Prevalence of non-spinal pathology and red flag diagnoses associated with care seeking for low back pain in the Military Health System

A study using data from the US Military Health System identified patients seeking care for low back pain (LBP) between 2015 and 2019. Of the 1.2 million individuals who sought care, 37.7% were female, 55.3% were active duty, and the average age was 34.7 years. Ten percent of these patients were seen in immediate care settings, such as emergency/urgent care clinics.

Among these patients, 2.9% received a red-flag diagnosis within 90 days of their initial LBP visit. The likelihood of red-flag diagnoses increased with female sex, non-active-duty status, and older age. Immediate care as the setting of initial LBP diagnosis also elevated the odds for most red-flag diagnoses. Serious pathology was uncommon, with only 2.9% of patients having red-flag diagnoses, which varied depending on the setting of initial diagnosis.

Active-duty service members had higher odds for vertebral fractures and cancer, while males had a higher risk for abdominal aortic aneurysm. The study emphasized the importance of identifying serious conditions early in patients with LBP, as they often require different treatments and have worse prognoses when delayed. Red flags serve to help clinicians differentiate non-specific low back pain from other serious conditions.