(201) Association between long-term opioid use and risk of depression, suicidal ideation and sleep disorders in patients with fibromyalgia: a population-based, propensity-weighted cohort study.

Background: Fibromyalgia (FM), the 3rd most frequent musculoskeletal condition, is a chronic disease characterized by widespread pain and mood disorders, depression and poor sleep quality. These in turn have been linked to increased risk of suicidal ideation.
Clinical guidelines generally do not recommended opioids in FM, but some recognize they may have a role if used scarcely. Meanwhile, opioids are routinely prescribed to a considerable proportion of FM patients, and frequently for prolonged periods of time. Effect of opioids on these FM-related outcomes are unknown.

Objectives: To assess the association of long-term opioid prescription of opioids to treat FM with sleep disorders, depression, and suicidal ideation, when compared short-term opioid use.

Methods: Retrospective cohort study combing several population-wide databases from the Valencia Health System Integrated Database, covering a population of five million inhabitants. We included all patients 18 years old and over who received an initial opioid prescription from 2014 to 2018 for FM. We examined the occurrence of sleep disorder, depression or suicidal ideation outcomes in patients with an initial long-term opioid prescription (>90 days) vs those who received a short-term treatment ( < 29 days). We carried out survival analyses employing multivariable Cox regression modelling and inverse probability of treatment weighting (IPTW) based on propensity scores. We performed several secondary and sensitivity analyses.

Results: 10,334 patients initiated short-term (8,309, 80.40%) or long-term (2,025, 19.60%) opioids for FM. Long-term opioid users were significantly more prone to be female, had more anxiety, depression, psychotic disorders, dementia, and other psychiatric disorders, and had more registered tobacco use. Daily MME in the long-term group was higher than in the short-term group, and overlap with benzodiazepines, gabapentinoids and antipsychotics at baseline was higher in long-term initiators. Mean follow-up was 981 days for short-term vs. 921 days for long-term users. In main adjusted analyses, long-term opioid use significantly increased risk for depression (HR: 1.58, 95%CI:1.29,1.95) and sleep disorder (HR: 1.3, 95%CI: 1.09,1.55) but not for suicidal ideation (HR: 1.59, 95%CI: 0.96,2.62). Analyses using competing risk of death, censoring short-term users if they initiate a non-short-term opioid use, and using dispensation data yielded comparable results. In models assessing outcomes since day 90, the association between long-term use and suicidal ideation turned significant (HR: 1.76, 95%CI: 1.05, 2.98).

Conclusions: These findings suggest that continued opioid use for 90 days or more may aggravate common complications of FM when compared to patterns of short-term treatment.