Military service members who are given non-drug therapies for chronic pain may have a reduced risk of long-term adverse outcomes, such as alcohol and drug use disorder and self-induced injuries, including suicide attempts, according to a new study published in the Journal of General Internal Medicine.
“Chronic pain is associated with adverse outcomes, such as substance use and suicidal thoughts and behavior,” said Dr. Esther Meerwijk, a statistician and suicide researcher at the VA Palo Alto Health Care System in California, and lead author.
“It made sense that if non-drug treatments are good at managing pain, their effect would go beyond only pain relief. However, I was surprised that the results of our analyses held, despite our attempts to prove them wrong. Often enough in research, significant results disappear once you start controlling for variables that can possibly affect the outcome of the study.”
Overall, the researchers found that service members with chronic pain who received non-drug therapies while in the military, such as massage or acupuncture, had a “significantly lower” risk in VA of new onset alcohol or drug disorder; poisoning with opioids and related narcotics, barbiturates, or sedatives; and suicidal thoughts and attempts. The research team did not study death by suicide.
The research team reviewed the VA health records of more than 140,000 U.S. Army soldiers who reported chronic pain following their deployment to Iraq or Afghanistan from 2008 to 2014. The median age of the participants was 26, and the median length of deployment was a little more than a year.
The most common types of chronic pain were joint discomfort, back and neck issues, and other problems involving muscles or bones.
The study controlled for length of a service member’s care in VA, whether the veteran had been exposed to non-drug therapies in VA, and the number of days a VA patient received opioids.
The researchers also tested to see if service members who received non-drug treatments were healthier to begin with and if more veterans who received non-drug therapies died before any of the adverse outcomes occurred.
It’s possible, Meerwijk explains, that soldiers who received non-drug therapies didn’t have to rely on opioids as much for their chronic pain and are therefore at lower risk for adverse outcomes.
“We may also be seeing a genuine effect of non-drug therapies that occurs regardless of whether soldiers use opioids or not,” she said. “If non-drug treatments make chronic pain more bearable, people may be more likely to have positive experiences in life. That makes them less likely to have thoughts of suicide or to turn to drugs.”
Chronic pain is often managed with prescription opioids. Especially at higher doses and longer length of use, opioids have been linked to a greater risk of substance use disorder and self-inflicted injuries, such as opioid overdose and suicide attempts.
While in service, the soldiers received non-drug therapies that included acupuncture, dry needling, biofeedback, chiropractic care, massage, exercise therapy, cold laser therapy, osteopathic spinal manipulation, electrical nerve stimulation, ultrasonography, superficial heat treatment, traction, and lumbar supports.
In the study, the researchers compared service members with chronic pain who did or didn’t receive non-drug therapies and described the links between such treatments in the military and long-term adverse outcomes.
They found that soldiers who received non-drug therapies were at lower risk of being diagnosed with drug use disorders and self-inflicted injuries, such as accidental poisoning and suicidal ideation.
The largest difference was seen with regard to accidental poisoning with opioids or other pain drugs: Those who received non-drug therapies were 35% less likely to injure themselves than those who didn’t receive such therapies while in the service.
Service members who received non-drug treatments were also 17% less likely to have self-inflicted injuries, including suicide attempts; 12% less likely to have suicidal ideation; and 8% less likely to have alcohol or drug use disorders.
The findings supported the researchers’ hypothesis that use of non-drug therapies in the military would be linked to fewer negative outcomes for patients in the VA system.
Because the study was only observational, it doesn’t show cause and effect — only an association. The researchers did use a method called propensity matching, which allowed them to carefully analyze differences and similarities between those soldiers who received non-drug therapies for pain and those who did not, to try and tease out the effects of that variable.
“We aimed statistically to create groups that, with the exception of receiving non-drug therapies, were as similar as possible,” Meerwijk said. “But we were limited to the observational data we had. That means that the groups may have been different in ways that we didn’t measure and, as a consequence, we don’t know about. We cannot rule out that one of those ways explains why we found what we found.”
Another limitation of the study is that the researchers didn’t look at specific non-drug therapies to gauge the extent to which they may have contributed — or not — to the overall finding.