Liliane Mendonça

Epidemiology of Chronic Pain: A Population-Based Nationwide Study on Its Prevalence, Characteristics and Associated Disability in Portugal

UNLABELLED A cross-sectional nationwide epidemiological study was performed in a random sample of the Portuguese adult population, aiming to describe the prevalence and impact of chronic pain (CP). The 5,094 participants were selected by random digit dialing, between January 2007 and March 2008, and estimates were adequately weighted for the population. Prevalence of CP was 36.7% (95% confidence interval [CI] [35.3-38.2]), based on the definition of the International Association for the Study of Pain. Recurrent or continuous pain was present in 85% of those with CP, and moderate-to-severe intensity and disability were present in 68 and 35%, respectively. Highest CP prevalence was observed among the elderly, retired, unemployed, and less educated. Highest disability was found in relation with family/home responsibilities, recreational activities, occupation/work, and sleep/rest; 13% reported a diagnosis of depression and 49% reported interference in their job. The main factors associated with disability were sex, pain intensity, and depression or depressive symptoms. CP is highly prevalent, causes high personal and social burden, and affects particularly the most vulnerable subgroups. Portugal, depending on CP definition, could be placed in the lower prevalence group in Europe. Improvement in pain intensity management and special attention to affective components of CP are recommended. PERSPECTIVE In this cross-sectional nationwide epidemiological study, we showed that chronic pain is a significant problem that is present in 37% of the Portuguese adult general population, is associated with high personal, family, and social burden, and affects in particular the most vulnerable subgroups of the population.

Chronic pain and health services utilization: is there overuse of diagnostic tests and inequalities in nonpharmacologic treatment methods utilization?

Background:Few studies have described patterns and determinants of health services utilization (HSU) in chronic pain (CP) subjects. We aimed to describe these, in particular, regarding medical consultations (MCs), diagnostic tests (DTs), pain medicines (PMs) and nonpharmacologic treatment methods (NTM) utilization. Methods:A cross-sectional nationwide study was conducted in a representative sample of the Portuguese population. The 5094 participants were selected using random digit dialling and were contacted by computer-assisted telephone interviews. Questionnaires included the brief pain inventory and pain disability index. Estimates were adequately weighted for the population. Results:Prevalence of CP and CP with moderate to severe disability was 36.7% and 10.8%, respectively. Most CP subjects were being managed/treated by health professionals (81%) and had high levels of HSU. More than half of them had used imaging DT in the previous 6 months. Main factors associated with HSU were as follows: pain-related disability, intensity, duration, and depressive symptoms for MC utilization; sex, pain-related disability, and duration for PM utilization; and education level and depression diagnosis for NTM utilization. Conclusions:The main drivers behind HSU are pain severity, psychological distress, and socio-economic determinants. An important set of benchmarks are presented regarding HSU in CP subjects, comprising useful tools for public health policy and decision-making. Results presented may suggest possible inequalities in the access to NTM, and interventions to improve access are encouraged. Moreover, possible indirect evidence of imaging DT overuse is presented, and it is recommended that their use in CP subjects should more closely follow existing guidelines.

A population-based study on chronic pain and the use of opioids in Portugal

Summary High rates of opioid use is not a ubiquitous problem. Very low opioid‐use rates in Portugal are described, and associated factors are explored. Abstract Although increasing doubts exist regarding the long‐term effectiveness and safety of opioids in patients with chronic pain (CP), most guidelines still recognize opioids as an option in effective management of CP. We aimed to describe the prevalence and factors associated with opioid use in subjects with CP in Portugal and to evaluate satisfaction and self‐assessed treatment effectiveness. A nationwide study was conducted in a representative sample of the adult Portuguese population. The 5094 participants were selected using random digit dialing and estimates were adequately weighted for the population. The prevalence of opioid use by subjects with CP was 4.37% (95% confidence interval [CI] 3.4–5.5); and in subjects experiencing CP with and without cancer, it was 10.13% and 4.24%, respectively. Use of strong opioids was reported by only 0.17% of CP subjects. Sex, pain severity and symptoms of depression and anxiety were significantly associated with opioid use; however, in multivariate modeling, only pain‐related disability remained significant. No significant differences among users and nonusers of opioids were observed regarding treatment satisfaction and self‐assessed effectiveness. Although extremely high rates of use of opioids exist in a few countries, it should not be seen as a ubiquitous problem. Indeed, we showed that in Portugal, as in many other regions in the world, opioids are used much less frequently than in those few countries. Moreover, we did not find significant differences among users and nonusers of opioids regarding satisfaction and self‐assessed effectiveness, eventually showing the results to be in line with reports that show doubt about opioids’ effectiveness. Further research and particular attention to and continuous monitoring of the trends of use and abuse of opioids worldwide are recommended.

Reliability and validity of the Bowel Function Index for evaluating opioid-induced constipation: translation, cultural adaptation and validation of the Portuguese version (BFI-P)

Abstract Objective: The Bowel Function Index (BFI) is a simple and sound bowel function and opioid-induced constipation (OIC) screening tool. We aimed to develop the translation and cultural adaptation of this measure (BFI-P) and to assess its reliability and validity for the Portuguese language and a chronic pain population. Methods: The BFI-P was created after a process including translation, back translation and cultural adaptation. Participants (n = 226) were recruited in a chronic pain clinic and were assessed at baseline and after one week. Internal consistency, test–retest reliability, responsiveness, construct (convergent and known groups) and factorial validity were assessed. Results: Test–retest reliability had an intra-class correlation of 0.605 for BFI mean score. Internal consistency of BFI had Cronbach’s alpha of 0.865. The construct validity of BFI-P was shown to be excellent and the exploratory factor analysis confirmed its unidimensional structure. The responsiveness of BFI-P was excellent, with a suggested 17–19 point and 8–12 point change in score constituting a clinically relevant change in constipation for patients with and without previous constipation, respectively. Conclusions: This study had some limitations, namely, the criterion validity of BFI-P was not directly assessed; and the absence of a direct criterion for OIC precluded the assessment of the criterion based responsiveness of BFI-P. Nevertheless, BFI may importantly contribute to better OIC screening and its Portuguese version (BFI-P) has been shown to have excellent reliability, internal consistency, validity and responsiveness. Further suggestions regarding statistically and clinically important change cut-offs for this instrument are presented.

Impact of the economic crisis on pain research: a bibliometric analysis of pain research publications from Ireland, Greece, and Portugal between 1997 and 2017

Abstract Background and aims The recent economic crisis started in the USA in 2008 but quickly had worldwide impact. Ireland, Greece, and Portugal were in economic distress in 2009 and received rescue monetary packages from the European Union (EU) and the International Monetary Fund (IMF) in the following years. Meanwhile, the economic recovery has begun for those countries, but at different paces. The aim of the present study was to evaluate if the economic crisis influenced pain research outcomes, by performing a bibliometric analysis based on the ISI Web of Science to evaluate the evolution of the scientific production and performance in the field of pain research between 1997 and 2017. Methods Articles search was conducted using the ISI Web of Science, search keywords “pain or nocicep*”, between 1997 and 2017, and one author affiliated in an Irish, Greek or Portuguese institution. The total number of published articles per country, total citations, h-index, document types and authors’ institution were tabulated to determine the quantity and quality of the publications in this field. Results The search retrieved 2,368 publications over the 20 years’ period, increasing from 26 in 1997 to 230 in 2017. The number of Irish publications per year increased steadily along the studied period, while the number of Greek publications stabilized from 2008 onward and Portuguese publications started to increase only in 2007 but declined slightly after 2014. In total, Irish authors published 1,143 articles, Greek authors 624 and Portuguese authors 618. There were nine articles with more than 100 citations, and Irish publications had a higher h-index (52) than Greek’s (45) or Portuguese’s (36) publications. Ireland had the highest number of pain publications per capita, but in 2016 Portugal had the lowest cost per publication, as measured by the GDP per capita per publication (in 1997 Portugal had the highest cost). The three major research fields of the publications were neurosciences/neurology (19%), general internal medicine (16%) and anaesthesiology (13%), and the affiliation institutions were mostly universities or universities hospitals. Conclusions The number of Irish, Greek, and Portuguese pain publications increased between 1997 and 2017, but at different paces. It appears that the economic crisis had no impact on the rate of pain publications in Ireland, had a delayed impact in Portugal, and affected mostly Greek pain scientific research. This may be related to the fact that Greece was the country that received more rescue packages and where the economic crisis was deepest and lasted longer. Implications Economics and scientific production have a mutual influence: usually research investment decreases in recession times (reducing grants and scientific employment), but health scientific production can improve health and quality of life and also benefit the economy. So in crisis periods, governments should create means to protect and foster scientific work.

Incidence and Health Related Quality of Life of Opioid-Induced Constipation in Chronic Noncancer Pain Patients: A Prospective Multicentre Cohort Study

Background High rates of opioid use for chronic noncancer pain (CNCP) have been reported worldwide, despite its association with adverse events, inappropriate use, and limited analgesic effect. Opioid-induced constipation (OIC) is the most prevalent and disabling adverse effect associated with opioid therapy. Our aim was to assess the incidence, health related quality of life (HRQOL), and disability in OIC patients. Methods A prospective cohort study was performed, with 6 months of follow-up, of adult CNCP patients consecutively admitted in 4 multidisciplinary pain clinics (MPC). Demographic and clinical data have been collected. Brief Pain Inventory (BPI) and Short version of Treatment Outcomes in Pain Survey (S-TOPS) were used to measure functional outcomes and HRQOL. OIC was assessed using Bowel Function Index (BFI). Results 694 patients were recruited. OIC prevalence at baseline was 25.8%. At 6 months, OIC incidence was 24.8%. Female gender (OR = 1.65, p = 0.039), opioid therapy (OR 1.65, p = 0.026), and interference pain score on BPI (OR 1.10, p = 0.009) were identified as OIC independent predictors. OIC patients presented higher disability and pain interference and severity scores. OIC patients reported less satisfaction with outcome (p = 0.038). Discussion Constipation is a common adverse event among opioid users with major functional and quality of life impairment. These findings emphasise the need of OIC adequate assessment and management.

The Impact of Anxiety and Depression on the Outcomes of Chronic Low Back Pain Multidisciplinary Pain Management—A Multicenter Prospective Cohort Study in Pain Clinics with One-Year Follow-up

Objective. The psychological health of patients with chronic low back pain (CLBP) influences their response to a number of conservative and invasive pain treatments. However, evidence is still scarce regarding the impact of anxiety and depression in the clinical outcomes of multidisciplinary pain management over time. This study, based on longitudinal data from a clinical practice setting, aimed to assess the effectiveness of the usual multidisciplinary approach provided to CLBP patients and to explore the impact of anxiety and depression symptoms and their interaction on clinical outcomes. Methods. In this study, participants included were adult patients in their first consultation in a multidisciplinary chronic pain clinic. Anxiety and depression symptoms were assessed with the Hospital Anxiety and Depression Scale (HADS). The Brief Pain Inventory (BPI) and the Shortened Treatment Outcomes in Pain Survey (S‐TOPS) were used to assess outcomes. Linear mixed effects models were used to assess the impact of anxiety, depression, and their interaction on treatment outcomes. Results. A total of 284 patients (age 60.4 ± 13.7 years, 74.6% female) with CLBP were included at baseline. The majority of patients had both anxiety and depression and experienced higher pain severity (P < 0.001) and higher pain‐related disability (P < 0.001). Anxiety and depression mainly predicted changes in pain interference over time. Their interaction significantly predicted changes in pain interference. Conclusions. Anxiety, depression, and their interaction are associated with changes in pain disability at one‐year follow‐up. These findings encourage the pretreatment screening of anxiety and depression as independent symptoms in patients with CLBP in order to design more tailored and effective multidisciplinary treatments.

Interventional Pain Management in Multidisciplinary Chronic Pain Clinics: A Prospective Multicenter Cohort Study with One-Year Follow-Up

Background Interventional Pain Management (IPM) is performed in multidisciplinary chronic pain clinics (MCPC), including a range of invasive techniques to diagnose and treat chronic pain (CP) conditions. Current patterns of use of those techniques in MCPC have not yet been reported. Objective We aimed to describe quantitatively and qualitatively the use of IPM and other therapeutic procedures performed on-site at four Portuguese MCPC. Methods A prospective cohort study with one-year follow-up was performed in adult patients. A structured case report form was systematically completed at baseline and six and 12 months. Results Among 808 patients referred to the MCPC, 17.2% had been prescribed IPM. Patients with IPM were on average younger and had longer CP duration and lower levels of maximum pain and pain interference/disability. The three main diagnoses were low back pain (n = 28), postoperative CP, and knee pain (n = 16 each). From 195 IPM prescribed, nerve blocks (n = 108), radiofrequency (n = 31), and viscosupplementation (n = 22) were the most prevalent. Some IPM techniques were only available in few MCPC. One MCPC did not provide IPM. Conclusions IPM are seldom prescribed in Portuguese MCPC. Further studies on IPM safety and effectiveness are necessary for clear understanding the role of these techniques in CP management.