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Effect of clinical peer review on mortality in patients ventilated for more than 24 hours: a cluster randomised controlled trial
  1. Jochen Schmitt1,
  2. Martin Roessler1,
  3. Peter Scriba2,
  4. Felix Walther1,3,
  5. Xina Grählert4,
  6. Maria Eberlein-Gonska3,
  7. Ralf Kuhlen2,
  8. Olaf Schoffer1
  1. 1Zentrum für Evidenzbasierte Gesundheitsversorgung, Universitätsklinikum Carl Gustav Carus, Dresden, Germany
  2. 2Initiative Qualitätsmedizin (IQM), Berlin, Germany
  3. 3Quality and Medical Risk Management, University Hospital Carl Gustav Carus Dresden, Dresden, Germany
  4. 4Koordinierungszentrum für Klinische Studien, Medizinische Fakultät Carl Gustav Carus der Technischen Universität Dresden, Dresden, Germany
  1. Correspondence to Dr Martin Roessler, Universitätsklinikum Carl Gustav Carus, Zentrum für Evidenzbasierte Gesundheitsversorgung, 01307 Dresden, Germany; martin.roessler{at}


Background Although clinical peer review is a well-established instrument for improving quality of care, clinical effectiveness is unclear.

Methods In a pragmatic cluster randomised controlled trial, we randomly assigned 60 German Initiative Qualitätsmedizin member hospitals with the highest mortality rates in ventilated patients in 2016 to intervention and control groups. The primary outcome was hospital mortality rate in patients ventilated fore more than 24 hours. Clinical peer review was conducted in intervention group hospitals only. We assessed the impact of clinical peer review on mortality using a difference-in-difference approach by applying weighted least squares (WLS) regression to changes in age-adjusted and sex-adjusted standardised mortality ratios (SMRs) 1 year before and 1 year after treatment. Recommendations for improvement from clinical peer review and hospital survey data were used for impact and process analysis.

Results We analysed 12 058 and 13 016 patients ventilated fore more than 24 hours in the intervention and control hospitals within the 1-year observation period. In-hospital mortality rates and SMRs were 40.6% and 1.23 in intervention group and 41.9% and 1.28 in control group hospitals in the preintervention period, respectively. The groups showed similar hospital (bed size, ownership) and patient (age, sex, mortality, main indications) characteristics. WLS regression did not yield a significant difference between intervention and control groups regarding changes in SMRs (estimate=0.04, 95% CI= −0.05 to 0.13, p=0.38). Mortality remained high in both groups (intervention: 41.8%, control: 42.1%). Impact and process analysis indicated few perceived outcome improvements or implemented process improvements following the introduction of clinical peer review.

Conclusions This study did not provide evidence for reductions in mortality in patients ventilated for more than 24 hours due to clinical peer review. A stronger focus on identification of structures and care processes related to mortality is required to improve the effectiveness of clinical peer review.

  • cluster trials
  • quality improvement
  • randomised controlled trial
  • critical care

Data availability statement

No data are available. Data are not publicly available due to confidentiality restrictions.

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Data availability statement

No data are available. Data are not publicly available due to confidentiality restrictions.

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  • JS and MR are joint first authors.

  • JS and MR contributed equally.

  • Contributors JS and OS designed the study. MR and XG prepared the RCT data. MR analysed the RCT data. JS, FW and OS validated the analyses. FW and OS designed the hospital survey. FW analysed the survey data. PS, ME-G and RK provided clinical and methodological expertise regarding IQM peer review. All authors discussed and interpreted the empirical findings. MR drafted the manuscript and all the remaining authors critically revised the manuscript. JS is responsible for the overall content as guarantor.

  • Funding This study was funded by the Joint Federal Committee (Gemeinsamer Bundesausschuss, G-BA), Germany (grant number: 01VSF16013).

  • Competing interests All authors report grant from Innovationsfonds des GBA for the conduct of the study. JS reports grants from ALK, Novartis, Pfizer, Sanofi; personal fees from ALK, Novartis, Lilly, Sanofi outside the submitted work. OS reports personal fees from Novartis outside the submitted work. RK reports that as an employee of Helios, a subsidiary of Fresenius, he is working for a healthcare company and is holding Fresenius stocks and stock options. XG reports grants from the German Federal Ministry of Health during the conduct of the study. XG further reports grants from Dräger AG & Co KGaA, Aesculap, Gesundheitsforen Leipzig, Novartis Pharma, University of Rostock and medichema outside the submitted work.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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