624). FFR and diastolic FFR showed significantly larger AUCs than resting Pd/Pa (0.62; 95% CI: 0.54-0.70; P = 0.033 and P = 0.046) but did not show significantly larger AUCs than dPR (0.62; 95% CI: 0.55-0.70; P = 0.102 and P = 0.113).

Conclusions

Diastolic FFR showed a similar diagnostic performance to FFR as compared with MPS. This result reaffirms the use of FFR as the most accurate invasive physiological lesion assessment. (Diagnostic accuracy of diastolic fractional flow reserve (d-FFR) for functional evaluation of coronary stenosis; UMIN000015906)

Severe hypofibrinogenemia in patients bitten by Gloydius tsushimaensis in Tsushima Island, Nagasaki, Japan, and treatment strategy

Gloydius tsushimaensis is an endemic species inhabiting only Tsushima, a remote Japanese island, and is a distinct species from Gloydius blomhoffii widely distributed throughout mainland Japan and Gloydius brevicaudus and Gloydius ussuriensis which are geographically distributed in South Korea. This is the first multicenter retrospective study of G. tsushimaensis bites in Japan. A study of seventy-two patients who visited the former Izuhara Hospital, the former Naka Tsushima Hospital, Tsushima Hospital, and Kamitsushima Hospital during the fourteen years from January 1, 2005, to December 31, 2018, revealed the typical clinical characteristics of G. tsushimaensis bites. Five out of seventy-two cases (6.9%) showed severe hypofibrinogenemia, in which fibrinogen levels were below 100 mg/dl, which is an unreported clinical finding for G. blomhoffii bites. Generally, when fibrinogen levels are lower than 100 mg/dl, the bleeding risk increases, and it is perilous. Severe hypofibrinogenemia cases did not improve after G. blomhoffii antivenom administration. Additionally, all five cases had disseminated intravascular coagulation, and there were two cases of acute kidney injury and one death. five cases had a median maximum creatine kinase level of 5171 IU/l (Interquartile range: 4992-41,310). Although the mechanism is not precise, coagulation tests showed that the G. tsushimaensis venom contains a thrombin-like enzyme. Based on this research, we created an algorithm for the treatment of G. tsushimaensis bites and unified the treatment methods used on the island.

Three-year outcomes after deferral of revascularization based on instantaneous wave-free ratio or fractional flow reserve: insights from the J-CONFIRM Registry

Background

The safety of deferral of revascularization based on instantaneous wave-free ratio (iFR) is established in randomized controlled trials. However, there is little data regarding long-term outcomes after deferral of revascularization based on iFR in real-world practice.

Purpose

We sought to assess clinical outcomes after deferral of revascularization based on iFR in clinical practice as compared with those based on fractional flow reserve (FFR).

Methods

This is a post hoc analysis of the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on fractional flow reserve in multicenter registry), in which 1262 patients with 1447 lesions deferred the revascularization based on FFR. Of these, both FFR and iFR were measured in 399 patients with 452 lesions. The patients were classified into the two groups: the iFR group (iFR &gt;0.89; 308 patients with 348 lesions) and the FFR group (FFR &gt;0.80; 740 patients with 855 lesions). The primary study endpoint was the 3-year target vessel failure (TVF) including cardiac death, target-vessel related myocardial infarction (TVMI), and clinically driven target vessel revascularization (CDTVR).

Results

Mean iFR was 0.96±0.04 in the iFR group. Mean FFR was significantly lower in the iFR group than in the FFR group (0.87±0.05 vs. 0.89±0.05, p=0.002). The iFR group included 35 lesions (11.4%) with FFR ≤0.80. At 3 years, the rate of TVF on a lesion basis were not significantly different between the iFR and FFR groups (8.8% vs. 6.1%, p=0.10), whereas CDTVR rate was significantly higher in the iFR group than in the FFR group (8.5% vs. 5.3%, p=0.044). Cardiac death and TVMI on a patient basis rarely occurred in both groups during the 3-year follow-up (0.33% vs. 0.77%, p=0.47; 0.66% vs. 0.56%, p=0.85, respectively).

Conclusion

At 3 years, TVF rate in deferred lesions was numerically higher in the iFR group than in the FFR group, driven by a higher rate of CDTVR. However, cardiac death and TVMI was very rare in both groups, highlighting the safety of both iFR- and FFR-based deferral of revascularization in daily practice.

Funding Acknowledgement

Type of funding source: None

Paclitaxel-coated Zilver PTX drug-eluting stent treatment does not result in increased long-term all-cause mortality compared to uncoated devices from Japan post-market surveillance study

Purpose

Favorable long-term outcomes with the Zilver PTX drug-eluting stent (DES) in treating patients with femoropopliteal lesions have been demonstrated. A multicenter, prospective, post-market surveillance study (PMS) in Japan evaluated this DES in a real-world patient population. Recently, meta-analysis that grouped both DES and drug-coated balloons (DCB) together indicated a higher incidence of late all-cause mortality for paclitaxel- based devices compared to uncoated balloon or bare-metal stent (BMS) at 2 years up to 5 years. To evaluate the long-term safety of the Zilver PTX DES, compared with BMS using Japan-PMS study.

Methods

The Japan DES PMS had no exclusion criteria and enrolled consecutive patients with symptomatic PAD involving the above-the-knee femoropopliteal arteries. Safety and effectiveness of the DES was evaluated in real-world patients with complex femoropopliteal artery lesions through 5 years. Follow-up in the study is complete. The concurrent Japan BMS PMS also had no exclusion criteria and enrolled consecutive patients with symptomatic PAD involving the above-the-knee femoropopliteal arteries. Patients who were enrolled in the BMS study but who also had a DES placed (n=18) were excluded from the current analysis. Follow-up in the BMS study was only required through 3 years and is complete.

Results

The Japan DES PMS enrolled 904 DES patients, and the Japan BMS PMS enrolled 190 BMS patients. In the DES group, there were 127 deaths through 3 years and 186deaths through 5 years. In the BMS group, there were 22 deaths through 3 years. Through 3 years, the risk of mortality was 15.7% for DES group and 15.3% for BMS group. Through 5 years, the risk of mortality was 25.8% for the DES group. There was no difference in mortality between the two groups (log-rank p=0.92).The Cox proportional hazards model revealed that CLI (p&lt;0.0001), age (p&lt;0.0001), gender (p=0.001), renal failure (p&lt;0.0001) were significantly associated with mortality. Hypercholesterolemia (p=0.004) was associated with lower risk of mortality. Treatment with Zilver PTX (p=0.49) was not associated with mortality. In the covariate analysis of paclitaxel dose, the significant factors were identical to the treatment analysis, and there was no association or trend of paclitaxel dose (p=0.07) with mortality.

Conclusion

Analyses of the paclitaxel-coated Zilver PTX DES utilizing patient-level data from the Japan PMS demonstrated no increase in long-term all-cause mortality. The 5-year results from this real-world, all-comers study continue to show positive long-term outcomes and demonstrate the benefit of the Zilver PTX DES across a broad patient population.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): COOK

P4704The efficacy of intravascular ultrasound for patients with peripheral artery diseases presenting aorto-iliac artery disease

Background

The use of intravascular ultrasound (IVUS) promotes better clinical outcomes for intervention in complex lesions. However, the data demonstrating whether use of IVUS improves primary patency following stenting for aorto-iliac lesions in patients with peripheral artery disease (PAD) are limited.

Purpose

The purpose of the current study was to investigate the impact of IVUS use on primary patency 12 months after stent implantation for aorto-iliac lesions.

Methods

We analyzed a clinical database of the OMOTENASHI registry (Observational prospective Multicenter registry study on Outcomes of peripheral arTErial disease patieNts treated by AngioplaSty tHerapy in aortoIliac artery), registering symptomatic PAD patients (Rutherford category 2, 3, or 4) undergoing endovascular therapy for aorto-iliac lesions between January 2014 and April 2016 in Japan. The current study analyzed 803 patients who underwent self-expandable stent implantation at 61 centers with the institutional volume known. The primary endpoint was 12-month restenosis, defined as ≥50% stenosis on computed tomography or angiography, or a peak systolic velocity ratio ≥2.5 on duplex ultrasound. When treatment strategies, endovascular procedures and clinical outcomes were compared between the patients treated with IVUS use and those treated without IVUS use, the propensity score matching was performed to minimize the inter-group difference in baseline characteristics.

Results

A total of 545 patients (67.9%) underwent IVUS-supported stent implantation. Patients treated with IVUS use had a lower prevalence of regular dialysis, whereas they had a higher prevalence of TASC II class D and chronic total occlusion. In patients treated with IVUS use, carbon dioxide contrast agent were more often used, and 0.035-inch guidewire was less frequently selected. Implanted stents in these patients were longer and smaller in diameter. The propensity score matching extracted 138 pairs, with no remarkable intergroup difference in baseline characteristics. Procedure time ≤1 hour was less frequent in patients treated with IVUS use; their radiation time was longer. Endovascular strategies, as well as postoperative medication were not significantly different between patients with and without IVUS use. The 12-month restenosis risk was not significantly different between patients with and without IVUS use (10.2% [6.9 to 14.9%] versus 10.3% [5.4 to 18.6%], P=0.99).

Conclusion

IVUS use in aorto-iliac stenting for patients with PAD was not associated with primary patency at 12 months.

Acknowledgement/Funding

None

Establishment of the MID-NET® medical information database network as a reliable and valuable database for drug safety assessments in Japan

Purpose

To establish a new medical information database network (designated MID‐NET^®) to provide real‐world data for drug safety assessments in Japan.

Methods

This network was designed and developed by the Ministry of Health, Labour and Welfare and the Pharmaceuticals and Medical Devices Agency in collaboration with 23 hospitals from 10 healthcare organizations across Japan. MID‐NET^® is a distributed and closed network system that connects all collaborative organizations through a central data center. A wide variety of data are available for analyses, including clinical and administrative information. Several coding standards are used to standardize the data stored in MID‐NET^® to allow the integration of information originating from different hospitals. A rigorous and consistent quality management system was implemented to ensure that MID‐NET^® data are of high quality and meet Japanese regulatory standards (good post‐marketing study practice and related guidelines).

Results

MID‐NET^® was successfully established as a reliable and valuable medical information database and was officially launched in April 2018. High data quality with almost 100% consistency was confirmed between original data in hospitals and the data stored in MID‐NET^®. A major advantage is that approximately 260 clinical laboratory test results are available for analysis.

Conclusions

MID‐NET^® is expected to be a major data source for drug safety assessments in Japan. Experiences and best practices established in MID‐NET^® may provide a model for the future development of similar database networks.

Evaluation of Similar Term Definitions in Medical Device Adverse Event Terminology

The purpose of this study is to extract similar term definitions used in the terminology of Japanese medical device adverse events. We employed Levenshtein and Jaro-Winkler distances as edit distances and Skip-gram, continuous-bag of words, and fast text to produce distributed representations in Word2Vec. A comparison of the accuracies of the models showed that Levenshtein distance had higher specificity whereas Skip-gram had higher sensitivity as compared to the other models.

Evaluating the impact of regulatory action on denosumab-induced hypocalcaemia in Japan

WHAT IS KNOWN AND OBJECTIVE

Since its introduction in April 2012, denosumab has been administered to approximately 7,300 patients as of August 2012, and 32 cases of serious hypocalcaemia after denosumab administration, including two deaths, have been reported in Japan. A Dear Healthcare Professional Letter of Rapid Safety Communication ('Blue letter') was released to warn about the risks of hypocalcaemia associated with denosumab. The goal of this study therefore was to measure the impact of regulatory action on denosumab-induced hypocalcaemia in Japan by using an electronic medical information database (MID).

METHODS

We used two different aggregated data sets based on MIDs (data sets one and two). The patients studied were those who were newly prescribed denosumab or zoledronic acid between April 2012 and September 2014. We assessed four indicators: (a) the proportion of patients with calcium supplementation at the initial denosumab treatment, (b) the proportion of patients who underwent a serum calcium test, (c) the average number of serum calcium tests performed and (d) the prevalence of hypocalcaemia. All indices were aggregated by every 3 months. To evaluate the impact of regulatory action, we used difference in difference (DID) analysis.

RESULTS AND DISCUSSION

The proportion of patients with calcium supplementation at the initial denosumab treatment increased year by year in both data sets. The average number of serum calcium tests increased year by year in data set two. There was a significant difference in the prevalence of hypocalcaemia in data set two. This suggests that the estimate of impact of the regulatory action may vary according to the database. In DID analysis, however, significant influences of the regulatory action on combination use with a calcium supplement were detected in both data sets.

WHAT IS NEW AND CONCLUSION

There was a significant influence on combination use of denosumab with vitamin D and/or calcium supplement in both data sets. That there was no apparent increase in the prevalence of denosumab-induced hypocalcaemia, suggests that the regulatory action had an impact in the clinical setting studied. Such regulatory actions may play an important role in the promotion of drug safety.

Identification of gastrointestinal perforation based on ICD-10 code in a Japanese administrative medical information database and associated drug exposure risk factors

PURPOSE

The purpose of this study is to evaluate the accuracy of gastrointestinal (GI) perforation ICD-10 coding in the Diagnosis Procedure Combination (DPC) database and to examine drug exposure risk factors for GI perforation.

METHODS

A total of 100 patients with GI perforation ICD-10 codes were selected randomly from Kagawa University Hospital's DPC database between April 2011 and December 2016. Two experienced specialist physicians independently reviewed the medical records and classified cases as "definite A," "definite B," "probable," or "no GI perforation." The positive predictive values (PPVs) of "definite A/B" cases were calculated after stratification by sex, age, ICD-10 code, and diagnostic information in the DPC data. The number of prescribed drugs with side effects of GI perforation according to historical data was compared between "definite A/B" and "no GI perforation" cases.

RESULTS

The overall PPV was 47.0% (95% confidence interval [CI], 36.9-57.2). However, the PPVs for the three categories of diagnostic information in the DPC data ("main diagnosis," "diagnosis causing admission," and "most resource-intensive diagnosis") were each more than 70% after excluding inappropriate patients. Additionally, the PPV focused on these three categories was 76.3% (95% CI, 59.8-88.6). Prescribed drugs with side effects of GI perforation were more frequently detected in "definite A/B" cases (P = .028).

CONCLUSIONS

Although the overall PPV for GI perforation based on ICD-10 code was low, our results suggest that the PPV could be improved by appropriate selection of DPC diagnosis category and that use of multiple medications enhances the risk of GI perforation.

Present Status and Perspectives on Future Roles of Japanese Clinical Research Coordinators

Background

The new Clinical Trials Act that recently came into effect in Japan emphasizes the reliability of investigator-initiated clinical trials. Although Japanese clinical research coordinators have been mainly engaged in operational roles in industry-initiated clinical trials for drug approval (registration trials), broadening their contribution to cover more types of clinical research may lead to quality improvement of clinical research. To ultimately establish a clinical research infrastructure that meets the needs of the new era of Clinical Trials Act, here we gathered basic information on how clinical research coordinators might make such contributions.

Methods

We conducted a survey using self-reporting questionnaires in clinical research-related personnel to examine present status and the perspectives toward broader contribution of clinical research coordinators. The study participants were attendee of group discussion of a clinical research-related meeting in Shikoku area of Japan held in August 2017.

Results

Among 88 participants, 69 responded (response rate: 78.4%) and 68 respondents (98.6%) were engaged in support and management of clinical research. The main area of involvement was industry-initiated registration trials (48, 69.7%), and main roles of involvement were cooperators who plays roles under the guidance of investigators (41, 59.5%). When divided by occupation into clinical research coordinators (n = 41) and other clinical research-related personnel (n = 28), approximately half of the respondents in each group replied positively to wanting broader involvement of clinical research coordinators as a clinical research professional.

Conclusion

The present study revealed that about half of the clinical research coordinators and other clinical research-related personnel view a broadening of involvement of clinical research coordinators in research activities positively. Accordingly, a structured practical program aimed at encouraging such involvement may help to expand and strengthen their contribution into the future. Whether greater involvement of clinical research coordinators in clinical research will help to ensure the reliability of investigator-initiated clinical research warrants further study.

Automatic DPC Code Selection from Electronic Medical Records

Objectives: We extracted index terms related to diseases recorded in hospital discharge summaries and examined the capability of the vector space model to select a suitable diagnosis with these terms.

Methods: By morphological analysis, we extracted index terms and constructed an original dictionary for the discharge summary analysis. We chose 125 different DPC (Japanese DRG system) codes for the diseases, each of which had more than 20 cases. We divided them into two groups. One group consisted of 5927 cases from 2004 fiscal year and was used to generate the document vector space according to the DPC. The other group of 3187 cases was collected to verify the automatic DPC selection by using data from 2005 fiscal year. The top 200 extracted index terms for each disease were used to calculate the weight of each disease.

Results: The DPC code obtained by the calculated similarity was compared with the original codes of patients for 125 DPCs of 3187 cases. Eighty percent of the cases matched the diagnosis of the DPC (first six digits) and 56% of the cases completely matched all 14 digits of the DPC.

Conclusions: We demonstrated that we could extract suitable terms for each disease and obtain characteristics, such as the diagnosis, from the calculated vectors. This technique can be used to measure the qualification of discharge summaries and to integrate discharge summaries among different facilities. By the text mining technique, we can characterize the contents of electronic discharge summaries and deduce diagnoses with the data.

[Gallbladder Malignant Lymphoma Diagnosed after Surgery for Acute Cholecystitis - A Case Report]

An 84-year-old man visited our hospital with epigastralgia.Levels of hepatic and biliary enzymes and CRP were elevated, as detected by a blood test.On a CT scan, a swollen gallbladder with stones was detected.The patient was admitted to the hospital with a diagnosis of Grade I acute cholecystitis.Conservative treatment was continued with antibiotic administration and the patient was discharged from the hospital with improvement on day 6 after admission.Three months later, the patient underwent laparoscopic cholecystectomy.In the gallbladder, a 45×45 mm tumor was found.Upon pathological examination, diffuse proliferation of lymphocyte-like heterotypic cells and subserosal invasion were observed.Immunohistochemistry results were negative for MUM1 and positive for CD10 and Bcl6 markers.A malignant diffuse large B-cell lymphoma was diagnosed.We experienced a case of malignant lymphoma of the gallbladder diagnosed after surgery for acute cholecystitis, which we herein report with literature consideration.

Integration of Japanese Medical Device Adverse Event Terminologies

The purpose of this study is to integrate Japanese medical device adverse event terminologies for evaluating terminological consistency. We represented hierarchy and relations among terms using Resource Description Framework (RDF). There were 3521 classes and 14650 properties. As a result of evaluating the consistency of the description in SPARQL, it was evident that the same notations existed within different terminologies (category terms and terms) and some terms had plural definitions.

Estimating Sample Size for a Feasibility Study of Computer-Assisted Input Support to EDC

The aim of this study was to to estimate the sample size for the assumed feasibility study of the computer-assisted input support on a clinica trial. More than 1,500 observations were required for the feasibility study with assumed settings. Further study was required for more efficient research design.

[A Case of Stage IV Gastric Cancer Successfully Treated Using Salvage Surgery after S-1/CDDP Therapy]

A 75-year-old man admitted for left lateral abdominal pain was found to have advanced poorly differentiated gastric adenocarcinoma with abdominal para-aortic and Virchow's lymph node metastases, which was diagnosed to be clinical Stage IV (T3N3H0M1[LYM]). As curative surgery was not deemed possible, we started chemotherapy administration using S-1 (120mg/day)administered orally for 3 weeks and cisplatin(CDDP 100mg/body)administered intravenously on day 8. After 6 courses of chemotherapy, a CT scan showed that all lymph nodes metastases had disappeared, resulting in downstaging to clinical Stage II (T3[SE]N0H0P0M0). Thus, we performed total gastrectomy, lymph node dissection(D2), and splenectomy. Histological findings showed no residual tumor cells in any of the lymph nodes. However, cancer cells remained in the primary gastric lesion. The pathological response to chemotherapy was judged to be Grade 2. The patient has been recurrence-free for 5 years after surgery.

Shock Index and Decreased Level of Consciousness as Terminal Cancer Patients' Survival Time Predictors: A Retrospective Cohort Study

CONTEXT

Predicting prognosis using noninvasive and objective tools may facilitate end-of-life decisions for terminal cancer patients, their families, and other health care professionals.

OBJECTIVES

To investigate if the shock index (SI), along with decreased level of consciousness (DLOC), is a reliable tool for predicting short-term survival time in terminal cancer patients.

METHODS

A two-part retrospective cohort study was performed on 670 consecutive adult hospice patients. Part 1 of the study was performed to investigate the reliability of SI and DLOC on admission and to make a simple tool for predicting survival time. Part 2 of the study was to validate the tool's reproducibility and analyze the correlation between SI, DLOC, and survival time.

RESULTS

In Part 1, multivariate Cox proportional hazards analyses for all study patients revealed that SI ≥ 1.0 in patients with DLOC was a significant risk factor of death (hazard ratio 3.08; 95% CI 1.72-5.53; P = 0.000). Generalized additive models confirmed that DLOC patients with SI = 1.0 had 9.58 days of mean survival time (MST). Receiver operating characteristic curve analyses of SI in patients with DLOC revealed that a survival time of less than three days was most reliably predicted. In Part 2, an increase in SI statistically decreased survival time. The upper 95% CIs of the calculated mean survival time for DLOC patients with SI ≥ 1.0 were less than one week. Bootstrap analyses revealed that the 95% CIs of the predicted survival time were 4.54-6.18 days in DLOC patients with SI = 1.0.

CONCLUSION

An SI ≥ 1.0 along with DLOC is a highly reliable tool for predicting short-term survival time in terminal cancer patients.

Schwannoma of the nasal septum presenting as a multicentric neuronal tumour

PROBLEM

Schwannomas (neurilemmomas) are benign primary tumours that arise from Schwann cells. Schwannomas arising from the nasal septum are exceptionally rare. Here, we report a unique case of schwannoma of the nasal septum presenting as a multicentric neuronal tumour.

RESULTS

A 40-year old male sustained intermittent left tinnitus. Magnetic resonance imaging revealed masses near the nasal septum and upper cervical cord in addition to a tumour in the left cerebellopontine (CP) angle. The tumour in the nasal septum was completely resected by endoscopic endonasal surgery and diagnosed as a typical schwannoma. The CP angle tumour was treated with stereotactic radiosurgery, while the asymptomatic cord lesion showed no significant growth and remains under observation.

CONCLUSION

Endoscopic endonasal surgery is useful for the resection of schwannomas of the nasal septum. Schwannomas of the nasal septum may present as multiple neuronal tumours.

Visualization Analysis of Asymmetric Fountain Flow Phenomenon in Injection Molding of Filler-reinforced Resins by Rotary Runner Exchange System

In this study, we attempted to visualize the flow patterns inside molded samples of glass-fibers or talc reinforced GPPS and PP especially in the vicinity of the flow front, using a rotary runner exchange system which instantaneously switches melt flowing into the cavity. From the visualization results, an extremely characteristic flow behavior was seen at the flow front area for resins with fillers which was not observed for those without fillers. Especially in the case of resins with 40 wt.% talc or 30 wt.% GF, a-symmetric zigzag fountain flows were generated alternately upward and downward along the cavity width direction. Moreover along the outer layer of the flow front, one observed a large amount of residual resin remaining for a long time during the cavity filling process, in the case of 40 wt.% GF, primarily due to the increase of viscosity which restricts the occurrence of diverging flow. Based on the above visualization results, we proposed a generic model of zigzag fountain flow; an a-symmetric upward flow in a certain area starts preventing the fountain flow in the upper side of the adjacent area, causing the diverging center to sink. This phenomenon subsequently causes an a-symmetric flow in the opposite direction in the next adjacent area, which continuously propagates along the cavity width direction.

Visualization Analysis of a Multilayer Foam Development Process in Microcellular Injection Molding

In this study, cross-sectional analyses were performed on microcellular injection-molded high-impact polystyrene products. The results confirm that the following five types of layers were formed: Skin layers I (the silver streak layer) and II (a nonfoamed layer), Core layers I (cell diameter, d > 150 μm), II (d < 50 μm), and III (d > 100 μm). As the maximum in-mold pressure (Pmax) was increased from 5 to 30 MPa, the thickness of Skin layer II remained nearly constant. However, the foam types in the core layers changed from I and II to II and III or III only, resulting in an increase in cell diameter and a decrease in cell density. The process of cellular structure formation was observed using a glass-inserted mold, which revealed that this process consists of a flow (with a burst of cells at the melt front and the subsequent flow of the melt containing the cells), an end of the filling (involving elastic compression or the dissolution and disappearance of cells formed in the flow stage), and a cooling (new cell generation and growth and cooling solidification). Based on these cross-sectional observations, in concert with melt-pressure measurements and visualizations, we developed a model describing the formation process of Skin layer II and the core layers including a new concept that considers the melt pressure inside the cavity. The following layers are incorporated into the model: Skin layer II: A nonfoamed layer is formed in the area of the melt front where gases diffuse out from within the melt during the filling stage, and this nonfoamed layer moves to from melt front to the surface of the product due to fountain flow. Core layers I and II: A multilayer is formed containing a distribution of cells preserved from the flow stage due to the low compression forces, Core layer III: cells are dissolved in the melt due to strong compression forces at the end of the filling stage and then reform and grow in the cooling stage.

Visualization Analysis of Resin Flow Behavior around a Flow Front Using a Rotary Runner Exchange System

In plastic injection molding, external defects such as flow marks are serious problems. These external defects are known to occur during cavity filling processes inside the mold, and are closely related to resin flow behavior in the flow front area. In this study, the authors propose a new method for visualizing in-mold resin flow behavior using a glass-inserted mold and rotary runner exchange system capable of instantaneously switching two types of melt at the runner just before the gate. This method is capable not only of dynamic visualization, but also static visualization by the observation of cross-sections of a sample, because colored resins switched multiple times at the gate spread in layers inside the sample and freeze. Using this method and general purpose polystyrene, visualization analysis of the flow behavior of inner layer resins near the flow front in simple rectangular cavities was carried out. As a result, it was found that resins reaching the flow front are not exposed at the molded product surface immediately after the fountain-flow process, but remain along the circumference of the flow front for a long period of time, and then stretch out into a thin film-like shape to form the surface of the molded product. In addition, the inner layer resins near the flow front form a converging flow just before reaching the flow front and then form a fountain flow. It was also confirmed that this is a general phenomenon in the fountain-flow process during injection molding regardless of whether the resin is crystalline or noncrystalline. Based on these results, we built a model on the flow of inner layer resins near the flow front of general resins.