Association between directional preference and centralization in patients with low back pain.
METHODS
Prospective, longitudinal, observational cohort.


OBJECTIVE
Primary aims were to determine (1) baseline prevalence of directional preference (DP) or no directional preference (no-DP) observed for patients with low back pain whose symptoms centralized (CEN), did not centralize (non-CEN), or could not be classified (NC), and (2) to determine if classifying patients at intake by DP or no-DP combined with CEN, non-CEN, or NC predicted functional status and pain intensity at discharge from rehabilitation.


BACKGROUND
Although evidence suggests that patient response classification criteria DP or CEN improve outcomes, previous studies did not delineate relations between DP and CEN findings and outcomes.


METHODS
Eight therapists classified patients using standardized definitions for DP and CEN. Prevalence rates for DP and no-DP and CEN,non-CEN, and NC were calculated. Ordinary least-squares multivariate regression models assessed whether multilevel classification combining DP and CEN (DP/CEN, DP/non-CEN, DP/NC, no-DP/non-CEN, and no-DP/NC categories) predicted discharge functional status (scale range, 0 to 100, with higher values representing better function) or pain intensity (scale range, 0 to 10, with higher values representing more pain).


RESULTS
Overall prevalence of DP and CEN was 60% and 41%, respectively. For those with DP, prevalence rates for DP/CEN, DP/non-CEN, and DP/NC were 65%, 27%, and 8%, respectively. The amount of variance explained (R2 values) for function and pain models was 0.50 and 0.39, respectively. Compared to patients classified as DP/CEN, patients classified as DP/non-CEN or no-DP/non-CEN reported 7.7 and 11.6 functional status units less at discharge (P<.001), respectively, and patients classified as no-DP/non-CEN reported 1.7 pain units more at discharge (P<.001).


CONCLUSIONS
Findings suggest that classification by pain pattern and DP can improve a therapist's ability to provide a short-term prognosis for function and pain outcomes.


METHODS
Prognosis, level 1b-.
Central State Medical Center, Freehold, NJ, USA. mwerneke@centrastate.com
Mark W
MW
Werneke
Dennis L
DL
Hart
Guillermo
G
Cutrone
Dave
D
Oliver
Troy
T
McGill
Jon
J
Weinberg
David
D
Grigsby
William
W
Oswald
Jason
J
Ward
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000145:classification* / Q000453:epidemiology / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000145:classification*; D026761:Physical Therapy Specialty / Q000706:statistics & numerical data; D015995:Prevalence; D011379:Prognosis; D016059:Range of Motion, Articular; D012044:Regression Analysis; D012720:Severity of Illness Index; D013714:Tennessee / Q000453:epidemiology