Article

Most studies of low back pain (LBP) and functional limitation have been
cross-sectional, and show only modest correlations between pain and function.
Though functional limitation may be superior for predicting disability outcomes,
there is a need to understand better the gap between pain and function. This
study analysed changes in intra-individual correlations between pain and function
over time. METHOD: Seventeen men and 16 women currently experiencing LBP provided
self-reports of LBP (0-to-10 scale) and functional status (Back Pain Functional
Scale) for a maximum of 8 weeks. Spearman correlation coefficients between pain
and function scores were calculated for each individual. The effects of pain
history, pain intensity, variability and trends over time on pain-function
correlations were assessed. RESULTS: There were no significant differences in
correlation due to gender, age or pain intensity (low versus high). Participants
with steeper slopes in change in pain score over the study period had
significantly stronger correlations to function than those with weaker trends, r
= -0.91 and r = -0.45, respectively. Participants with at least one pain-free
score during the reporting period had significantly stronger correlations than
those with no pain-free reports, r = -0.80 and r = -0.51, respectively.
Participants having the first episode LBP had stronger correlations (r = -0.85)
than those with persistent symptoms of LBP (r = -0.62). CONCLUSIONS: The results
suggest that over the course of LBP, within-person pain-function correlations are
stronger than those reported in cross-sectional, population-based studies.
Changes in pain ratings over time may have more clinical relevance than
differences in pain levels between individuals. Among those with more
long-standing pain, factors other than pain intensity, such as pain
catastrophising or fear avoidant beliefs, may have a greater effect on day-to-day
perceptions of functional limitation.

Langue : ANGLAIS