Yellow flag scores in a compensable New Zealand cohort suffering acute low back pain

BACKGROUND: Despite its high prevalence, most acute low back pain (ALBP) is nonspecific, self-limiting with no definable pathology. Recurrence is prevalent, as is resultant chronicity. Psychosocial factors (yellow flags comprising depression and anxiety, negative pain beliefs, job dissatisfaction) are associated with the development of chronic LBP. METHODS: A national insurer (Accident Compensation Corporation, New Zealand [NZ]), in conjunction with a NZ primary health organization, piloted a strategy for more effective management of patients with ALBP, by following the NZ ALBP Guideline. The guidelines recommend the use of a psychosocial screening instrument (Yellow Flags Screening Instrument, a derivative of Örebro Musculoskeletal Pain Questionnaire). This instrument was recommended for administration on the second visit to a general medical practitioner (GP). This paper tests whether published cut-points of yellow flag scores to predict LBP claims length and costs were valid in this cohort. RESULTS: Data was available for 902 claimants appropriately enrolled into the pilot. 25% claimants consulted the GP once only, and thus were not requested to provide a yellow flag score. Yellow flag scores were provided by 48% claimants who consumed two or more GP services. Approximately 60% LBP presentations resolved within five GP visits. Yellow flag scores were significantly and positively associated with treatment costs and service use, although the association was nonlinear. Claimants with moderate yellow flag scores were similarly likely to incur lengthy claims as claimants with at-risk scores. DISCUSSION: Capturing data on psychosocial factors for compensable patients with ALBP has merit in predicting lengthy claims. The validity of the published yellow flag cut-points requires further testing.