gms | German Medical Science

53. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V. (GMDS)

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie

15. bis 18.09.2008, Stuttgart

Application of Patient Safety Indicators in OECD Member Countries: Results from a First Pilot among seven Countries

Meeting Abstract

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  • Saskia E Drösler - Hochschule Niederrhein, Krefeld, Deutschland
  • Niek S Klazinga - University of Amsterdam, Amsterdam, Deutschland
  • Patrick S Romano - UC Davis, Sacramento, CA, USA

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie. 53. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds). Stuttgart, 15.-19.09.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocMBIO3-6

The electronic version of this article is the complete one and can be found online at:

Published: September 10, 2008

© 2008 Drösler et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




We investigated whether the AHRQ PSI definitions can be applied using routine hospital data from seven OECD member countries. This pilot project was intended to establish the feasibility of more in-depth comparative analyses of hospital safety across nations.


In its attempt to compare the performance of health care systems, the Organization for Economic Cooperation and Development (OECD) has explored the possibilities for collecting data on safety in health care [1]. The present evaluation is based on Patient Safety Indicators (PSI) originally published by the US Agency for Healthcare Research and Quality (AHRQ) [2]. These indicators rely exclusively on administrative hospital data (e.g. diagnosis, procedures, DRG). The routine documentation of these data varies among countries. For example, diagnosis coding is heterogeneous because some of the OECD member countries still use the ICD-9-CM diagnosis classification and others use the ICD-10. The study population consisted of adults admitted to acute care hospitals in the United States, United Kingdom, Sweden, Spain, Germany, Canada, and Australia in 2005 or 2005-2006 (except that German cases were from 2004). The number of eligible discharges across the seven countries varied between 1.3 and 32.1 million. 12 PSIs were calculated following a definition manual prepared by OECD [3]. As five countries use ICD-10 and two use ICD-9-CM, the manual contains PSI definitions in both systems. The coding manual also includes specific algorithms to account for the fact that not all participating countries use DRGs for hospital reimbursement.


All seven volunteering countries estimated PSI rates, although one reported only 9 of the 12 PSIs. We found very high correlations between country-specific PSI rates and US rates published by AHRQ (and re-estimated as part of this study). Pearson`s correlation coefficient varied from 0.821 for the country with the lowest concordance with the US to 0.936 for the country with the highest concordance. However, there was substantial systematic variation in PSI rates across countries, ranging from a 3.4 fold difference across countries for “obstetric trauma” (coefficient of variation [CV] = 22.0) and a 4-fold difference for “foreign body left in” (CV=32.0) to an 11-fold difference across countries for “birth trauma” (CV=80.9) and a 48-fold difference for “complications of anesthesia” (CV=56.7).


This pilot study reveals that AHRQ PSIs can be applied to international hospital data. We have overcome some potential problems, such as international differences in ICD versions and DRG systems. However, our analyses suggest that certain PSIs (e.g., “birth trauma,” “complications of anesthesia”) may be too unreliable for international comparisons. Data quality varies across countries; underreporting may be a systematic problem in some countries.

International use of the AHRQ PSI not only supports comparative reporting at the country level, but will also lead to intensified application at the institutional level in countries outside the US. These efforts may stimulate increased attention to patient safety throughout the developed world. Twelve additional OECD member countries are seriously interested in participating in a consecutive PSI project in 2008. In this next phase, risk-stratified data will be collected to explore whether international differences in PSI rates may be attributable to variation in the age-gender distribution of hospitalized patients, medical-surgical case mix, inpatient length of stay, or the completeness of diagnosis coding.


McLoughlin V, Millar J, Mattke S, Franca M, Jonsson PM, Somekh D, Bates D. Selecting indicators for patient safety at the health system level in OECD countries. Int J Qual Health Care 2006; Suppl. 1: 14-20.
Agency for Healthcare Research and Quality Department of Health and Human Services. AHRQ Quality Indicators. Guide to Patient Safety Indicators. March 2003 Version 3.0a (May 1, 2006).
Drösler SE. Facilitating Cross-National Comparisons of Indicators for Patient Safety at the Health-System Level in the OECD Countries. OECD Health Technical Paper 19, 2008.