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Observational Study
. 2022 May 18:10:e13424.
doi: 10.7717/peerj.13424. eCollection 2022.

Hospital-level characteristics of the standardised mortality ratio for ischemic heart disease: a retrospective observational study using Japanese administrative claim data from 2012 to 2019

Ryo Onishi  1 , Yosuke Hatakeyama  1 , Kunichika Matsumoto  1 , Kanako Seto  1 , Koki Hirata  1 , Yinghui Wu  2 , Tomonori Hasegawa  1
Affiliations
Observational Study

Hospital-level characteristics of the standardised mortality ratio for ischemic heart disease: a retrospective observational study using Japanese administrative claim data from 2012 to 2019

Ryo Onishi et al. PeerJ. .

Abstract

Background: Ischemic heart disease (IHD) is one of the leading causes of mortality worldwide and imposes a heavy burden on patients. Previous studies have indicated that the optimal care for IHD during hospitalisation may reduce the risk of in-hospital mortality. The standardised mortality ratio (SMR) is an indicator for assessing the risk-adjusted in-hospital mortality ratio based on case-mix. This indicator can crucially identify hospitals that can be changed to improve patient safety and the quality of care. This study aimed to determine the hospital-level characteristics of the SMR for IHD in Japan.

Methods: This study was designed as a retrospective observational study using the Japanese administrative claim data from 2012 to 2019. The data of all hospital admissions with a primary diagnosis of IHD (ICD-10, I20-I25) were used. Patients with complete variables data were included in this study. Hospitals with less than 200 IHD inpatients in each 2-year period were excluded. The SMR was defined as the ratio of the observed number of in-hospital deaths to the expected number of in-hospital deaths multiplied by 100.The observed number of in-hospital deaths was the sum of the actual number of in-hospital deaths at that hospital, and the expected number of in-hospital deaths was the sum of the probabilities of in-hospital deaths. Ratios of in-hospital mortality was risk-adjusted using multivariable logistic regression analyses. The c-statistic and Hosmer-Lemeshow test were used to evaluate the predictive accuracy of the logistic models. Changes in SMRs in each consecutive period were assessed using Spearman's correlation coefficient.

Results: A total of 64,831 were admitted patients with IHD in 27 hospitals as complete submission data. The SMRs showed wide variation among hospitals, ranging from 35.4 to 197.6, and analysis models indicated good predictive ability with a c-statistic of 0.93 (95% CI [0.92-0.94]) and Hosmer-Lemeshow test of 0.30. The results of chi-square tests and t-tests for all variables to assess the association with in-hospital mortality were P < 0.001. In the analysis of trends in each consecutive period, the SMRs showed positive correlations.

Conclusions: This study denoted that the SMRs for IHD could be calculated using Japanese administrative claim data. The SMR for IHD might contribute to the development of more appropriate benchmarking systems for hospitals to improve quality of care.

Keywords: Administrative claim data; In-hospital mortality; Ischemic heart disease; Japan; Quality indicator.

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Conflict of interest statement

The authors declare there are no competing interests.

Figures

Figure 1
Figure 1. Mean and SD of the HSMR for each hospital (8-year data analysis, 27 hospitals).
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References

    1. Amin R, Hatakeyama Y, Kitazawa T, Matsumoto K, Fujita S, Seto K, Hasegawa T. Capturing the trends in hospital standardized mortality ratios for pneumonia: a retrospective observational study in Japan (2010 to 2018) Environmental Health and Preventive Medicine. 2020;25(1):2. doi: 10.1186/s12199-019-0842-4. - DOI - PMC - PubMed
    1. Amin R, Kitazawa T, Hatakeyama Y, Matsumoto K, Fujita S, Seto K, Hasegawa T. Trends in hospital standardized mortality ratios for Stroke in Japan between 2012 and 2016: a retrospective observational study. International Journal for Quality in Health Care. 2019;31(9):G119–G125. doi: 10.1093/intqhc/mzz091. - DOI - PubMed
    1. Aylin P, Bottle A, Majeed A. Use of administrative data or clinical databases as predictors of risk of death in hospital: comparison of models. BMJ. 2007;334:1044. doi: 10.1136/bmj.39168.496366.55. - DOI - PMC - PubMed
    1. Campeau L. The Canadian Cardiovascular Society grading of angina pectoris revisited 30 years later. 2002;18(4):371–379. - PubMed
    1. Canadian Institute for Health Information Hospital Standardized Mortality Ratio (HSMR) 2019. [01 May 2019]. https://www.cihi.ca/en/hospital-standardized-mortality-ratio-hsmr https://www.cihi.ca/en/hospital-standardized-mortality-ratio-hsmr

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