Use of opioid medications for chronic noncancer pain syndromes in primary care

Abstract

Objectives: To define the spectrum of chronic noncancer pain treated with opioid medications in 2 primary care settings, and the prevalence of psychiatric comorbidity in this patient population. We also sought to determine the proportion of patients who manifested prescription opioid abuse behaviors and the factors associated with these behaviors.

Design: A retrospective cohort study.

Setting: A VA primary care clinic and an urban hospital-based primary care center (PCC) located in the northeastern United States.

Patients: A random sample of VA patients ( n=50) and all PCC patients ( n=48) with chronic noncancer pain who received 6 or more months of opioid prescriptions during a 1-year period (April 1, 1997 through March 31, 1998) and were not on methadone maintenance.

Measurements: Information regarding patients' type of chronic pain disorder, demographic, medical, and psychiatric status, and the presence of prescription opioid abuse behaviors was obtained by medical record review.

Main results: Low back pain was the most common disorder accounting for 44% and 25% of all chronic pain diagnoses in the VA and PCC samples, respectively, followed by injury-related (10% and 13%), diabetic neuropathy (8% and 10%), degenerative joint disease (16% and 13%), spinal stenosis (10% and 4%), headache (4% and 13%) and other chronic pain disorders (8% and 22%). The median duration of pain was 10 years (range 3 to 50 years) in the VA and 13 years in the PCC sample (range 1 to 49 years). Among VA and PCC patients, the lifetime prevalence rates of psychiatric comorbidities were: depressive disorder (44% and 54%), anxiety disorder (20% and 21%), alcohol abuse/dependence (46% and 31%), and narcotic abuse/dependence (18% and 38%). Prescription opioid abusive behaviors were recorded for 24% of VA and 31% of PCC patients. A lifetime history of a substance use disorder (adjusted odds ratio [OR], 3.8; 95% confidence interval [CI], 1.4 to 10.8) and age (adjusted OR, 0.94; 95% CI, 0.89 to 0.99) were independent predictors of prescription opioid abuse behavior.

Conclusions: A broad spectrum of chronic noncancer pain disorders are treated with opioid medications in primary care settings. The lifetime prevalence of psychiatric comorbidity was substantial in our study population. A significant minority of patients manifested prescription opioid abusive behaviors, and a lifetime history of a substance use disorder and decreasing age were associated with prescription opioid abuse behavior. Prospective studies are needed to determine the potential benefits as well as risks associated with opioid use for chronic noncancer pain in primary care.