Real World Data in Japan: Chapter II The Diagnosis Procedure Combination Database

With advances in the effectiveness of treatment and disease management, the contribution of chronic comorbid diseases (comorbidities) found within the Charlson comorbidity index to mortality is likely to have changed since development of the index in 1984. The authors reevaluated the Charlson index and reassigned weights to each condition by identifying and following patients to observe mortality within 1 year after hospital discharge. They applied the updated index and weights to hospital discharge data from 6 countries and tested for their ability to predict in-hospital mortality. Compared with the original Charlson weights, weights generated from the Calgary, Alberta, Canada, data (2004) were 0 for 5 comorbidities, decreased for 3 comorbidities, increased for 4 comorbidities, and did not change for 5 comorbidities. The C statistics for discriminating in-hospital mortality between the new score generated from the 12 comorbidities and the Charlson score were 0.825 (new) and 0.808 (old), respectively, in Australian data (2008), 0.828 and 0.825 in Canadian data (2008), 0.878 and 0.882 in French data (2004), 0.727 and 0.723 in Japanese data (2008), 0.831 and 0.836 in New Zealand data (2008), and 0.869 and 0.876 in Swiss data (2008). The updated index of 12 comorbidities showed good-to-excellent discrimination in predicting in-hospital mortality in data from 6 countries and may be more appropriate for use with more recent administrative data. © The Author 2011. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved.

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.

Objectives Prompt assessment of consciousness levels is vitally important during the emergency care of stroke patients. The Japan Coma Scale (JCS) is a one-axis coma scale published in 1974 with outstanding simplicity. The hypothesis is that JCS is sufficient to predict stroke outcome. The aim of the study was to verify the predictability of JCS, which should help JCS attain international recognition. Design A cohort study. Setting A prefectural stroke registry. Participants We analysed 13 788 stroke patients identified from January 1999 to December 2009 inclusive in the entire Kyoto prefecture and registered in the Kyoto Stroke Registry (KSR). Main outcome measures We investigated the relationship between consciousness levels, based on JCS at stroke onset and activities of daily living (ADL) at 30 days or deaths within 30 days in a large population-based stroke registry. We calculated Spearman's coefficient for the correlation between JCS and the ADL scale, generated estimated survival curves by the Kaplan-Meier method and finally compared HRs for death within 30 days after onset, comparing patients with different conscious levels based on JCS. Results A total of 13 406 (97.2%) patients were graded based on JCS. JCS correlated to the ADL scale with Spearman's correlation coefficient of 0.61. HRs for death within 30 days were 1 (reference) (95% CIs), 5.55 (4.19 to 7.37), 9.54 (7.16 to 12.71) and 35.21 (26.10 to 44.83) in those scored as JCS0, JCS1, JCS2 and JCS3, respectively. Conclusions Using a single test of eye response, JCS has outstanding merits as a coma scale, that is, simplicity and applicability. The present study adds predictability for early outcome in stroke patients. JCS is valuable, especially in an emergency setting, when a prompt assessment of consciousness levels is needed.