Nature and Determinants of the Course of Chronic Low Back Pain Over a 12-Month Period: A Cluster Analysis

Luciana Gazzi Macedo; Christopher G. Maher; Jane Latimer; James H. McAuley; Paul W. Hodges; W. Todd Rogers

doi:10.2522/ptj.20120416

Figures

Figure 1.

Dendogram of hierarchical cluster analysis based on R-square and number of fluctuations as clustering variables (n=155). Each short vertical line on the x-axis represents an individual participant.

Figure 2.

Pain scores from a random sample of 5 participants included in clusters 1, 2, and 3 from the first step of the cluster analysis: (A) cluster 1 (5 of 134 participants), (B) cluster 2 (5 of 16 participants), and (C) cluster 3 (5 of 5 participants).

Figure 3.

Dendogram of the hierarchical cluster analysis of the secondary analysis of the study based on pain fluctuations from baseline to 12-month follow-up (n=134). Each short vertical line on the x-axis represents an individual participant.

Figure 4.

Mean pain scores in each cluster of the secondary analysis of recovering mild pain (cluster 1 [n=73]), persistent moderate pain (cluster 2 [n=38]), and severe chronic pain (cluster 3 [n=23]).

Tables

Table 1.

Demographic and Baseline Characteristics of Patients With Fluctuating Pain and Patients With Nonfluctuating Pain

^a Scores range from 0 (good coping strategy) to 36 (worst coping strategy).
^b Scores range from 11 (low risk of pain becoming persistent) to 192 (high risk of pain becoming persistent).
^c Scores range from 0 (low anxiety) to 100 (high anxiety).
^d Scores range from 0 (high fear avoidance) to 100 (no fear avoidance).
^e MET-minutes/week.
^f Scores range from 0 (no instability) to 15 (high instability).
^g Scores range from 0 (no pain) to 10 (worst pain).
^h Scores range from 0 (unable to perform activity) to 10 (able to perform activity in preinjury level).
ⁱ Scores range from 0 (no disability) to 24 (high disability).

Table 2.

Baseline Characteristics of Patients With Nonfluctuating Pain Stratified by Clusters Identified in the Secondary Analysis

^a Scores range from 0 (good coping strategy) to 36 (worst coping strategy).
^b Scores range from 11 (low risk of pain becoming persistent) to 192 (high risk of pain becoming persistent).
^c Scores range from 0 (low anxiety) to 100 (high anxiety).
^d Scores range from 0 (high fear avoidance) to 100 (no fear avoidance).
^e MET-minutes/week.
^f Scores range from 0 (no instability) to 15 (high instability).
^g Scores range from 0 (no pain) to 10 (worst pain).
^h Scores range from 0 (unable to perform activity) to 10 (able to perform activity in preinjury level).
ⁱ Scores range from 0 (no disability) to 24 (high disability).