Adolescent Adult Aged Analgesics--therapeutic use Anti-Inflammatory Agents, Non-Steroidal--therapeutic use Antibodies, Monoclonal, Humanized--therapeutic use Chronic Pain--drug therapy Double-Blind Method Drug-Related Side Effects and Adverse Reactions--epidemiology Female Humans Low Back Pain--drug therapy Male Middle Aged Naproxen--therapeutic use Pain Measurement--drug effects Placebo Effect Prevalence Risk Factors Treatment Outcome United States--epidemiology Young Adult