Validation of "nine equivalents of nursing manpower use score" on an independent data sample.
OBJECTIVE
To compare the recently developed "nine equivalents of nursing manpower use score" (NEMS) with the simplified Therapeutic Intervention Scoring System (TISS-28).


METHODS
Prospective single centre study.


METHODS
Adult 30-bed medical-surgical intensive care unit (ICU) in a tertiary care university hospital.


METHODS
Data from all patients admitted in 1997 to the ICU were included in the study.


RESULTS
NEMS and TISS-28 items were recorded prospectively for each nursing shift. There were three shifts per day. The Simplified Acute Physiology Score (SAPS) II was calculated for the first 24 h of ICU stay and each patient's basic demographic data were collected. The agreement between NEMS and TISS-28 was assessed by calculating the mean difference and the standard deviation of the differences between the two measures. Further, regression techniques and Pearson's correlation were used. Altogether, 2743 patients with a total of 28,220 nursing shifts were included; 62% of the shifts were used for postoperative/trauma patients and 38% for medical patients. Mean NEMS was 26.0 +/- 8.1 and mean TISS-28 was 26.5 +/- 7.9. The scores differed by < or = 3 points in 49 % of all shifts. The bias was -0.5 +/- 5.3 (95% confidence interval -0.47 to -0.60) and the limits of agreement were -11.1 to +10.1. The relation between the two systems was NEMS = 4.7 +/- 0.8 x TISS-28 (r = 0.78, r2 = 0.62, p < 0.001). Including postoperative/trauma patients only: NEMS = 1.9 +/- 0.9 x TISS-28, for medical patients this equation was: NEMS = 6.0 + 0.8 x TISS-28. First-day SAPS II explained 11% of the variability in first-shift NEMS and 5% of the variability in first-shift TISS-28.


CONCLUSIONS
This study confirms a good agreement between TISS-28 and NEMS in a large, independent sample. However, as shown by the differences between medical and postoperative/trauma patients, a change in case mix may result in different regression equations. Further, wide limits of agreement indicate that there may be a rather large variability between the two measures at the individual level.
Rothen
H U
HU
Department of Anaesthesiology and Intensive Care, University Hospital, Bern, Switzerland. hrothen@insel.ch
Küng
V
V
Ryser
D H
DH
Zürcher
R
R
Regli
B
B
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003422:Critical Care; D006801:Humans; D008875:Middle Aged; D009729:Nursing; D012720:Severity of Illness Index; D000078329:Workforce; D016526:Workload