Pain, substance use disorders and opioid analgesic prescription patterns in veterans with hepatitis C

The burden of significant pain in the cirrhosis population: Risk factors, analgesic use, and impact on health care utilization and clinical outcomes

BACKGROUND

We aimed to characterize pain and analgesic use in a large contemporary cohort of patients with cirrhosis and to associate pain with unplanned health care utilization and clinical outcomes in this population.

METHODS

We included all patients with cirrhosis seen in UCSF hepatology clinics from 2013 to 2020. Pain severity and location were determined using documented pain scores at the initial visit; "significant pain" was defined as moderate or severe using established cutoffs. Demographic, clinical, and medication data were abstracted from electronic medical records. Associations between significant pain and our primary outcome of 1-year unplanned health care utilization (ie, emergency department visit or hospitalization) and our secondary outcomes of mortality and liver transplantation were explored in multivariable models.

RESULTS

Among 5333 patients with cirrhosis, 32% had a nonzero pain score at their initial visit and 25% had significant (ie moderate/severe) pain. Sixty percent of patients with significant pain used ≥1 analgesic; 34% used opioids. Patients with cirrhosis with significant pain had similar Model for End-Stage Liver Disease-Sodium scores (14 vs. 13), but higher rates of decompensation (65% vs. 55%). The most common pain location was the abdomen (44%). Patients with abdominal pain, compared to pain in other locations, were more likely to have decompensation (72% vs. 56%). Significant pain was independently associated with unplanned health care utilization (adjusted odds ratio: 1.3, 95% CI: 1.1-1.5) and mortality (adjusted hazard ratio: 1.4, 95% CI: 1.2-1.6).

CONCLUSIONS

Pain among patients with cirrhosis is often not well-controlled despite analgesic use, and significant pain is associated with unplanned health care utilization and mortality in this population. Effectively identifying and treating pain are essential in reducing costs and improving quality of life and outcomes among patients with cirrhosis.

Association Between Prescription Opioid Therapy for Noncancer Pain and Hepatitis C Virus Seroconversion

IMPORTANCE

Initiation of injection drug use may be more frequent among people dispensed prescription opioid therapy for noncancer pain, potentially increasing the risk of hepatitis C virus (HCV) acquisition.

OBJECTIVE

To assess the association between medically dispensed long-term prescription opioid therapy for noncancer pain and HCV seroconversion among individuals who were initially injection drug use-naive.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, retrospective cohort study of individuals tested for HCV in British Columbia, Canada, with linkage to outpatient pharmacy dispensations, was conducted. Individuals with an initial HCV-negative test result followed by 1 additional test between January 1, 2000, and December 31, 2017, and who had no history of substance use at baseline (first HCV-negative test), were included. Participants were followed up from baseline to the last HCV-negative test or estimated date of seroconversion (midpoint between HCV-positive and the preceding HCV-negative test).

EXPOSURES

Episodes of prescription opioid use for noncancer pain were defined as acute (<90 days) or long-term (≥90 days). Prescription opioid exposure status (long-term vs prescription opioid-naive/acute) was treated as time-varying in survival analyses. In secondary analyses, long-term exposure was stratified by intensity of use (chronic vs. episodic) and by average daily dose in morphine equivalents (MEQ).

MAIN OUTCOMES AND MEASURES

Multivariable Cox regression models were used to assess the association between time-varying prescription opioid status and HCV seroconversion.

RESULTS

A total of 382 478 individuals who had more than 1 HCV test were included, of whom more than half were female (224 373 [58.7%]), born before 1974 (201 944 [52.8%]), and younger than 35 years at baseline (196 298 [53.9%]). Participants were followed up for 2 057 668 person-years and 1947 HCV seroconversions occurred. Of the participants, 41 755 people (10.9%) were exposed to long-term prescription opioid therapy at baseline or during follow-up. The HCV seroconversion rate per 1000 person-years was 0.8 among the individuals who were prescription opioid-naive/acute (1489 of 1947 [76.5%] seroconversions; 0.4% seroconverted within 5 years) and 2.1 with long-term prescription opioid therapy (458 of 1947 [23.5%] seroconversions; 1.1% seroconverted within 5 years). In multivariable analysis, exposure to long-term prescription opioid therapy was associated with a 3.2-fold (95% CI, 2.9-3.6) higher risk of HCV seroconversion (vs prescription opioid-naive/acute). In separate Cox models, long-term chronic use was associated with a 4.7-fold higher risk of HCV seroconversion (vs naive/acute use 95% CI, 3.9-5.8), and long-term higher-dose use (≥90 MEQ) was associated with a 5.1-fold higher risk (vs naive/acute use 95% CI, 3.7-7.1).

CONCLUSIONS AND RELEVANCE

In this cohort study of people with more than 1 HCV test, long-term prescription opioid therapy for noncancer pain was associated with a higher risk of HCV seroconversion among individuals who were injection drug use-naive at baseline or at prescription opioid initiation. These results suggest injection drug use initiation risk is higher among people dispensed long-term therapy and may be useful for informing approaches to identify and prevent HCV infection. These findings should not be used to justify abrupt discontinuation of long-term therapy, which could increase risk of harms.

Short-Term Safety of Repeated Acetaminophen Use in Patients With Compensated Cirrhosis

Current guidelines recommend restricting acetaminophen (APAP) use in patients with cirrhosis, but evidence to support that recommendation is lacking. Prior studies focused on pharmacokinetics (PK) of APAP in cirrhosis but did not rigorously examine clinical outcomes, sensitive biomarkers of liver damage, or serum APAP‐protein adducts, which are a specific marker of toxic bioactivation. Hence, the goal of this pilot study was to test the effects of regularly scheduled APAP dosing in a well‐defined compensated cirrhosis group compared to control subjects without cirrhosis, using the abovementioned outcomes. After a 2‐week washout, 12 subjects with and 12 subjects without cirrhosis received 650 mg APAP twice per day (1.3 g/day) for 4 days, followed by 650 mg on the morning of day 5. Patients were assessed in‐person at study initiation (day 1) and on days 3 and 5. APAP‐protein adducts and both conventional (alanine aminotransferase) and sensitive (glutamate dehydrogenase [GLDH], full‐length keratin 18 [K18], and total high‐mobility group box 1 protein) biomarkers of liver injury were measured in serum on the mornings of days 1, 3, and 5, with detailed PK analysis of APAP, metabolites, and APAP‐protein adducts throughout day 5. No subject experienced adverse clinical outcomes. GLDH and K18 were significantly different at baseline but did not change in either group during APAP administration. In contrast, clearance of APAP‐protein adducts was dramatically delayed in the cirrhosis group. Minor differences for other APAP metabolites were also detected. Conclusion: Short‐term administration of low‐dose APAP (650 mg twice per day, <1 week) is likely safe in patients with compensated cirrhosis. These data provide a foundation for future studies to test higher doses, longer treatment, and subjects who are decompensated, especially in light of the remarkably delayed adduct clearance in subjects with cirrhosis.

Prevalence and Medication Treatment of Opioid Use Disorder Among Primary Care Patients with Hepatitis C and HIV

BACKGROUND

Hepatitis C and HIV are associated with opioid use disorders (OUD) and injection drug use. Medications for OUD can prevent the spread of HCV and HIV.

OBJECTIVE

To describe the prevalence of documented OUD, as well as receipt of office-based medication treatment, among primary care patients with HCV or HIV.

DESIGN

Retrospective observational cohort study using electronic health record and insurance data.

PARTICIPANTS

Adults ≥ 18 years with ≥ 2 visits to primary care during the study (2014-2016) at 6 healthcare systems across five states (CO, CA, OR, WA, and MN).

MAIN MEASURES

The primary outcome was the diagnosis of OUD; the secondary outcome was OUD treatment with buprenorphine or oral/injectable naltrexone. Prevalence of OUD and OUD treatment was calculated across four groups: HCV only; HIV only; HCV and HIV; and neither HCV nor HIV. In addition, adjusted odds ratios (AOR) of OUD treatment associated with HCV and HIV (separately) were estimated, adjusting for age, gender, race/ethnicity, and site.

KEY RESULTS

The sample included 1,368,604 persons, of whom 10,042 had HCV, 5821 HIV, and 422 both. The prevalence of diagnosed OUD varied across groups: 11.9% (95% CI: 11.3%, 12.5%) for those with HCV; 1.6% (1.3%, 2.0%) for those with HIV; 8.8% (6.2%, 11.9%) for those with both; and 0.92% (0.91%, 0.94%) among those with neither. Among those with diagnosed OUD, the prevalence of OUD medication treatment was 20.9%, 16.0%, 10.8%, and 22.3%, for those with HCV, HIV, both, and neither, respectively. HCV was not associated with OUD treatment (AOR = 1.03; 0.88, 1.21), whereas patients with HIV had a lower probability of OUD treatment (AOR = 0.43; 0.26, 0.72).

CONCLUSIONS

Among patients receiving primary care, those diagnosed with HCV and HIV were more likely to have documented OUD than those without. Patients with HIV were less likely to have documented medication treatment for OUD.

Prevalence and Patterns of Opioid Use Before and After Liver Transplantation

BACKGROUND

Opioid use in liver transplantation is poorly understood and has potential associated morbidity.

METHODS

Using a national data set of employer-based insurance claims, we identified 1257 adults who underwent liver transplantation between December 2009 and February 2015. We categorized patients based on their duration of opioid fills over the year before and after transplant admission as opioid-naive/no fills, chronic opioid use (≥120 d supply), and intermittent use (all other use). We calculated risk-adjusted prevalence of peritransplant opioid fills, assessed changes in opioid use after transplant, and identified correlates of persistent or increased opioid use posttransplant.

RESULTS

Overall, 45% of patients filled ≥1 opioid prescription in the year before transplant (35% intermittent use, 10% chronic). Posttransplant, 61% of patients filled an opioid prescription 0-2 months after discharge, and 21% filled an opioid between 10-12 months after discharge. Among previously opioid-naive patients, 4% developed chronic use posttransplant. Among patients with pretransplant opioid use, 84% remained intermittent or increased to chronic use, and 73% of chronic users remained chronic users after transplant. Pretransplant opioid use (risk factor) and hepatobiliary malignancy (protective) were the only factors independently associated with risk of persistent or increased posttransplant opioid use.

CONCLUSIONS

Prescription opioid use is common before and after liver transplant, with intermittent and chronic use largely persisting, and a small development of new chronic use posttransplant. To minimize the morbidity of long-term opioid use, it is critical to improve pain management and optimize opioid use before and after liver transplant.

Prescription of High-Dose Opioids Among People Living with HIV in British Columbia, Canada

People living with HIV (PLHIV) often experience pain for which opioid medications may be prescribed. Thus, these individuals are particularly vulnerable to opioid-related harms, including overdose, misuse, and addiction, particularly when prescribed at high doses. We used a comprehensive linked population-level database of PLHIV in British Columbia (BC) to identify demographic and clinical characteristics associated with being prescribed any high-dose opioid analgesic, defined as > 90 daily morphine milligram equivalents (MME/day). Among PLHIV who were prescribed opioids between 1996 and 2015 (n = 10,780), 28.2% received prescriptions of > 90 MME/day at least once during the study period. Factors positively associated with being prescribed high-dose opioid analgesics included: co-prescription of benzodiazepines (adjusted odds ratio [AOR] = 1.14; 95% confidence interval 1.11-1.17); presence of an AIDS-defining illness (ADI; AOR = 1.78; 95% CI 1.57-2.02); seen by an HIV specialist (AOR = 1.24; 95% CI 1.20-1.29); substance use disorder (AOR = 1.46; 95% CI 1.25-1.71); and more recent calendar year (AOR = 1.05; 95% CI 1.04-1.06). Given the known risks associated with high-dose opioid prescribing, future research efforts should focus on the clinical indication and outcomes associated with these prescribing practices.

Characterising the association between positive hepatitis C virus antibody and pain among people who inject drugs

INTRODUCTION AND AIMS

People who inject drugs (PWID) are a key group within the hepatitis C virus (HCV) pandemic. Chronic pain is a common condition among PWID as these individuals are often exposed to soft tissue infections due to injections and violence. This study aims to characterise the relationship between HCV exposure and pain among PWID.

DESIGN AND METHODS

Data were derived from three prospective cohorts of PWID in Vancouver, Canada, between December 2011 and November 2016. The primary outcome was pain severity, which was defined based on the Euroqol EQ-5D-3L pain subscale. A bivariable and multivariable ordinal generalised estimating equations model was used to quantify the association between HCV exposure and pain among participants.

RESULTS

One thousand and twelve of 2038 participants (50%) reported moderate/extreme pain at baseline. In total, 1473 (72%) participants were HCV-antibody positive. In unadjusted analyses, HCV exposure was positively associated with increased pain [odds ratio (OR) = 1.47; 95% confidence interval (CI): 1.20-1.81]. However, once adjusted for known confounders in multivariable analyses, HCV exposure did not remain significantly associated with increased pain (adjusted OR = 1.00; 95%CI: 0.78-1.28).

DISCUSSION AND CONCLUSIONS

In this sample of PWID, HCV exposure was not significantly associated with pain once other factors were considered. These various factors may explain the elevated risk of pain among PWID and should be addressed in future initiatives when managing pain among PWID with HCV exposure. Future studies should also examine whether pain changes with changes in HCV status (i.e. active vs. cleared infection).

Impact of Cigarette Smoking Status on Pain Intensity Among Veterans With and Without Hepatitis C

Objective

Chronic pain is a significant problem in patients living with hepatitis C virus (HCV). Tobacco smoking is an independent risk factor for high pain intensity among veterans. This study aims to examine the independent associations with smoking and HCV on pain intensity, as well as the interaction of smoking and HCV on the association with pain intensity.

Design/Particpants

Cross-sectional analysis of a cohort study of veterans of Operations Enduring Freedom/Iraqi Freedom/New Dawn (OEF/OIF/OND) who had at least one visit to a Veterans Health Administration (VHA) primary care clinic between 2001 and 2014.

Methods

HCV was identified using ICD-9 codes from electronic medical records (EMRs). Pain intensity, reported on a 0-10 numeric rating scale, was categorized as none/mild (0-3) and moderate/severe (4-10).

Results

Among 654,841 OEF/OIF/OND veterans (median age [interquartile range] = 26 [23-36] years), 2,942 (0.4%) were diagnosed with HCV. Overall, moderate/severe pain intensity was reported in 36% of veterans, and 37% were current smokers. The adjusted odds of reporting moderate/severe pain intensity were 1.23 times higher (95% confidence interval [CI] = 1.14-1.33) for those with HCV and 1.26 times higher (95% CI = 1.25-1.28) for current smokers. In the interaction model, there was a significant Smoking Status × HCV interaction (P = 0.03). Among veterans with HCV, smoking had a significantly larger association with moderate/severe pain (adjusted odds ratio [OR] = 1.50, P < 0.001) than among veterans without HCV (adjusted OR = 1.26, P < 0.001).

Conclusions

We found that current smoking is more strongly linked to pain intensity among veterans with HCV. Further investigations are needed to explore the impact of smoking status on pain and to promote smoking cessation and pain management in veterans with HCV.

Opioid and benzodiazepine prescription among patients with cirrhosis compared to other forms of chronic disease

Objective

Data on patterns and correlates of opioid and benzodiazepines prescriptions among patients with chronic conditions are limited. Given a diminished capacity for hepatic clearance, patients with cirrhosis represent a high risk group for use. The aim of this study was to characterise the patterns and correlates of prescription opioid, benzodiazepine and dual drug prescriptions among individuals with common chronic diseases.

Design

Analysis of Truven Marketscan database to evaluate individuals with drug coverage with cirrhosis (n=169,181), chronic hepatitis C without cirrhosis (n=210 191), congestive heart failure (n=766 840) or chronic obstructive pulmonary disease (n=1 438 798). Pharmacy files were examined for outpatient prescriptions.

Results

Patients with cirrhosis had a significantly higher prevalence of opioid prescriptions (37.1 per 100 person-years vs 24.3–26.0, p≤0.001) and benzodiazepine prescriptions (21.3 per 100 person-years vs 12.1–12.9, p<0.001). High dose opioid prescription (>90 daily oral morphine equivalents) (29.1% vs 14.4%, p<0.001) and dual opioid and benzodiazepine prescription (17.5% vs 9.6%–10.5 %, p<0.001) were also significantly more prevalent in cirrhosis. High dose opioid prescription was greater in men, individuals ages 40–59, in the Western USA, and among those with a mental health or substance abuse condition. Dual opioid and benzodiazepine prescription were highest among those with alcoholic cirrhosis and middle aged-adults.

Conclusion

Persons with cirrhosis have significantly higher rates of prescription opioid and benzodiazepine prescription compared to others with chronic diseases despite their high risk for adverse drug reactions. Demographics and mental health or substance abuse history can help identify high risk groups to target interventions.

Impact of hepatitis C treatment on pain intensity, prescription opioid use and arthritis

OBJECTIVE

To assess the impact of direct acting anti-viral (DAA) therapy for hepatitis C virus (HCV) infection on changes in pain intensity and prescription opioid use among Veterans.

METHODS

We conducted a retrospective cohort study of Veterans with HCV who were seen in a rheumatology clinic at least once while receiving DAA therapy between January 1, 2010 and December 31st 2016. Demographic characteristics, HCV status, HCV treatment characteristics, numeric rating scale (NRS) pain scores and opioid prescription data were extracted from the electronic medical record. Pain scores were averaged over 6 months prior to HCV treatment and 6 months after completion of treatment. Prescription opioid dose was converted to a morphine equivalent daily dose (MEDD) and averaged across the two 6-month intervals. Generalized estimating equations were used to model the change in average pain and MEDD from pre- to post-HCV treatment. Effect size was assessed using Cohen's d.

RESULTS

A total of 121 Veterans, 91% male with average age of 59 were included. Average pre-treatment pain was 4.4 (SD 2.4). The average reduction in pain scores was 0.6 points (P = 0.02, Cohen's d = 0.22) after treatment. Among 67 patients prescribed chronic opioid therapy at baseline, average pre-treatment MEDD was 52.4 mg (SD = 62.5 mg) and post-DAA treatment average MEDD was 49.5 mg (SD = 69.3 mg), representing a decrease by 2.9 mg (P < 0.01, Cohen's d = 0.14). Opioid dose reduction was seen in 43/67 patients and 12 patients discontinued opioids entirely.

CONCLUSION

Among US Veterans, subjective pain scores had modest improvement and opioid prescriptions were mildly reduced following treatment with DAA.

Adaption of the Biopsychosocial Model of Chronic Noncancer Pain in Veterans

Population

Veterans with chronic noncancer pain (CNCP) are a vulnerable population whose care remains a challenge for clinicians, policy-makers, and researchers. As a result of military experience, veterans are exposed to high rates of musculoskeletal injuries, trauma, psychological stressors (e.g., post-traumatic stress disorder, depression, anxiety, substance abuse), and social factors (e.g., homelessness, social isolation, disability, decreased access to medical care) that contribute to the magnitude and impact of CNCP. In the veteran population, sound theoretical models are needed to understand the specific physiological, psychological, and social factors that influence this unique experience.

Objective

This paper describes an adaption of Gatchel and colleagues' biopsychosocial model of CNCP to veterans and summarizes research findings that support each component of the revised model. The paper concludes with a discussion of important implications for the use of this revised model in clinical practice and future directions for research.

Conclusions

The adaption of the biopsychosocial model of CNCP for veterans provides a useful and relevant conceptual framework that can be used to guide future research and improve clinical care in this vulnerable population.

Functional MRI and delay discounting in patients infected with hepatitis C

Hepatitis C virus-infected (HCV+) adults evidence increased rates of psychiatric and cognitive difficulties. This is the first study to use functional magnetic resonance imaging (fMRI) to examine brain activation in untreated HCV+ adults. To determine whether, relative to non-infected controls (CTLs), HCV+ adults exhibit differences in brain activation during a delay discounting task (DDT), a measure of one's tendency to choose smaller immediate rewards over larger delayed rewards-one aspect of impulsivity. Twenty adults with HCV and 26 CTLs completed an fMRI protocol during the DDT. Mixed effects regression analyses of hard versus easy trials of the DDT showed that, compared with CTLs, the HCV+ group exhibited less activation in the left lateral occipital gyrus, precuneus, and superior frontal gyrus. There were also significant interactive effects for hard-easy contrasts in the bilateral medial frontal gyrus, left insula, left precuneus, left inferior parietal lobule, and right temporal occipital gyrus; the CTL group evidenced a positive relationship between impulsivity and activation, while the HCV+ group exhibited a negative relationship. Within the HCV+ group, those with high viral load chose immediate rewards more often than those with low viral load, regardless of choice difficulty; those with low viral load chose immediate rewards more often on hard choices relative to easy choices. Results show that HCV+ patients exhibit greater impulsive behavior when presented with difficult choices, and impulsivity is negatively related to activation in regions important for cognitive control. Thus, interventions that decrease impulsive choice may be warranted with some HCV+ patients.

The assessment and management of pain in cirrhosis

Purpose of review

The treatment of pain in patients with cirrhosis is complicated by unpredictable hepatic drug metabolism and a higher risk of adverse drug reactions. We aimed to conduct a scoping review regarding pain management in cirrhosis.

Recent findings

Despite the high prevalence of pain in patients with cirrhosis, there is little literature to guide the management of pain in this population. Complex pain syndromes and disease-specific pain etiologies exist are common in patients with cirrhosis. There are numerous contraindications and limitations when considering pharmacotherapy for analgesia in cirrhosis, specifically with non-steroidal anti-inflammatory drugs (NSAIDS) and opioid medications. Non-pharmacologic therapies for pain have not been specifically assessed in this population.

Summary

As with other populations, a multi-dimensional treatment approach to pain with a focus on physical, behavioral, procedural and pharmacologic treatment is recommended when caring for patients with cirrhosis and pain. However, more research is needed to evaluate opioid-sparing and non-pharmacologic analgesia in this population.

Chronic Pain Opioid-Maintained Patients Receive Less Analgesic Opioid Prescriptions

Treating pain and opioid use disorder represents a clinical challenge. While most studies that have assessed opioid analgesic use in opioid substitution treatment (OST) patients primarily address opioid analgesic misuse (1, 2), only few studies focused on OST patients assessed the prescription of analgesic opioids for chronic pain. We sought to compare the prevalence of analgesic opioid prescription (AOP) in two groups of chronic non-cancer pain (CNCP) patients: OST patients vs. the general population. This was a population-based cross-sectional study based on the French national healthcare claims database SNIIRAM (Système National d'Informations Inter-Régimes de l'Assurance Maladie) covering over 66 million people (98.8% of the French population). Overall, 67,173 participants ≥15 years old undergoing continuous OST in 2015 ("OST patients" group) were included and age- and gender-matched by means of a 1:1 ratio with 67,173 patients without OST ("control" group). In each group, patients with cancer conditions were excluded and those having received opioid and non-opioid analgesics for at least 3 months were identified (CNCP patients). Compared to control patients, CNCP OST patients received less AOP (47.8 vs. 68.0%, p < 0.0001) and more often non-opioid prescription (52.2 vs. 32.0%, p < 0.0001). In multivariate analysis, CNCP OST patients were 2.7 times less likely to be prescribed analgesic opioids (adjusted odds ratio [OR] = 2.7 [2.42-3.01], p < 0.0001) than control patients. AOP correlated in CNCP OST patients with: age ≤ 40 years old, female gender, low-income status, methadone-maintained treatment, mental health disorder, hepatitis C virus (HCV) infection, and alcohol abuse disorder. Opioid analgesics were less often prescribed in CNCP OST patients. AOP prevalence was 2.7-fold lower than in the general population. Chronic pain management in OST patients needs to be reinforced through additional physician training and a multidisciplinary approach.

Correlates of prescription opioid therapy in Veterans with chronic pain and history of substance use disorder

Patients with a history of substance use disorder (SUD) are more likely to be prescribed opioid medications for chronic pain than patients without an SUD history; however, little is known about prescription opioid therapy in populations composed exclusively of patients with SUD. This study examined correlates of prescription opioid therapy in 214 Veterans with chronic noncancer pain and an SUD history. Participants completed psychosocial questionnaires and participated in a structured mental health diagnostic interview, and medical diagnoses and opioid pharmacy data were abstracted from their Department of Veterans Affairs electronic medical records. Participants were categorized into three groups based on opioid prescriptions in the past 90 d: no opioid therapy (n = 134), short-term (<90 d) opioid therapy (n = 31), or long-term (>/= 90 d) opioid therapy (n = 49). Relative to participants prescribed no or short-term opioid therapy, participants who were prescribed long-term opioid therapy had a greater number of pain diagnoses; reported higher levels of pain severity, interference, and catastrophizing; and endorsed lower chronic pain self-efficacy. In a multivariate model, number of pain diagnoses and pain interference were associated with a greater likelihood of being prescribed long-term opioid therapy after controlling for demographic and clinical characteristics. Findings highlight the poor pain-related functioning in patients with SUD histories who are prescribed long-term opioid therapy.

Co-occurring Depression, Chronic Pain and Substance Use Disorders in People with Hepatitis C

Chronic infection with Hepatitis C virus (HCV) is common and can result in serious and sometimes fatal liver complications. The impact of HCV on the liver can be further complicated by medical and psychological comorbidities. Depression, substance use, and pain syndromes are frequent co-morbid conditions in people with HCV and diminish functioning, quality of life, and treatment compliance. Understanding the underlying biological mechanisms of these comorbid conditions within the context of HCV may help elucidate factors contributing to their co-occurrence, perhaps mediatedviapro-inflammatory cytokines. The current review provides a synthesis of the literature on depression, substance use disorders and chronic pain in the presence of HCV. The review includes studies conducted with both veteran and civilian populations. The implications for assessment and antiviral treatment of HCV will be considered.

Development and Preliminary Evaluation of an Integrated Cognitive-Behavior Treatment for Chronic Pain and Substance Use Disorder in Patients with the Hepatitis C Virus

OBJECTIVE

Individuals with the hepatitis C virus (HCV) have high rates of both chronic pain and substance use disorder (SUD). Despite high comorbidity, there are limited data available on effective methods of treatment for co-occurring chronic pain and SUD. In this study, we sought to develop and conduct preliminary testing of an integrated cognitive-behavior therapy (CBT) for chronic pain and SUD in patients with HCV.

DESIGN

Descriptive, including pretreatment, posttreatment, and follow-up testing.

SETTING AND PATIENTS

Outpatient clinic as part of one VA Medical Center.

PARTICIPANTS

Veterans with chronic pain, SUD, and HCV.

INTERVENTION

Eight-session integrated group CBT for chronic pain and SUD in patients with HCV.

METHODS

Participants completed standardized measures of pain, function, depression severity, and alcohol and substance use at baseline, post-treatment, and 3-month follow-up.

RESULTS

Generalized estimating equations identified improvements in pain interference, reducing cravings for alcohol and other substances, and decreasing past-month alcohol and substance use. The proportion of participants who met diagnostic criteria for current SUD demonstrated a four-fold decrease over the course of the study from 24% at baseline to 15% at post-treatment and 6% at 3-month follow-up. On response to a global impression of change, 94% of participants noted improvement from baseline.

CONCLUSIONS

Results from this pilot study suggest that a customized CBT for patients with both chronic pain and SUD (CBT-cp.sud) may be beneficial in improving important pain and addiction-related outcomes in patients with HCV. Larger scale investigations of this intervention appear warranted.

Hepatitis C virus infection and pain sensitivity in patients on methadone or buprenorphine maintenance therapy for opioid use disorders

BACKGROUND

Patients with opioid use disorders on opioid agonist therapy (OAT) have lower pain tolerance compared to controls. While chronic viral infections such as HCV and HIV have been associated with chronic pain in this population, no studies have examined their impact on pain sensitivity.

METHODS

We recruited 106 adults (41 uninfected controls; 40 HCV mono-infected; and 25 HCV/HIV co-infected) on buprenorphine or methadone to assess whether HCV infection (with or without HIV) was associated with increased experimental pain sensitivity and self-reported pain. The primary outcome was cold pain tolerance assessed by cold-pressor test. Secondary outcomes were cold pain thresholds, wind-up ratios to repetitive mechanical stimulation (i.e., temporal summation) and acute and chronic pain. Multivariable regression models evaluated associations between viral infection status and outcomes, adjusting for other factors.

RESULTS

No significant differences were detected across groups for primary or secondary outcomes. Adjusted mean cold pain tolerance was 25.7 (uninfected controls) vs. 26.8 (HCV mono-infection) vs. 25.3 (HCV/HIV co-infection) seconds (global p-value=0.93). Current pain appeared more prevalent among HCV mono-infected (93%) compared to HCV/HIV co-infected participants (76%) and uninfected controls (80%), as did chronic pain (77% vs. 64% vs. 61%, respectively). However, differences were not statistically significant in multivariable models.

CONCLUSION

This study did not detect an association between HCV infection and increased sensitivity to pain among adults with and without HIV who were treated with buprenorphine or methadone for opioid use disorders. Results reinforce that pain and hyperalgesia are common problems in this population.

Psychiatric and substance use disorders co-morbidities and hepatitis C: Diagnostic and treatment implications

Chronic hepatitis C virus (HCV) viral infection is the most common blood-borne viral infection and approximately 2%-3% of the world’s population or 170-200 million people are infected. In the United States as many as 3-5 million people may have HCV. Psychiatric and substance use disorders (SUDs) are common co-morbid conditions found in people with HCV and are factors in predisposing people to HCV infection. Also, these co-morbidities are reasons that clinicians exclude people from antiviral therapy in spite of evidence that people with HCV and co-morbid psychiatric and SUD can be safely and effectively treated. Furthermore, the neuropsychiatric side effects of interferon (IFN), until recently the mainstay of antiviral therapy, have necessitated an appreciation and assessment of psychiatric co-morbidities present in people with HCV. The availability of new medications and IFN-free antiviral therapy medication combinations will shorten the duration of treatment and exposure to IFN and thus decrease the risk of neuropsychiatric side effects. This will have the consequence of dramatically altering the clinical landscape of HCV care and will increase the number of eligible treatment candidates as treatment of people with HCV and co-morbid psychiatric and SUDs will become increasingly viable. While economically developed countries will rely on expensive IFN-free antiviral therapy, less developed countries will likely continue to use IFN-based therapies at least until such time as IFN-free antiviral medications become generic. The current manuscript discusses the efficacy and viability of treating HCV in people with psychiatric and SUDs comorbidities, the treatment of the neuropsychiatric side effects of IFN -based therapies and the impact of new medications and new treatment options for HCV that offer the promise of increasing the availability of antiviral therapy in this vulnerable population.

Opioid use and risk of liver fibrosis in HIV/hepatitis C virus-coinfected patients in Canada

OBJECTIVES

Opioid use and opioid-related mortality have increased dramatically since the 1990s in North America. The effect of opioids on the liver is incompletely understood. Some studies have suggested that opioids cause liver damage and others have failed to show any harm. HIV/hepatitis C virus (HCV)-coinfected persons may be particularly vulnerable to factors increasing liver fibrosis. We aimed to describe opioid use in an HIV/HCV-coinfected population in Canada and to estimate the association between opioid use and liver fibrosis.

METHODS

We conducted a cross-sectional descriptive analysis of the Canadian Co-infection Cohort Study data to characterize opioid use. We then conducted a longitudinal analysis to assess the average change in aspartate aminotransferase-to-platelet ratio index (APRI) score associated with opioid use using a generalized estimating equation with linear regression. We assessed the progression to significant liver fibrosis (APRI ≥ 1.5) associated with opioid use with pooled logistic regression.

RESULTS

In the 6 months preceding cohort entry, 32% of the participants had received an opioid prescription, 28% had used opioids illicitly and 18% had both received a prescription and used opioids illicitly. Neither prescribed nor illicit opioid use was associated with a change in the median APRI score [exp(β) 0.99 (95% confidence interval (CI) 0.82, 1.12) and exp(β) 0.95 (95% CI 0.81, 1.10), respectively] or with faster progression to liver fibrosis [hazard odds ratio (HOR) 1.20 (95% CI 0.73, 1.67) and HOR 1.09 (95% CI 0.63, 1.55), respectively].

CONCLUSIONS

Although opioids were commonly used both legally and illegally in our cohort, we were unable to demonstrate a negative impact on liver fibrosis progression.

PTSD and substance use disorder among veterans: characteristics, service utilization and pharmacotherapy

OBJECTIVE

While there has been considerable concern about veterans with dually diagnosed posttraumatic stress disorder (PTSD) and comorbid substance use disorders, a national study of clinical characteristics, service utilization, and psychotropic medication use of such veterans in Veterans Affairs (VA) has yet to be conducted. We hypothesized that veterans having both PTSD and substance use disorder would have lower socioeconomic status, greater medical and psychiatric comorbidity, higher medical service utilization, and more psychotropic pharmacotherapy fills.

METHODS

National VA data from fiscal year 2012 were used to compare veterans with dually diagnosed PTSD and substance use disorder to veterans with PTSD without substance use disorder on sociodemographic characteristics, psychiatric and medical comorbidities, mental health and medical service utilization, and psychotropic pharmacotherapy. Comparisons were based on bivariate and Poisson regression analyses.

RESULTS

The sample included all 638,451 veterans who received the diagnosis of PTSD in the VA in fiscal year 2012: 498,720 (78.1%) with PTSD alone and 139,731 (21.9%) with dually diagnosed PTSD and a comorbid substance use disorder. Veterans with dual diagnoses were more likely to have been homeless and to have received a VA disability pension. Medical diagnoses that were more strongly associated with veterans with dual diagnosis included seizure disorders, liver disease, and human immunodeficiency virus (HIV). Psychiatric comorbidities that distinguished veterans with dual diagnoses included bipolar disorder and schizophrenia. Veterans with dually diagnosed PTSD and substance use disorder also had a greater likelihood of having had mental health inpatient treatment. There were no substantial differences in other measures of service use or prescription fills for psychotropic medications.

CONCLUSIONS

Several substantial differences were observed, each of which represented more severe medical and psychiatric illness among veterans with dually diagnosed PTSD and substance use disorder compared to those with PTSD alone. However, effective treatments are available for these disorders and special efforts should be made to ensure that veterans with dual diagnoses receive them.

Pain-related anxiety mediates the relationship between depressive symptoms and pain interference in veterans with hepatitis C

OBJECTIVE

Depression and chronic pain are common in persons chronically infected with the hepatitis C virus (HCV), although little is known about the rate of co-occurrence or mechanisms by which they are associated. We evaluated whether pain-related anxiety mediates the relationship between depressive symptoms and pain-related physical functioning in patients with HCV.

METHODS

Patients with HCV (n=175) completed self-report measures assessing demographic characteristics, pain-related function and mental health. Path analyses examined direct effects of cognitive-affective and somatic symptoms of depression on pain interference and indirect effects of these relationships via four subscales of the Pain Anxiety Symptoms Scale-20.

RESULTS

Cognitive-affective and somatic symptoms of depression were positively and significantly related to pain interference. Pain-related anxiety mediated the relationship between both cognitive-affective and somatic symptoms of depression, and this mediation was predominantly accounted for by the escape-avoidance component of pain-related anxiety.

CONCLUSIONS

Findings indicate a potential mediating role of pain-related anxiety, particularly escape-avoidance anxiety, on the relationship between depression and pain interference in patients with HCV. These findings suggest that escape-avoidance anxiety may be a particularly germane target for treatment in patients with HCV and chronic pain, particularly when depression, with characteristic features of withdrawal and inhibition, is a comorbid condition.

Multi-analyte profile analysis of plasma immune proteins: altered expression of peripheral immune factors is associated with neuropsychiatric symptom severity in adults with and without chronic hepatitis C virus infection

BackgroundThe purpose of this study was to characterize hepatitis C virus (HCV)-associated differences in the expression of 47 inflammatory factors and to evaluate the potential role of peripheral immune activation in HCV-associated neuropsychiatric symptoms-depression, anxiety, fatigue, and pain. An additional objective was to evaluate the role of immune factor dysregulation in the expression of specific neuropsychiatric symptoms to identify biomarkers that may be relevant to the treatment of these neuropsychiatric symptoms in adults with or without HCV. MethodsBlood samples and neuropsychiatric symptom severity scales were collected from HCV-infected adults (HCV+, n = 39) and demographically similar noninfected controls (HCV-, n = 40). Multi-analyte profile analysis was used to evaluate plasma biomarkers. ResultsCompared with HCV- controls, HCV+ adults reported significantly (P < 0.050) greater depression, anxiety, fatigue, and pain, and they were more likely to present with an increased inflammatory profile as indicated by significantly higher plasma levels of 40% (19/47) of the factors assessed (21%, after correcting for multiple comparisons). Within the HCV+ group, but not within the HCV- group, an increased inflammatory profile (indicated by the number of immune factors > the LDC) significantly correlated with depression, anxiety, and pain. Within the total sample, neuropsychiatric symptom severity was significantly predicted by protein signatures consisting of 4-10 plasma immune factors; protein signatures significantly accounted for 19-40% of the variance in depression, anxiety, fatigue, and pain. ConclusionsOverall, the results demonstrate that altered expression of a network of plasma immune factors contributes to neuropsychiatric symptom severity. These findings offer new biomarkers to potentially facilitate pharmacotherapeutic development and to increase our understanding of the molecular pathways associated with neuropsychiatric symptoms in adults with or without HCV.

Biopsychosocial factors associated with pain in veterans with the hepatitis C virus

Little research has examined etiological factors associated with pain in patients with the hepatitis C virus (HCV). The purpose of this study was to evaluate the relationship between biopsychosocial factors and pain among patients with HCV. Patients with HCV and pain (n = 119) completed self-report measures of pain, mental health functioning, pain-specific psychosocial variables (pain catastrophizing, self-efficacy for managing pain, social support), prescription opioid use, and demographic characteristics. In multivariate models, biopsychosocial factors accounted for 37% of the variance in pain severity and 56% of the variance in pain interference. In adjusted models, factors associated with pain severity include pain catastrophizing and social support, whereas variables associated with pain interference were age, pain intensity, prescription opioid use, and chronic pain self-efficacy (all p values <0.05). The results provide empirical support for incorporating the biopsychosocial model in evaluating and treating chronic pain in patients with HCV.

Healthcare utilization in chronic liver disease: the importance of pain and prescription opioid use

BACKGROUND & AIMS

The aim of this study was to assess factors associated with healthcare utilization in patients with chronic liver disease with a focus on pain, opioid use and psychiatric symptoms.

METHODS

We retrospectively assessed a consecutive sample of 1286 visitors to a hepatology clinic with chronic liver disease. Baseline psychiatric symptoms, pain and opioid prescriptions were collected. Liver-related clinic visits, total clinic visits, phone calls and hospitalizations were assessed over a subsequent 6-month period. Multivariable logistic and negative binomial regression models were used to determine the medical and psychosocial factors associated with increased healthcare utilization.

RESULTS

Over a 6-month period, hospitalization was more common among patients with pain (13% vs. 7%, P < 0.0001) and opioid usage (18% vs. 6% P < 0.0001). Pain and opioid usage were independently and significantly associated with an increased hospitalizations and median number of clinic visits and phone calls (P < 0.0001). In multivariable modelling, hospitalization was significantly associated with opioid use (OR = 2.72, CI = 1.72, 4.29), Child's Class B (OR = 2.24, CI = 1.19, 4.14) and C (OR = 8.51, CI = 4.18, 17.27) cirrhosis, and cardiopulmonary disease (OR = 2.11, CI = 1.28, 3.41). Pain and opioid usage were independently and significantly associated with the numbers of phone calls and total outpatient visits, as were medical comorbidities and Child's Class. The significant predictors of increased outpatient liver-related visits were pain (IRR = 1.13, CI = 1.02, 1.26), interferon usage (IRR = 1.75, CI = 1.54, 1.98) and more advanced liver disease (IRR = 1.58, CI = 1.32, 1.88).

CONCLUSIONS

Pain and prescription opioid usage were significantly linked to increased healthcare utilization, suggesting the need to evaluate and incorporate evidence-based pain management strategies into routine care of patients with chronic liver disease.

Pain and opioid use in chronic liver disease

BACKGROUND

Pain is common in patients with liver disease, difficult to treat, and poorly understood.

AIMS

The aim of this study was to determine factors associated with pain and prescription opioid use in a large cohort of patients with confirmed chronic liver disease.

METHODS

This was a retrospective cohort study of consecutive patients with chronic liver disease visiting a tertiary-care hepatology clinic. Pain was determined by self-report and rated numerically from 0 to 10. Symptoms of mood and sleep disorders and emotional distress were based on a symptom checklist. Etiology and stage of liver disease and use of prescribed opioids were abstracted from the electronic medical record. Logistic regression was used to establish factors associated with pain and prescription opioid use.

RESULTS

Among 1,286 patients with chronic liver disease, 34 % had pain and 25 % used opioids. The strongest predictor of pain in multivariate modeling was emotional distress (OR 3.66, 95 % CI 2.40-5.64), followed by non-white race (OR 1.87, 95 % CI 1.24-2.79), mood symptoms (OR 1.47, 95 % CI 1.04-2.07), sleep disturbance/fatigue (OR 1.70, 95 % CI 1.24-2.32), and advanced liver disease (Child class B: OR 1.73, 95 % CI 1.15-2.60; Child class C: OR 2.78, 95 % CI 1.49-5.24) compared to no cirrhosis. Emotional distress, mood-related symptoms, and advanced liver disease were also significant predictors of prescription opioid use, as were age, nicotine use, and etiology of liver disease.

CONCLUSIONS

This large cohort study demonstrates the high prevalence of pain and opioid use in chronic liver disease. While disease variables contribute to pain, psychological symptoms were most strongly associated with pain and opioid use, providing rationale and target for therapeutic interventions.

Evaluation of the psychometric properties of the revised short-form McGill Pain Questionnaire

The recently revised version of the Short-Form McGill Pain Questionnaire (SF-MPQ-2) was created to assess both neuropathic and non-neuropathic pain. The current study extends prior research by testing the reliability and validity of the SF-MPQ-2 in a sample of U.S. veteran patients with a range of chronic pain diagnoses. Participants (N = 186) completed the SF-MPQ-2, a sociodemographic questionnaire, the Structured Clinical Interview for the DSM-IV, and self-report pain and psychiatric measures. Pain diagnoses were extracted from the electronic medical record. The SF-MPQ-2 total and scale scores demonstrated good-to-excellent internal consistency. Convergent and discriminant validity were supported, and SF-MPQ-2 total and scale scores increased with number of pain diagnoses and pain severity. Confirmatory factor analyses indicated that a 4-factor model fit the data better than a single-factor model. However, high intercorrelations among the 4 latent constructs were observed, and a second-order global pain construct also emerged. Overall, the SF-MPQ-2 demonstrated excellent reliability and validity in a sample of U.S. veteran patients with chronic neuropathic and non-neuropathic pain. Future psychometric studies of the SF-MPQ-2 should employ longitudinal data to evaluate the ability of scale scores to uniquely predict clinical and health service outcomes.

PERSPECTIVE

This article presents the psychometric properties of a revised version of the SF-MPQ-2. This measure may have great utility as a screening tool in clinical practice and as an outcome measure in clinical trials.

Epidemiology of pain among outpatients in methadone maintenance treatment programs

BACKGROUND

This analysis explored the prevalence and correlates of pain in patients enrolled in methadone maintenance treatment (MMT).

METHODS

Patients in two MMT programs starting a hepatitis care coordination randomized controlled trial completed the Brief Pain Inventory Short-Form and other questionnaires. Associations between clinically significant pain (average daily pain≥5 or mean pain interference≥5 during the past week) and sociodemographic data, medical status, depressive symptoms, and health-related quality of life, and current substance use were evaluated in multivariate analyses.

RESULTS

The 489 patients included 31.8% women; 30.3% Hispanics, 29.4% non-Hispanic Blacks, and 36.0% non-Hispanic Whites; 60.1% had hepatitis C, 10.6% had HIV, and 46.8% had moderate or severe depressive symptomatology. Mean methadone dose was 95.7mg (SD 48.9) and urine drug screening (UDS) was positive for opiates, cocaine, and amphetamines in 32.9%, 40.1%, and 2.9%, respectively. Overall, 237 (48.5%) reported clinically significant pain. Pain treatments included prescribed opioids (38.8%) and non-opioids (48.9%), and self-management approaches (60.8%), including prayer (33.8%), vitamins (29.5%), and distraction (12.7%). Pain was associated with higher methadone dose, more medical comorbidities, prescribed opioid therapy, and more severe depressive symptomatology; it was not associated with UDS or self-reported substance use.

CONCLUSIONS

Clinically significant pain was reported by almost half of the patients in MMT programs and was associated with medical and psychological comorbidity. Pain was often treated with opioids and was not associated with measures of drug use. Studies are needed to further clarify these associations and determine their importance for pain treatment strategies.

Risk for prescription opioid misuse among patients with a history of substance use disorder

BACKGROUND

History of substance use disorder (SUD) is associated with risk for prescription opioid misuse in chronic pain patients; however, little data are available regarding risk for prescription opioid misuse within the subgroup of patients with SUD histories.

METHODS

Participants with chronic pain, histories of SUD, and current opioid prescriptions were recruited from a single VA Medical Center. Participants (n=80) completed measures of risk for prescription opioid misuse, pain severity, pain-related interference, pain catastrophizing, attitudes about managing pain, emotional functioning, and substance abuse.

RESULTS

Participants were divided into three groups based on risk for prescription opioid misuse, as assessed by the Pain Medication Questionnaire (PMQ). Participants in the High-PMQ group reported more pain severity, interference, catastrophizing, depressive symptoms, and lowest self-efficacy for managing pain, relative to the Low-PMQ group; the High-PMQ group and Moderate-PMQ group differed on measures of pain severity, catastrophizing, and psychiatric symptoms (all p-values <0.05). The High-PMQ group had the highest rates of current SUD (32% versus 20% and 0, p=0.009). A regression analysis evaluated factors associated with PMQ scores: pain catastrophizing was the only variable significantly associated with risk for prescription opioid misuse.

CONCLUSIONS

Among patients with SUD histories, those with higher risk for prescription opioid misuse reported more pain and impairment, symptoms of depression, and were more likely to have current SUD, relative to patients with lower risk for prescription opioid misuse. In adjusted analyses, pain catastrophizing was significantly associated with risk for prescription opioid misuse, but current SUD status was not a significant predictor.

Receipt of opioid analgesics by HIV-infected and uninfected patients

BACKGROUND

Opioids are increasingly prescribed, but there are limited data on opioid receipt by HIV status.

OBJECTIVES

To describe patterns of opioid receipt by HIV status and the relationship between HIV status and receiving any, high-dose, and long-term opioids.

DESIGN

Cross-sectional analysis of the Veterans Aging Cohort Study.

PARTICIPANTS

HIV-infected (HIV+) patients receiving Veterans Health Administration care, and uninfected matched controls.

MAIN MEASURES

Pain-related diagnoses were determined using ICD-9 codes. Any opioid receipt was defined as at least one opioid prescription; high-dose was defined as an average daily dose ≥ 120 mg of morphine equivalents; long-term opioids was defined as ≥ 90 consecutive days, allowing a 30 day refill gap. Multivariable models were used to assess the relationship between HIV infection and the three outcomes.

KEY RESULTS

Among the HIV+ (n = 23,651) and uninfected (n = 55,097) patients, 31 % of HIV+ and 28 % of uninfected (p < 0.001) received opioids. Among patients receiving opioids, HIV+ patients were more likely to have an acute pain diagnosis (7 % vs. 4 %), but less likely to have a chronic pain diagnosis (53 % vs. 69 %). HIV+ patients received a higher mean daily morphine equivalent dose than uninfected patients (41 mg vs. 37 mg, p = 0.001) and were more likely to receive high-dose opioids (6 % vs. 5 %, p < 0.001). HIV+ patients received fewer days of opioids than uninfected patients (median 44 vs. 60, p < 0.001), and were less likely to receive long-term opioids (31 % vs. 34 %, p < 0.001). In multivariable analysis, HIV+ status was associated with receipt of any opioids (AOR 1.40, 95 % CI 1.35, 1.46) and high-dose opioids (AOR 1.22, 95 % CI 1.07, 1.39), but not long-term opioids (AOR 0.94, 95 % CI 0.88, 1.01).

CONCLUSIONS

Patients with HIV infection are more likely to be prescribed opioids than uninfected individuals, and there is a variable association with pain diagnoses. Efforts to standardize approaches to pain management may be warranted in this highly complex and vulnerable patient population.

Chronic pain treatment and health service utilization of veterans with hepatitis C virus infection

OBJECTIVES

Hepatitis C virus (HCV) infection is estimated to affect 2% of the general U.S. population and chronic pain is a common comorbidity among persons with HCV. The primary purpose of this study was to compare health service utilization of U.S. military veterans with HCV with and without the presence of comorbid chronic pain.

DESIGN

Cross-sectional study with retrospective review of patient medical records.

PATIENTS

 One hundred seventy-one U.S. military veterans with confirmed HCV, recruited through a single U.S. Veterans Administration hospital.

OUTCOME MEASURES

Medical service utilization data from the past 5 years were extracted from participants' electronic medical records.

RESULTS

Sixty-four percent of veterans with HCV (N = 110) had chronic pain. Veterans with HCV and chronic pain utilized more health services including total inpatient stays (odds ratio [OR] = 2.58 [1.46, 4.56]) and days hospitalized for psychiatric services (OR = 5.50 [3.37, 8.99]), compared to participants with HCV and no chronic pain, after statistically adjusting for demographic, psychiatric, substance use, medical comorbidity, and disability covariates. In addition, those with HCV and chronic pain had more total outpatient visits with primary care providers (OR = 1.73 [1.15, 2.59]), physical therapists (OR = 9.57 [4.79, 19.11]), and occupational therapists (OR = 2.72 [1.00, 7.48]).

CONCLUSIONS

 Patients with HCV and chronic pain utilize medical services to a greater extent than patients with HCV but no chronic pain. Future studies that examine the efficacy of both pharmacological and nonpharmacological pain treatment for patients with comorbid HCV and chronic pain appear warranted.

Hepatitis C virus infection is associated with painful symptoms in HIV-infected adults

The study aim was to assess whether hepatitis C virus (HCV) was associated with painful symptoms among patients with HIV. Using data from a prospective cohort of HIV-infected adults with alcohol problems, we assessed the effects of HCV on pain that interfered with daily living and painful symptoms (muscle/joint pain, headache and peripheral neuropathy). Exploratory analyses assessed whether depressive symptoms and inflammatory cytokines mediated the relationship between HCV and pain. HCV-infected participants (n = 200) had higher odds of pain that interfered with daily living over time (adjusted odds ratio [AOR] 1.43; 95% CI: 1.02-2.01; p = 0.04) compared to those not infected with HCV. HIV/HCV co-infected participants had higher odds of muscle or joint pain (AOR 1.45; 95% CI: 1.06-1.97; p = 0.02) and headache (AOR 1.57; 95% CI: 1.18-2.07; p<0.01). The association between HCV and peripheral neuropathy did not reach statistical significance (AOR 1.33; 95% CI: 0.96-1.85; p = 0.09). Depressive symptoms and inflammatory cytokines did not appear to mediate the relationship between HCV and pain. Adults with HIV who are also co-infected with HCV are more likely to experience pain that interfered with daily living, muscle or joint pain, and headaches compared to those not co-infected. Research is needed to explore the association between HCV infection and pain, and to determine whether HCV treatment is an effective intervention.

Chronic pain and hepatitis C virus infection in opioid dependent injection drug users

It is unknown whether infection with hepatitis C is a risk factor for pain among people who have used injection drugs. Multivariate regression was used to determine whether hepatitis C was associated with greater likelihood of reporting significant chronic pain and discomfort intolerance in a cohort of 97 injection drug users dependent on opioids. Study results suggest that participants with hepatitis C may be more likely to experience chronic pain (aOR=1.98; 95% confidence interval=0.76 to 5.12, p=0.16). Furthermore, hepatitis C was found to be associated with a higher discomfort intolerance scale score, reflecting intolerance to physical discomfort (β=2.34; 95% confidence interval=0.06 to 4.62; p=0.04). Hepatitis C may be a cause for chronic pain and discomfort intolerance that is overlooked among injection drug users dependent on opioids.

Systematic review of prevalence, correlates, and treatment outcomes for chronic non-cancer pain in patients with comorbid substance use disorder

Recent data suggest that comorbid substance use disorders (SUDs) are common among chronic non-cancer pain (CNCP) patients; however, prevalence rates vary across studies and findings are limited regarding treatment options for CNCP patients with comorbid SUD. The purpose of this systematic review is to assess the prevalence, associated demographic and clinical characteristics, and treatment outcomes for CNCP patients with comorbid SUD. We conducted searches from Ovid MEDLINE, PsychINFO, and PubMED from 1950 through February 2010 and retrieved the references. Thirty-eight studies met inclusion criteria and provided data that addressed our key questions. Three to forty-eight percent of CNCP patients have a current SUD. There are no demographic or clinical factors that consistently differentiate CNCP patients with comorbid SUD from patients without SUD, though SUD patients appear to be at greater risk for aberrant medication-related behaviors. CNCP patients with SUD are more likely to be prescribed opioid medications and at higher doses than CNCP patients without a history of SUD. CNCP patients with comorbid SUD do not significantly differ in their responses to treatment compared to CNCP patients without SUD, though the quality of this evidence is low. Limited data are available to identify predictors of treatment outcome. Although clinical experience and research suggests that SUDs are common among CNCP patients, only limited data are available to guide clinicians who treat this population. Research is needed to increase understanding of the prevalence, correlates, and responses to treatment of CNCP patients with comorbid SUDs.

Predictors of pain intensity and pain functioning in patients with the hepatitis C virus

OBJECTIVE

To examine the relationships among biological and psychological variables with pain intensity and pain functioning in patients with the hepatitis C virus (HCV).

METHODS

Participants were 49 patients with HCV who completed well-validated assessments of pain intensity and pain functioning. Participants also completed measures of psychological functioning, and medical records were reviewed.

RESULTS

Thirty-three (67.3%) of 49 participants had a current diagnosis for a pain-related condition. Regression analyses were conducted to examine variables associated with pain intensity and pain functioning. The psychosocial variables, particularly depression severity, accounted for an additional 21% of the variance in average pain intensity (P=.002) and 33% of the variance in pain functioning (P<.001). These results remained significant even after controlling for demographic characteristics, opioid prescription status and disease-related variables.

CONCLUSION

These results provide preliminary support for the role of biological and psychological factors in the development and exacerbation of pain in HCV patients. Future studies should include a more comprehensive assessment of pain-related factors and examine their associations with additional disease-related and biological variables. Developing a better understanding of the factors associated with pain in HCV patients will help to inform future interventions for chronic pain in this patient population.

The cognitive effects of hepatitis C in the presence and absence of a history of substance use disorder

The aim of the study was to determine whether infection with the hepatitis C virus (HCV) is associated with cognitive impairment beyond the effects of prevalent comorbidities and a history of substance use disorder (SUD). Adult veterans were recruited from the Portland Veterans Affairs Medical Center into three groups: (1) HCV+/SUD+ (n = 39), (2) HCV+/SUD- (n = 24), and (3) HCV-/SUD- (n = 56). SUD+ participants were in remission for > or =90 days, while SUD- participants had no history of SUD. Groups did not significantly differ in terms of rates of psychiatric or medical comorbidities. Procedures included clinical interviews, medical record reviews, and neuropsychological testing. Significant group differences were found in the domains of Verbal Memory, Auditory Attention, Speeded Visual Information Processing, and Reasoning/Mental Flexibility (p <or = .05). Post hoc comparisons indicated that HCV+/SUD- patients performed significantly worse than HCV-/SUD- controls on tests measuring verbal learning, auditory attention, and reasoning/mental flexibility, but only HCV+/SUD+ patients did worse than HCV-/SUD- controls on tests of speeded visual information processing. Results indicate that chronic HCV is associated with cognitive impairment in the absence of a history of SUD. The most robust deficits appear to be in verbal learning and reasoning/mental flexibility. (JINS, 2009, 15, 69-82.).