Improving medication adherence in hypertensive patients: A scoping review.

In recent years, interest in medication adherence has greatly increased. Adherence has been particularly well studied in the context of arterial hypertension treatment. Numerous interventions have addressed this issue, however, the effort to improve adherence has been often frustrating and frequently disorganized. The aim of present study was to perform a scoping review of medication adherence interventions in hypertensive patients, so that a clear overview was achieved. Moreover, an evidence-based categorization of interventions was developed. The review was performed according to the PRISMA-ScR statement. MEDLINE and Web of Science were searched, and studies published from database inception until August 17, 2020 were included. A total of 2994 non-duplicate studies were retrieved. After screening and eligibility phases, a total of 45 articles were included. Studies were analyzed regarding their design, participant characteristics and management of adherence strategies employed. Furthermore, medication adherence and blood pressure outcomes, as well as adherence measuring tools were evaluated. Each study's intervention was then categorized using a novel evidence-based system of categorization, derived from the conceptual clustering framework used in machine learning. This work is an important step in pushing for better informed and more efficient future research efforts, both by providing an overview of the research field and by creating a new, evidence-based intervention categorization tool. It also provides valuable information to clinicians about medication adherence to antihypertensive therapy.

A Two-Year Prospective Multicenter Study of Opioid Therapy for Chronic Noncancer Pain: Prescription Trends and Predictors.

OBJECTIVES: Opioid use in chronic pain has increased worldwide in recent years. The aims of this study were to describe the trends and patterns of opioid therapy over two years of follow-up in a cohort of chronic noncancer pain (CNCP) patients and to assess predictors of long-term opioid use and clinical outcomes. METHODS: A prospective cohort study with two years of follow-up was undertaken in four multidisciplinary chronic pain clinics. Demographic data, pain characteristics, and opioid prescriptions were recorded at baseline, three, six, 12, and 24 months. RESULTS: Six hundred seventy-four CNCP patients were recruited. The prevalence of opioid prescriptions at baseline was 59.6% (N = 402), and 13% (N = 86) were strong opioid prescriptions. At 24 months, opioid prescription prevalence was as high as 74.3% (N = 501), and strong opioid prescription was 31% (N = 207). Most opioid users (71%, N = 479) maintained their prescription during the two years of follow-up. Our opioid discontinuation was very low (1%, N = 5). Opioid users reported higher severity and interference pain scores, both at baseline and after two years of follow-up. Opioid use was independently associated with continuous pain, pain location in the lower limbs, and higher pain interference scores. CONCLUSIONS: This study describes a pattern of increasing opioid prescription in chronic pain patients. Despite the limited improvement of clinical outcomes, most patients keep their long-term opioid prescriptions. Our results underscore the need for changes in clinical practice and further research into the effectiveness and safety of chronic opioid therapy for CNPC.

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.

Portuguese Version of the Pain Beliefs and Perceptions Inventory: A Multicenter Validation Study.

BACKGROUND: We aimed to perform the translation, cultural adaptation, and validation of the Pain Beliefs and Perceptions Inventory (PBPI) for the European Portuguese language and chronic pain population. METHODS: This is a longitudinal multicenter validation study. A Portuguese version of the PBPI (PBPI-P) was created through a process of translation, back translation, and expert panel evaluation. The PBPI-P was administered to a total of 122 patients from 13 chronic pain clinics in Portugal, at baseline and after 7 days. Internal consistency and test-retest reliability were assessed by Cronbach's alpha (α) and intraclass correlation coefficient (ICC). Construct (convergent and discriminant) validity was assessed based on a set of previously developed theoretical hypotheses about interrelations between the PBPI-P and other measures. Exploratory and confirmatory factor analyses were performed to test the theoretical structure of the PBPI-P. RESULTS: The internal consistency and test-retest reliability coefficients for each respective subscale were α = 0.620 and ICC = 0.801 for mystery; α = 0.744 and ICC = 0.841 for permanence; α = 0.778 and ICC = 0.791 for constancy; and α = 0.764 and ICC = 0.881 for self-blame. Exploratory and confirmatory factor analysis revealed a four-factor structure (performance, constancy, self-blame, and mystery) that explained 63% of the variance. The construct validity of the PBPI-P was shown to be adequate, with more than 90% of the previously defined hypotheses regarding interrelations with other measures confirmed. CONCLUSION: The PBPI-P has been shown to be adequate and to have excellent reliability, internal consistency, and validity. It may contribute to a better pain assessment and is suitable for research and clinical use.

Obstructive sleep apnea representations, self-efficacy and family coping regarding APAP adherence: a longitudinal study.

Adherence is still an important issue considering new advances in Obstructive Sleep Apnea (OSA) treatment, as automatic positive airway pressure (APAP). The aim of the present study was to identify and explore relationships between identified predictors of adherence, over time. After overnight sleep study and OSA diagnosis and during a six-month APAP treatment period, a total of 153 patients underwent a three time psychological protocol evaluation. Generalized estimating equations were applied to analyzed repeated measurements in the same individuals. Results show that 40% of patients were poorly adherent and 60% were adherent after six months of treatment. The results confirmed a predictive value of age, self-efficacy, decisional balance index and health-related quality of life (HRQoL) in APAP adherence. Furthermore, the results revealed an interaction between time and illness cognitive representations, and self-efficacy and family coping, in explaining adherence patterns over time. Therefore, understanding the causality of theoretically derived constructs is crucial to predict the continuity of APAP adherence.

A systematic review on experimental studies about patient adherence to treatment.

A better understanding of patients' adherence to treatment is a prerequisite to maximize the benefit of healthcare provision for patients, reduce treatment costs, and is a key factor in a variety of subsequent health outcomes. We aim to understand the state of the art of scientific evidence about which factors influence patients' adherence to treatment. A systematic literature review was conducted using PRISMA guidelines in five separate electronic databases of scientific publications: PubMed, PsycINFO (ProQuest), Cochrane library (Ovid), Google Scholar, and Web of Science. The search focused on literature reporting the significance of factors in adherence to treatment between 2011 and 2021, including only experimental studies (e.g., randomized controlled trials [RCT], clinical trials, etc.). We included 47 experimental studies. The results of the systematic review (SR) are grouped according to predetermined categories of the World Health Organization (WHO): socioeconomic, treatment, condition, personal, and healthcare-related factors. This review gives an actual overview of evidence-based studies on adherence and analyzed the significance of factors defined by the WHO classification. By showing the strength of certain factors in several independent studies and concomitantly uncovering gaps in research, these insights could serve as a basis for the design of future adherence studies and models.

A new characterization of adherence patterns to auto-adjusting positive airway pressure in severe obstructive sleep apnea syndrome: clinical and psychological determinants.

PURPOSE: The aim of this study was to examine the joint role of demographic, clinical, psychological and family coping variables as predictors of adherence patterns to auto-adjusting positive airway pressure (APAP). METHODS: A total of 153 patients diagnosed with obstructive sleep apnea syndrome (OSAS) were assessed during a 6-months APAP treatment period. All patients underwent psychological evaluation prior to treatment (T1) and 1 to 3 months (T2) and 4 to 6 months (T3) post-APAP treatment. Of these, 107 patients maintained a stable adherence pattern to APAP during the treatment period. RESULTS: Forty-seven percent were poorly adherent, 27 % were moderately adherent and 26 % were optimally adherent OSAS patients. Several factors distinguished the three adherence patterns and some of these emerged as the main predictors. In T1, the first model included age, apnea-hypopnea index, outcome expectations and coping spiritual support, as main predictors to distinguish adherence patterns. In T2 and T3, two models emerged adjusted to the variables of model 1 that included leakage, self-efficacy, mobilizing family acquire/accept support and reframing in model 2 and self-efficacy in model 3. Generally, the areas under the ROC curve, presented a good discrimination. CONCLUSIONS: Findings revealed an integrative heuristic model that accounted for the joint influence of demographic, clinical, psychological, and family coping factors on poor, moderate, and optimal adherence patterns.

Effectiveness of a group education session on adherence with APAP in obstructive sleep apnea--a randomized controlled study.

PURPOSE: Auto-titrating continuous positive airway pressure (APAP) is an effective treatment for obstructive sleep apnea/hypopnea syndrome (OSAHS). We investigated whether a single group education session on APAP therapy is effective in promoting adherence among patients with OSAHS. METHODS: This prospective, randomized, controlled, parallel group study included patients newly diagnosed with OSAHS who met criteria for APAP therapy. Patients were randomized into a study group and a control group. All patients in the study group were assigned to a single group education session, 1 month after beginning APAP therapy. RESULTS: We evaluated 146 patients. The median percentage of APAP usage days was 88.3 %, with a median duration per day of use of 6.02 h; 59 % were classified as adherent. Overall, no significant difference in adherence was seen between the study and the control groups. Analyzing patient subgroups, the group session significantly improved APAP adherence among males and patients who were younger (<65 years old), obese (BMI ≥ 35 kg/m(2)), non-sleepy (Epworth sleepiness scale ≤ 11), smokers or past smokers, had hypertension or nocturia and those with non-severe OSAHS. CONCLUSION: To maximize the impact of group education sessions and, by that, saving resources, it may be important to select patients likely to benefit from these sessions.

Adherence to glucose monitoring with intermittently scanned continuous glucose monitoring in patients with type 1 diabetes.

PURPOSE: This study aims to predict the Intermittently scanned continuous glucose monitoring (isCGM) adherence behavior of patients with Type 1 Diabetes. METHODS: Patients with Type 1 Diabetes mellitus using FreeStyle Libre™ System (FL), a isCGM device, that attended the "Insulin Infusion Pump clinic" at Centro Hospitalar de São João were enrolled and evaluated for sociodemographic and clinical characterization, beliefs and concerns about Diabetes Mellitus, as well as isCGM's perceptions. Intermittently scanned continuous glucose monitoring data were collected to characterize monitoring patterns and to measure isCGM's adherence-FL average of scans/day. RESULTS: Seventy-two patients with a mean of 30.36 years (sd=11.35) participate in this study. A median of 7 scans/day was performed. The adherence predictors found was Age (ß = 0.191, p = 0.006), Time in target (ß = 0.530, p = 0.002), isCGM Necessity (ß = 2.631, p = 0.048), Body Mass Index (ß = -0.549, p = 0.017) and Sex (ß = -3.996; p = 0.011). CONCLUSIONS: This study emphasizes the relevance of glucose monitoring adherence in disease control and shows that males of younger ages, presenting with higher body mass index levels, lower time in target, and reporting lower isCGM necessity are less adherent to isCGM. Therefore, these patients should be closely followed and object of personalized strategies to promote treatment adherence.

Managing Non-Cancer Chronic Pain in Frail Older Adults: A Pilot Study Based on a Multidisciplinary Approach.

Considering the multidimensionality of chronic pain, it is crucial to develop comprehensive strategies for its effective management. However, establishing well-defined, evidence-based guidelines for such approaches remains challenging. To overcome this, we present the finding from a 4-month intervention to enhance the management of non-cancer chronic pain in older adults with pre-frailty and frailty. The intervention's core elements comprised a multidisciplinary individualized plan, a case manager, and patient education. This pilot study involved 22 participants (≥65 years). It assessed changes in pain frequency and intensity (pain scale), frailty (Fried frailty phenotype criteria), and medication adherence (Brief Adherence Rating Scale) before and after the 4-month intervention. The results were encouraging: pain frequency and intensity and frailty score tended to decrease, and medication adherence showed significant improvement. This preliminary small-scale pilot study provides a foundation for further research and for exploring the potential scalability of this multidisciplinary patient-centred intervention.

Translation and cross-cultural adaptation of the ABC taxonomy for medication adherence into Portuguese - Updating patients into people.

BACKGROUND: The Ascertaining Barriers to Compliance (ABC) taxonomy for describing medication adherence was created in 2012, aiming to standardize terms and definitions in research and practice. The taxonomy comprises seven terms and definitions. Originally developed in English, subsequently translated into French and German, is currently being translated to Portuguese, Spanish, Czech, Romanian and Italian, aiming to promote its global use and overcome cultural barriers. OBJECTIVES: To cross-culturally translate the ABC taxonomy into Portuguese for Portugal and Brazil. METHODS: A systematic literature search was conducted to identify published taxonomy terms and definitions in Portuguese, and to identify panelists in medication adherence. Initial mapping of terms and definitions retrieved was scrutinized by the research team to build an e-survey. The e-survey was piloted and then sent to panelists in both countries seeking consensus using a three-round Delphi method. Consensus was defined as ≥ 85% for round 1 and ≥ 75% for round 2. Terms with agreement <10% were dropped between rounds. In round 3, terms and definitions reaching agreement between 50 and 75% were classified as moderate consensus,>75-95% as consensus and >95% as strong consensus. RESULTS: A total of 778 studies were identified and 84 included, enabling the extraction of 154 terms and 32 definitions. In round 1, 164 panelists participated, 115 in round 2 and 99 in the round 3. Consensus was achieved in both countries for all seven terms and definitions, although with varying intensity of agreement. The term "Management of adherence" and the definition of "Discontinuation" obtained moderate consensus in both countries. CONCLUSIONS: A unified and unique ABC taxonomy in Portuguese was possible to develop for use in Portugal and in Brazil. Its use will harmonize and standardize the terms and definitions used in clinical practice and research.

Strategies to combat COVID-19 in long -term care facilities for older people.

OBJECTIVE: To describe the strategies to combat COVID-19 in Long-Term Care Facilities for older people in Bahia state. METHODOLOGY: This is a qualitative study based on documentary analysis of the collection produced by the Intersectoral Committee on Monitoring Long-Term Care for older people in the state of Bahia, from April 2020 to June 2021. Data analysis was based on Bardin's content analysis. RESULTS: The commission produced seven documents in the period analyzed. Two thematic categories emerged: Intersectoral Networks and Telemonitoring of Long-Term Care Facilities for the Elderly. CONCLUSION: The coordination in an intersector network and the telemonitoring carried out by the Intersector Committee on Monitoring Long-Term Care Facilities were the main strategies to fight COVID-19 in these institutions. The need to implement effective public policies to support long-term care facilities for older people is highlighted.

Psychological morbidity, illness representations, and quality of life in female and male patients with obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is a sleep-related breathing disorder that affects both women and men. The aim of this study was to characterize and investigate the differences in terms of anxiety, depression, illness perception, and quality of life between female and male OSAS patients from a total of 111 patients (33 women and 78 men) who were recently diagnosed with OSAS in an outpatient clinic of a University Hospital in Portugal. They underwent a standardized protocol that included evaluation to assess of psychological morbidity (anxiety and depression - Hospital Anxiety and Depression Scale), illness representations (Brief Illness Perception Questionnaire), and quality of life (Sleep Apnea Quality of Life Index). The most significant differences between female and male OSAS patients result of apnea/hypopnea index (AHI), after controlling for body mass index (p < 0.05); anxiety (p = 0.000) and depression (p < 0.005); consequences (p < 0.005), identity (p = 0.000), coherence (p < 0.01), and emotional representation (p < 0.005) of OSAS; and for daily functioning (p = 0.000), emotional (p = 0.001), and symptoms (p < 0.05) domains of quality of life. Data suggest that women revealed more psychological morbidity associated with OSAS. Therefore, it seems extremely important to look at women as potential patients for sleep apnea and avoid looking up for a pattern of symptoms that rely on men as a norm to which women are compared.

Behaviour Change Interventions in Healthcare.

In September 2021, the Special Issue "Evidence-based Behaviour Change Interventions in Healthcare" was proposed as the manifestation of a will to compile multidisciplinary works of academic research focused on the effect of health education, psychology, and socio-cultural dimensions on the improvement in health habits in the population [...].

Patients and healthcare professionals perspectives on creating a chronic pain support line in Portugal: A qualitative study protocol.

Chronic pain affects almost 38% of the Portuguese adult population, with high costs for both patients and society. Those who suffer with chronic pain frequently complain of feeling misunderstood and of lack of support. These complaints are the main reason why support telephone lines for chronic pain were created in some countries. However, there is no scientific data supporting their creation or evaluating their performance. This paper presents a qualitative study protocol to assess patients and healthcare professionals' perspectives on the creation of a telephone support line for chronic pain. It constitutes the first step to attain the main goal of developing and implementing a functioning support line for chronic pain in Portugal. The methodology to assess patients and healthcare professionals' perspectives and needs is presented. In order to gather information as close to reality as possible, focus groups interviews were chosen as data sources. Given the present context of the COVID-19 pandemic, meetings will take place online, using a digital platform. All interviews will be transcribed verbatim, coded and synthesised into categories and main themes. Thematic analysis will be conducted using NVivo® V12 software, employing an iterative and reflexive approach. Finally, comparative and relational analysis will be performed in order to identify topics where patients and professionals converge or greatly diverge. The findings will be useful for grounding the creation of a telephone support line for chronic pain patients. Results dissemination will be important for policy-makers to develop a new perspective towards chronic pain services available.

Pharmacological Adherence Behavior Changes during COVID-19 Outbreak in a Portugal Patient Cohort.

Concerns, behaviours, and beliefs influence how people deal with COVID-19. Understanding the factors influencing adherence behaviour is of utmost importance to develop tailored interventions to increase adherence within this context. Hence, we aimed to understand how COVID-19 affected adherence behaviour in Portugal. A cross-sectional online survey was conducted between 1 March and 3 April 2021. Descriptive statistics were performed, as well as univariable and multivariable regression models. Of the 1202 participants, 476 who were taking at least one medication prescribed by the doctor were selected. Of these, 78.2% were female, and the mean age was 40.3 ± 17.9 years old. About 74.2% were classified as being highly adherent. During the pandemic, 8.2% of participants reported that their adherence improved, while 5.9% had worsened adherence results. Compared with being single, widowers were 3 times more prone to be less adherent (OR:3.390 [1.106-10.390], p = 0.033). Comorbid patients were 1.8 times (OR:1.824 [1.155-2.881], p = 0.010) more prone to be less adherent. Participants who reported that COVID-19 negatively impacted their adherence were 5.6 times more prone to be less adherent, compared with those who reported no changes (OR:5.576 [2.420-12.847], p < 0.001). None of the other variables showed to be significantly associated with pharmacological adherence.

Acceptance and Adherence to COVID-19 Vaccination-The Role of Cognitive and Emotional Representations.

Vaccine hesitation is a topic of utmost importance, with the COVID-19 pandemic serving as a clear reminder of its timeliness. Besides evaluating COVID-19 vaccine acceptance in a sample of Portuguese people, this study aims at understanding cognitive and emotional representations related to vaccination, and their influence on vaccination hesitation. A cross-sectional online survey was conducted between 27 December 2020 and 27 January 2021. It assessed cognitive and emotional COVID-19 representations; vaccination status; cognitive and emotional representations of vaccination and perceived necessity and concerns about vaccines. Of 31 × 58 participants, 91% accepted taking a COVID-19 vaccine. Among several other significant findings, women (71.3%) more often considered that the pandemic affected their lives (p < 0.001) and were more often concerned with being infected (p < 0.001). Likewise, there were significantly more female participants concerned about taking a COVID-19 vaccine and its possible effects, when compared to the number of male participants (p < 0.001). The number of participants with a higher education level that were more worried about becoming infected was greater (p = 0.001), when compared with those less educated. Regarding age groups, people aged 18 to 24 had fewer concerned participants (9.6%), while the number of individuals aged 55 to 64 had the most (p < 0.001). Somewhat surprisingly, perceiving oneself as extremely informed about COVID-19 was not associated with greater vaccine acceptance (OR = 1.534 [1.160−2.029]; (p = 0.003)). Moreover, people aged 25 to 64 years old and with lower education level were more likely not to accept vaccination (OR = 2.799 [1.085−7.221]; (p = 0.033)). Finally, being more concerned about taking a vaccine lowers its acceptance (OR = 4.001 [2.518−6.356]; (p < 0.001)). Cognitive and emotional representations have a great impact and are reliable predictors of vaccine acceptance. Thus, it is of extreme importance that public health messages be adapted to the different characteristics of the population.

Portuguese Version of the Intentional Non-Adherence Scale: Validation in a Population of Chronic Pain Patients.

Objective: Despite the effectiveness of pain medicines, nonadherence to prescribed medication remains a major problem faced by healthcare systems. The aim of present study was to perform the translation, cultural adaptation, and validation of the Intentional Non-Adherence Scale (INAS) for the European Portuguese language in a sample of chronic pain patients. Methods: A Portuguese version of the INAS scale was constructed through a process of translation, back translation, and expert's panel evaluation. A total of 133 chronic pain patients were selected from two chronic pain clinics from tertiary hospitals in Porto, Portugal. The protocol interview included the assessment of pain beliefs (PBPI), beliefs about medicine (BMQ), medication adherence (MARS-P9), and two direct questions about adherence previously validated. Results: The internal consistency in all subscales was α = 0.902 for testing treatment; α = 0.930 for mistrust treatment; α = 0.917 for resisting treatment; and α = 0.889 for resisting illness. Exploratory and confirmatory factor analysis revealed a four-factor structure that explained 74% of the variance. The construct validity of the INAS was shown to be adequate, with the majority of the previously defined hypotheses regarding intercorrelations with other measures confirmed. Conclusion: The Portuguese version of INAS could be a valuable and available instrument for Portuguese researchers and clinicians to assess the intentional nonadherence determinants during the management of chronic pain.

Non-Adherence to Pharmacotherapy: A Prospective Multicentre Study About Its Incidence and Its Causes Perceived by Chronic Pain Patients.

OBJECTIVE: Pharmacological interventions remain the cornerstone of chronic pain treatment; however, nearly 40% of the prescription medicines are not taken as prescribed. The present study aims at understanding and describing non-adherence from the perspective of chronic pain patients during a 1-year follow-up study. METHODS: A cohort of 950 consecutive patients referred to a first consultation in Multidisciplinary Chronic Pain Clinics was followed with a standardized protocol for 1 year. This included assessment of pain characteristics; prescribed medication; therapeutic adherence; effectiveness of treatment, non-adherence and its perceived reasons; clinical outcomes and quality of life. We used a mixed methods approach, including qualitative and quantitative analyses. RESULTS: Forty-nine percent of the 562 patients who responded to all assessments during follow-up were adherent after 1 year of chronic pain treatment. The core associations between each "non-adherence reason" and Anatomical Therapeutic Chemical Code (ATC) group were perceived side effects (p=0.019) and delayed start (p=0.022) for narcotic analgesics (opioids); perceived non-efficacy (p=0.017) and delayed start (p=0.004) for antiepileptics and anticonvulsants; perceived low necessity (p=0.041) and delayed start (p=0.036) for analgesics antipyretics; change in prescriptions because of a new clinical condition for antidepressants (p=0.024); high concerns (p=0.045) and change in prescriptions because of a new clinical condition (p<0.001) for non-steroidal anti-inflammatory drugs; delayed start (p=0.016) and financial constraints (p=0.018) for other medications. DISCUSSION: This study emphasizes the patient's perspective regarding non-adherence to pharmacological treatment of chronic pain, providing valuable and novel information to be used in future interventions to help patients make an informed choice about their adherence behavior.

Portuguese version of the Medication Adherence Report Scale (MARS-9): Validation in a population of chronic pain patients.

AIM: The aim of present study was to perform the translation, cultural adaptation, and validation of the Medication Adherence Report Scale (MARS-P9) for the European Portuguese language in a sample of chronic pain patients. METHODS: A Portuguese version of the nine-item MARS (©Professor Rob Horne) scale (MARS-P9) was constructed through a process of translation, back translation, and experts' panel evaluation. A total of 141 chronic pain patients were subsequently evaluated at four time assessments during a 1-year pain medication treatment. The protocol interview included the assessment of pain intensity and interference (BPI), clinical outcomes and quality of life (S-TOPS), and MARS-P9. RESULTS: The internal consistency coefficient was acceptable for the total scale (α = 0.84). Exploratory factor analysis revealed a two-factor structure (intentional and unintentional nonadherence) that explained 61% of the variance. Convergent and discriminant validity were demonstrated by correlations between MARS scores and pain interference (r = 0.180, P ≤ 0.01) and S-TOPS (r = 0.242, P ≤ 0.05). CONCLUSION: MARS-P9 has been shown to be an adequate instrument for Portuguese researchers and clinicians to assess the pattern of adherence during the management of chronic pain.