Costs of Neuropathic Pain in Patients with Spinal Cord Injury

Phoenix—During the first year after being diagnosed with neuropathic pain, patients who had already suffered from a spinal cord injury had a mean healthcare cost that was $35,939 higher than patients who had a spinal cord injury but no neuropathic pain, according to a retrospective longitudinal cohort study.

Results were presented during the AAPM meeting in a poster session. The poster was titled Economic Burden of Spinal Cord Injury with Neuropathic Pain.

Previous research found that as many as 94% of patients with spinal cord injury experience pain, including nociceptive (musculoskeletal, visceral), neuropathic (at-level or below-level of injury), or other types of pain.

The authors noted that 50% of patients with spinal cord injury have neuropathic pain, which results from a lesion or disease of the somatosensory nervous system related to the injury. Neuropathic pain is often associated with a negative effect on daily activities, quality of life, mood, and rehabilitation outcome.

To treat spinal cord injury-associated neuropathic pain, clinicians typically prescribe antidepressants, antiepileptic drugs, opioids, and intrathecal medications. The FDA has only approved 1 drug (pregabalin, an antipsychotic) for patients with spinal cord injury-associated neuropathic pain.

In this analysis, the authors examined observational administrative medical and pharmacy claims data from the Thomson Reuters MarketScan^® Commercial Database from January 1, 2005, through December 31, 2010.

Patients included in the study had a spinal cord injury, were ≥18 years of age, had medical and pharmacy benefits, and had been enrolled in the database for 12 months before and after the index date. They were excluded if they had epilepsy, amyotrophic lateral sclerosis, or multiple sclerosis, or if they had submitted claims for medications used to treat multiple sclerosis.

There were 193 people with neuropathic pain and 9679 who did not have neuropathic pain. In the neuropathic group, 57.0% were female, and the average age was 48.0 years. Among the patients without neuropathic pain, the average age was 45.4 years, and 42.9% were female. The differences in age (P=.003) and gender (P<.001) between the groups were statistically significant.

In the 12 months before the baseline period, patients with neuropathic pain had significantly higher rates of musculoskeletal pain, gastrointestinal conditions, hypertension, renal/bladder conditions, respiratory conditions, arthritis, depression, substance abuse, diabetes, sleep disorders, anxiety, and deep vein thrombosis.

When managing neuropathic pain, patients were most likely to take short-acting opioids (89% preindex and 90% postindex), antiepileptics (52% preindex and 58% postindex), long-acting opioids (47% preindex and 53% postindex), antidepressants (36% preindex and 45% postindex), and intrathecal medications (12% preindex and 19% postindex).

Patients were significantly more likely to utilize healthcare resources if they had neuropathic pain. Sixty-two point 2 percent of patients with neuropathic pain had an inpatient admission compared with 11.7% of patients without pain; 62.2% of patients with neuropathic pain visited an emergency department compared with 21.8% of patients without pain; 98.4% of patients with neuropathic pain visited a physician compared with 89.9% of patients without pain; and 61.1% of patients with neuropathic pain had a pain intervention procedure compared with 26.9% of patients without pain (P<.001 for all comparisons).

For the 12 months postindex date, the mean total healthcare expenditures for the neuropathic pain group were $46,672 compared with $10,733 for patients who did not suffer from neuropathic pain. The authors noted that the difference (with a 95% confidence interval of $27,791 to $44,568) was adjusted for the presence of comorbidities and confounders.