Nine equivalents of nursing manpower use score (NEMS).

OBJECTIVES

To develop a simplified Therapeutic Intervention Scoring System (TISS) based on the TISS-28 items and to validate the new score in an independent database.

DESIGN

Retrospective statistical analysis of a database and a prospective multicentre study.

SETTING

Development in the database of the Foundation for Research on Intensive Care in Europe with external validation in 64 intensive care units (ICUs) of 11 European countries.

MEASUREMENTS AND RESULTS

Development of NEMS on a random sample of TISS-28 items, cross validation on another random sample of TISS-28, and external validation of NEMS in comparison with TISS-28 scored by two independent raters on the day of the visit to the ICUs participating in an international study. Multivariable regression techniques, Pearson's correlation, and paired sample t-tests were used (significance at p < 0.05 level). Intraclass correlation, rate of agreement, and kappa statistics were used for interrater reliability tests. The TISS-28 items were reduced to NEMS (9 items) in a random sample of 2000 records; the means of the two scores were no different: TISS-28 26.23 +/- 10.38, NEMS 26.19 +/- 9.12, NS. Cross-validation in a random sample of 996 records; mean TISS-28 26.13 +/- 10.38, NEMS 26.17 +/- 9.38, NS; R2 = 0.76. External validation on 369 pairs of TISS-28 and NEMS has shown that the means of the two scores were no different: TISS-28 27.56 +/- 11.03, NEMS 27.02 +/- 8.98, NS; R2 = 0.59. Reliability tests have shown an "almost perfect" interrater correlation. Similar to studies correlating TISS with Simplified Acute Physiology Score (SAPS)-I and/or Acute Physiology and Chronic Health Evaluation II scores, the value of NEMS scored on the first day accounts for 30.4% of the variation of SAPS-II score.

CONCLUSIONS

NEMS is a suitable therapeutic index to measure nursing workload at the ICU level. The use of NEMS is indicated for: (a) multicentre ICU studies; (b) management purposes in the general (macro) evaluation and comparison of workload at the ICU level; (c) the prediction of workload and planning of nursing staff allocation at the individual patient level.