RESEARCH REPORT POSTER DISPLAY

PSYCHOSOCIAL VARIABLES IN PATIENTS WITH SUBACUTE LOW BACK PAIN. AN INCEPTION COHORT IN PRIMARY CARE PHYSICAL THERAPY IN THE NETHERLANDS. Heneweer H¹, Aufdemkampe G¹, van Tulder M², Kiers H¹, Vanhees L³; ¹Research department Lifestyle and Health and Department of Physical Therapy, University of Professional Education, Utrecht, The Netherlands. ²Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands and Institute for Health Sciences, Faculty of Earth & Life Sciences, Vrije Universiteit, Amsterdam, The Netherlands. ³Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Belgium and Faculty Chair research department Lifestyle and Health, University of Professional Education, Utrecht, The Netherlands

PURPOSE: To study the association between psychosocial factors and the transition from acute or sub acute low back pain to chronic low back pain in primary care physical therapy. RELEVANCE: Given the serious consequences of chronic LBP, it is important to study interventions that may prevent acute complaints becoming chronic. Psychosocial factors have long been believed to be associated with chronic pain only. More recent research1-8 focuses on psychosocial factors associated with acute or sub acute pain. Physical therapy in primary care may play an effective role in identifying patients at risk of developing chronic LBP. PARTICIPANTS: The participants (n=56) in the study were consecutive new referrals consulting their physical therapist for the first time with a first or new episode of LBP. Subjects were recruited from 20 primary care physical therapy centers in the Netherlands between September 2002 and September 2004. All subjects were referred by their general practitioner or medical specialist. The main inclusion criterion was non-specific low back pain preceded by a pain-free period of at least 3 months in which no physical therapist was seen for treatment. METHODS: At baseline subjects were asked to complete a comprehensive set of questionnaires including sociodemographic characteristics, cause and further development of LBP, fear-avoidance, anxiety, depression, kinesiophobia and pain-coping behavior. Follow-up questionnaires, administered by post at week 2, 4, 8 and 12, measured pain intensity, disability and overall improvement. Except for the sociodemographic characteristics, all baseline measurements were repeated in week 12. ANALYSIS: The effect of the predictor variables on the risk of non recovery was assessed in logistic regression models. All the variables were studied one at a time in a base model, followed by stepwise approaches (pin <0.05, pout>0.10). A receiver operating characteristic curve was used to compare the accuracy of the models without the use of a specific cutoff point. RESULTS: At week twelve, 35 patients (51%) judged their status as ‘not recovered’ of whom six (17%) reported work absenteeism. A multivariate logistic regression including the Acute Low Back Pain Scale (ALBPSQ), Fear Avoidance Beliefs Questionnaire, Tampa Scale for Kinesiophobia and Pain Coping Inventory resulted in a model in which the ALBPSQ appeared to be the only significant variable. Scores on the subscale ‘pain’ of the ALBPSQ proved to be the strongest risk factor (p ≤.001) with an overall accuracy of 75.4%. Predicted scores resulted in a relative risk of 3.09 (95% CI 1.64%-5.82%) for not being recovered after 12 weeks. CONCLUSIONS: The study revealed pain-related items to be essential factors in the development of chronic low back pain and long-term disability in primary care physical therapy. The development of chronic low back pain can be considered as a dynamic system of health-related items. Small differences in the initial state of the host and in intensity, quality, and meaning of the nociceptive stimulus can produce major differences in the manner in which this process unfolds. IMPLICATIONS: Results suggest pain management should be a priority in patients with acute and sub acute low back pain. KEYWORDS: acute low back pain, prediction, psychosocial. FUNDING ACKNOWLEDGEMENTS: The work was funded by the Hogeschool Utrecht, University of Professional Education. CONTACT: hans.heneweer@hu.nl