Oral Posters: Innovative Technologies

Presented by: R. Rampersaud - View Audio/Video Presentation (Members Only)

Author(s):

J. Wong(1), R. Rampersaud(2), E. Badley(1,3), A. Perruccio(3,4)

(1) University of Toronto, Dalla Lana School of Public Health, Toronto, ON, Canada
(2) University of Toronto, Surgery - Orthopaedics, Toronto, ON, Canada
(3) Krembil Research Institute, Healthcare & Outcomes Research, Toronto, ON, Canada
(4) University of Toronto, IHPME, Dalla Lana School of Public Health, Toronto, ON, Canada

Abstract

Objective: This study sought to identify risk factors for failure 6 months following a non-surgical low back pain (LBP) stratified education and self-management program. A particular focus was on differences in outcomes between pain pattern groups (back vs. leg dominant) and the potential for differences in gender effects.

Study Design/Setting: This is a retrospective study of patients referred to the Inter-professional Spine Assessment and Education Clinics (ISAEC: www.ISAEC.org). ISAEC uses an interdisciplinary shared-care model to provide standardized clinical evaluation and stratified education and self-management recommendations. Patients completed health questionnaires at initial visit and 6 months following.

Patient Sample: Patients who sought care for chronic LBP from primary care practitioners within the ISAEC network from 3 cities in Ontario, Canada, who were referred to the ISAEC program. Outcome measure: Failure was defined as an improvement in Oswestry Disability Index (ODI) score (scaled 0-100; higher indicates worse status) of < 10 units (minimally clinically important difference) from assessment to 6-months post.

Methods: Adjusted log-Poisson regression analysis (with robust variance estimation) was used to identify independent risk factors for failure, considering baseline age, sex, body mass index, # of comorbidities, pain intensity, ODI score, smoking, duration of LBP symptoms (< 3 months, 3-6 months, >6 months), STarT Back chronicity risk ('low', 'medium', 'high'), self-efficacy and dominant LBP pattern. An interaction between pattern and gender was tested. Subsequently, a stratified analysis by pain pattern subgroup was undertaken. Within each subgroup, pain pattern was further deconstructed (back pain exacerbated by extension vs. flexion, and constant vs. intermittent leg pain). The analytical sample was restricted to those who could achieve ≥10 unit change in ODI score and who completed the follow-up questionnaire ≥6 months after baseline.

Results: 435 patients were included (240 back dominant, 195 leg dominant); mean age was 51.8 years in the back group, 54.4 in leg group. At baseline, the leg dominant group reported greater disability and pain. There was a significantly higher proportion of women in the back (62%) compared to leg dominant group (52%). Overall failure rate was higher in the back (58%) compared to leg group (44%). 18% of the back group was deemed to have 'high' chronicity risk, compared to 28% among the leg group. Adjusted analyses: Younger age and worse baseline ODI score was associated with a decreased risk of failure. Smoking (vs. not) in the leg dominant group was associated with a 2-fold increased risk of failure (p< 0.01). Females in the leg dominant group were nearly twice as likely to fail as males (p< 0.01); the same effect was not observed in the back group (p=0.57). 'Moderate' and 'high' chronicity risks (vs. 'low') were associated with an increased, and similar, risk of failure (RR=1.7 and 1.9; (p< 0.01)) in the leg dominant group; no effect was observed in the back group (p>0.5).

Conclusions: Patients classified by back dominant pain appear to be at greater risk for failure overall, and the risk appears fairly equally distributed across patients. In contrast, the risk for failure within the leg dominant group appears to be greater for certain subgroups (women and those at moderate to high risk of chronicity).