Accuracy of Self-reported Prescribed Analgesic Medication Use: Linkage Between the Quebec Pain Registry and the Quebec Administrative Prescription Claims Databases

Association of Regular Opioid Use With Incident Dementia and Neuroimaging Markers of Brain Health in Chronic Pain Patients: Analysis of UK Biobank

OBJECTIVES

We aimed to investigate the association of regular opioid use, compared with non-opioid analgesics, with incident dementia and neuroimaging outcomes among chronic pain patients.

DESIGN

The primary design is a prospective cohort study. To triangulate evidence, we also conducted a nested case-control study analyzing opioid prescriptions and a cross-sectional study analyzing neuroimaging outcomes.

SETTING AND PARTICIPANTS

Dementia-free UK Biobank participants with chronic pain and regular analgesic use.

MEASUREMENTS

Chronic pain status and regular analgesic use were captured using self-reported questionnaires and verbal interviews. Opioid prescription data were obtained from primary care records. Dementia cases were ascertained using primary care, hospital, and death registry records. Propensity score-matched Cox proportional hazards analysis, conditional logistic regression, and linear regression were applied to the data in the prospective cohort, nested case-control, and cross-sectional studies, respectively.

RESULTS

Prospective analyses revealed that regular opioid use, compared with non-opioid analgesics, was associated with an increased dementia risk over the 15-year follow-up (Hazard ratio [HR], 1.18 [95% confidence interval (CI): 1.08-1.30]; Absolute rate difference [ARD], 0.44 [95% CI: 0.19-0.71] per 1000 person-years; Wald χ2 = 3.65; df = 1; p <0.001). The nested case-control study suggested that a higher number of opioid prescriptions was associated with an increased risk of dementia (1 to 5 prescriptions: OR = 1.21, 95% CI: 1.07-1.37, Wald χ2 = 3.02, df = 1, p = 0.003; 6 to 20: OR = 1.27, 95% CI: 1.08-1.50, Wald χ2 = 2.93, df = 1, p = 0.003; more than 20: OR = 1.43, 95% CI: 1.23-1.67, Wald χ2 = 4.57, df = 1, p < 0.001). Finally, neuroimaging analyses revealed that regular opioid use was associated with lower total grey matter and hippocampal volumes, and higher white matter hyperintensities volumes.

CONCLUSION

Regular opioid use in chronic pain patients was associated with an increased risk of dementia and poorer brain health when compared to non-opioid analgesic use. These findings imply a need for re-evaluation of opioid prescription practices for chronic pain patients and, if further evidence supports causality, provide insights into strategies to mitigate the burden of dementia.

Duloxetine and cognitive behavioral therapy with phone-based support for the treatment of chronic musculoskeletal pain: study protocol of the PRECICE randomized control trial

BACKGROUND

Chronic musculoskeletal pain (CMP) is the most common, disabling, and costly of all pain conditions. While evidence exists for the efficacy of both duloxetine and web-based cognitive behavioral therapy (CBT) as monotherapy, there is a clear need to consider study of treatment components that may complement each other. In addition, given the reported association between patient's adherence and treatment outcomes, strategies are needed to enhance participant's motivation to adopt and maintain continued use of newly learned pain coping skills from CBT.

METHODS

Two hundred eighty participants will be recruited from the primary care clinics of a large academic health care system in North Carolina. Participants with CMP will be randomized to one of three treatment arms: (1) combination treatment (duloxetine + web-based self-guided CBT) with phone-based motivational interviewing (MI), (2) combination treatment without phone-based MI, and (3) duloxetine monotherapy. Participants will be in the study for 24 weeks and will be assessed at baseline, week 13, and week 25. The primary outcome is the Brief Pain Inventory (BPI)-Global Pain Severity score, which combines BPI pain severity and BPI pain interference. Secondary measures include between-group comparisons in mean BPI pain severity and BPI pain interference scores. Data collection and outcome assessment will be blinded to treatment group assignment.

DISCUSSION

This randomized controlled trial (RCT) will determine if combination treatment with duloxetine and web-based CBT is superior to duloxetine monotherapy for the management of CMP. Furthermore, this RCT will determine the effectiveness of phone-based motivational interviewing in promoting the continued practice of pain coping skills, thereby enhancing treatment outcomes.

TRIAL REGISTRATION

NCT04395001 ClinicalTrials.gov. Registered on May 15, 2020.

Polypharmacy and Excessive Polypharmacy Among Persons Living with Chronic Pain: A Cross-Sectional Study on the Prevalence and Associated Factors

Purpose

Polypharmacy can be defined as the concomitant use of ≥5 medications and excessive polypharmacy, as the use of ≥10 medications. Objectives were to (1) assess the prevalence of polypharmacy and excessive polypharmacy among persons living with chronic pain, and (2) identify sociodemographic and clinical factors associated with excessive polypharmacy.

Patients and Methods

This cross-sectional study used data from 1342 persons from the ChrOnic Pain trEatment (COPE) Cohort (Quebec, Canada). The self-reported number of medications currently used by participants (regardless of whether they were prescribed or taken over-the-counter, or were used for treating pain or other health issues) was categorized to assess polypharmacy and excessive polypharmacy.

Results

Participants reported using an average of 6 medications (median: 5). The prevalence of polypharmacy was 71.4% (95% CI: 69.0-73.8) and excessive polypharmacy was 25.9% (95% CI: 23.6-28.3). No significant differences were found across gender identity groups. Multivariable logistic regression revealed that factors associated with greater chances of reporting excessive polypharmacy (vs <10 medications) included being born in Canada, using prescribed pain medications, and reporting greater pain intensity (0-10) or pain relief from currently used pain treatments (0-100%). Factors associated with lower chances of excessive polypharmacy were using physical and psychological pain treatments, reporting better general health/physical functioning, considering pain to be terrible/feeling like it will never get better, and being employed.

Conclusion

Polypharmacy is the rule rather than the exception among persons living with chronic pain. Close monitoring and evaluation of the different medications used are important for all persons, especially those with limited access to care.

Pain Medications Used by Persons Living With Fibromyalgia: A Comparison Between the Profile of a Quebec Sample and Clinical Practice Guidelines

Background

Pharmacological management of fibromyalgia is complex. Chronic pain management is characterized by off-label prescribing and use, multimorbidity, and polypharmacy.

Aims

This study aimed to describe pain medications use and perceived risk among people living with fibromyalgia and compare this use to evidence-based recommendations.

Methods

Directive telephone interviews were conducted with 63 individuals self-reporting a diagnosis of fibromyalgia (Quebec, Canada). The questionnaire addressed specific questions about their pain and pharmacological treatments currently used for pain management (prescribed and over-the-counter). Collected data were compared to the Canadian Fibromyalgia Clinical Practice Guidelines and to evidence reports published by recognized organizations.

Results

Despite a lack of robust scientific evidence to support opioids use to manage pain in fibromyalgia, 33% of our sample reported using them. Nonsteroidal anti-inflammatory drugs were used by 54.0% of participants, although this medication is not recommended due to lack of efficacy. Tramadol, which is recommended, was used by 23.8% of participants. Among the medications strongly recommended, anticonvulsants were used by 36.5%, serotonin norepinephrine reuptake inhibitor antidepressants by 55.6%, and tricyclic antidepressants by 22.2%. Cannabinoids (17.5%) and medical cannabis (34.9%) use were also reported. For all of these medication subclasses, no differences were found between participants not reporting (n = 35) or reporting (n = 28) more than one pain diagnosis (P < 0.05). Medication subclasses considered most at risk of adverse effects by participants were the least used.

Conclusions

Results reveal discordance between evidence-based recommendations and medications use, which highlights the complexity of pharmacological treatment of fibromyalgia.

Accuracy of a self-report prescription opioid use diary for patients discharge from the emergency department with acute pain: a multicentre prospective cohort study

OBJECTIVES

Self-reported approaches that assess opioid usage can be subject to social desirability and recall biases that may underestimate actual pill consumption. Our objective was to determine the accuracy of patient self-reported opioid consumption using a 14-day daily paper or electronic diary.

DESIGN

Prospective cohort study.

SETTING

Multicentre study conducted in four Québec (Canada) emergency departments (ED): three university-affiliated centres, two of them Level I trauma centres and one urban community hospital.

PARTICIPANTS

ED patients aged ≥18 years with acute pain (≤2 weeks) who were discharged with an opioid prescription. Patients completed a 14-day daily diary (paper or electronic) assessing the quantity of opioids consumed. On diary completion, a random sample from the main cohort was selected for a follow-up visit to the hospital or a virtual video visit where they had to show and count the remaining pills. Patients were blinded to the main objective of the follow-up visit.

OUTCOMES

Quantity of opioid pills consumed during the 2-week follow-up period self-reported in the 14-day diary (paper or electronic) and calculated from remaining pills counted during the follow-up visit. Intraclass correlation coefficient (ICC) and Bland-Altman plots were used to assess accuracy.

RESULTS

A total of 166 participants completed the 14-day diary as well as the in-person or virtual visit; 49.4% were women and median age was 47 years (IQR=21). The self-reported consumed quantity of opioid in the 14-day diary and the one calculated from counting remaining opioid pills during the follow-up visit were very similar (ICC=0.992; 95% CI: 0.989 to 0.994). The mean difference between both measures from Bland-Altman analysis was almost zero (0.048 pills; 95% CI: -3.77 to 3.87).

CONCLUSION

Self-reported prescription opioid use in a 14-day diary is an accurate assessment of the quantity of opioids consumed in ED discharged patients.

TRIAL REGISTRATION NUMBER

NCT03953534.

SRS-22r question 11 is a valid opioid screen and stratifies opioid consumption

PURPOSE

To validate the Scoliosis Research Society-22r (SRS-22r) question 11 (Q11) response as a measure to assess and quantify opioid consumption.

METHODS

A post hoc analysis of a prospective study regarding opioid use during ASD surgery was performed. Data were collected at enrollment and 2-year follow-up including the SRS-22r and a standardized data collection form (CRF) for self-reported opioid consumption. Responses to Q11 of the SS-22r were compared with responses to the opioid consumption CRF (as measured by morphine equivalent dose (MED)). Inter-rater agreement was calculated. Sensitivity and specificity for the Q11 (+) responses were calculated using MED reports as the "true" value.

RESULTS

Cohen's kappa indicated almost perfect agreement between the MED CRF and Q11 (k = 0.878, p < 0.001). Mean daily MED consumption for patients reporting "Daily Narcotic" use was 62.0 (Median: 38.7, SD 87.5) mg; for patients reporting "Narcotics weekly or less", mean daily MED consumption was 21.6 (15.0, 29.0) mg. The positive Q11 responses were 96% sensitive and 92% specific for opioid users.

CONCLUSION

SRS-22r Q11 exhibits almost perfect agreement with an independent questionnaire designed to assess opioid consumption in this cohort. "Daily narcotic" users report nearly three times the mean daily MED of "Weekly or less" users (62.0 ± 87.5 mg vs 21.6 ± 29 mg, p = 0.037). Q11 exhibited excellent sensitivity and specificity for determining opioid users and non-users. Given the need for opioid research in ASD, Q11 may be useful to use existing registries and observational cohorts to design more definitive studies regarding opioid consumption.

LEVEL OF EVIDENCE

III.

Utilization Patterns of Skeletal Muscle Relaxants Among Commercially Insured Adults in the United States from 2006 to 2018

OBJECTIVE

To examine the prevalence and duration of skeletal muscle relaxant (SMR) treatment among commercially insured adults in the United States.

METHODS

We used the MarketScan Research Database to identify a cohort of adults 18 to 64 years who had ≥2-year continuous enrollment between 2005 and 2018. We estimated the prevalence of SMR treatment using a repeated cross-sectional design and derived treatment duration using the Kaplan-Meier method. Analyses were stratified by age group, sex, geographic region, individual SMR agent, and musculoskeletal disorder.

RESULTS

48.7 million individuals were included. Treatment prevalence ranged from 61.5 to 68.3 per 1,000. About one-third of users did not have a preceding musculoskeletal disorder diagnosis. Cyclobenzaprine was the dominant agent accounting for >50% of prescriptions. The considerable growth in the use of baclofen, tizanidine, and methocarbamol paralleled with a decline in carisoprodol and metaxalone use. The prevalence was highest in the South while lowest in the Northeast. The median treatment duration was 14 days with 4.0%, 1.9%, and 1.0% of individuals using SMRs for more than 90, 180, and 365 days, respectively. Compared with cyclobenzaprine, patients initiating baclofen, tizanidine, and carisoprodol had longer treatment duration.

CONCLUSIONS

SMRs are widely used in the United States. Their use slightly increased in recent years, but trends varied among individual agents, patient groups, and geographic regions. Despite limited evidence to support efficacy, a sizable number of U.S. adults used SMRs for long-term and off-label conditions. Further study is needed to understand determinants of treatment as well as outcomes associated with such use.

Analgesic use and the risk of renal cell carcinoma - Findings from the Consortium for the Investigation of Renal Malignancies (CONFIRM) study

PURPOSE

The incidence of renal cell carcinoma (RCC) is rising. Use of analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol may affect renal function. The aim of this study was to assess associations between analgesic use and risk of RCC.

METHODS

A population-based case-control family design was used. Cases were recruited via two Australian state cancer registries. Controls were siblings or partners of cases. Analgesic use was captured by self-completed questionnaire. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for RCC risk associated with regular analgesic use (at least 5 times per month for 6 months or more) and duration and frequency of use.

RESULTS

The analysis included 1064 cases and 724 controls. Regular use of paracetamol was associated with an increased risk of RCC (OR 1.41, 95%CI 1.13-1.77). Regular use of NSAIDs was associated with increased risk of RCC for women (OR 1.71, 95% CI 1.23-2.39) but not men (OR 0.83, 95% CI 0.58-1.18; p-interaction=0.003). There was no evidence of a dose-response for duration of use of paracetamol (linear trend p = 0.77) and weak evidence for non- aspirin NSAID use by women (linear trend p = 0.054).

CONCLUSION

This study found that regular use of paracetamol was associated with increased risk of RCC. NSAID use was associated with increased risk only for women.

Self-reported medication intake vs information from other data sources such as pharmacy records or medical records: Identification and description of existing publications, and comparison of agreement results for publications focusing on patients with cancer - a systematic review

PURPOSE

To identify and describe publications addressing the agreement between self-reported medication and other data sources among adults and, in a subgroup of studies dealing with cancer patients, seek to identify parameters which are associated with agreement.

METHODS

A systematic review including a systematic search within five biomedical databases up to February 28, 2019 was conducted as per the PRISMA Statement. Studies and agreement results were described. For a subgroup of studies dealing with cancer, we searched for associations between agreement and patients' characteristics, study design, comparison data source, and self-report modality.

RESULTS

The literature search retrieved 3392 publications. Included articles (n = 120) show heterogeneous agreement. Eighteen publications focused on cancer populations, with relatively good agreement identified in those which analyzed hormone therapy, estrogen, and chemotherapy (n = 11). Agreement was especially good for chemotherapy (proportion correct ≥93.6%, kappa ≥0.88). No distinct associations between agreement and age, education or marital status were identified in the results. There was little evaluation of associations between agreement and study design, self-report modality and comparison data source, thus not allowing for any conclusions to be drawn.

CONCLUSION

An overview of the evidence available from validation studies with a description of several characteristics is provided. Studies with experimental design which evaluate factors that might affect agreement between self-report and other data sources are lacking.

Polypharmacy in patients with epilepsy: A nationally representative cross-sectional study

OBJECTIVE

The objective of the study was to characterize the prevalence of polypharmacy and central nervous system (CNS)-acting medications in patients with epilepsy, and particular types of medications.

METHODS

This was a retrospective cross-sectional study using data from the nationally representative National Health and Nutrition Examination Survey (NHANES). We included patients who reported taking at least one prescription medication in order to treat seizures or epilepsy during NHANES survey years 2013-2016. We assessed the number and types of drugs and predictors of total number of medications using a negative binomial regression. We then assessed prevalence of polypharmacy (≥5 medications), CNS polypharmacy (≥3 CNS-acting medications) and additional CNS-acting medications, and drugs that lower the seizure threshold (i.e., bupropion and tramadol), and extrapolated prevalence to estimated affected US population.

RESULTS

The NHANES contained 20,146 participants, of whom 135 reported taking ≥1 antiseizure medication (ASM) for seizures or epilepsy representing 2,399,520 US citizens using NHANES's sampling frame. Patients reported taking a mean 5.3 (95% confidence interval (CI): 4.3-6.3) prescription medications. Adjusting for race, sex, and uninsurance, both age and number of chronic conditions predicted increased number of medications (incident rate ratio (IRR) per decade: 1.16, 95% CI: 1.04-1.28; IRR per chronic condition: 1.19, 95% CI: 1.11-1.27). Polypharmacy was reported by 47% (95% CI: 38%-57%) of patients, CNS polypharmacy by 34% (23%-47%), benzodiazepine use by 21% (14%-30%), opioid use by 16% (11%-24%), benzodiazepine plus opioid use by 6% (3%-14%), and 6% (2%-15%) reported a drug that lowers the seizure threshold. Twelve percent (7%-20%) took an opioid with either a benzodiazepine or gabapentinoid.

CONCLUSIONS

Polypharmacy is common in patients with epilepsy. Patients taking ASMs frequently reported also taking other CNS-acting medications (i.e., opioids, benzodiazepines, seizure threshold-lowering medications), and medication combinations with black box warnings. Central nervous system polypharmacy poses health risks. Future research is needed to explore drivers of polypharmacy and strategies to help mitigate potentially harmful prescription use in this high-risk population.

Patterns of opioid use (codeine, morphine or meperidine) in the Canadian population over time: analysis of the Longitudinal National Population Health Survey 1994-2011

OBJECTIVE

This study aimed to investigate cohort effects in selected opioids use and determine whether cohort differences were associated with changes in risk factors for use over time.

DESIGN

This study presents secondary analyses of a longitudinal survey panel of the general population that collected data biannually.

SETTING

Data from the Canadian Longitudinal National Population Health Survey 1994-2011.

POPULATION

This study included 12 542 participants from the following birth cohorts: post-World War I (born 1915-1924), pre-World War II (born 1925-1934), World War II (born 1935-1944), Older Baby Boom (born 1945-1954), Younger Baby Boom (born 1955-1964), Older Generation X (born 1965-1974) and Younger Generation X (born 1975-1984).

MAIN OUTCOME

Responses to a single question asking about the use of codeine, morphine or meperidine in the past month (yes/no) were examined.

RESULTS

Over and above age and period effects, there were significant cohort differences in selected opioids use: each succeeding recent cohort had greater use than their predecessors (eg, Gen Xers had greater use than younger baby boomers). Selected opioids use increased significantly from 1994 to 2002, plateauing between 2002 and 2006 and then declining until 2011. After accounting for cohort and period effects, there was a decline in use of these opioids with increasing age. Although pain was significantly associated with greater selected opioids use (OR=3.63, 95% CI 3.39 to 3.94), pain did not explain cohort differences. Cohort and period effects were no longer significant after adjusting for the number of chronic conditions. Cohort differences in selected opioids use mirrored cohort differences in multimorbidity. Use of these opioids was significantly associated with taking antidepressants or tranquillisers (OR=2.52, 95% CI 2.27 to 2.81 and OR=1.60, 95% CI 1.46 to 1.75, respectively).

CONCLUSIONS

The findings underscore the need to consider multimorbidity including possible psychological disorders and associated medications when prescribing opioids (codeine, morphine, meperidine), particularly for recent birth cohorts. Continued efforts to monitor prescription patterns and develop specific opioid use guidelines for multimorbidity appear warranted.

Risk of myocardial infarction associated with non‐steroidal anti‐inflammatory drugs: Impact of additional confounding control for variables collected from self‐reported data

What is known and objective

Important risk factors and over‐the‐counter (OTC) dispensing of non‐steroidal anti‐inflammatory drugs (NSAIDs) are often not routinely recorded in electronic health records. This study aimed to assess the impact of patient's reports on these factors on the risk of acute myocardial infarction (AMI) for NSAID use.

Methods

A nested case‐control study was conducted among adults in the Utrecht Cardiovascular Pharmacogenetics study. Cases were patients with a first diagnosis of AMI as a hospital discharge diagnosis and controls were those without AMI. NSAID exposure was either current use of selective COX‐2 inhibitors or conventional NSAIDs. Information was collected from The Dutch PHARMO Database Network (pharmacy records of drug dispensing linked to hospitalization records) and the patient's questionnaire (lifestyle factors, body mass index and history of cardiovascular diseases). Unconditional logistic regression analysis was used to calculate odds ratios (ORs) and to control for confounding factors.

Results

We identified 970 AMI cases and 2974 controls. Among cases, 11 (1.1%) and 185 (19.1%) were exposed to selective COX‐2 inhibitors and conventional NSAIDs, respectively. Compared to non‐use, none of these drug classes were associated with an increased risk of AMI (adjusted OR 1.07, 95% CI: 0.52‐2.18 and 0.93, 95% CI: 0.77‐1.12, respectively). Additional adjustment for potential confounders from patient's reports did not change the risk estimates (adjusted OR 1.08, 95% CI: 0.53‐2.22 and 0.89, 95% CI: 0.73‐1.09, respectively).

What is new and conclusion

Additional confounding control for variables from self‐reported data or considering self‐reported OTC NSAID use did not change the risk estimates for the association between NSAIDs and AMI.

Chronic Opioid Use in Rheumatoid Arthritis: Prevalence and Predictors

OBJECTIVE

The opioid epidemic is a major public health concern. However, little is known about opioid use among rheumatoid arthritis (RA) patients. We undertook this study to examine trends in chronic opioid use in RA patients in 2002-2015 and to identify clinical predictors.

METHODS

RA patients were identified from the Corrona registry. Opioid use was ascertained from surveys obtained at clinical visits as often as every 3 months. Chronic opioid use was defined as any opioid use reported during ≥2 consecutive study visits. Annual prevalence of chronic opioid use was calculated using data from 33,739 RA patients with information on opioid use from ≥2 visits. Among the 26,288 individuals who were not taking opioids at baseline, Cox proportional hazards models identified associations between patient characteristics and incident chronic opioid use. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Chronic opioid use increased from 7.4% in 2002 to 16.9% in 2015. Severe pain (HR 2.53 [95% CI 2.19-2.92]) and antidepressant use (HR 1.79 [95% CI 1.64-1.92]) were associated with an increased risk of chronic opioid use. High disease activity (HR 1.55 [95% CI 1.30-1.84]) and a high level of disability (HR 1.45 [95% CI 1.27-1.65]) were also associated with chronic opioid use, whereas Asian ethnicity (HR 0.49 [95% CI 0.36-0.68]) was associated with a decreased risk of chronic opioid use.

CONCLUSION

Among RA patients, chronic opioid use doubled from 2002 to 2015. Pain and antidepressant use were the strongest predictors of chronic opioid use. To curb the rise in chronic opioid use, strategies for stringent control of RA disease activity and management of pain and depression should be research priorities.

A systematic review of methods for determining cross-sectional active medications using pharmacy databases

PURPOSE

Pharmacy dispensing databases are often used to identify patients' medications at a particular time point, for example to measure prescribing quality or the impact of medication use on clinical outcomes. We performed a systematic review of studies that examined methods to assess medications in use at a specific point in time.

METHODS

Comprehensive literature search to identify studies that compared active medications identified using pharmacy databases to medications identified using nonautomated data sources. Two investigators independently reviewed abstracts and full-text material.

RESULTS

Of 496 studies screened, 29 studies evaluating 50 comparisons met inclusion criteria. Twenty-nine comparisons evaluated fixed look-back period approaches, defining active medications as those filled in a specified period prior to the index date (range 84-730 days). Fourteen comparisons evaluated medication-on-hand approaches, defining active medications as those for which the most recent fill provided sufficient supply to last through the study index date. Sensitivity ranged from 48% to 93% for fixed look-back period approaches and 35% to 97% for medication-on-hand approaches. Interpretation of comparative performance of methods was limited by use of different reference sources, target medication classes, and databases across studies. In four studies with head-to-head comparisons of these methods, sensitivity of the medication-on-hand approach was a median of 7% lower than the corresponding fixed look-back approach.

CONCLUSIONS

The reported accuracy of methods for identifying active medications using pharmacy databases differs greatly across studies. More direct comparisons of common approaches are needed to establish the accuracy of methods within and across populations, medication classes, and databases.

Opioid use prior to knee arthroplasty in patients who catastrophize about their pain: preoperative data from a multisite randomized clinical trial

Background

Opioid use rates prior to knee arthroplasty (KA) among people who catastrophize about their pain are unknown. We determined prevalence of opioid use and compared patterns of preoperative opioid use and oral morphine equivalent (OME), a measure of daily opioid dose, across varied geographic sites. We also determined which baseline variables were associated with opioid use and OME.

Patients and methods

Preoperative opioid use data described type of opioid, dosage, and frequency among 397 patients scheduled for KA. Demographic, knee-related pain, and psychological distress dimensions were examined to identify variables associated with opioid use and opioid dose (OME). Opioid use prevalence and OME were compared across the four sites. A three-level censored regression determined variables associated with opioid use and OME.

Results

The overall opioid use prevalence was 31.7% (95% confidence interval [CI] = 27.0, 36.3) and varied across sites from 15.9% (95% CI = 9.0, 22.8) to 51.2% (95% CI = 40.5, 61.9). After adjustment, patients using opioids were more likely to be younger, African American, and have higher self-efficacy and comorbidity scores (P < 0.05). The only variable independently associated with OME was lower depressive symptoms (P < 0.05).

Conclusion

People who catastrophized prior to KA did not demonstrate increased preoperative opioid use based on current evidence, but variation in the prevalence of opioid use across study sites was substantial. Variables associated with opioid use were non-modifiable demographic and comorbidity variables.

Agreement between different recall periods in drug utilization studies

ABSTRACT: Objective: To assess the agreement between three recall periods for self-reported drug use using a 24-hour recall period as reference. Methods: Participants were allocated into three groups with different recall periods of 7, 14 and 30 days and were interviewed at two different times. A 24-hour recall questionnaire was answered during the first interview, and a questionnaire on drug use over the different recall periods tested was answered during the second interview. The agreement between the questionnaires was evaluated using percent agreement and kappa. Results: For continuous drugs, percent agreement varied between 92 and 99% and kappa varied between 0.71 and 0.97 for three periods tested. For drugs of occasional use, percent agreement varied between 63 and 81% and kappa varied between 0.27 and 0.52. The prevalence of drugs, particularly those of occasional use, increases with time. Conclusions: The high level of agreement between the three recall periods suggests that all of them are valid for the investigation of drugs of continuous use.

Development and Implementation of a Registry of Patients Attending Multidisciplinary Pain Treatment Clinics: The Quebec Pain Registry

The Quebec Pain Registry (QPR) is a large research database of patients suffering from various chronic pain (CP) syndromes who were referred to one of five tertiary care centres in the province of Quebec (Canada). Patients were monitored using common demographics, identical clinical descriptors, and uniform validated outcomes. This paper describes the development, implementation, and research potential of the QPR. Between 2008 and 2013, 6902 patients were enrolled in the QPR, and data were collected prior to their first visit at the pain clinic and six months later. More than 90% of them (mean age ± SD: 52.76 ± 4.60, females: 59.1%) consented that their QPR data be used for research purposes. The results suggest that, compared to patients with serious chronic medical disorders, CP patients referred to tertiary care clinics are more severely impaired in multiple domains including emotional and physical functioning. The QPR is also a powerful and comprehensive tool for conducting research in a “real-world” context with 27 observational studies and satellite research projects which have been completed or are underway. It contains data on the clinical evolution of thousands of patients and provides the opportunity of answering important research questions on various aspects of CP (or specific pain syndromes) and its management.

Associations of individual characteristics and lifestyle factors with metabolism of di-2-ethylhexyl phthalate in NHANES 2001-2012

BACKGROUND

Previous studies suggest that a higher ratio of primary to secondary metabolites of di-2-ethylhexyl phthalate (DEHP), reflective of a slower DEHP conversion rate, is associated with a greater physiologic effect. We examined associations of several individual characteristics and lifestyle factors with the ratio of mono-2-ethylhexyl phthalate to mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHP:MEHHP) and %MEHP (the ratio of MEHP to the sum of the secondary metabolites).

METHODS

We used the data from the National Health and Nutrition Examination Survey, 2001-2012. The study included adults with BMI<30 and no diabetes. Pregnant women were excluded. We examined associations of age, race, gender, Body Mass Index, smoking, alcohol and caffeine consumption, medication use, cancer history, and menopausal status and postmenopausal hormone use (in women) with MEHP:MEHHP and %MEHP using multivariable linear regression. The values for %MEHP were log-transformed in the analysis.

RESULTS

In multivariable analysis, non-Caucasian individuals had higher %MEHP (non-Hispanic Blacks: β=0.114, 95% Confidence interval [CI]: 0.050, 0.177; Hispanic: β=0.089, 95% CI: 0.024, 0.154; other race: β=0.126, 95% CI: 0.033, 0.219). Age was inversely associated with MEHP:MEHHP (β=-0.001, 95% CI: -0.002, -0.001) and %MEHP (β=-0.006, 95% CI: -0.008, -0.004). Overweight individuals had lower MEHP: MEHHP and lower %MEHP (β=-0.035, 95% CI: 0.062, -0.008 and β=-0.104, 95% CI: -0.162, -0.046, respectively). Alcohol consumption was inversely associated with %MEHP among men (p-trend=0.03).

CONCLUSIONS

Individual and lifestyle characteristics are associated with differences in DEHP metabolism. Understanding underlying biological mechanisms could help to identify individuals at a greater risk of adverse effects from DEHP exposure.