A four-stage model of pain processing was proposed, consisting of pain
sensation intensity, pain unpleasantness (stage 1 affect), suffering
(stage 2 affect), and pain behavior. We studied 506 chronic pain patie
nts (230 male and 276 female) using a multivariate statistical techniq
ue (LISREL) in order to demonstrate the structural relationship among
multiple indicators of pain processing; and to characterize these stag
es in terms of their interactions. A strong relationship was revealed
between the majority of the underlying indicators of each pain process
ing stage. A linear stage sequence best fitted the relationship betwee
n the four stages. Successive stages did not have recursive effects on
earlier pain components, A confirmatory LISREL analysis was conducted
with an additional sample of 502 chronic pain patients. In this repli
cation analysis the structural equation model consisted of pain intens
ity, unpleasantness (stage 1 affect), emotional suffering (stage 2 aff
ect), and pain behavior. This study extends the validation of these pa
in dimensions, as well as the validity of the measure(s) of each separ
ate stage.