Global assessment of performance of ICUs: a French experience

Introduction

We conducted research to assess simultaneously patient-related and ICU-related determinants of performance.

Methods

A prospective study involving 26 ICUs from a regional network in the Paris area, France (CubRéa), 33,471 patients treated in 1999 and 2000, and 1,000 caregivers (doctor, nurse) from these ICUs. Severity was evaluated by a revised version of SAPS II [1]. Organisational performance was assessed through a composite score related to coordination, communication, conflict management, organizational learning, and skills developed in relationship with patients [2]. We studied the association between clinical performance, measured standardised mortality ratio (SMR), and ICU factors (organisational performance, volume, specialisation, team cultural values and caregiver well-being) by multilevel logistic regression, to account for correlation within ICUs.

Results

The ICUs were heterogeneous (severity, mean workload, volume, specialisation, caregiver/bed ratios). The revised SAPS II gave SMRs between 0.64 and 1.37. Higher values of organisational score were related to team satisfaction-oriented culture, a high workload, and a high level of satisfaction at work. In univariate screening, a higher volume (all patients, ventilated patients) and a higher organisational score were associated with lower SMRs, while the nurse/bed ratio had a rising then decreasing relationship. Multivariate regression retained SAPS II (P < 10^-4) then volume (P < 10^-3), which were respectively related to upper and lower mortality. The organisational score was borderline (P = 0.09). Sensitivity analysis proved robustness of the results. See Figure 1.

Figure 1

Relation between volume and revised standardised mortality ratio (SMR).

Conclusion

Performance is mainly related to the case mix and volume. Outcomes other than death may be more sensible to organisational factors.