Hydrogen isotope fractionation is controlled by CO2 in coccolithophore lipids.

Hydrogen isotope ratios (δ2H) represent an important natural tracer of metabolic processes, but quantitative models of processes controlling H-fractionation in aquatic photosynthetic organisms are lacking. Here, we elucidate the underlying physiological controls of 2H/1H fractionation in algal lipids by systematically manipulating temperature, light, and CO2(aq) in continuous cultures of the haptophyte Gephyrocapsa oceanica. We analyze the hydrogen isotope fractionation in alkenones (αalkenone), a class of acyl lipids specific to this species and other haptophyte algae. We find a strong decrease in the αalkenone with increasing CO2(aq) and confirm αalkenone correlates with temperature and light. Based on the known biosynthesis pathways, we develop a cellular model of the δ2H of algal acyl lipids to evaluate processes contributing to these controls on fractionation. Simulations show that longer residence times of NADPH in the chloroplast favor a greater exchange of NADPH with 2H-richer intracellular water, increasing αalkenone. Higher chloroplast CO2(aq) and temperature shorten NADPH residence time by enhancing the carbon fixation and lipid synthesis rates. The inverse correlation of αalkenone to CO2(aq) in our cultures suggests that carbon concentrating mechanisms (CCM) do not achieve a constant saturation of CO2 at the Rubisco site, but rather that chloroplast CO2 varies with external CO2(aq). The pervasive inverse correlation of αalkenone with CO2(aq) in the modern and preindustrial ocean also suggests that natural populations may not attain a constant saturation of Rubisco with the CCM. Rather than reconstructing growth water, αalkenone may be a powerful tool to elucidate the carbon limitation of photosynthesis.

Child catastrophizing about parent chronic pain: A potential child vulnerability factor.

Objective Robust evidence suggests children's catastrophizing about their own pain is a risk factor for poor child pain-related outcomes. In children of parents with chronic pain, child catastrophizing about their parents' pain might be a unique predictor of child pain-related outcomes given their increased exposure to parental chronic pain and disability. The objective of this study was to examine associations between child and parent catastrophizing about their own and each other's pain and child and parent pain-related outcomes. Methods Seventy-two parents with chronic pain and their children (ages 8-15) completed questionnaires assessing their trait catastrophizing about their own and each other's pain, their own pain, and the child's internalizing symptoms. Children completed the cold pressor task (CPT) in the presence of their parent. Parents and children rated children's worst pain intensity and their own anxiety during the task. Analyses were guided by the Actor-Partner Interdependence Model. Results Greater child catastrophizing about parent pain was associated with children's and parents' increased catastrophizing about their own pain. Child catastrophizing about parent pain was associated with greater child- and parent-reported child internalizing symptoms and greater CPT pain intensity for the child, but not parent/child usual pain or CPT anxiety, over and above the influence of parent and child catastrophizing about their own pain. Conclusions Child catastrophizing about parent pain is a potential vulnerability factor associated with poor pain-related outcomes in children of parents with chronic pain that should be considered in future research and clinical settings. Statement of contribution What is already known on this subject? Higher rates of pain and internalizing symptoms are observed in offspring of parents with vs. without chronic pain. Greater child and parent pain catastrophizing are associated with poorer pain-related outcomes in children. Child catastrophizing about parent chronic pain and its association with child outcomes has not been examined. What does this study add? Greater child catastrophizing about parent chronic pain is associated with greater child internalizing and CPT pain. These effects were seen beyond the association of child and parent catastrophizing about their own pain.

Testing the intergenerational model of transmission of risk for chronic pain from parents to their children: an empirical investigation of social transmission pathways.

Children of parents with chronic pain have higher rates of pain and internalizing (eg, anxiety and depressive) symptoms than children of parents without chronic pain. Parental modeling of pain behaviour and reinforcement of child pain have been hypothesized to underlie these relationships. These mechanisms were tested in a sample of 72 parents with chronic pain and their children (aged 8-15 years). Standardized measures were completed by parents (pain characteristics, pain interference, and child internalizing) and children (pain catastrophizing, pain over previous 3 months, and internalizing). In a laboratory session, children completed the cold pressor task in the presence of their parent, and parent-child verbalizations were coded. Significant indirect effects of parental pain interference on child self-reported (B = 0.12, 95% confidence interval [CI]: 0.01-0.29) and parent-reported (B = 0.16, 95% CI: 0.03-0.40) internalizing symptoms through child pain catastrophizing were found (parental modeling mechanism), and were not moderated by child chronic pain status. Significant indirect effects were found between parent pain-attending verbalizations and child self-reported (B = 2.58, 95% CI: 1.03-5.31) and parent-reported (B = 2.18, 95% CI: 0.93-4.27) cold pressor task pain intensity and tolerance (B = -1.02, 95% CI: -1.92 to -0.42) through child pain-attending verbalizations (parental reinforcement mechanism). Although further understanding of the temporal relationships between these variables is needed, the current study identifies constructs (eg, parent pain interference, child pain catastrophizing, and parent reinforcement of child pain) that should be further examined as potential targets for prevention and intervention of pain and internalizing symptoms in children of parents with chronic pain.

Compulsory Use of the Backboard is Associated with Increased Frequency of Thoracolumbar Imaging.

BACKGROUND: Backboards have been shown to cause pain in uninjured patients. This may alter physical exam findings, leading emergency department (ED) providers to suspect a spinal injury when none exists resulting in additional imaging of the thoracolumbar spine. New York had previously employed a "Spinal Immobilization" protocol that included compulsory backboard application for all patients with suspected spinal injuries. In 2015, New York instituted a new "Spinal Motion Restriction" protocol that made backboard use optional for these patients. The objective of this study was to determine if this protocol change was associated with decreased backboard utilization and ED thoracolumbar spine imaging. METHODS: This was a retrospective before-and-after chart review of subjects transported by a single emergency medical services (EMS) agency to one of four EDs for emergency calls dispatched as motor vehicle collisions (MVC). EMS and ED data were included for all calls within a 6-month interval before and after the protocol change. The protocol change was implemented in the second half of 2015. Subject demographics, backboard use, and spine imaging were reviewed for the intervals January-June 2015 and January-June 2016. RESULTS: There were 818 subjects in the before period and 796 subjects in the after period. Subjects were similar in terms of gender, age and type of MVC in both periods. A backboard was utilized for 440 (54%) subjects in the before period and 92 (12%) subjects in the after period (p < 0.001). ED thoracic spine imaging was performed on 285 (35%) subjects in the before period, and 235 (30%) subjects in the after period (p = 0.02). ED lumbar spine imaging was performed for 335 (41%) subjects in the before period, and 281 (35%) subjects in the after period (p = 0.02). CONCLUSION: A shift from a spinal immobilization protocol to a spinal motion restriction protocol was associated with a decrease in backboard utilization by EMS providers and a decrease in thoracolumbar spine imaging by ED providers.

Sensitivity of the DN4 in Screening for Neuropathic Pain Syndromes.

OBJECTIVES: Several tools have been developed to screen for neuropathic pain. This study examined the sensitivity of the Douleur Neuropathique en 4 Questions (DN4) in screening for various neuropathic pain syndromes. MATERIALS AND METHODS: This prospective observational study was conducted in 7 Canadian academic pain centers between April 2008 and December 2011. All newly admitted patients (n=2199) were approached and 789 eligible participants form the sample for this analysis. Baseline data included demographics, disability, health-related quality of life, and pain characteristics. Diagnosis of probable or definite neuropathic pain was on the basis of history, neurological examination, and ancillary diagnostic tests. RESULTS: The mean age of study participants was 53.5 years and 54.7% were female; 83% (n=652/789) screened positive on the DN4 (≥4/10). The sensitivity was highest for central neuropathic pain (92.5%, n=74/80) and generalized polyneuropathies (92.1%, n=139/151), and lowest for trigeminal neuralgia (69.2%, n=36/52). After controlling for confounders, the sensitivity of the DN4 remained significantly higher for individuals with generalized polyneuropathies (odds ratio [OR]=4.35; 95% confidence interval [CI]: 2.15, 8.81), central neuropathic pain (OR=3.76; 95% CI: 1.56, 9.07), and multifocal polyneuropathies (OR=1.72; 95% CI: 1.03, 2.85) compared with focal neuropathies. DISCUSSION: The DN4 performed well; however, sensitivity varied by syndrome and the lowest sensitivity was found for trigeminal neuralgia. A positive DN4 was associated with greater pain catastrophizing, disability and anxiety/depression, which may be because of disease severity, and/or these scales may reflect magnification of sensory symptoms and findings. Future research should examine how the DN4 could be refined to improve its sensitivity for specific neuropathic pain conditions.

Medical cannabis: considerations for the anesthesiologist and pain physician.

PURPOSE: New regulations are in place at the federal and provincial levels in Canada regarding the way medical cannabis is to be controlled. We present them together with guidance for the safe use of medical cannabis and recent clinical trials on cannabis and pain. SOURCE: The new Canadian regulations on the use of medical cannabis, the provincial regulations, and the various cannabis products available from the Canadian Licensed Producers were reviewed from Health Canada, provincial licensing authorities, and the licensed producers website, respectively. Recent clinical trials on cannabis and pain were reviewed from the existing literature. PRINCIPAL FINDINGS: Health Canada has approved a new regulation on medical marijuana/cannabis, the Marihuana for Medical Purposes Regulations: The production of medical cannabis by individuals is illegal. Health Canada, however, has licensed authorized producers across the country, limiting the production to specific licenses of certain cannabis products. There are currently 26 authorized licensed producers from seven Canadian provinces offering more than 200 strains of marijuana. We provide guidance for the safe use of medical cannabis. The recent literature indicates that currently available cannabinoids are modestly effective analgesics that provide a safe, reasonable therapeutic option for managing chronic non-cancer-related pain. CONCLUSION: The science of medical cannabis and the need for education of healthcare professionals and patients require continued effort. Although cannabinoids work to decrease pain, there is still a need to confirm these beneficial effects clinically and to exploit them with acceptable benefit-to-risk ratios.

The reciprocal associations between catastrophizing and pain outcomes in patients being treated for neuropathic pain: a cross-lagged panel analysis study.

Catastrophizing is recognized as a key psychosocial factor associated with pain-related negative outcomes in individuals with chronic pain. Longitudinal studies are needed to better understand the temporal relationship between these constructs. The aim of this study was to determine if changes in catastrophizing early in treatment predicted subsequent changes in pain intensity and interference later in treatment, or alternately, if early changes in pain intensity and interference predicted subsequent changes in catastrophizing. A total of 538 patients with neuropathic pain were recruited from 6 multidisciplinary pain clinics across Canada. Study participants were asked to complete measures of catastrophizing, pain intensity, and interference when first seen in the clinic and then again at 3- and 6-month follow-ups. Cross-lagged panel analyses were used to determine the temporal associations among the study variables. The results showed that decreases in catastrophizing early in treatment prospectively predicted improvement in both pain intensity and interference later in treatment. Converse temporal relationships were also found, where a reduction in pain intensity and interference early in treatment predicted a subsequent diminishing of catastrophizing. All 4 unique cross-lagged correlations significantly accounted for an additional 4% to 7% of the total variance. The findings are consistent with theoretical models hypothesizing a causal impact of catastrophizing on pain, suggesting a mutual causation between these factors. The results support that treatments targeting catastrophizing may influence other pain-related outcomes, and conversely that treatments aiming to reduce pain could potentially influence catastrophizing. There may therefore be multiple paths to positive outcomes.

Physician-to-physician telephone consultations for chronic pain patients: A pragmatic randomized trial.

BACKGROUND: The impact of telephone consultations between pain specialists and primary care physicians regarding the care of patients with chronic pain is unknown. OBJECTIVES: To evaluate the impact of telephone consultations between pain specialists and primary care physicians regarding the care of patients with chronic pain. METHODS: Patients referred to an interdisciplinary chronic pain service were randomly assigned to either receive usual care by the primary care physician, or to have their case discussed in a telephone consultation between a pain specialist and the referring primary care physician. Patients completed a numerical rating scale for pain, the Pain Disability Index and the Short Form-36 on referral, as well as three and six months later. Primary care physicians completed a brief survey to assess their impressions of the telephone consultation. RESULTS: Eighty patients were randomly assigned to either the usual care group or the standard telephone consultation group, and 67 completed the study protocol. Patients were comparable on baseline pain and demographic characteristics. No differences were found between the groups at six months after referral in regard to pain, disability or quality of life measures. Eighty percent of primary care physicians indicated that they learned new patient care strategies from the telephone consultation, and 97% reported that the consultation answered their questions and helped in the care of their patient. DISCUSSION: Most primary care physicians reported that a telephone consultation with a pain specialist answered their questions, improved their patients' care and resulted in new learning. Differences in patient status compared with a usual care control group were not detectable at six-month follow-up. CONCLUSIONS: While telephone consultations are clearly an acceptable strategy for knowledge translation, additional strategies may be required to actually impact patient outcomes.

Offspring of parents with chronic pain: a systematic review and meta-analysis of pain, health, psychological, and family outcomes.

Offspring of parents with chronic pain may be at risk for poorer outcomes than offspring of healthy parents. The objective of this research was to provide a comprehensive mixed-methods systematic synthesis of all available research on outcomes in offspring of parents with chronic pain. A systematic search was conducted for published articles in English examining pain, health, psychological, or family outcomes in offspring of parents with chronic pain. Fifty-nine eligible articles were identified (31 population-based, 25 clinical, 3 qualitative), including offspring from birth to adulthood and parents with varying chronic pain diagnoses (eg, mixed pain samples, arthritis). Meta-analysis was used to synthesize the results from population-based and clinical studies, while meta-ethnography was used to synthesize the results of qualitative studies. Increased pain complaints were found in offspring of mothers and of fathers with chronic pain and when both parents had chronic pain. Newborns of mothers with chronic pain were more likely to have adverse birth outcomes, including low birthweight, preterm delivery, caesarian section, intensive care admission, and mortality. Offspring of parents with chronic pain had greater externalizing and internalizing problems and poorer social competence and family outcomes. No significant differences were found on teacher-reported externalizing problems. The meta-ethnography identified 6 key concepts (developing independence, developing compassion, learning about health and coping, missing out, emotional health, and struggles communicating with parents). Across study designs, offspring of parents with chronic pain had poorer outcomes than other offspring, although the meta-ethnography noted some constructive impact of having a parent with chronic pain.

Physical Functioning and Opioid use in Patients with Neuropathic Pain.

OBJECTIVE: To evaluate the association between opioid dosage and ongoing therapy with physical function and disability in patients with neuropathic pain (NeP). DESIGN: Secondary analysis of a prospective cohort. SETTING: Multicenter clinical NeP registry. SUBJECTS: Seven hundred eighty-nine patients treated for various NeP diagnoses. METHODS: The following measures were included: dependent variables. 12-month self-reported physical function (pain disability index [PDI] and medical outcomes study short form-12 physical function [PCSS-12]); independent variables: baseline opioid dose (none, ≤200 mg and >200 mg of morphine equivalent), ongoing opioid use; potential confounding variables: age, sex, baseline pain intensity, and psychological distress (profile of mood states). Analysis of covariance models was created to examine the relationship between opioid therapy and both physical functioning outcomes with adjustment for confounding. RESULTS: Complete data was available for 535 patients (68%). Compared with the lower and high dose opioid groups, NeP patients not taking opioids had statistically lower disability and higher physical functioning scores, after adjusting for disease severity. Compared with patients prescribed opioid therapy on an ongoing basis, NeP patients who were not prescribed had statistically lower disability and higher physical functioning scores, after adjusting for disease severity. Improvements in disability and physical functioning scores from baseline and 12-months in all groups were modest and may not be clinically significant. CONCLUSIONS: Physical functioning and disability did not improve in patients with NeP who were prescribed opioids compared with those who are not prescribed, even after adjusting for disease severity.

Immunoglobulin g for the treatment of chronic pain: report of an expert workshop.

BACKGROUND: The treatment of chronic pain is still unsatisfactory. Despite the availability of different drugs, most patients with chronic pain do not receive satisfactory pain relief or report side effects. Converging evidence implicates involvement of the immune system in the pathogenesis of different types of nociceptive and neuropathic chronic pain. DESIGN: At a workshop in Liverpool, UK (October 2012), experts presented evidence suggesting immunological involvement in chronic pain and recent data supporting the concept that the established immune-modulating drug, polyvalent immunoglobulin G (IgG), either given intravenously (IVIg) or subcutaneously (SCIg), may reduce pain in some peripheral neuropathies and a range of other pain disorders. Workshop's attendees discussed the practicalities of using IVIg and SCIg in these disorders, including indications, cost-effectiveness, and side effects. RESULTS: IgG may reduce pain in a range of nociceptive and neuropathic chronic pain conditions, including diabetes mellitus, Sjögren's syndrome, fibromyalgia, complex regional pain syndrome, post-polio syndrome, and pain secondary to pathological autoantibodies. CONCLUSIONS: IgG is a promising treatment in several chronic pain conditions. IgG is a relatively safe therapeutic strategy, with uncommon and mild side effects but high costs. Randomized, controlled trials and predictive tests are needed to better support the use of IgG for refractory chronic pain.

The Canadian STOP-PAIN project: the burden of chronic pain-does sex really matter?

OBJECTIVES: The Canadian STOP-PAIN Project assessed the human and economic burden of chronic pain (CP) in individuals on waitlists of Canadian multidisciplinary pain treatment facilities. This article focuses on sex differences. Objectives were to (1) determine the pain characteristics and related biopsychosocial factors that best differentiated women and men with CP; and (2) examine whether public and private costs associated with CP differed according to sex. MATERIALS AND METHODS: Sample consisted of 441 women and 287 men who were evaluated using self-administered questionnaires and a structured interview protocol. A subsample (233 women and 137 men) recorded all pain-related expenditures in a comprehensive diary over 3 months. RESULTS: Results revealed that the burden of illness associated with CP was comparable in both sexes for average and worst pain intensity, pain impact on daily living, quality of life, and psychological well-being. The same was true for pain-related costs. The results of a hierarchical logistic regression analysis, in which sex was treated as the dependent variable, showed that factors that differentiated men and women were: work status, certain circumstances surrounding pain onset, present pain intensity, intake of particular types of pain medication, use of certain pain management strategies, pain beliefs, and utilization of particular health care resources. DISCUSSION: This study suggests that women and men who are referred to multidisciplinary pain treatment facilities do not differ significantly in terms of their pain-related experience. However, the aspects that differ may warrant further clinical attention when assessing and managing pain.

A brief educational intervention about pain and aging for older members of the community and health care workers.

UNLABELLED: Developing educational interventions about pain may lead to improved pain management for older people. A public group educational session, entitled "Pain in the Older Person," was presented in 7 cities across Canada (Vancouver, Calgary, London, Toronto, Ottawa, Montreal, and Halifax). The presentation lasted approximately 90 minutes and was followed by a question and answer period of at least 20 minutes. Prior to the educational session, participants provided demographic data and completed measures of pain intensity, frequency, interference, and treatment; of subjective health; and of knowledge about pain. Following the session, participants completed the same knowledge items again as well as items assessing satisfaction. Data were provided by 54 health care workers (HCW) and 54 older community members (66.3 ± 10.2 years old). Prior to the educational session, knowledge gaps were evident among the older community members, especially about analgesic use. Among the HCW, knowledge gaps were found about addiction and the relationship between pain and aging. Comparison of knowledge scores before and after the educational session revealed that both groups demonstrated significant knowledge gains. Satisfaction scores were very high, with no significant difference between HCW and older community members. This is the first study to show that a brief educational intervention is associated with gains in knowledge about pain and aging among both older community members and HCW. These results suggest that a brief public educational session is a promising method of pain education that may reduce barriers to pain management in older people. PERSPECTIVE: This article describes the results of a brief public educational session about pain and aging attended by older members of the community and health care workers. This intervention could potentially improve pain management for older people.

Buprenorphine transdermal system for opioid therapy in patients with chronic low back pain.

OBJECTIVE: The present randomized, double-blinded, crossover study compared the efficacy and safety of a seven-day buprenorphine transdermal system (BTDS) and placebo in patients with low back pain of moderate or greater severity for at least six weeks. METHODS: Prestudy analgesics were discontinued the evening before random assignment to 5 microg/h BTDS or placebo, with acetaminophen 300 mg/codeine 30 mg, one to two tablets every 4 h to 6 h as needed, for rescue analgesia. The dose was titrated to effect weekly, if tolerated, to 10 microg/h and 20 microg/h BTDS. Each treatment phase was four weeks. RESULTS: Fifty-three patients (28 men, 25 women, mean [+/- SD] age 54.5+/-12.7 years) were evaluable for efficacy (completed two weeks or more in each phase). Baseline pain was 62.1+/-15.5 mm (100 mm visual analogue scale) and 2.5+/-0.6 (five-point ordinal scale). BTDS resulted in lower mean daily pain scores than in the placebo group (37.6+/-20.7 mm versus 43.6+/-21.2 mm on a visual analogue scale, P=0.0487; and 1.7+/-0.6 versus 2.0+/-0.7 on the ordinal scale, P=0.0358). Most patients titrated to the highest dose of BTDS (59% 20 microg/h, 31% 10 microg/h and 10% 5 microg/h). There were improvements from baseline in pain and disability (Pain Disability Index), Pain and Sleep (visual analogue scale), Quebec Back Pain Disability Scale and Short-Form 36 Health Survey scores for both BTDS and placebo groups, without significant differences between treatments. While there were more opioid-related side effects with BTDS treatment than with placebo, there were no serious adverse events. A total of 82% of patients chose to continue BTDS in a long-term open-label evaluation, in whom improvements in pain intensity, functionality and quality of life were sustained for up to six months without analgesic tolerance. CONCLUSION: BTDS (5 microg/h to 20 microg/h) represents a new treatment option for initial opioid therapy in patients with chronic low back pain.

The Canadian STOP-PAIN project - Part 1: Who are the patients on the waitlists of multidisciplinary pain treatment facilities?

PURPOSE: The Canadian STOP-PAIN Project assessed the human and economic burden of chronic pain in individuals on waitlists of Multidisciplinary Pain Treatment Facilities (MPTF). This article presents the patients' bio-psycho-social profile. METHODS: A sample of 728 patients was recruited from waitlists of eight university-affiliated MPTFs across Canada. Subjects completed validated questionnaires to: 1) assess the characteristics and impact of their pain; and 2) evaluate their emotional functioning and quality of life (QoL). Follow-up questionnaires were completed by a subgroup of 271 patients three months later. RESULTS: Close to 2/3 of the participants reported severe pain (> or = 7/10) that interfered substantially with various aspects of their daily living and QoL. Severe or extremely severe levels of depression were common (50.0%) along with suicidal ideation (34.6%). Patients aged > 60 yr were twice as likely to experience severe pain (> or = 7/10) as their younger counterparts (P = 0.002). Patients with frequent sleep problems were more at risk of reporting severe pain (P < or = 0.003). Intense pain was also associated with a greater tendency to catastrophize (P < 0.0001) severe depressive symptoms (P = 0.003) and higher anger levels (P = 0.016). Small but statistically significant changes in pain intensity and emotional distress were observed over a three-month wait time (all P < 0.05). CONCLUSION: This study highlights the severe impairment that patients experience waiting for treatment in MPTFs. Knowing that current facilities cannot meet the clinical demand, it is clear that effective prevention/treatment strategies are needed earlier in primary and secondary care settings to minimize suffering and chronicity.

The Canadian STOP-PAIN project - Part 2: What is the cost of pain for patients on waitlists of multidisciplinary pain treatment facilities?

PURPOSE: The Canadian STOP-PAIN Project was designed to document the human and economic burden of chronic pain in individuals on waitlists of Multidisciplinary Pain Treatment Facilities (MPTF). This paper describes the societal costs of their pain. METHODS: A subgroup of 370 patients was selected randomly from The Canadian STOP-PAIN Project. Participants completed a self-administered costing tool (the Ambulatory and Home Care Record) on a daily basis for three months. They provided information about publicly financed resources, such as health care professional consultations and diagnostic tests as well as privately financed costs, including out-of-pocket expenditures and time devoted to seeking, receiving, and providing care. To determine the cost of care, resources were valued using various costing methods, and multivariate linear regression was used to predict total cost. RESULTS: Overall, the median monthly cost of care was $1,462 (CDN) per study participant. Ninety-five percent of the total expenditures were privately financed. The final regression model consisted of the following determinants: educational level, employment status, province, pain duration, depression, and health-related quality of life. This model accounted for 35% of the variance in total expenditure (P < 0.001). CONCLUSION: The economic burden of chronic pain is substantial in patients on waitlists of MPTFs. Consequently, it is essential to consider this burden when making decisions regarding resource allocation and waitlist assignment for a MPTF. Resource allocation decision-making should include the economic implications of having patients wait for an assessment and for care.

A systematic review of the effect of waiting for treatment for chronic pain.

In many countries timely access to care is a growing problem. As medical costs escalate health care resources must be prioritized. In this context there is an increasing need for benchmarks and best practices in wait-time management. The Canadian Pain Society struck a Task Force in December 2005 to identify benchmarks for acceptable wait-times for treatment of chronic pain. As part of the mandate a systematic review of the literature regarding the relationship between waiting times, health status and health outcomes for patients awaiting treatment for chronic pain was undertaken. Twenty-four studies met the inclusion criteria for the review. The current review supports that patients experience a significant deterioration in health related quality of life and psychological well being while waiting for treatment for chronic pain during the 6 months from the time of referral to treatment. It is unknown at what point this deterioration begins as results from the 14 trials involving wait-times of 10 weeks or less yielded mixed results with wait-times amounting to as little as 5 weeks, associated with deterioration. It was concluded that wait-times for chronic pain treatment of 6 months or longer are medically unacceptable. Further study is necessary to determine at what stage the deterioration begins from the onset of pain to treatment and the impact of waiting on treatment outcomes. Most important is the need to improve access to appropriate care for patients with chronic pain, an escalating public health care problem with significant human and economic costs.

Waiting for treatment for chronic pain - a survey of existing benchmarks: toward establishing evidence-based benchmarks for medically acceptable waiting times.

As medical costs escalate, health care resources must be prioritized. In this context, there is an increasing need for benchmarks and best practices in wait time management. In December 2005, the Canadian Pain Society struck a Task Force to identify benchmarks for acceptable wait times for treatment of chronic pain. The task force mandate included a systematic review and survey to identify national or international wait time benchmarks for chronic pain, proposed or in use, along with a review of the evidence upon which they are based. An extensive systematic review of the literature and a survey of International Association for the Study of Pain Chapter Presidents and key informants has identified that there are no established benchmarks or guidelines for acceptable wait times for the treatment of chronic pain in use in the world. In countries with generic guidelines or wait time standards that apply to all outpatient clinics, there have been significant challenges faced by pain clinics in meeting the established targets. Important next steps are to ensure appropriate additional research and the establishment of international benchmarks or guidelines for acceptable wait times for the treatment of chronic pain. This will facilitate advocacy for improved access to appropriate care for people suffering from chronic pain around the world.