Obesity and Incident Prescription Opioid Use in the U.S., 2000-2015

Prior studies have identified associations between obesity and numerous conditions that increase risks for chronic pain. However, the impact of obesity on prescription opioid use is not well known. This study investigates the association between obesity and incidence of long-term prescription opioid use.

Fifteen panels of the Medical Expenditure Panel Survey from 2000 to 2015 were pooled to generate a sample of civilian non-institutionalized adults aged 30-84 years who were prescription opioid-naïve for approximately 9 months. Incident long-term prescription opioid use was defined as reporting use at 2 of 3 interviews during a 15-month follow-up. BMI was reported at baseline. Analyses were completed in 2019.

Among opioid-naïve adults (n=89,629), obesity was strongly associated with incident long-term prescription opioid use. The association increased at progressively higher BMI values, with 24% elevated odds (95% CI=7%, 44%) in adults with overweight (25-29.9 kg/m²) and 158% increased odds (95% CI=106%, 224%) among adults with Class III obesity (40-49.9 kg/m²). These associations grew with higher-dosage opioids. Of the reasons for opioid use, joint pain, back pain, injury, and muscle/nerve pain contributed the most to the excess use observed among adults with obesity. At the population level, 27.0% of incident long-term prescription opioid use (95% CI=19.0%, 34.8%) was attributable to adults having a BMI above normal weight (25-49.9 kg/m²).

These findings suggest that obesity has contributed to prescription opioid use in the U.S. Future investments in chronic pain reduction may benefit from increased integration with obesity prevention and treatment.