April 2015
David Craig, PharmD | Editor


The Journal of Pain Highlights

Journal of Pain cover

The following highlights summarize selected articles from The Journal of Pain (Volume 16, Issue 4, April 2015).

On the Importance of Being Vocal: Saying “Ow” Improves Pain Tolerance 

Genevieve Swee and Annett Schirmer, National University of Singapore

Vocalizing can be helpful in coping with pain, according to research published in The Journal of Pain. Researchers at the National University of Singapore explored the effect of saying “ow” in alleviating pain. A previous study showed that both direct and self-reported measures of pain differed when study participants exposed to experimental pain stimuli used profanity compared to normal speech. Swearing was associated with reduced magnitude of perceived pain.

It has been reported that vocalizing can be analgesic, but the assumption had never been tested. The researchers of this study sought to evaluate the analgesic benefit of vocalizing (saying “ow”) in a controlled study. The study’s 56 participants were asked to immerse one hand in ice-cold water while saying “ow,” listening to a recording of themselves say “ow,” listening to another person say “ow,” pressing a response button, and doing nothing. The authors predicted that saying “ow” would reduce pain. Comparison with other experimental responses would reveal the relative contribution of sound and motor processes to vocalizing analgesia.

Results showed that participants had higher pain tolerance when saying “ow” compared to doing nothing. Participants also tolerated cold-water hand immersion longer when saying “ow” than when being silent.

Assessing Risk for Drug Overdose in a National Cohort: Role for Both Daily and Total Opioid Dose?

Yuanyuan Liang and Barbara J. Turner, University of Texas Health Sciences Center

Death from overdoses of opioid analgesics increased four-fold nationally from 1999 to 2009. Opioid analgesics are involved in three in four drug overdose deaths in the United States.

While mean daily doses of opioids are widely used to assess risk for overdose death, research reported in The Journal of Pain shows that the total dose of an opioid prescription over time might offer a complimentary measure of risk. Total dose is not necessarily a simple linear transformation of the daily dose because not all patients use opioids every day. It reflects the total amount of opioids available to a patient.

For the study, the authors examined time from first opioid prescriptions until drug overdose for more than 200,000 patients in an HMO database. Selected beneficiaries filled at least two prescriptions for opioid analgesics to treat non-cancer pain between January 2009 and July 2012.

Result of the analysis confirmed the significant association of daily opioid dose with overdose risk, but found that total opioid doses received within a 6-month interval adds significant risk for drug overdose. The data suggest that prescribers, pharmacists, and state prescription monitoring programs should monitor total doses as well as daily doses over 6 months or longer. They also concluded that prescribers should avoid daily doses of more than 100 mg, and doses may need to be tapered when patients are taking lower doses over a long term.


Pain Medicine Highlights

Pain Medicine Cover

The following highlights summarize selected articles from Pain Medicine (Volume 16, Issue 4, April 2015).

Racial Disparities Across Provider Specialties in Opioid Prescriptions Dispensed to Medicaid Beneficiaries with Chronic Noncancer Pain

Chris Ringwalt, Andrew W. Roberts, Hallam Gugelmann, and Asheley Cockrell Skinner; Injury Prevention Research Center, Division of Pharmaceutical Outcomes and Policy, UNC Eshelman School of Pharmacy, Cecil G. Sheps Center for Health Services Research, Division of General Pediatrics and Adolescent Medicine, Department of Pediatrics in the School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC; California Poison Control System, San Francisco Division, Veterans Affairs Medical Center, University of California at San Francisco, San Francisco,CA

Multiple studies have demonstrated race- and ethnicity-based disparities in opioid-prescribing practices. Although the reasons underlying these discrepancies remain undefined, the literature documents that Blacks receive fewer prescriptions than non-Hispanic whites in response to descriptions of chronic noncancer pain (CNCP). Several studies indicate that providers are more likely to underestimate pain reported by minority patients than by White patients and are less likely to document their minority patients' pain scores. These findings suggest that providers may be partially responsible for issues related to oligoanalgesia among minority patients. The purpose of this study of a North Carolina Medicaid population with CNCP was to examine differences across providers' specialties in prescriptions filled by White and Black Medicaid beneficiaries with CNCP. Investigators hypothesized that patients treated by specialists would be less likely to experience race-based discrimination, as manifest in filled opioid prescriptions, than patients cared for by general practitioners (GPs).

Investigators used bivariate statistics and logistic regression analysis to examine race-based discrepancies in opioid prescribing by physician specialty. They found that when controlling for age, sex, and chronic pain diagnosis, Blacks were 9% less likely than Whites to fill opioid prescriptions. Obstetrics/gynecology, internal medicine, and GP/family medicine specialties were primary contributors to this disparity; relative to White beneficiaries with CNCP, Black beneficiaries with CNCP were 22%, 14%, and 9% (respectively, by specialty) less likely to fill opioid prescriptions.

Another factor that may explain lower rates of opioid prescribing among Black patients is inadequate access to care. Inadequate access may lead to physicians' inability to properly manage continuous opioid therapy, leading to reduced rates of prescribing. Both obstetrics/gynecology practitioners and internal medicine specialists were less likely than GPs to prescribe opioids to their Black patients with CNCP. Future studies should attempt to examine the effects of these disparities and address whether White patients are overtreated with opioids or Black patients are undertreated.

Prompt action is needed on many fronts, including the promotion of more accurate assessments of pain levels, enhancement of provider training related to cultural competence and the recognition and reduction of racial stereotyping, and the education of patients with CNCP so they can learn how to enhance their communication with their providers about optimal strategies to manage their pain.

Perioperative Factors Associated with HCAHPS Responses of 2,758 Surgical Patients

Dermot P. Maher, Waylan Wong, Pauline Woo, Cesar Padilla, Xiao Zhang, Bahman Shamloo, Howard Rosner, Ronald Wender, Roya Yumul, and Charles Louy; Department of Anesthesia, Cedars-Sinai Medical Center, Los Angeles, CA

The Centers for Medicare & Medicaid Services (CMS) encourages improvements in clinical care quality by making patient satisfaction a factor in modifying monetary reimbursement. CMS and the Joint Commission have started to collect and release data on patient satisfaction using the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey. HCAHPS is a 32-question survey designed to assess numerous domains of the inpatient experience, including overall patient satisfaction, likelihood of recommending a hospital, communication with doctors and nurses, and satisfaction with pain control. The survey tool employs "top-box only" reporting, meaning that only the highest possible response is counted as an affirmative.

Investigators in this retrospective analysis hypothesized that patients' responses to the HCAHPS survey are associated with preoperative and demographic factors as well as intraoperative anesthetic and pain management strategies. This study analyzed the associations between preoperative, intraoperative, and postoperative factors and patient satisfaction with their overall hospitalization and their pain management.

Interestingly, the results of this study left investigators with more questions than answers. They determined that the new "bottom line" is measured not by how little pain a patient experiences after surgery, but by the totality of their perceptions of their care. Few intraoperative treatments and events under the control of anesthesiologists and pain management physicians were strongly associated with overall hospital satisfaction or satisfaction with pain management.

One interpretation of these results is that intraoperative management does not have as great an effect, as measured by HCAHPS responses, as preoperative and postoperative management factors. This significantly shifts the onus of improving HCAHPS scores away from intraoperative physicians and onto the healthcare professionals who provide preoperative and postoperative care. This also shifts the focus of anesthetic management to the total perioperative phase of care.

It is possible that an expanded role of anesthesiologists and pain management physicians in the perioperative surgical home can increase the positive impact and added value of these specialties.

PAIN Highlights

Pain Medicine Cover

The following highlights summarize selected articles from PAIN (Volume 156, Issue 4, April 2015).

Pain, Agitation, and Behavioural Problems in People with Dementia Admitted to General Hospital Wards: A Longitudinal Cohort Study

Little attention has been paid to pain among hospitalized patients with dementia despite the fact that dementia is common in older inpatients, with a prevalence on medical units of around 40%. Identifying pain in people with dementia is vital because poor pain recognition and management slows recovery, increases functional decline, and may be associated with behavioral and psychiatric symptoms of dementia (BPSD).

The aim of this study was to define the prevalence of pain using self-rated and observational pain scales in hospital patients with dementia. Investigators also examined demographic and clinical factors associated with pain in this population and explored a hypothesized association between pain and BPSD, including agitation. They conducted a longitudinal cohort study of 230 people ages 70 and older with dementia who had unplanned admissions to two U.K. hospitals. Participants were assessed at baseline and every 4 days for self-reported and observed pain.

More than one-third of those with dementia reported having pain at some time during admission, which is similar to prevalence among community-dwelling older people and nursing home residents with dementia (22%–33%). Pain prevalence rose when assessed by observation; 57% of patients had pain with movement at some time during their admission, and in 16%, this pain was persistent, occurring throughout their hospital stay. This finding illustrates how self-report may lead to underestimation of pain in people with dementia and stresses the importance of careful observation for pain during times of rest and movement.

These results suggest that mood may be a useful indicator of pain in the inpatient setting. Consequently, improved detection of low mood in hospitals may lead to improved pain management.

Predictors of New-Onset Distal Neuropathic Pain in HIV-Infected Individuals in the Era of Combination Antiretroviral Therapy

Jemily Malvar, Florin Vaida, Chelsea Fitzsimons Sanders, J. Hampton Atkinson, William Bohannon, John Keltner, Jessica Robinson-Papp, David M. Simpson, Christina M. Marra, David B. Clifford, Benjamin Gelman, Juanjuan Fan, Igor Grant, and Ronald J. Ellis, for the CHARTER Group; Children's Hospital, Los Angeles, Los Angeles, CA; HIV Neurobehavioral Research Program, University of California, San Diego,CA.; Icahn School of Medicine at Mount Sinai, New York, NY; University of Washington, Seattle,WA; Washington University, St Louis,MO; University of Texas Medical Branch, Galveston, TX; San Diego State University, San Diego, CA; Alliant International University, San Diego, CA

Sensory neuropathy (SN) is a common cause of chronic neuropathic pain that contributes to disability, unemployment, depression, medication overuse, and frequent medical provider visits. HIV frequently leads to SN and attendant distal neuropathic pain (DNP). Distal neuropathic pain typically appears first in the toes and feet and often is described with words such as "stabbing," "burning," and "aching."

Factors that predict new-onset DNP in HIV are unknown. Neuropsychiatric conditions such as substance use and mood disorders have been shown to influence the prevalence and incidence of neuropathic pain in other diseases. Investigators set out to evaluate the influence of these conditions on new-onset DNP in HIV. They evaluated risk factors for new-onset DNP in the CNS Antiretroviral Therapy Effects Research study, an observational cohort. Standardized semiannual clinical evaluations were administered at six U.S. sites. Distal neuropathic pain was defined by using a clinician-administered instrument standardized across sites. All participants analyzed were free of DNP at study entry. New-onset DNP was recorded at the first follow-up visit at which it was reported.

Investigators observed new-onset DNP—defined as bilateral distal leg and foot pain with neuropathic qualities in participants who did not report this at study entry—in one-quarter of HIV-infected individuals over an average of 2 years. Independent of other risk factors, older age was associated with higher rates of new DNP. Neuropsychiatric factors, specifically opioid use disorders and worsening depressed mood, also were associated with increased rates of new DNP. Sensitivity analyses demonstrated that these risk factors were robust to model assumptions because they remained significant when limited only to individuals with clear clinical evidence of SN and when the end point was limited to those with moderate or severe DNP. Distal neuropathic pain was associated with past opioid abuse rather than recent use of opioids. This implies that new-onset DNP reflects a shared vulnerability, perhaps mediated by brain reward circuits. Future studies might address prevention strategies to reduce new DNP among individuals at high risk, such as those with opioid use disorders or depression.