RT doctoral thesis
T1 Prevalence and associated factors of the use of opioids in the treatment of chronic non-cancer pain. Perspective of the general Spanish population and the experience of patients.
A1 Sola Perea, Helena de
A2 BiomedicinaBiotecnología y Salud Pública
K1 Opioids
K1 Chronic pain
K1 Prevalence
K1 Mortality
K1 Experiences
AB AimsThe general aim of this thesis was to study the situation of opioid treatments for chronic noncancer pain (CNCP). The specific aims were: first, to determine and synthesize the prevalence ofthe therapeutic use of opioids in patients with CNCP, and to analyze the factors associated withtheir use through a systematic review of the literature and a meta-analysis; second, toinvestigate the evolution of opioid-related mortality and potential years of life lost in the generalpopulation in Spain from 2008 to 2017 and to compare the results by gender and age with theUnited States; third, to describe the current perspective of the Spanish population toward opioiduse in the treatment of pain and to identify groups of individuals based on their point of viewon these drugs; and finally, to explore the experiences of patients with chronic non-malignantlow back pain in Spain undergoing long-term treatment (>3 months) with opioids.MethodsIn the first study of the thesis, a systematic review of the current literature and meta-analysiswere performed using two databases (PubMed and SCOPUS). For this purpose, original crosssectional studies published in English or Spanish between 2009 and 2019 with the main objectiveof determining the prevalence of opioid use in CNCP patients were included. Search terms andsearch strategies were adapted to each database. The articles included in the meta-analysiswere stratified according to the source of the sample, the type of pain, and the duration of theopioid treatment.The second paper of the thesis is a descriptive study using retrospective annual data from 2008to 2017 in the general population of Spain and the United States. Information on the populationand opioid-related deaths stratified by age and sex was obtained from the Spanish NationalStatistics Institute and from the Centers for Disease Control and Prevention (CDC) WONDERMultiple Cause of Death Database, according to the ICD-10 codes. Years of life lost, crude andstandardized mortality rates were calculated and compared with the results in US.The third article included in the thesis is a cross-sectional study carried out on a nationwiderepresentative sample of 1,299 Spanish adults. Data and information about beliefs, knowledge,fears, opinions and, attitudes towards the use of opioids were collected via a computer assistedtelephone interview (CATI). A descriptive analysis of the variables studied and a cluster analysiswere performed to identify groups of people based on these parameters. In addition, a 18ABSTRACT. 18multinomial logistic regression model was developed to analyze the variables related to theclusters.Finally, in the last part of the thesis, a qualitative study was performed using semi-structuredinterviews. Recruitment and data collection were conducted from April to October 2018. Fifteenparticipants were recruited from the Pain Clinic in Hospital Puerta del Mar. Inclusion criteria forthe study were: adults suffering from chronic non-malignant low back pain and receiving longterm treatment (>3 months) with opioids. We conducted interviews until very similarexperiences were described in the last interviews as in the previous ones. A constructionistperspective was adopted. The interviews were analyzed by the qualitative content methoddescribed by Graneheim and Lundman, and developed categories and themes discussed in thelight biomedicalization theoretical framework.ResultsIn the first article, we identified that of the 1062 potential articles found in the systematicreview, 23 studies fulfilled the inclusion criteria. In the general population, the prevalence oflong-term (>3 months) opioid use was 2.3% (95%CI:1.5%-3.6%), the prevalence of short-termopioid use was 7.3% (95%CI:4.3%-11.9%), and 5.8% among people with chronic low back pain(95% CI:0.5% - 45.5%). The prevalence of opioid use among patients from the health records ormedical surveys was 41% (95%CI:23.3%-61.3%). Finally, in patients with musculoskeletal pain,the prevalence was 20.5% (95%CI:12.9%-30.9%) and 24.5% among patients with fibromyalgia(95%CI:22.9%-26.2%). A higher prevalence of opioid use was observed among the followinggroups: men; younger people; patients receiving prescriptions of different types of drugs;smokers and patients without insurance or with non-commercial insurance. In addition, nonwhite and Asian patients were less likely to receive opioids than non-Hispanic white patients.The results of the second study showed that the crude rate of opioid-related deaths per 10^5inhabitants has changed from 1.68 in 2008 to 2.25 in 2017 in Spain, with around 30,000 years oflife lost per year. The most affected groups were middle-aged men and women over 65, and themain cause of death was accidental poisoning. The standardized rates per 10^5 inhabitantsacross the years were between 1.19 and 1.62 in Spain and between 11.17 and 20.68 in the USpopulation. 19ABSTRACT. 19In the analysis of the beliefs, fears, opinions and attitude towards opioids analyzed in the thirdarticle in the general Spanish population, three groups of subjects were identified: a group witha positive point of view (N=448) composed of people >65 years who would accept a treatmentif prescribed and were less fearful of these drugs; a group with a moderate point of view (N=337)formed of younger subjects with university education, and who were better informed aboutopioids, afraid of these drugs (OR=2.67), and more frequently associated them with drowsiness(OR=2.58), nausea (OR=3.04), and tolerance (OR=2.16); a third group with a negative point ofview (N=468), with a lower educational level who would more often reject treatment withopioids, and were more afraid of them (OR=3.95), considering that they may not be able to stopthe treatment (OR=3.04) and that the opioids may produce tolerance (OR=3.03).Finally, in the analysis of the experiences of people with chronic pain (CP) taking opioids,described in the fourth article, we developed one overarching theme - living with opioids:dependence and autonomy while seeking relief - which crosscut three categories: 1) The longpathway to opioids due to the invisibility of pain, 2) Opioids: from blind date to a long-termrelationship and 3) What opioids cannot fix. The results show that the long and difficult processto obtain effective treatment was a fundamental part of the struggle to cope with pain, involvinglong-term relationships with the health system. The two first categories refer to the journeyparticipants made to get a diagnosis and treatment with opioids, and their experiences duringthis long and difficult process, which was quite unique for each person. The third categorydescribes the circumstances and situations experienced by the patients before and after thepainful episode started, and how these influenced the whole process.ConclusionsThe results obtained in the different studies lead to the following conclusions:- The prevalence of opioid use in patients with CNCP varies depending on the durationof treatment and the population analyzed, with higher prevalence in clinical studiesbased on health registries and occasional users. Age, race, and the access to thehealth service delivery system and its characteristics are the factors most related tothe use of opioids.- Regarding opioid-related mortality, an opioid overuse crisis does not seem a likelyscenario in Spain. However, it is a social problem that requires special healthsurveillance, particularly in middle-aged men and women over 65.20ABSTRACT. 20- The different perspectives of patients regarding the use of opioids to treat painshould be taken into consideration by physicians when designing strategies toinform patients about the treatment of pain with opioids. This should promote theircorrect use, and prevent their misuse in particular.- The experiences of patients should be considered to a greater extent by healthcareprofessionals when giving information about opioids and setting treatment goals.Greater consideration of the social determinants of health that affect chronic painexperiences might lead to more effective solutions to chronic pain.
YR 2020
FD 2020-07-07
LK http://hdl.handle.net/10498/23642
UL http://hdl.handle.net/10498/23642
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 08-may-2026