Avoidance-endurance fast screening (AE-FS): Content and predictive validity of a 9-item screening instrument for patients with unspecific subacute low back pain

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 ( 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.