Differences and similarities among questionnaires to assess pain status in chronic widespread pain population: a quantitative analysis.

Our findings demonstrated that BSA and VAS scores were independent clinical measures of widespread chronic pain, while the FDC and CSI scores were not independent, were highly correlated and provided redundant information. Clinicians should continue using both the BSA and VAS; however, either only FDC or CSI will be beneficial during clinical assessment of widespread chronic pain.