Functional mapping of hospitals by diagnosis-dominant case-mix analysis

An Alternative Application of Natural Language Processing to Express a Characteristic Feature of Diseases in Japanese Medical Records

BACKGROUND

Owing to the linguistic situation, Japanese natural language processing (NLP) requires morphological analyses for word segmentation using dictionary techniques.

OBJECTIVE

We aimed to clarify whether it can be substituted with an open-end discovery-based NLP (OD-NLP), which does not use any dictionary techniques.

METHODS

Clinical texts at the first medical visit were collected for comparison of OD-NLP with word dictionary-based-NLP (WD-NLP). Topics were generated in each document using a topic model, which later corresponded to the respective diseases determined in International Statistical Classification of Diseases and Related Health Problems 10 revision. The prediction accuracy and expressivity of each disease were examined in equivalent number of entities/words after filtration with either term frequency and inverse document frequency (TF-IDF) or dominance value (DMV).

RESULTS

In documents from 10,520 observed patients, 169,913 entities and 44,758 words were segmented using OD-NLP and WD-NLP, simultaneously. Without filtering, accuracy and recall levels were low, and there was no difference in the harmonic mean of the F-measure between NLPs. However, physicians reported OD-NLP contained more meaningful words than WD-NLP. When datasets were created in an equivalent number of entities/words with TF-IDF, F-measure in OD-NLP was higher than WD-NLP at lower thresholds. When the threshold increased, the number of datasets created decreased, resulting in increased values of F-measure, although the differences disappeared. Two datasets near the maximum threshold showing differences in F-measure were examined whether their topics were associated with diseases. The results showed that more diseases were found in OD-NLP at lower thresholds, indicating that the topics described characteristics of diseases. The superiority remained as much as that of TF-IDF when filtration was changed to DMV.

CONCLUSION

The current findings prefer the use of OD-NLP to express characteristics of diseases from Japanese clinical texts and may help in the construction of document summaries and retrieval in clinical settings.

The Current Status of Secondary Use of Claims, Electronic Medical Records, and Electronic Health Records in Epidemiology in Japan: Narrative Literature Review

BACKGROUND

Real-world data, such as claims, electronic medical records (EMRs), and electronic health records (EHRs), are increasingly being used in clinical epidemiology. Understanding the current status of existing approaches can help in designing high-quality epidemiological studies.

OBJECTIVE

We conducted a comprehensive narrative literature review to clarify the secondary use of claims, EMRs, and EHRs in clinical epidemiology in Japan.

METHODS

We searched peer-reviewed publications in PubMed from January 1, 2006, to June 30, 2021 (the date of search), which met the following 3 inclusion criteria: involvement of claims, EMRs, EHRs, or medical receipt data; mention of Japan; and published from January 1, 2006, to June 30, 2021. Eligible articles that met any of the following 6 exclusion criteria were filtered: review articles; non-disease-related articles; articles in which the Japanese population is not the sample; articles without claims, EMRs, or EHRs; full text not available; and articles without statistical analysis. Investigations of the titles, abstracts, and full texts of eligible articles were conducted automatically or manually, from which 7 categories of key information were collected. The information included organization, study design, real-world data type, database, disease, outcome, and statistical method.

RESULTS

A total of 620 eligible articles were identified for this narrative literature review. The results of the 7 categories suggested that most of the studies were conducted by academic institutes (n=429); the cohort study was the primary design that longitudinally measured outcomes of proper patients (n=533); 594 studies used claims data; the use of databases was concentrated in well-known commercial and public databases; infections (n=105), cardiovascular diseases (n=100), neoplasms (n=78), and nutritional and metabolic diseases (n=75) were the most studied diseases; most studies have focused on measuring treatment patterns (n=218), physiological or clinical characteristics (n=184), and mortality (n=137); and multivariate models were commonly used (n=414). Most (375/414, 90.6%) of these multivariate modeling studies were performed for confounder adjustment. Logistic regression was the first choice for assessing many of the outcomes, with the exception of hospitalization or hospital stay and resource use or costs, for both of which linear regression was commonly used.

CONCLUSIONS

This literature review provides a good understanding of the current status and trends in the use of claims, EMRs, and EHRs data in clinical epidemiology in Japan. The results demonstrated appropriate statistical methods regarding different outcomes, Japan-specific trends of disease areas, and the lack of use of artificial intelligence techniques in existing studies. In the future, a more precise comparison of relevant domestic research with worldwide research will be conducted to clarify the Japan-specific status and challenges.

Fractures within 2 years of an obstetric hospitalization: analysis of nationwide administrative data in Japan

INTRODUCTION

Pregnancy- and lactation-associated osteoporosis (PLO) is a condition in which young women develop fractures during pregnancy or breastfeeding. Though PLO is a severely debilitating disease, its pathophysiology and epidemiology have not been clarified and its treatment has not been established. We aimed to identify the incidence and factors associated with fractures occurring within 2 years following an obstetric hospitalization.

MATERIALS AND METHODS

We extracted data on fractures occurring within 2 years of an obstetric hospitalization from the Japanese Diagnosis Procedure Combination database. We analyzed the implementation of bone mineral density and bone metabolism marker tests, prescription status, and factors associated with fractures occurring within 2 years of an obstetric hospitalization.

RESULTS

Among 837,347 patients with a history of obstetric hospitalization from 2010 to 2014, 379 patients had a history of hospitalization due to a fracture occurring within 2 years (4.5/10,000 pregnancies). Among the patients with fractures occurring within 2 years of an obstetric hospitalization, 6.7% underwent bone mineral quantification or a bone metabolism marker test, and 7.5% were prescribed a lactation inhibitor or osteoporosis treatment. Factors associated with fractures occurring within 2 years following an obstetric hospitalization identified included Cushing syndrome, Charlson Comorbidity Index score ≥ 1, age ≥ 40 years old at pregnancy, smoking history, and steroid administration.

CONCLUSION

We investigated fracture cases occurring within 2 years of an obstetrics hospitalization. This finding may be useful in selecting preventative measures for patients at risk of fractures within 2 years after obstetric hospitalization, including PLO.

Economic and clinical burden from carbapenem-resistant bacterial infections and factors contributing: a retrospective study using electronic medical records in Japan

Background

Antimicrobial resistance is a major threat to global health and the world economy. The economic burden of carbapenem-resistant infections has not previously been evaluated. We aimed to compare the potential economic burden and clinical outcomes between carbapenem-resistant infections and carbapenem-susceptible infections in Japan.

Methods

We conducted a retrospective cohort study using electronic medical records. Patients aged 15 years or older and with the diagnosis of pneumonia, urinary tract infection, biliary infection, and sepsis were included. Multivariable regression models with random effects were used to estimate the impact of carbapenem resistance on cost, length of hospital stay, and in-hospital mortality.

Results

Among the 9,517 patients, 86 (0.9%) had carbapenem-resistant (CR) infections. Compared to carbapenem-susceptible (CS) infections, the patients with the CR infections were significantly more likely to receive mechanical ventilation (37.2 vs. 21.2%, P-value = 0.003), antibiotics (88.4 vs. 63.0%, P-value < 0.001), and especially carbapenem (31.4 vs. 8.3%, P-value < 0.001), before the bacterial culture test positive. Significantly higher median costs were found for the CR infections than the CS infections in the categories of medications (3477 US dollars vs. 1609 US dollars), laboratory tests (2498 US dollars, vs. 1845 US dollars), and hospital stay (14,307 US dollars vs. 10,560 US dollars). In the multivariable regression analysis, the length of stay was 42.1% longer and the cost was 50.4% higher in the CR infections than in the CS infections. The risk of in-hospital mortality did not differ between the two groups (odds ratio 1.24, 95% CI 0.72–2.11), due to the small sample size. The result was robust with a similar trend in the analysis using the inverse probability treatment weighting method.

Conclusions

Compared to carbapenem-susceptible infections, carbapenem-resistant infections were associated with a higher cost and a longer length of stay. Detailed cost analysis showed significant differences in the categories of medication, laboratory tests, and hospital stay. To our knowledge, this study is the first to assess the potential economic burden of carbapenem-resistant infections using a large hospital-based database.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07548-3.

Existing Data Sources for Clinical Epidemiology: Database of the National Hospital Organization in Japan

This review introduces the National Hospital Organization (NHO) database in Japan. The NHO has maintained two databases through a system of data collection from 140 hospitals in the NHO. National Hospital Organization Clinical Data Archives (NCDA) is collecting clinical information in real time from the electronic medical records since January 2016, and Medical Information Analysis (MIA) databank is collecting daily insurance claims data since April 2010. The NHO database covers more than 8 million patients in 140 hospitals throughout Japan. The database consists of the information of patient profiles, hospital admission and discharge, diagnosis with ICD-10 codes, text data from medical chart, daily health insurance claims such as medical procedures, medications or surgeries, vital signs and laboratory data, and so on. The NHO database includes a wide variety of diseases and settings, including acute, chronic and intractable diseases, emergency medical services, disaster medicine, response to emerging infectious disease outbreaks, medical care according to health policies such as psychiatry, tuberculosis, or muscular dystrophy, and health systems in sparsely populated non-urban areas. Among several common diseases, the database has representativeness in terms of age distribution compared with the Patient Survey 2017 by the Ministry of Health, Labour and Welfare. Interested researchers can contact (700-dbproject@mail.hosp.go.jp) the NHO database division to obtain more information about the NHO database for utilization.

Risk factors leading to trabeculectomy surgery of glaucoma patient using Japanese nationwide administrative claims data: a retrospective non-interventional cohort study

BACKGROUND

Early recognition and management of baseline risk factors may play an important role in reducing glaucoma surgery burdens. However, no studies have investigated them using real-world data in Japan or other countries. This study aimed to clarify the risk factors leading to trabeculectomy surgery, which is the most common procedure of glaucoma surgery, of glaucoma patient using the Japanese nationwide administrative claims data associated with the diagnosis procedure combination (DPC) system.

METHODS

It was a retrospective, non-interventional cohort study. Data were collected from patients who were admitted to DPC participating hospitals, nationwide acute care hospitals and were diagnosed with glaucoma between 2012 to 2018. The primary outcome was the risk factors associated with trabeculectomy surgery. The association between baseline characteristics and trabeculectomy surgery was identified using multivariable logistic regression analysis by comparing patients with and without trabeculectomy surgery. Meanwhile, the secondary outcomes included the rate of comorbidities, the rate of concomitant drug use and the treatment patterns of glaucoma eye drops at the index admission. Among patients with trabeculectomy surgery, the risk factors leading to cataract surgery were also evaluated as subgroup analysis.

RESULTS

A total of 29,599 patients included in the analysis, 12,038 and 17,561 patients were in the glaucoma surgery and non-glaucoma surgery cohorts, respectively. The factors associated with the increase in trabeculectomy surgery were having allergies, taking concomitant drugs including cancer, depression, ischemic heart disease and peptic ulcer, being diagnosed with primary open-angle glaucoma and longer length of stay in hospital. In contrast, the factors associated with the decrease in trabeculectomy surgery were having hypertension, taking hypertension drug, age ≥ 80 and female.

CONCLUSIONS

Special focus on Japanese patients with glaucoma who have allergy-related comorbidities or take immune, nervous, circulatory or gastrointestinal system-related concomitant drugs seems to be desirable.

The relationship of hospital stay and readmission with employment status

The Inpatient Clinico-Occupational Survey collected data from 3.76 million patients, showing that the average length of stay declined by 16.1 d in FY2008 and by 14.1 d in FY2015. In this study, we assessed the length of hospital stay and readmission, stratified by ICD-10 and employment status. A cross-sectional study was conducted on data from FY2008, including those from 65,806 first hospitalizations and 16,653 readmissions in FY2008, where 62,260 first admissions and 29,242 readmissions in FY 2015. The length of hospital stay was longest in those admitted due to external influences (24.8 d), followed by musculoskeletal disorders (22.5 d). This remained unchanged in FY2015, however, lengths of stay of those were reduced by 20.1 and 20.0 d, respectively. The length of hospital stay for most diseases was longer upon readmission than on first admission, and longer for those who were unemployed. It is necessary to give attention to patients who need to be discharged early due to work, or plan for frequent hospitalization in order to reduce the length of each hospital stay because of the expected increase in the number of elderly workers brought on by a declining birth rate and an aging population.

History and Profile of Diagnosis Procedure Combination (DPC): Development of a Real Data Collection System for Acute Inpatient Care in Japan

DPC, which is an acronym for “Diagnosis Procedure Combination,” is a patient classification method developed in Japan for inpatients in the acute phase of illness. It was developed as a measuring tool intended to make acute inpatient care transparent, aiming at standardization of Japanese medical care, as well as evaluation and improvement of its quality. Subsequently, this classification method came to be used in the Japanese medical service reimbursement system for acute inpatient care and appropriate allocation of medical resources. Furthermore, it has recently contributed to the development and maintenance of an appropriate medical care provision system at a regional level, which is accomplished based on DPC data used for patient classification. In this paper, we first provide an overview of DPC. Next, we will look back at over 15 years of DPC history; in particular, we will explore how DPC has been refined to become an appropriate medical service reimbursement system. Finally, we will introduce an outline of DPC-related research, starting with research using DPC data.

An analysis of equity in treatment of hip fractures for older patients with dementia in acute care hospitals: observational study using nationwide hospital claims data in Japan

Background

Globally, and particularly in countries with rapidly ageing populations like Japan, there are growing concerns over the heavy burden of ill health borne by older people, and the capacity of the health system to ensure their access to quality care. Older people with dementia may face even greater barriers to appropriate care in acute care settings. Yet, studies about the care quality for older patients with dementia in acute care settings are still few. The objective of this study is to assess whether dementia status is associated with poorer treatment by examining the association of a patient’s dementia status with the probability of receiving surgery and the waiting time until surgery for a hip fracture in acute care hospitals in Japan.

Methods

All patients with closed hip fracture were extracted from the Diagnosis Procedure Combination (DPC) database between April 2014 and March 2018. After excluding complicated cases, we conducted regressions with multilevel models. We used two outcome measures: (i) whether the patient received a surgery or was treated by watchful waiting; and (ii) number of waiting days until surgery after admission.

Results

Two hundred fourteen thousand six hundred one patients discharged from 1328 hospitals were identified. Among them, 159,173 patients received surgery. Both 80–89 year-olds (OR 0.87; 95% CI, 0.84, 0.90) and those 90 years old and above (OR 0.67; 95% CI, 0.65, 0.70) had significantly lower odds ratios for receiving surgery compared to 65–79 year-olds. Those with severe dementia had a significantly greater likelihood of receiving surgery compared to those without dementia (OR 1.21; 95% CI, 1.16, 1.25). Patients aged 90 years old and above had shorter waiting time for surgery (Coef. -0.06; 95% CI, − 0.11, − 0.01). Mild dementia did not have a statistically significant impact on the number of waiting days until surgery (P = 0.34), whereas severe dementia was associated with shorter waiting days (Coef. -0.08; 95% CI, − 0.12, − 0.03).

Conclusions

These findings suggest physicians may be taking proactive measures to preserve physical function for those with severe dementia and to avoid prolonged hospitalization although there are no formal guidelines on prioritization for the aged and dementia patients.

Early enteral nutrition in patients with severe traumatic brain injury: a propensity score-matched analysis using a nationwide inpatient database in Japan

BACKGROUND

Whether enteral nutrition (EN) should be administered early in severe traumatic brain injury (TBI) patients has not been fully addressed.

OBJECTIVE

The present study aimed to evaluate whether early EN can reduce mortality or nosocomial pneumonia among severe TBI patients.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from April 2014 to March 2017 linked with the Survey for Medical Institutions, we identified patients admitted for intracranial injury with Japan Coma Scale scores ≥30 (corresponding to Glasgow Coma Scale scores ≤8) at admission. We designated patients who started EN within 2 d of admission as the early EN group, and those who started EN at 3-5 d after admission as the delayed EN group. The primary outcome was in-hospital mortality. The secondary outcome was nosocomial pneumonia. Propensity score-matched analyses were performed to compare the outcomes between the 2 groups.

RESULTS

We identified 3080 eligible patients during the 36-mo study period, comprising 1100 (36%) in the early EN group and 1980 (64%) in the delayed EN group. After propensity score matching, there was no significant difference in in-hospital mortality (difference: -0.3%; 95% CI: -3.7%, 3.1%) between the 2 groups. The proportion of nosocomial pneumonia was significantly lower in the early EN group than in the delayed EN group (difference: -3.2%; 95% CI: -5.9%, -0.4%).

CONCLUSIONS

Early EN may not reduce mortality, but may reduce nosocomial pneumonia in patients with severe TBI.

Risk factors for early unplanned readmission in patients with bipolar disorder: A retrospective observational study

OBJECTIVES

Evidence regarding the relationships between patient, hospital, and regional factors and early unplanned readmission (short-term outcome) in patients with bipolar disorder is lacking. This study aimed to examine risk factors associated with early unplanned readmission in patients with bipolar disorder.

METHOD

We retrospectively analyzed adult bipolar patients (ICD-10; F31) between April 2012 and March 2014 in the Japanese Diagnosis Procedure Combination database. We examined factors affecting the 30-day unplanned readmission using multivariable logistic regression analysis.

RESULTS

A total of 2688 patients admitted to psychiatric beds were included. Multivariate analysis showed that unchanged or exacerbation discharge outcome (adjusted odds ratio [aOR]: 1.93; 95% confidence interval [CI]: 1.06-3.51, p = 0.031), unplanned or urgent admission settings (aOR: 1.51; 95% CI: 1.00-2.26, p = 0.048), physical comorbidity (chronic pulmonary disease) (aOR: 4.74; 95% CI: 1.30-17.29, p = 0.018), presence of psychiatric acute-care beds (aOR: 1.72; 95% CI: 1.02-2.87, p = 0.040), and intermediate-level hospital psychiatric staffing (aOR: 1.82; 95% CI: 1.14-2.91, p = 0.012) were significantly associated with higher early unplanned readmission, while higher density of psychiatrists in the area (aOR: 0.50; 95% CI: 0.29-0.87, p = 0.014) was significantly associated with lower early unplanned readmission.

CONCLUSIONS

The results suggest that not only careful management of high-risk patients but also consideration of functional differentiation in psychiatric inpatient care, psychiatric resource allocation, and follow-up support for patients with bipolar disorder are needed for reducing the early unplanned readmission rate.

Volume effect in paediatric brain tumour resection surgery: analysis of data from the Japanese national inpatient database

BACKGROUND

Paediatric brain tumours are the second most common type of malignancies that occur during childhood. Surgical resection is usually the first step in the treatment of these patients; however, evidence pertaining to a 'volume effect' in paediatric brain tumour resection surgery and the associations among the surgical volume, clinical features and treatments are not well characterised.

METHODS

Data pertaining to paediatric patients (age ≤ 15 years) who underwent brain tumour resection surgery between April 2012 and March 2016 were retrieved from the Japanese administrative inpatient database and retrospectively analysed. Demographic characteristics, therapeutic procedures and in-hospital mortality were summarised according to the hospital surgical volume. Penalised logistic regression analysis was used to investigate the association between the hospital surgical volume and in-hospital mortality.

RESULTS

A total of 1354 paediatric patients were included. About 40% of the patients were in the 11- to 15-year age group. The male:female ratio was 53:47, the overall crude in-hospital mortality was 1.8% (n = 24) and the 30-day postoperative mortality was 0.4% (n = 6). The crude mortality ratio was 3.3% in the lowest quartile and 0.8% in the highest quartile by volume. After adjusting for covariates, a higher hospital surgical volume was associated with lower in-hospital mortality (compared with 1-4 surgeries per 4 years, 15-25 surgeries, odds ratio [OR]: 0.25; 95% confidence interval [CI]: 0.05-0.90, p = 0.033; ≥26 surgeries, OR: 0.31; 95% CI: 0.08-0.96, p = 0.042).

CONCLUSIONS

The present study indicated a volume-outcome relationship in paediatric brain tumour resection surgery cases. Further centralisation of surgeries should be considered to achieve better outcomes.

Incidence and In-Hospital Mortality of Neonatal Disseminated Intravascular Coagulation in Japan: An Observational Study of a Nationwide Hospital Claims Database

This study aimed to estimate the incidence and prognosis of neonatal disseminated intravascular coagulation (DIC) in Japan by analyzing data retrieved from a national administrative database. Clinically, the prognosis of DIC in neonates is poor, but there is little epidemiological data in Japan. This retrospective observational study identified patients diagnosed with neonatal DIC and who were registered in the Japanese diagnosis procedure combination (DPC) database between April 1, 2014 and March 31, 2016. The patients, who were diagnosed with neonatal DIC, included those with ICD-10 code D65 or P60 in primary and secondary diagnosis, with comorbid conditions existing at admission, and with complications occurring after admission. Of 78,073 neonates admitted to 1,474 neonatal intensive care units, 1,864 (2.4%) were diagnosed with DIC. There was no difference between sexes in incidence of DIC; the incidence of DIC was higher in extremely low birth weight infants (9.8%), and significantly higher than that in normal birth weight infants. The overall mean length of hospital stay was longer in neonates with DIC (69.5 days) than in those without DIC (32.6 days, P < 0.001). The number of deaths was 1,156 (1.5%). In-hospital mortality was significantly higher in neonates with DIC (14.1%) than in those without DIC (1.2%, P < 0.001), especially in premature babies. This nationwide study was the first report to investigate the incidence and in-hospital mortality of neonatal DIC in Japan. Neonatal DIC has a significant impact on prognosis, and its influence is greater in premature than in term infants.

Donepezil is associated with decreased in-hospital mortality as a result of pneumonia among older patients with dementia: A retrospective cohort study

AIM

Pneumonia is one of the major causes of mortality in older adults. As the average lifespan has extended and new modalities to prevent or treat pneumonia are developed, the factors that affect the length of hospital stay (LHS) and in-hospital mortality of older patients with pneumonia have changed. The object of the present study was to determine the factors associated with LHS and mortality as a result of pneumonia among older patients with dementia.

METHODS

With a retrospective cohort study design, we used the data derived from the Japanese Administrative Database and diagnosis procedure combination/per diem payment system (DPC/PDPS) database. There were 39 336 admissions of older patients for pneumonia between August 2010 and March 2012. Patients with incomplete data were excluded, leaving 25 602 patients for analysis.

RESULTS

Having dementia decreased mortality (OR 0.71, P < 0.001) and increased LHS. Multiple logistic regression analysis identified donepezil as an independent factor that decreased mortality in patients with dementia (OR 0.36, P < 0.001). Donepezil was prescribed for 28.7% of these patients, and their mortality rate was significantly lower than those of patients with dementia who were not treated with donepezil and of patients without dementia. The mortality rate was higher for patients with dementia who were not treated with donepezil compared with patients who did not have dementia. All other factors that influenced LHS and mortality were similar to those reported by others.

CONCLUSIONS

Donepezil seems to decrease in-hospital mortality as a result of pneumonia among older patients with dementia. Geriatr Gerontol Int 2018; 18: 269-275.

Association Between Financial Incentives for Regional Care Coordination and Health Care Resource Utilization Among Older Patients after Femoral Neck Fracture Surgery: A Retrospective Cohort Study Using a Claims Database

The incidence rates of hip fracture have been increasing in Japan. Length of stay among hip fracture patients in Japan is much longer than other developed countries, and the Japanese government introduced financial incentives for regionally coordinated femoral neck fracture care to reduce health care resource utilization. The objective of this study was to evaluate whether the financial incentives reduce health care resource utilization among patients 75 years or older with femoral neck fracture in Japan. Claims data from the Fukuoka Prefecture Regional Association for Late-Stage Healthcare for Older People were analyzed for the period from April 2010 to March 2016. The authors identified 4641 eligible subjects after femoral neck fracture surgery, and categorized them into groups based on care pathways: coordinated care, integrated care, and other. Length of stay by care phase and total charges were used as measures of health care resource utilization. The models showed that coordinated and integrated care were significantly associated with shorter length of stay during perioperative care: coordinated care, multiplicative effect, 0.90 (P < 0.001); integrated care, 0.77 (P < 0.001). However, only integrated care was associated with shorter rehabilitation and overall length of stay: 0.66 (P < 0.001) in rehabilitation; 0.70 (P < 0.001) in overall duration. Integrated care also was associated with lower total charges: 0.70 (P < 0.001). Current financial incentives for regionally coordinated femoral neck fracture care do not affect health care resource utilization. Further health care reforms should be implemented to promote effective regional care coordination in Japan.

Impact of financial incentives for inter-provider care coordination on health-care resource utilization among elderly acute stroke patients

Objective

To examine the impact of inter-provider care coordination on health-care resource utilization among elderly acute stroke patients.

Design

A retrospective cohort study using health-care insurance claims data.

Setting

Claims data of the Fukuoka Prefecture Wide-Area Association of Latter-Stage Elderly Healthcare.

Participants

About, 6409 patients aged 75 years or older admitted for acute stroke and moved to rehabilitation wards from 1 April 2010 to 30 September 2015.

Main outcome measure

Lengths of stay (LOS) and total charge (TC) were evaluated according to three groups of care pathways (coordinated care, integrated care and other pathways).

Results

Compared with the other care pathway, the coordinated care groups had significantly shorter LOS of 2.0 days in acute ischemic stroke care; they had 2.5 days shorter LOS in hemorrhagic stroke care. However, there were no significant differences in rehabilitation care LOS and TC.

Conclusions

Our findings suggest that a payment system for care coordination is inappropriate since it was not associated with a reduction in overall health-care resource utilization. Further, health-care system reform is necessary to improve care continuity across multiple health-care institutions in Japan.

Investigation into the causes of indwelling urethral catheter implementation and its effects on clinical outcomes and health care resources among dementia patients with pneumonia: A retrospective cohort study

There is a possibility that unnecessary treatments and low-quality medical care, such as inappropriate indwelling urethral catheter use, are being provided to older Japanese individuals.The aim of this study was to investigate contextual effects relating to indwelling urethral catheters in older people with dementia and to clarify the effects of indwelling urethral catheter use on patients' mortality, length of stay (LOS), and health care spending. This retrospective cohort study involved 4501 male and female Japanese participants. Those who were aged 75 or older with dementia and had a primary diagnosis of acute lower respiratory disease with antibiotics administered during hospitalization were eligible for inclusion. Patient mortality, LOS, and total charge during hospitalization were the main study outcomes. This study showed that indwelling urethral catheter use was significantly associated with higher mortality, longer LOS, and higher total charge for hospitalization. The pattern of indwelling urethral catheter use was clustered by care facility level. Physician density was significantly associated with indwelling urethral catheter use; the relationship was not linear but U-shaped, such that the approximate median had the lowest rate of urethral catheter use and this increased gradually toward both lower and higher physician densities. Our study found considerable variation in indwelling urethral catheter use between care facilities in older people with dementia. Additionally, indwelling urethral catheter use was related to poor outcomes. Based on these findings, we consider there to be an urgent need for constructing a framework to measure, report on, and promote the improvement of care quality for older individuals in Japan.

Preoperative factors affecting cost and length of stay for isolated off-pump coronary artery bypass grafting: hierarchical linear model analysis

OBJECTIVE

To determine the effect of preoperative patient and hospital factors on resource use, cost and length of stay (LOS) among patients undergoing off-pump coronary artery bypass grafting (OPCAB).

DESIGN

Observational retrospective study.

SETTINGS

Data from the Japanese Administrative Database.

PARTICIPANTS

Patients who underwent isolated, elective OPCAB between April 2011 and March 2012.

PRIMARY OUTCOME MEASURES

The primary outcomes of this study were inpatient cost and LOS associated with OPCAB. A two-level hierarchical linear model was used to examine the effects of patient and hospital characteristics on inpatient costs and LOS. The independent variables were patient and hospital factors.

RESULTS

We identified 2491 patients who underwent OPCAB at 268 hospitals. The mean cost of OPCAB was $40 665 ±7774, and the mean LOS was 23.4±8.2 days. The study found that select patient factors and certain comorbidities were associated with a high cost and long LOS. A high hospital OPCAB volume was associated with a low cost (-6.6%; p=0.024) as well as a short LOS (-17.6%, p<0.001).

CONCLUSIONS

The hospital OPCAB volume is associated with efficient resource use. The findings of the present study indicate the need to focus on hospital elective OPCAB volume in Japan in order to improve cost and LOS.

Factors associated with 30-day readmission of patients with heart failure from a Japanese administrative database

Background

Numerous studies have been conducted in many countries to identify the factors associated with readmission of patients with heart failure (HF). However, there have been no such studies utilizing a large-scale administrative database in Japan. This study aimed to establish the factors associated with 30-day readmission of patients with HF using a Japanese nationwide administrative database.

Methods

Data of the index admissions of 68,257 patients discharged from 1057 participating hospitals between April 1, 2012 and March 31, 2013 were analyzed. Patients were divided into the 30-day readmission group and no readmission group according to whether unplanned HF readmission occurred within 30 days after discharge. Study variables included age, sex, New York Heart Association functional class (NYHA) at admission, Charlson Comorbidity Index (CCI), length of stay in hospital (LOS), body mass index (BMI) at admission, hospital volume reflected by the number of cases hospitalized with HF, and medical treatment at discharge.

Results

The 30-day readmission and no readmission groups included 4479 and 63,778 patients, respectively. The independent factors associated with the increase in 30-day readmission were older age, higher NYHA, higher CCI, and use of the following drugs at discharge: beta blockers, loop diuretics, thiazide, and nitrates. In contrast, the independent factors associated with the decrease in 30-day readmission were longer LOS, higher BMI, and the use of angiotensin converting enzyme inhibitors (ACEs) or angiotensin II receptor blockers (ARBs), calcium channel blockers, and spironolactone.

Conclusions

The results suggest that, especially during the first few weeks after discharge, careful management of HF outpatients with advanced age, high disease severity, multiple comorbidities, or taking beta blockers, loop diuretics, thiazide, and nitrates at discharge may be crucial for reducing the 30-day readmission rate.

Body mass index influences the outcome of acute pancreatitis: an analysis based on the Japanese administrative database

OBJECTIVE

This study aimed to investigate the relationship between body mass index (BMI) and risk of death in patients with acute pancreatitis (AP) using a Japanese national administrative database.

METHODS

We analyzed a total of 6002 patients with AP. We collected patient information, including sex, age, BMI, severity of AP based on the Japan Pancreas Society scoring system, and prognosis. We classified BMI into 5 categories (underweight [BMI, <18.5], normal range [18.5-24.9], preobese [25-29.9], obese class I [30-34.9], and obese class II/III [>35]) and investigated the relationship between each category and risk of death in AP.

RESULTS

There was a good correlation between the Japanese AP severity score and in-hospital mortality. Overall mortality of severe pancreatitis was 7.0% (n = 2245). Mortality in each BMI category was as follows: underweight, 6.4%; normal range, 3.6%; preobese, 2.4%; obese class I, 3.2%; and obese class II/III, 5.7%. Underweight and obese class II/III patients had significantly higher relative risk (RR) of death in AP compared with preobese patients after adjusting for sex, age, and severity of AP (RR, 2.7; 95% confidence interval, 1.6-4.5; and RR, 6.4; 95% confidence interval, 1.9-20.9, respectively).

CONCLUSIONS

Underweight or overweight was the independent risk factor for mortality in AP.

The trends in EMR and CPOE adoption in Japan under the national strategy

PURPOSE

We evaluate the status of health information system (HIS) adoption (In this paper, "HIS" means electronic medical record system (EMR) and computerized provider order entry system (CPOE)). We also evaluate the affect of the policies of Japanese government.

METHODS

The status of HIS adoption in Japan from 2002 to 2011 was investigated using reports from complete surveys of all medical institutions conducted by the Ministry of Health, Labour and Welfare (MHLW). HIS-related budgets invested by the Japanese government from 2000 to 2008 were surveyed mainly using literatures and administrative documents of the Japanese government (MHLW and Ministry of Economy, Trade and Industry).

RESULTS

The rates of HIS adoption in Japan in 2011 were: 20.9% for the rate of EMR adoption in clinics, 20.1% for the rate of EMR adoption and 36.6% for the rate of CPOE adoption in hospitals. In hospitals, the rate of EMR and CPOE adoption were 51.5% and 78.6% in 822 large hospitals (400 or more beds), 27.3% and 52.1% in 1832 medium hospitals (200-399 beds), and 13.5% and 26.0% in 5951 small hospitals (less than 200 beds), respectively. Japan has a large number of medical institutions (99,547 clinics and 8605 hospitals) with a low rate of EMR adoption in clinics and a high rate of HIS adoption in hospitals. The national budget to expand HIS use was implemented for medium and large hospitals mainly. The policy target of New IT Reform Strategy was not achieved.

CONCLUSION

The rate of HIS adoption in Japanese medium and large hospitals is high compared to small hospitals and clinics, and this is attributable to the fact that the Japanese government placed the target for HIS adoption on key hospitals with a large number of beds and concentrated budget investment in those hospitals. Besides, legal approval of EMR and the introduction of Diagnostic Procedure Combination system facilitated EMR adoption. There is less financial support for small hospitals than medium and large hospitals. The low rate of EMR adoption in clinics stems from the facts that there was little subsidies or incentives in the national remuneration for medical services, lack of cooperation from medical associations, and a failed attempt to mandate computerization of medical accounting (medical billing). Giving financial incentives is an effective means of raising EMR adoption rate. For wide usage of HIS, more financial support and incentive may be necessary for small hospitals and clinics.

Multivariate analysis of factors influencing length of hospitalization and medical costs of cholecystectomy for acute cholecystitis in Japan: a national database analysis

Little information is available on the factors influencing length of stay (LOS) in hospital and medical costs during hospitalization associated with cholecystectomy for acute cholecystitis. We determined the independent factors affecting LOS and medical costs of patients who underwent cholecystectomy for acute cholecystitis based on data from the Diagnosis Procedure Combination (DPC) database. In 2008, a total of 2176 patients with acute cholecystitis were referred for cholecystectomy to 624 hospitals in Japan. We collected patient characteristics and data on treatments for acute cholecystitis using the DPC database and identified independent factors affecting LOS and medical costs during hospitalization using multiple linear regression models. Analysis revealed that early cholecystectomy was significantly associated with a decrease in LOS, whereas longer preoperative antimicrobial therapy was significantly associated with an increase of LOS: the standardized coefficient for early cholecystectomy was -0.372 and that for preoperative antimicrobial therapy was 0.353 (P < 0.001). These procedures were also significant independent factors with regard to medical costs during hospitalization: the standardized coefficient for early cholecystectomy was -0.391 and that for preoperative antimicrobial therapy was 0.335 (P < 0.001). Early cholecystectomy significantly reduces the LOS and medical costs of cholecystectomy for acute cholecystitis, while preoperative antimicrobial therapy increases LOS and medical costs during hospitalization. These results highlight the need for health care implementations such as promotion of early cholecystectomy, appropriate use of antimicrobial drugs, and centralization of patients with cholecystectomy for acute cholecystitis in Japan.

Pyloromyotomy versus i.v. atropine therapy for the treatment of infantile pyloric stenosis: nationwide hospital discharge database analysis

BACKGROUND

Several studies have suggested that i.v. atropine has a potential role in treating infantile hypertrophic pyloric stenosis (IHPS). It remains unclear, however, whether surgery can be replaced by i.v. therapy.

METHODS

Data were extracted on infants with IHPS who were treated with atropine and/or surgery, from a nationwide administrative database through 2006-2008. Patient demographic data, treatment effects and length of hospital stay were analyzed in each treatment group.

RESULTS

A total of 585 infants met the criteria for IHPS; 188 patients (32%) were initially treated with atropine (i.v. form, n = 180; oral form, n = 8), while 397 were treated with surgery as a first-line therapy. Of the 180 infants receiving i.v. atropine, 38 were withdrawn from medical management and subsequently underwent surgery. Thus, the overall success rate of i.v. atropine was 78.9% (142/180). Surgery had a success rate of 100%, and postoperative complications were found in 2.8% of patients (12/435). Medical management required longer hospital stay than surgery (mean, 13.5 days vs 8.0 days; P < 0.001).

CONCLUSION

Surgery remains the suitable standard management option for IHPS, with its high success rate, minimal complications and shorter hospital stay compared with i.v. atropine therapy.

Impact of teaching intensity and academic status on medical resource utilization by teaching hospitals in Japan

Teaching hospitals require excess medical resources to maintain high-quality care and medical education. To evaluate the appropriateness of such surplus costs, we examined the impact of teaching intensity defined as activities for postgraduate training, and academic status as functions of medical research and undergraduate teaching on medical resource utilization. Administrative data for 47,397 discharges from 40 academic and 12 non-academic teaching hospitals in Japan were collected. Hospitals were classified into three groups according to intern/resident-to-bed (IRB) ratio. Resource utilization of medical services was estimated using fee-for-service charge schedules and normalized with case mix grouping. 15-24% more resource utilization for laboratory examinations, radiological imaging, and medications were observed in hospitals with higher IRB ratios. With multivariate adjustment for case mix and academic status, higher IRB ratios were associated with 10-15% more use of radiological imaging, injections, and medications; up to 5% shorter hospital stays; and not with total resource utilization. Conversely, academic status was associated with 21-33% more laboratory examinations, radiological imaging, and medications; 13% longer hospital stays; and 10% more total resource utilization. While differences in medical resource utilization by teaching intensity may not be associated with indirect educational costs, those by academic status may be. Therefore, academic hospitals may need efficiency improvement and financial compensation.

Association between hospital volume and outcomes of elderly and non-elderly patients with acute biliary diseases: a national administrative database analysis

AIM

This study aimed to investigate the relationship between hospital volume and clinical outcomes of elderly and non-elderly patients with acute biliary diseases using data from a national administrative database.

METHODS

Overall, 26720 elderly and 33774 non-elderly patients with acute biliary diseases were referred to 820 hospitals in Japan. Hospital volume was categorized into three groups based on the case numbers during the study period: low-volume, medium-volume and high-volume. We compared the risk-adjusted length of stay (LOS) and in-hospital mortality in relation to hospital volume. These analyses were stratified according to the presence of invasive treatments for acute biliary diseases.

RESULTS

Multiple linear regression analyses showed that increased hospital volume was significantly associated with shorter LOS in both elderly and non-elderly patients with and without invasive treatments. Increased hospital volume was significantly associated with decreased relative risk of in-hospital mortality in elderly patients. The odds ratio for high-volume hospitals was 0.672 in elderly patients without invasive treatments (95% confidence interval [CI] 0.533-0.847, P=0.001) and 0.715 in those with invasive treatments (95% C, 0.566-0.904, P=0.005). However, no significant differences for in-hospital mortality were seen in non-elderly patients with and without invasive treatments.

CONCLUSION

  This study has highlighted that higher volume hospitals significantly reduced LOS and in-hospital mortality for elderly patients with acute biliary diseases, but not non-elderly patients. The current results are of value for elderly healthcare policy decision-making, and highlight the need for further studies into the quality of care for elderly patients.

Clinical features of infants hospitalized for 2009 pandemic influenza A (H1N1) in Japan: analysis using a national hospital discharge database

BACKGROUND

Earlier studies reported that infants <12 months of age were at high risk of hospitalization for 2009 pandemic influenza A H1N1 virus (2009 H1N1) infection, but there was little information about the clinical courses in these patients.

METHODS

A retrospective study was performed using the nationwide inpatient Diagnosis Procedure Combination Database in Japan. We searched data on hospitalizations, between July and December 2009, of infants (<12 months) and children 12 to <24 months of age with influenza. We examined their demographic data and hospitalization details, including treatment, complications, and outcomes.

RESULTS

During the study period, 1023 infants were hospitalized for influenza; 98.1% of them were previously healthy. Complications attributed to influenza were found in 181 (17.7%) infants, including 3 critical illnesses and 1 death. Oseltamivir was prescribed to 535 (53.3%) infants. We found no evidence that oseltamivir was associated with either complications or length of hospital stay. During the same period, 579 children 1 year of age were admitted for 2009 H1N1, and 56.5% of them had influenza-related complications.

CONCLUSIONS

In Japan, infants with 2009 H1N1 were twice as likely to be hospitalized as children 1 year of age. However, the clinical course of the hospitalized infants was generally uncomplicated.

Intussusception among Japanese children: an epidemiologic study using an administrative database

Background

The epidemiology of intussusception, including its incidence, can vary between different countries. The aim of this study was to describe the epidemiology of childhood intussusception in Japan using data from a nationwide inpatient database.

Methods

We screened the database for eligible cases ≤ 18 years of age, who were coded with a discharge diagnosis of intussusception (International Classification of Diseases, 10th revision: K-561) between July to December in 2007 and 2008. We then selected cases according to Level 1 of the diagnostic certainty criteria developed by the Brighton Collaboration Intussusception Working Group. We examined the demographics, management, and outcomes of cases, and estimated the incidence of intussusception.

Results

We identified 2,427 cases of intussusception. There were an estimated 2,000 cases of infantile intussusception annually in Japan, an incidence of 180-190 cases per 100,000 infants. The median age at diagnosis was 17 months, and two-thirds of the patients were male. Treatment with an enema was successful in 93.0% of cases (2255/2427). The remainder required surgery. Secondary cases accounted for 3.1% (76/2427). Median length of hospital stay was 3 days. Of the 2,427 cases, we found 2 fatal cases associated with intussusception.

Conclusions

This is currently the largest survey of childhood intussusception in Asia using a standardized case definition. Our results provide an estimate of the baseline risk of intussusception in Japan, and it is higher than the risk observed in other countries.

The incidence of pertussis hospitalizations among Japanese infants: excess hospitalizations and complications?

We examined pertussis hospitalizations among infants aged <1 year between 2006 and 2008 using the nationwide inpatient database in Japan. A total of 660 infants hospitalized for pertussis were identified. Peak incidence occurred at age 1 month and infants aged 0-2 months (too young for pertussis vaccination) and ≥3 months (eligible for at least one dose of vaccination) accounted for 44·5% and 55·5% of hospitalizations, respectively. Complications related to pertussis were found in 165 (25·0%) cases, including one death; the age at admission did not differ significantly between patients with and those without complications (mean age 4·1 vs. 4·5 months, P=0·12). Seventeen patients required mechanical ventilation. Of the 17 cases, 14 infants were aged <3 months and three infants were aged ≥3 months. Our findings highlight that the vaccination schedule against pertussis may often be delayed in Japan.

Prevalence of type 2 diabetes among acute inpatients and its impact on length of hospital stay in Japan

OBJECTIVE

The goal of this study was to determine the prevalence of type 2 diabetes among acute inpatients and evaluate its impact on the length of hospital stay in Japan.

RESEARCH DESIGN AND METHODS

The discharge records of 2,120,170 acute inpatients who were 30 years old or older and discharged between July and December of 2008 were obtained from the Japanese administrative case-mix system, Diagnosis Procedure Combination (DPC), and allocated for analysis. Type 2 diabetes was defined by E11 of the ICD-10 coding system on patient records. Other types of diabetes, including type 1 diabetes and diabetes in pregnancy (defined by ICD-10 codes E10 E12-14 and O24, respectively) were excluded from the analyses.

RESULTS

Type 2 diabetes was observed among 11.4% of the records, 9.9% of which were cases of diabetes as a comorbidity. Total length of hospital stay was 33,468,152 days, with diabetes patients occupying 13.9% of the total bed days. Patients with type 2 diabetes as a comorbidity had prolonged lengths of hospital stay compared to patients free from diabetes, and stratification by sex, age, surgical treatment, and disease category did not alter these results. The median length of hospital stay was 9 days among patients without diabetes and 13 days among patients with diabetes.

CONCLUSION

Japanese acute health care is experiencing an epidemic of type 2 diabetes, with 1 out of 10 acute inpatients suffering from the disease. Complication of type 2 diabetes is associated with prolonged length of hospital stay.

Profiling of the care processes for laryngeal cancer with the Japanese administrative database

At present, there is a shortage of detailed data on head and neck cancer treatment in acute care hospitals in Japan. We conducted an analysis of the care process for laryngeal cancer inpatients in Japan using a national administrative database based on the case-mix system known as the Diagnosis Procedure Combination to evaluate the recent clinical situation of a relatively high incidence of head and neck cancers. We obtained discharge data relating to 2790 cases (one case = one hospitalization) involving 2319 laryngeal cancer patients from 346 acute care hospitals that participated in the Japanese national case-mix project between July and December of 2008. The details of their treatment procedures were analyzed according to the Japanese procedure codes managed by the Ministry of Health, Labour, and Welfare of Japan. There were 2156 male and 163 female patients. The median age was 69 years (range: 22-96 years). The most frequent surgical procedure was endoscopic resection which was performed for 781 cases. Chemotherapy was given in 31.6% of cases in the < 60 age group, 28.2% in the 60-79, and 14.1% in the ≥ 80. The most frequently used chemotherapy regimen was a single drug, S-1 (compound of tegafur, gimeracil and oteracil potassium), which was more frequently used in the ≥ 70 age group than in the younger age group. The Diagnosis Procedure Combination database, which collects a large volume of data from all over the country, is useful for analysis of the care process for head and neck cancers in Japan.

New indicators based on personnel cost for management efficiency in a hospital

A simple and fair benchmarking system or financial indicators for use on the clinical department level have been lacking to evaluate the management efficiency and activity of each clinical department or division of a hospital. New financial indicators have therefore been developed based on personnel costs. Indicator 1: The ratio of marginal profit after personnel cost per personnel cost (RMP). Indicator 2: The ratio of investment (=indirect cost) per personnel cost (RIP). The difference between RMP and RIP demonstrates the operation profit in US Dollars for personnel cost (OPP). A turning point in profitability similar to the break-even point (BEP) and break-even ratio (BER) could be also defined by the combination of the RMP and RIP. The merits of these two indicators are not only the ability to indicate the relationship between the medical profit and the investments in the hospital, but also the capability to demonstrate such indicators as BEP, BER and OPP on a single graph. The two indicators were applied to the hospitals in the National Hospital Organization and to the clinical department in one hospital. Using these two indicators, it was possible to evaluate the management efficiency and medical activity not only in the whole hospital but also in each department and DPC/DRG group. This will be of use to a manager of a hospital in checking the management efficiency of his/her hospital despite the variations among hospitals, departments and divisions.

Contribution of case-mix classification to profiling hospital characteristics and productivity

Case-mix classification has made it possible to analyze acute care delivery case volumes and resources. Data arising from observed differences have a role in planning health policy. Aggregated length of hospital stay (LOS) and total charges (TC) as measures of resource use were calculated from 34 case-mix groups at 469 hospitals (1,721,274 eligible patients). The difference between mean resource use of all hospitals and the mean resource use of each hospital was subdivided into three components: amount of variation attributable to hospital practice behavior (efficiency); amount attributable to hospital case-mix (complexity); and amount attributable to the interaction. Hospital characteristics were teaching status (academic or community), ownership, disease coverage, patients, and hospital volume. Multivariate analysis was employed to determine the impact of hospital characteristics on efficiency. Mean LOS and TC were greater for academic than community hospitals. Academic hospitals were least associated with LOS and TC efficiency. Low disease coverage was a predictor of TC efficiency while low patient volume was a predictor of unnecessarily long hospital stays. There was an inverse correlation between complexity and efficiency for both LOS and TC. Policy makers should acknowledge that differentiation of hospital function needs careful consideration when measuring efficiency.

Assessment of hospital performance with a case-mix standardized mortality model using an existing administrative database in Japan

Background

Few studies have examined whether risk adjustment is evenly applicable to hospitals with various characteristics and case-mix. In this study, we applied a generic prediction model to nationwide discharge data from hospitals with various characteristics.

Method

We used standardized data of 1,878,767 discharged patients provided by 469 hospitals from July 1 to October 31, 2006. We generated and validated a case-mix in-hospital mortality prediction model using 50/50 split sample validation. We classified hospitals into two groups based on c-index value (hospitals with c-index ≥ 0.8; hospitals with c-index < 0.8) and examined differences in their characteristics.

Results

The model demonstrated excellent discrimination as indicated by the high average c-index and small standard deviation (c-index = 0.88 ± 0.04). Expected mortality rate of each hospital was highly correlated with observed mortality rate (r = 0.693, p < 0.001). Among the studied hospitals, 446 (95%) had a c-index of ≥0.8 and were classified as the higher c-index group. A significantly higher proportion of hospitals in the lower c-index group were specialized hospitals and hospitals with convalescent wards.

Conclusion

The model fits well to a group of hospitals with a wide variety of acute care events, though model fit is less satisfactory for specialized hospitals and those with convalescent wards. Further sophistication of the generic prediction model would be recommended to obtain optimal indices to region specific conditions.

A new accounting system for financial balance based on personnel cost after the introduction of a DPC/DRG system

A hospital director must estimate the revenues and expenses not only in a hospital but also in each clinical division to determine the proper management strategy. A new prospective payment system based on the Diagnosis Procedure Combination (DPC/PPS) introduced in 2003 has made the attribution of revenues and expenses for each clinical department very complicated because of the intricate involvement between the overall or blanket component and a fee-for service (FFS). Few reports have so far presented a programmatic method for the calculation of medical costs and financial balance. A simple method has been devised, based on personnel cost, for calculating medical costs and financial balance. Using this method, one individual was able to complete the calculations for a hospital which contains 535 beds and 16 clinics, without using the central hospital computer system.

Development and analysis of a nationwide cost database of acute-care hospitals in Japan

OBJECTIVES

Understanding of hospital cost is crucial to achieve an ideal balance between the assurance and improvement of patient safety and quality, and efficient use of finite resources. However, neither a standardized calculation methodology nor a large-scale database of costs in acute-care hospitals exists in Japan. This study aims to develop a standardized methodology, construct a nationwide cost database in Japan, analyse the characteristics of the database and examine the relationship between the cost and the charge from the viewpoint of an appropriate reflection of the cost to the price.

METHOD

We designed the costing framework, gathered the data for patients discharged from 139 acute-care hospitals in Japan between July 2004 and October 2004 and constructed a database containing information on 284,730 patients. The characteristics of the database and the relationship between the cost and the charge were investigated.

RESULTS

In the nationwide database we constructed, a wide range in the average cost per hospitalization and average cost per diem was observed. A wide variation of cost components was seen across major diagnostic categories. Moreover, there was a high correlation between the cost and the charge (Correlation coefficient = 0.94).

CONCLUSIONS

After designing a costing framework, a nationwide database comprised of individual case-level costs with components for acute-care hospitals in Japan was successfully developed. We hope this study contributes to appropriate decision making and helps motivate further research geared towards efficient hospital management and a rational payment system in Japan.

The impact of a new payment system with case-mix measurement on hospital practices for breast cancer patients in Japan

Breast cancer is the most common cancer in Japanese women. As the incidence of breast cancer rises, the economic burden of breast cancer treatment increases as well. In 2003, the Japanese government introduced a new payment system with case-mix measurement to encourage hospitals to utilize more effective inpatient management. The present study investigates the impact of the new payment system on hospital practices, as determined by changes in length of stay (LOS) and costs of health resource use in breast cancer treatment by either surgery or chemotherapy. Administrative claims data were collected from 41 national university-affiliated hospitals between 2003 and 2005, and multivariate analyses were performed using a multilevel modeling approach. We found shortened LOS for both treatments, which was the main contributor to the reduction in total costs of health resource use. Medication costs were significantly decreased due to increased use of generic medication in surgery cases, but not in chemotherapy. Surgery practices were determined to be more affected by the new payment system than chemotherapy. These results indicate that hospitals responded to the new payment system by controlling costs while maintaining the quality of care.

Performance of in-hospital mortality prediction models for acute hospitalization: hospital standardized mortality ratio in Japan

OBJECTIVE

In-hospital mortality is an important performance measure for quality improvement, although it requires proper risk adjustment. We set out to develop in-hospital mortality prediction models for acute hospitalization using a nation-wide electronic administrative record system in Japan.

METHODS

Administrative records of 224,207 patients (patients discharged from 82 hospitals in Japan between July 1, 2002 and October 31, 2002) were randomly split into preliminary (179,156 records) and test (45,051 records) groups. Study variables included Major Diagnostic Category, age, gender, ambulance use, admission status, length of hospital stay, comorbidity, and in-hospital mortality. ICD-10 codes were converted to calculate comorbidity scores based on Quan's methodology. Multivariate logistic regression analysis was then performed using in-hospital mortality as a dependent variable. C-indexes were calculated across risk groups in order to evaluate model performances.

RESULTS

In-hospital mortality rates were 2.68% and 2.76% for the preliminary and test datasets, respectively. C-index values were 0.869 for the model that excluded length of stay and 0.841 for the model that included length of stay.

CONCLUSION

Risk models developed in this study included a set of variables easily accessible from administrative data, and still successfully exhibited a high degree of prediction accuracy. These models can be used to estimate in-hospital mortality rates of various diagnoses and procedures.