The association of persistent pain with out-patient addiction treatment outcomes and service utilization.
OBJECTIVE
To estimate the prevalence of persistent pain among veterans in out-patient addiction treatment and examine associated addiction treatment outcomes and medical and psychiatric service use.


METHODS
Analysis of data from a prospective randomized controlled trial comparing on-site versus referral primary care of veterans with substance dependence (n = 582), excluding opioid dependence who had at least one follow-up interview during the 12-month study period in a Veterans Affairs (VA) out-patient addiction treatment center.


METHODS
Pain status was classified as persistent (pain was rated moderate to very severe at all time-points), low (pain was rated none to mild at all time-points) or intermittent (all others). Main outcome measures were addiction treatment retention, addiction severity index (ASI) alcohol and drug composite scores, VA service utilization and treatment costs.


RESULTS
A total of 33.2% of veterans reported persistent pain and 47.3% reported intermittent pain. All groups benefited from addiction treatment, but veterans with persistent pain were in treatment for an estimated 35.1 fewer days [95% confidence interval (CI) = -64.1, -6.1, P = 0.018], less likely to be abstinent from alcohol or drugs at 12 months [odds ratio (OR)(adj) = 0.52; 95% CI = 0.30,0.89; P = 0.018], had worse ASI alcohol composite scores at 12 months (beta(adj) = 0.09; 95% CI = 0.02,0.15; P = 0.007), were more likely to be medically hospitalized (OR(adj) = 2.70; 95% CI = 1.02,7.13; P = 0.046) and had higher total service costs compared to those with low pain ($17 766 versus $13 261, P = 0.012).


CONCLUSIONS
Persistent pain is common among veterans in out-patient addiction treatment and is associated with poorer rates of abstinence, worse alcohol use severity and greater service utilization and costs than those with low pain.
Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA 98195-6560, USA. caldeiro@u.washington.edu
Ryan M
RM
Caldeiro
Carol A
CA
Malte
Donald A
DA
Calsyn
John S
JS
Baer
Paul
P
Nichol
Daniel R
DR
Kivlahan
Andrew J
AJ
Saxon
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010044:Outpatient Clinics, Hospital; D010146:Pain / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D010147:Pain Measurement; D010349:Patient Compliance / Q000523:psychology; D015995:Prevalence; D011446:Prospective Studies; D016320:Substance Abuse Treatment Centers / Q000706:statistics & numerical data*; D019966:Substance-Related Disorders / Q000150:complications / Q000534:rehabilitation*; D016896:Treatment Outcome; D014728:Veterans