Cost analysis of chronic pain due to musculoskeletal disorders in Chile.

The magnitude of the cost of chronic pain has been a matter of concern in many countries worldwide. The high prevalence, the cost it implies for the health system, productivity, and absenteeism need to be addressed urgently. Studies have begun describing this problem in Chile, but there is still a debt in highlighting its importance and urgency on contributing to chronic pain financial coverage. This study objective is to estimate the expected cost of chronic pain and its related musculoskeletal diseases in the Chilean adult population. We conducted a mathematical decision model exercise, Markov Model, to estimate costs and consequences. Patients were classified into severe, moderate, and mild pain groups, restricted to five diseases: knee osteoarthritis, hip osteoarthritis, lower back pain, shoulder pain, and fibromyalgia. Data analysis considered a set of transition probabilities to estimate the total cost, sick leave payment, and productivity losses. Results show that the total annual cost for chronic pain in Chile is USD 943,413,490, corresponding an 80% to the five diseases studied. The highest costs are related to therapeutic management, followed by productivity losses and sick leave days. Low back pain and fibromyalgia are both the costlier chronic pain-related musculoskeletal diseases. We can conclude that the magnitude of the cost in our country's approach to chronic pain is related to increased productivity losses and sick leave payments. Incorporating actions to ensure access and financial coverage and new care strategies that reorganize care delivery to more integrated and comprehensive care could potentially impact costs in both patients and the health system. Finally, the impact of the COVID-19 pandemic will probably deepen even more this problem.

Prevalence, burden of disease, and lost in health state utilities attributable to chronic musculoskeletal disorders and pain in Chile.

BACKGROUND: Musculoskeletal disorders are a leading cause of disability adjusted life years (DALY) in the world. We aim to describe the prevalence and to compare the DALYs and loss of health state utilities (LHSU) attributable to common musculoskeletal disorders in Chile. METHODS: We used data from the Chilean National Health Survey carried out in 2016-2017. Six musculoskeletal disorders were detected through the COPCOPRD questionnaire: chronic musculoskeletal pain, chronic low back pain, chronic shoulder pain, osteoarthritis of hip and knee, and fibromyalgia. We calculated the DALY for each disorder for 18 sex and age strata, and LHSU following an individual and population level approaches. We also calculated the fraction of LHSU attributable to pain. RESULTS: Chronic musculoskeletal pain disorder affects a fifth of the adult population, with a significant difference between sexes. Among specific musculoskeletal disorders highlights chronic low back pain with the highest prevalence. Musculoskeletal disorders are a significant cause of LHSU at the individual level, especially in the case of fibromyalgia. Chronic musculoskeletal pain caused 503,919 [283,940 - 815,132] DALYs in 2017, and roughly two hundred thousand LSHU at population level, which represents 9.7% [8.8-10.6] of the total LSHU occurred in that year. Discrepancy in the burden of musculoskeletal disorders was observed according to DALY or LSHU estimation. The pain and discomfort domain of LHSU accounted for around half of total LHSU in people with musculoskeletal disorders. CONCLUSION: Chronic musculoskeletal pain is a major source of burden and LHSU. Fibromyalgia should deserve more attention in future studies. Using the attributable fraction offers a straightforward and flexible way to explore the burden of musculoskeletal disorders.

Different Alternatives to Assess the Burden of Disease Using Attributable Fraction on a Disability Variable: The Case of Pain and Chronic Musculoskeletal Disorders in Chile.

OBJECTIVES: To estimate the burden of disease through 4 complementary procedures to years lived with disability (YLDs) using the concept of attributable fraction and including analysis of subdomains of disability. METHODS: We explored the burden on disability for 7 common musculoskeletal disorders (CMD) using the 2009 to 2010 Chilean National Health Survey, which included the Community Oriented Programme for the Control of Rheumatic Disease Core Questionnaire to identify cases with CMD, and an 8-domain questionnaire for health state descriptions. We calculated the proportion of disability attributable to pain in the general population and people with CMD. We also estimated the burden of CMD expressed as YLD and as the proportion of the disability in the general population attributable to people with CMD, with a particular focus in the pain domain of disability. Second order of uncertainty around point estimations was also characterized. RESULTS: Pain domain of disability accounted for 23.4% of the total disability in the general population, and between 20% (fibromyalgia) to 27.1% (osteoarthritis of the hip) in people with some of the selected CMD. People with chronic musculoskeletal pain accounted for 21.2% of total disability from general population, which generated 1.2 million of YLD (6679 YLD/100 000 inhabitants). Chronic low back pain and osteoarthritis of the knee were in the top position of specific CMDs, explaining the highest national burden. CONCLUSION: Pain is an essential component of disability in people with CMD and also in the general population. The approach used can be easily applied to other health conditions and other domains of disability.

Costs and consequences of chronic pain due to musculoskeletal disorders from a health system perspective in Chile.

BACKGROUND: Chronic pain is a prevalent and distressing condition caused by an unceasing pain lasting more than 3 months or a pain that persists beyond the normal healing time. There is evidence of inadequate management partly explained by the unawareness regarding the magnitude of the problem. OBJECTIVES: To estimate the annual expected costs and consequences of chronic pain caused by musculoskeletal diseases from the health system perspective in Chile. METHODS: A Markov cohort model was built to represent chronic pain and estimate expected costs and consequences over 1-year time horizon. Transition probabilities were obtained through expert elicitation. Consequences examined were: years lost to disability (YLD), depression, anxiety, and productivity losses. Direct health care costs were estimated using local sources. Probabilistic sensitivity analysis was performed to characterize second-order uncertainty. RESULTS: The annual expected cost due to musculoskeletal chronic pain was estimated in USD $1387.2 million, equivalent to 0.417% of the national GDP. Lower back pain and osteoarthritis of the knee explained the larger proportion of the total cost, 31.8% and 27.1%, respectively. Depression attributed to chronic pain is another important consequence accounting for USD $94 million (Bayesian credibility interval 95% $49.1-$156.26). Productivity losses were also important cost, although early retirement and presenteeism were not measured. Chronic pain causes 137,037 YLDs. CONCLUSION: Chronic pain is not only an important cause of disability but also responsible for high social and financial burden in Chile. Public health programs focused on managing chronic pain may decrease burden of disease and possibly reduce costs.

Survey of chronic pain in Chile - prevalence and treatment, impact on mood, daily activities and quality of life.

Background and aims The prevalence of chronic non-cancer pain has not been specifically reported in Chile. Methods In order to assess its prevalence and impact, we designed a tool based on previously published survey studies. We analyzed a sample of 784 subjects to determine the prevalence of chronic non-cancer pain, with a maximum variability of 50%, a confidence interval (CI) of 95%, and an estimation error of 3.5%. Finally, a cross-sectional cell phone survey was conducted on a nationally representative probability sample of 865 subjects of over 18 years, in November 2013. The prevalence of chronic non-cancer pain was estimated by using expansion factors according to national projections by age group and gender, from the Chilean National Institute of Statistics for the year 2010. Results The estimated prevalence of chronic non-cancer pain was 32.1% (95% CI: 26.5-36.0). The respondents with chronic non-cancer pain presented the following results: 65.7% had moderate pain, and 20.8%, severe pain; 65.6% had somatic pain, 31.7% neuropathic pain, and 2.7% visceral pain. Approximately 70% reported they were receiving some kind of pharmacological treatment with certain frequency. In 64.9%, medication was prescribed by a physician. The prevalence of sick leave in workers was 30.22%, with a median duration of 14 days (interquartile range: 14; range: 1-60). Conclusions Chronic non-oncological pain occurs in 32% of Chilean adults. These figures provide the first measurement of chronic non-cancer pain in the Chilean population. Implications Chronic non-oncological pain impact as a public health problem is revealed, given the high prevalence found, and the elevated private and social costs involved.

Validación primera encuesta chilena de dolor crónico no oncológico / Chilean validation survey of chronic non cancer pain

Existen escasos estudios sobre prevalencia de dolor crónico no oncológico en nuestro país. Objetivo: Realizar y presentar un instrumento validado que permita estimar la prevalencia y el impacto del dolor crónico no oncológico en Chile. Método: Se diseñó un instrumento basado en European Survey of Pain, Pain Survey U.S. Population, Canadian Chronic Pain Survey y la Encuesta Prevalencia de Dolor de la Federación Latinoamericana de Dolor. Se realizó una encuesta sobre teléfonos móviles, en un estudio piloto, en una muestra probabilística representativa a nivel nacional de 20 sujetos, mayores de 18 años de edad. Resultados: Se realizó un instrumento validado de 27 secciones, en el cual se determinó una prevalencia de 30,2 (IC95 por ciento: 22,5 – 37,4). Conclusiones: Presentamos un instrumento validado con el objetivo de determinar la prevalencia y las características clínicas del dolor crónico no oncológico a nivel chileno...

There are few studies on the prevalence of chronic non-cancer pain in our country. Aim of Investigation: To make and present a validated instrument that will allow to estimate the prevalence and impact of chronic non-cancer pain in Chile. Methods: We designed an instrument based on the European Survey of Pain, the US Population-Based Pain Survey, the Canadian Chronic Pain Survey and the Latin American Federation of Pain Prevalence Survey. A cross sectional cell phone survey was conducted in a pilot study in a nationally representative probability sample of 20 subjects, over 18 years old. Results: We made a validated instrument of 27 sections, the prevalence of chronic non-cancer pain was 30.2 (95 percent CI 22.5 - 37.4). Conclusions: We present a validated instrument to determine the prevalence and clinical characteristics of non-cancer chronic pain in Chilean people...

Revisión sistemática: epidemiología de dolor crónico no oncológico en Chile / Systematic review: epidemiology of non-oncologic chronic pain in Chile

El dolor es una de las causas más comunes de consulta clínica dentro de la población. En las consultas médicas de los pacientes, el dolor está presente en aproximadamente el 70 por ciento .A pesar de que el dolor crónico es común, existe escasa literatura publicada que refleja la epidemiología del dolor crónico dentro de la población. Entre los países, la prevalencia oscila entre el 5 por ciento - 45 por ciento. Debido a que el dolor crónico se puede analizar, a través, de diferentes perspectivas de los médicos, es difícil comparar los estudios que se han publicado a nivel nacional como internacional. En Chile, hay estimaciones que un 41,1 por ciento de la población mayor de 17 años presentan dolor. Cuando se hace una comparación con otros estudios, aunque la prevalencia numérica puede variar significativamente, existen similitudes, el dolor crónico no oncológico es más frecuente en las mujeres, en las personas mayores y está presente cuando hay otras enfermedades que tenga el paciente. En la siguiente revisión sistemática exponemos información sobre los distintos aspectos epidemiológicos de dolor crónico que se encuentran en Chile y algunos otros países en el mundo. A pesar de que no hay información disponible, existe una importante necesidad de de publicar estudios que reflejen la prevalencia de los pacientes con dolor crónico, para lograr un tratamiento de este síntoma de manera más eficiente y mejorar la calidad de vida de estos pacientes...

Pain is the most common cause of clinical consultation within the population. In the history of patients that go to the doctor, pain is present in approximately 70 percent of the time. Even though chronic pain is very common, there is not much literature published that reflects the epidemiology of chronic pain within the population. Between countries, the prevalence reported varies from 5 percent - 45 percent. Because chronic pain can be analyzed through different perspectives by physicians, it is difficult to compare studies that have been published nationally and internationally. In Chile,41,1 percent of the population older than 17 years could present pain. When a comparison is made with other studies, though the prevalence numbers may vary significantly, there is a similarity. Non-oncologic chronic pain is more frequent in women, in the elderly and it is present when there are other illnesses that the patient has. In the following systematic review we expose information regarding the different epidemiologic aspects of chronic pain found especially in Chile and some other countries in the world. Even though there is information available, there is an important need to further continue to publish studies that reflect the prevalence of patients with chronic pain, to further treat this symptom more efficiently and to improve the quality of life of these patients...

Guía para definición y manejo del dolor neuropático localizado (DNL): consenso chileno / Guidelines for definition and management of localized neuropathic pain (LNP): Chilean consensus

En los últimos años, diversas Guías para el Manejo del Dolor Neuropático (DN) se han elaborado por grupos de expertos en Dolor. La Asociación Chilena para el Estudio del Dolor (ACHED), representada por diversos especialistas, se reunió los días 5 y6 de agosto para elaborar la “Guía para Definición y Manejo del Dolor Neuropático Localizado (DNL): Consenso Chileno”.Utilizando el Método Delphi, se establecieron consensos con respecto a la entidad Dolor Neuropático Localizado (DNL), tanto en su Definición, Diagnóstico, Manejo Farmacológico y No Farmacológico, constituyendo de este modo, cuatro (4) grupos de trabajo; se establecieron asimismo comisiones para Dolor Pediátrico y Procedimientos Intervencionistas. Los principales resultados permiten contar con una definición clara de DNL, innovaciones en su diagnóstico, algoritmos sencillos para su manejo y recomendaciones no farmacológicas de importancia. Esta Guía para la Definición, Diagnóstico y Manejo del DNL será una herramienta de mucha utilidad en la práctica clínica, especialmente para los médicos generales y para la conformación de equipos multidisciplinarios para la mejor atención de los pacientes de DNL. El Consenso, luego de revisar evidencias y por la experiencia clínica de los expertos, recomiendan las terapias tópicas como las más indicadas en tratamiento del DNL.

In recent years, several Guidelines for the Management of Neuropathic Pain (NP) have been developed by groups that specialize in pain. The Chilean Association for the Study of Pain (ACHED), represented by different specialists, met on the5th and 6th of August to develop the Guidelines for Definition and Management of Localized Neuropathic Pain (LNP): Chilean Consensus”. Using the Delphi method, a series of consensus have been established regarding the Localized Neuropathic Pain (LNP) entity, both in its definition, diagnosis, pharmacological and non pharmacological management, thus constituting four (4) workgroups; committees were also established for pediatric pain and interventional procedures. The main results allow us to have a clear definition of LPN, innovations in its diagnosis, simple algorithms for its management and important non-pharmacological recommendations. The Guidelines for Definition and Management of the LNP will be a very useful tool in clinical practice, especially for general practitioners and for the formation of multidisciplinary teams to improve healthcare for LNP patients. The Consensus, after reviewing evidence and clinical experience, recommends topical therapies as the most appropriate treatment in LPN.

Effect of natural and synthetic polyamines on ethanol intake in UChB drinker rats.

Because of the important glutamatergic mediation of the behavioral effects of ethanol, glutamatergic agents have attracted attention for the treatment of ethanol abuse and dependence in preclinical and clinical studies. In the present study, we investigated the effect of pharmacological doses of the natural polyamines putrescine, spermine, and spermidine and the synthetic polyamine N,N'-bis-(3-aminopropyl)cyclohexane-1,4-diamine (DCD) on alcohol consumption in a free-choice paradigm carried out in genetically high-ethanol-consumer UChB rats. Short 3-day treatment with either polyamine, administered p.o., significantly reduced ethanol intake without modifying water and food intakes. Neither polyamine was able to increase markedly blood acetaldehyde in rats submitted to a standard challenge dose of ethanol, to rule out a disulfiram-like effect. Besides, blood ethanol disappearance after a test dose of ethanol was not affected by the synthetic polyamine DCD. Long-term treatment with DCD dose-dependently reduced ethanol intake in UChB rats without producing any observable effect on overt behavior, food consumption, and total fluid intake. The present results indicate that pharmacological doses of polyamines can reduce ethanol consumption in genetically drinking rats without producing significant side effects, suggesting that modulation of brain N-methyl-d-aspartate receptors by polyamines could represent a suitable strategy to reduce appetite for ethanol. However, caution must be exercised in interpreting the results because polyamines can also affect neuronal excitability by acting at other receptor targets, such as AMPA and kainate receptors, as well as at some voltage-dependent ion channels.

A new polyamine derivative, a structural analog of spermine, with in vivo activity as an inhibitor of ethanol appetite.

This report describes the design and synthesis of the synthetic polyamine DCD (N,N'-bis-(3-aminopropyl)cyclohexane-1,4-diamine, tetramethanesulfonate), a structural analog of spermine, and its in vivo activity as an inhibitor of alcohol consumption in a free-paradigm carried out on genetically high-ethanol-consuming UChB rats. After acute treatment with DCD (daily single dose, 20 mg/kg, p.o., 3 days), a 19% decrease in ethanol intake was obtained, without affecting the levels of food and water intake. After chronic treatment (daily single dose, 20mg/kg, p.o., 60 days) a decrease of up to 60% in ethanol intake with respect to the basal period was provoked; this effect was significantly maintained during the post-treatment period and, according to the data obtained from the determination of acetaldehyde levels in blood, was not related to a possible disulfiram-like effect. The design of this new compound was carried out using molecular modeling techniques, with the structures of natural polyamines (putrescine, spermidine, and spermine) and biosynthetically related diamines (1,3-diaminopropane; DAP) as templates. These polyamines have shown activity as inhibitors of ethanol appetite in the same experimental model.

Effect of the synthetic polyamine N,N'-bis-(3-aminopropyl) cyclohexane-1,4-diamine (DCD) on rat spinal cord nociceptive transmission.

In rats submitted to a C-fiber reflex response paradigm, intravenous (i.v.) administration of 2.5, 5 and 10 mg/kg of the synthetic polyamine N,N'-bis-(3-aminopropyl) cyclohexane-1,4-diamine (DCD) dose-dependently reduced both the integrated C reflex responses and wind-up activity. Inhibitory effects of the polyamine on spinal cord nociceptive transmission are likely to be consequence of blockade by extracellular DCD of NMDA receptor channels localized in dorsal horn neurons, although modulatory actions at supraspinal level and at other ion channels could also be possible.