Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Spine
Abstract number: 23715
LEG PAIN AND PSYCHOLOGICAL VARIABLES PREDICT OUTRCOME 2-3
YEARS AFTER LUMBAR FUSION SURGERY
Allan ABBOTT 1 , Raija TYNI-LENNÉ 2 , Rune HEDLUND 3
1 Karolinska Institute, Stockholm (SWEDEN), 2 Karolinska University Hospital,
Stockholm (SWEDEN), 3 Sahlgrenska Akademin, Gothenburg (SWEDEN)
Study Design: Prospective cohort study. Objective: To examine predictions of
functional disability, back pain intensity and HRQOL 2-3 years after lumbar fusion by
regressing nonlinear relations in a multivariate predictive model of pre-surgical
variables. Summary of Background Data: Prediction studies testing a thorough range
of psychological variables in addition to demographic, work related and clinical
variables is lacking in spinal surgery research. Previous studies have not investigated
nonlinear relations between response and predictor variables or addressed predictive
model validity. Methods: 107 lumbar fusion patients completed questionnaires before
and 2-3 years after surgery investigating demographics, work related variables,
clinical variables, functional self-efficacy, outcome expectancy, fear of
movement/(re)injury, catastrophizing and mental health and pain coping. CATREG
regression with optimal scaling transformation, elastic net regularization and
bootstrapping were used to investigate predictor variables and address predictive
model validity. Results: The most parsimonious subset of pre-surgical predictor
variables explained 41.6%, 32.2% and 25.6% of the variance in functional disability,
back pain intensity and HRQOL 2-3 years after lumbar fusion. Control over pain
significantly predicted functional disability and HRQOL while leg pain intensity and
catastrophizing significantly predicted functional disability and back pain. Postoperative
rehabilitation focusing on cognition, behaviour and motor control also
significantly predicted functional disability while outcome expectations significantly
predicted HRQOL. The discriminative ability of the prediction models was of good
quality. Conclusions: The study demonstrates the importance of pre-surgical leg pain
and psychological factors in the predictions of functional disability, back pain and
HRQOL related lumbar fusion outcomes.
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