English to Italian Medical Medical (general)

Avete qualche idea di come tradurre "random noise" in questo contesto?
Si tratta di un articolo di oculistica nel quale si parla della correlazione tra i valori clinici misurati sui pazienti e il grado di gravità della malattia (sindrome dell'occhio secco):


Figure 1 displays the relationship between each of the
clinical signs and the composite disease severity index. Each
sign is plotted with disease severity on the x-axis and the raw
clinical data on the y-axis. The correlation coefficient of each
sign is as follows: osmolarity (r2
0.55), TBUT (r2
0.30),
Schirmer (r2
0.17), corneal staining (r2
0.43), conjunctival
staining (r2
0.47), meibomian score (r2
0.37), and OSDI
(r2
0.41).
The resulting average correlation coefficients for the random
control dataset were: osmolarity (r2
0.10), TBUT
(r2
0.15), Schirmer (r2
0.08), corneal staining (r2
0.09),
conjunctival staining (r2
0.10), meibomian score (r2
0.09),
and OSDI (r2
0.24). Therefore, high correlation against the
index is not guaranteed, simply because the individual measurements
are part of the composite. The one exception was
the mapping used for OSDI, which showed a small correlation
with the index, even when random noise replaced the clinical
values. Removal of OSDI from the composite did not alter the
interpretation of the results.