Avoidance-endurance fast screening (AE-FS) : Content and predictive validity of a9-item screening instrument for patients with unspecific subacute low back pain.

Abstract

Background Among screening measures to assess psychosocial risk factors (yellow flags) for chronic low back pain (LBP) economic tools which address dysfunctional endurance pain responses besides emotional distress and fear-avoidance pain processing are rare. Targeting contrasting types of pain processing might improve stratified patient counselling. Objective The aim of the study was to develop a short screening method, based on the avoidance-endurance model of pain and to investigate the prognostic validity for pain intensity, disability and physical function. Material and methods A prospective observational study was carried out on 144 patients with subacute LBP ( Results The classification of subgroups as high and low risk by both measures had considerable agreement with a value of 0.71 (Cohen's Kappa). The sensitivity to predict pain intensity >2 was high (82%) as was the positive predictive value (80%) but the negative predictive value was moderate (61%). The ROC (AUC) characteristics (95% confidence interval CI) were 0.70 (0.60-0.80) for pain intensity and for limitations in the pain disability index (PDI) 0.70 (0.55-0.87). Discussion The 9‑item AE-FS displayed sufficient prognostic validity for all three outcomes in a sample of primary care patients with subacute LBP. The differentiation of the high-risk patients into fear-avoidance and endurance-related pain processing enables the physician to provide an individualized counselling with the aim of a healthy balance between stress and relaxation.