Table 1.

Characteristics of the Study Population

CharacteristicValue
Study population (n)418,565
Sex, female (%)52.7
Employee relation (%)
    Employee65.2
    Spouse27.1
    Child/other7.8
Region (%)
    North East14.7
    North Central22.3
    South47.2
    West15.8
Rural (%)14.6
Plain film radiograph* (%)14.9

  • ↵* Proportion of the study population that had a plain film radiograph associated with the reference encounter for low back pain.