Hayato Yamana

Validity of diagnoses, procedures, and laboratory data in Japanese administrative data

Background Validation of recorded data is a prerequisite for studies that utilize administrative databases. The present study evaluated the validity of diagnoses and procedure records in the Japanese Diagnosis Procedure Combination (DPC) data, along with laboratory test results in the newly-introduced Standardized Structured Medical Record Information Exchange (SS-MIX) data. Methods Between November 2015 and February 2016, we conducted chart reviews of 315 patients hospitalized between April 2014 and March 2015 in four middle-sized acute-care hospitals in Shizuoka, Kochi, Fukuoka, and Saga Prefectures and used them as reference standards. The sensitivity and specificity of DPC data in identifying 16 diseases and 10 common procedures were identified. The accuracy of SS-MIX data for 13 laboratory test results was also examined. Results The specificity of diagnoses in the DPC data exceeded 96%, while the sensitivity was below 50% for seven diseases and variable across diseases. When limited to primary diagnoses, the sensitivity and specificity were 78.9% and 93.2%, respectively. The sensitivity of procedure records exceeded 90% for six procedures, and the specificity exceeded 90% for nine procedures. Agreement between the SS-MIX data and the chart reviews was above 95% for all 13 items. Conclusion The validity of diagnoses and procedure records in the DPC data and laboratory results in the SS-MIX data was high in general, supporting their use in future studies.

Categorized diagnoses and procedure records in an administrative database improved mortality prediction

OBJECTIVES Comorbidity measures are widely used in administrative databases to predict mortality. The Japanese Diagnosis Procedure Combination database is unique in that secondary diagnoses are recorded into subcategories, and procedures are precisely recorded. We investigated the influence of these features on the performance of mortality prediction models. STUDY DESIGN AND SETTING We obtained data of adult patients with main diagnosis of acute myocardial infarction, congestive heart failure, acute cerebrovascular disease, gastrointestinal hemorrhage, pneumonia, or septicemia during a 1-year period. Multiple models were constructed representing different subcategories from which Charlson and Elixhauser comorbidities were extracted. Prevalence of comorbidities and C statistics of logistic regression models predicting in-hospital mortality was compared. Associations between four procedures (computed tomography, oxygen administration, urinary catheter, and vasopressors) and mortality were also evaluated. RESULTS C statistics of the model using all secondary diagnoses (Charlson: 0.717; Elixhauser: 0.762) were greater than those using a limited subcategory to strictly specify comorbidities (Charlson: 0.708; Elixhauser: 0.744). However, misidentification of complications and main diagnoses as comorbidities was observed in the all-diagnosis model. The four procedures were associated with mortality. CONCLUSION Subcategorized diagnoses allowed correct identification of comorbidities and procedures predicted mortality. Incorporation of these two features should be considered for other administrative databases.

Comparison of Procedure-Based and Diagnosis-Based Identifications of Severe Sepsis and Disseminated Intravascular Coagulation in Administrative Data.

Background Diagnoses recorded in administrative databases have limited utility for accurate identification of severe sepsis and disseminated intravascular coagulation (DIC). We evaluated the performance of alternative identification methods that use procedure records. Methods We obtained data for adult patients admitted to intensive care units in three hospitals during a 1-year period. Severe sepsis and DIC were identified by three means: laboratory data, diagnoses, and procedures. Using laboratory data as a reference, the sensitivity and specificity of procedure-based methods and diagnosis-based methods were compared. Results Of 595 intensive care unit admissions, 212 (35.6%) and 81 (13.6%) were identified as severe sepsis and DIC, respectively, using laboratory data. The sensitivity of procedure-based methods for identifying severe sepsis was 64.2%, and the specificity was 65.3%. Two diagnosis-based methods —the Angus and Martin algorithms— exhibited sensitivities of 21.7% and 14.6% and specificities of 98.7% and 99.5%, respectively, for severe sepsis. For DIC, the sensitivity of procedure-based methods was 55.6%, and the specificity was 67.1%, and the sensitivity and specificity of diagnosis-based methods were 35.8% and 98.2%, respectively. Conclusions Procedure-based methods were more sensitive and less specific than diagnosis-based methods in identifying severe sepsis and DIC. Procedure records could improve disease identification in administrative databases.

Procedure-based severity index for inpatients: development and validation using administrative database

BackgroundRisk adjustment is important in studies using administrative databases. Although utilization of diagnostic and therapeutic procedures can represent patient severity, the usability of procedure records in risk adjustment is not well-documented. Therefore, we aimed to develop and validate a severity index calculable from procedure records.MethodsUsing the Japanese nationwide Diagnosis Procedure Combination database of acute-care hospitals, we identified patients discharged between 1 April 2012 and 31 March 2013 with an admission-precipitating diagnosis of acute myocardial infarction, congestive heart failure, acute cerebrovascular disease, gastrointestinal hemorrhage, pneumonia, or septicemia. Subjects were randomly assigned to the derivation cohort or the validation cohort. In the derivation cohort, we used multivariable logistic regression analysis to identify procedures performed on admission day which were significantly associated with in-hospital death, and a point corresponding to regression coefficient was assigned to each procedure. An index was then calculated in the validation cohort as sum of points for performed procedures, and performance of mortality-predicting model using the index and other patient characteristics was evaluated.ResultsOf the 539 385 hospitalizations included, 270 054 and 269 331 were assigned to the derivation and validation cohorts, respectively. Nineteen significant procedures were identified from the derivation cohort with points ranging from −3 to 23, producing a severity index with possible range of −13 to 69. In the validation cohort, c-statistic of mortality-predicting model was 0.767 (95 % confidence interval: 0.764–0.770). The ω-statistic representing contribution of the index relative to other variables was 1.09 (95 % confidence interval: 1.03–1.17).ConclusionsProcedure-based severity index predicted mortality well, suggesting that procedure records in administrative database are useful for risk adjustment.

Development and validation of a new ICD-10-based trauma mortality prediction scoring system using a Japanese national inpatient database.

Introduction To develop and validate a new trauma mortality prediction scoring system based on International Statistical Classification of Diseases (ICD)-10 codes, using a Japanese administrative claims and discharge abstract database. Methods This retrospective observational study used the Japanese Diagnosis Procedure Combination database. Injuries were categorised into 33 groups with 5 additional groups based on injury sites and types. A multivariable logistic regression analysis was performed for in-hospital mortality in a derivation cohort after adjusting for the 38 groups, patients sex, age and Charlson Comorbidity Index score. Each variable was assigned a score that was equal to the value of the regression coefficient. The new severity score was defined as the sum of the scores. The new scoring system was tested in a validation cohort. Results The mortality rates were 2.4% (9270/393 395) and 2.5% (8778/349 285) in the derivation and validation cohorts, respectively. The area under the receiver operating curve (AUROC) of the new scoring system was 0.887 (95% CI 0.884 to 0.890) in the validation cohort. Subgroup analyses showed that the scoring system retained high predictive performance both for patients <65 years (AUROC 0.934, 95% CI 0.928 to 0.939) and for elderly patients at the age of ≥65 years (AUROC 0.825, 95% CI 0.820 to 0.829). Conclusions A new ICD-10-based injury severity scoring system was developed and validated. Further studies are required to validate the scoring system in other databases.

Psychiatric intervention and repeated admission to emergency centres due to drug overdose

Background Repeated drug overdose is a major risk factor for suicide. Data are lacking on the effect of psychiatric intervention on preventing repeated drug overdose. Aims To investigate whether psychiatric intervention was associated with reduced readmission to emergency centres due to drug overdose. Method Using a Japanese national in-patient database, we identified patients who were first admitted to emergency centres for drug overdose in 2010–2012. We used propensity score matching for patient and hospital factors to compare readmission rates between intervention (patients undergoing psychosocial assessment) and unexposed groups. Results Of 29 564 eligible patients, 13 035 underwent psychiatric intervention. In the propensity-matched 7938 pairs, 1304 patients were readmitted because of drug overdose. Readmission rate was lower in the intervention than in the unexposed group (7.3% v. 9.1% respectively, P<0.001). Conclusions Psychiatric intervention was associated with reduced readmission in patients who had taken a drug overdose. Declaration of interest None. Copyright and usage

Effect of intravenous magnesium sulfate on mortality in patients with severe acute asthma

Intravenous magnesium sulfate is used as adjunctive therapy for severe asthma exacerbations. However, previous randomized controlled trials of the administration of intravenous magnesium sulfate for asthma exacerbations have shown mixed results, and no study has evaluated its effect on mortality in patients with life‐threatening asthma. The objective of this study was to investigate the association between intravenous magnesium sulfate administration and mortality in patients with severe asthma.

Tuberculosis screening prior to anti-tumor necrosis factor therapy among patients with immune-mediated inflammatory diseases in Japan: a longitudinal study using a large-scale health insurance claims database

Tuberculosis screening is recommended for patients with immune‐mediated inflammatory diseases (IMIDs) prior to anti‐tumor necrosis factor (TNF) therapy. However, adherence to the recommended practice is unknown in the current clinical setting in Japan.

Treatment options and outcomes of hospitalised tuberculosis patients: a nationwide study.

SETTING Although standardised multidrug treatments exist, mortality among hospitalised tuberculosis (TB) patients is high. OBJECTIVE To characterise TB patients requiring acute hospital care and identify factors associated with in-hospital mortality. DESIGN Using a Japanese national database of acute-care hospitals, we identified patients with sputum smear-positive pulmonary TB who were discharged (both deceased and alive) between July 2010 and March 2013. Demographic characteristics, comorbidity, procedures and treatments were examined. We performed a multivariable logistic regression analysis to identify risk factors for in-hospital mortality. RESULTS Of 877 treated patients (566 males, mean age 74.5 years) identified, 152 (17.3%) died. A standard four-drug regimen of isoniazid (INH), rifampicin (RMP), ethambutol (EMB) and pyrazinamide was given to 279 (31.8%) patients, and INH, RMP and EMB to 335 (38.2%) patients. Multivariable analysis showed that the three-drug regimen was significantly associated with higher rates of in-hospital mortality (OR 1.87, 95%CI 1.07-3.27, P = 0.028). Other factors associated with in-hospital death were age, male sex, smoking habit, emergency admission, dementia and severe respiratory condition. CONCLUSION The risk factors for in-hospital death identified include the use of the three-drug regimen. Treatment choice could influence the outcome of hospitalised TB patients.

Problems with study on secondhand smoke and children’s tooth enamel

Using data from municipal health check-ups in Japan, Tanaka and colleagues found an association between secondhand smoke and dental caries in children.1 However, several factors should be considered. The authors used numerous variables to calculate the propensity score—the probability of an infant being exposed to secondhand smoke at 4 months. However, this model was inadequate for distinguishing the exposed from the unexposed. The discriminatory ability of the logistic regression model …