Psychiatric comorbidities were found to be common among patients with chronic pain; however, receipt of high-dose, long-term opioid treatment (LTOT) was not influenced by mental health status, according to results of a retrospective study published in Pain Medicine.
Medical records collected between 2011 and 2015 at the outpatient clinic at the Otto-von-Guericke University in Germany were retrospectively reviewed for this study. Patients (N=769) who had at least 2 follow-up appointments within 1 year for chronic pain were evaluated for use and dosage of LTOT on the basis of psychiatric diagnoses. Long-term opioid use was defined as receipt of an opioid prescription for more than 90 consecutive days, and high-dose opioid treatment was defined as greater than 120 morphine milligram equivalents (MME) per day.
Of the cohort, 415 patients received nonopioid pain management, 308 received guideline-directed LTOT, and 46 received high-dose LTOT. The mean ages of patients in the 3 groups were 57.9, 61.2, and 61.0 years (P =.009), and 64.0%, 60.7%, and 47.8% were women. Duration of chronic pain among the nonopioid, guideline-directed LTOT, and high-dose LTOT groups was 7.5, 8.2, and 9.5 years; and 66.7%, 64.0%, and 52.2%, respectively, had a psychiatric comorbidity. Stratified by type of psychiatric disorder, rates of psychiatric comorbidity were similar between pain management groups, except that those receiving guideline-directed LTOT had a higher prevalence of addiction (22.7%; P =.017) compared with those receiving high-dose LTOT (19.6%) and nonopioid treatment (15.9%).
In general, individuals who did not receive opioids were more likely to have a main pain syndrome of headache or facial pain, whereas those receiving high-dose LTOT were more likely to have chronic back pain with radiculopathy or cancer pain (P <.001). The proportion of patients classified as Mainz Pain Staging System (MPSS) stage III was 49.7% for those not receiving opioids, 57.4% for those receiving guideline-recommended LTOT, and 66.7% for those on high-dose LTOT (all P =.009).
Among the guideline-recommended group, 61.4% were receiving low-potency opioids and 38.6% were receiving high-potency opioids. Tramadol (86.8%) was the most common low-potency treatment, and morphine (55.5%) and tapentadol (25.2%) were the most common high-potency treatments. For the high-dose group, all patients were receiving high-potency opioids, and tapentadol (45.7%) and morphine (30.4%) were the most common.
The average MME dose of LTOT was 47.2±34.5 mg for the guideline-recommended cohort compared with 206.3±71.8 mg for the high-dose cohort.
Predictors for receiving high-dose opioids among LTOT recipients included MPSS stage (r, 0.238; P =0.000), antidepressant use (η, 0.173; P =.001), and gender (η, 0.115; P =.031). However, in the multiple regression analysis, these significant predictors could explain only 7.9% of the variance in MME (F[4,343], 8.404; P <.001).
This study may have been limited its lack of access to data about medication adherence.
In this study, psychiatric comorbidities were common among patients with chronic pain, including among those receiving LTOT. However, the presence and type of psychiatric conditions did not predict receipt of high-dose LTOT, although patients who received antidepressants were also more likely to receive high-dose LTOT. The study authors advise that “[l]iaison psychiatric care within pain clinics allows for more optimally meeting the needs of chronic pain patients with mental illness and may greatly help to better weigh up the potential benefits of opioid therapy against the risk of harm in this vulnerable patient group.”
Vogt S, Pfau G, Vielhaber S, Haghikia A, Hachenberg T, Brinkers M. Long-term opioid therapy and mental health comorbidity in chronic pain patients. Pain Med. Published online January 20, 2023. doi:10.1093/pm/pnad004