Antibody-ligand interactions on a high-capacity staphylococcal protein A resin.

Staphylococcal protein-A affinity chromatography has been optimized for antibody purification, achieving a current capacity of up to 90 mg/ml in packed bed. The morphology of the particles, the number of antibodies bound per ligand and the spatial arrangement of the ligands were assessed by in-situ Small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) combined with measurement of adsorption isotherms. We employed SAXS measurements to probe the nanoscale structure of the chromatographic resin. From scanning electron microcopy, the morphology and area of the beads were obtained. The adsorption isotherm revealed a bi-Langmuirian behavior where the association constant varied with the critical bulk concentration, indicating multilayer adsorption. Determining the antibody-ligand stoichiometry was crucial for understanding the adsorption mechanism, which was estimated to be 4 at lower concentrations and 4.5 at higher concentrations, suggestive of reversible protein-protein interactions. The same results were reached from the in-situ small angle X-ray scattering measurements. A stoichiometry of 6 cannot be achieved since the two protein A monomers are anchored to the stationary phase and thus sterically hindered. Normalization through ellipsoids facilitated SAXS analysis, enabling the determination of distances between ligands and antibody-ligand complexes. Density fluctuations were examined by subtracting the elliptical fit, providing insights into ligand density distribution. The dense ligand packing of TOYOPEARL® AF-rProtein A HC was confirmed, making further increases in ligand density impractical. Additionally, SAXS analysis revealed structural rearrangements of the antibody-ligand complex with increasing antibody surface load, suggesting reversible association of antibodies.

Discrepancies among equations to estimate the glomerular filtration rate for drug dosing decision making in aged patients: a cross sectional study.

BACKGROUND: Patients often require adjustments to drug doses due to impaired renal function. Glomerular filtration rate (GFR) estimation using various equations can result in discrepancies, potentially leading to different dose adjustment recommendations. AIM: To determine the clinical significance of discrepancies observed between different equations used to estimate GFR for drug dose adjustments in a real-world group of patients over 65 years in primary care. METHOD: The Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Berlin Initiative Study 1 equations were applied to estimate GFR in a group of patients over 65 years old attending a primary care center. Results were compared using Bland-Altman plots, and limits of agreement (LoA) and overall bias were calculated. Regression analyses were conducted to identify the null difference GFR and the slope of differences for each pairwise comparison. RESULTS: A total of 1886 patients were analyzed. Differences between patient-adjusted and body surface area (BSA)-normalized versions of the equations were not clinically relevant for dose adjustments, with LoAs below 20 mL/min. However, discrepancies among the original versions of several equations presented LoAs over 30 mL/min. Greater differences were found between CG and MDRD or CKD-EPI equations. CONCLUSION: Clinically relevant differences in GFR estimation were observed among different equations, potentially impacting drug dose adjustments. However, discrepancies were not considered significant when comparing patient-adjusted and BSA-normalized versions of the equations, particularly for patients with BSA close to the average.

Development and validation of a Medication Adherence Universal Questionnaire: the MAUQ.

BACKGROUND: Different questionnaires assess self-reported medication adherence and others quantify aspects of patients attitudes towards medication, but not together in a single instrument. Gathering these two aspects in a single instrument could reduce patients survey burden. AIM: The aim of this study was to develop the Medication Adherence Universal Questionnaire (MAUQ) using the Maastricht Utrecht Adherence in Hypertension short version (MUAH-16) factorial structure as the hypothesized model. METHOD: A multistep process started with the modification of the MUAH-16 to obtain the MAUQ. Patients using at least one antihypertensive medicine were recruited. The two questionnaires, the MUAH-16 and MAUQ, were applied. A confirmatory factor analysis (CFA) was performed using the initial MUAH-16 s-order 4-factor model. An additional bifactor model with four uncorrelated factors and an overall score was tested. The comparative fit index (CFI), root mean square error of approximation (RMSEA) with confidence intervals (CIs), and standardized root mean squared residual (SRMR) were used to assess both models. RESULTS: A sample of 300 hypertensive patients completed the instruments. The CFA with the second-order 4-factor solution resulted in similar results for the MUAH-16 and MAUQ: CFIs of 0.934 and 0.930, RMSEAs of 0.043 [CI 0.030-0.056] and 0.045 [CI 0.031-0.057] and SRMRs of 0.060 and 0.061, respectively. The CFA with the bifactor model showed slightly better results for both the MUAH-16 and MAUQ: CFIs of 0.974 and 0.976, RMSEAs of 0.030 [CI 0.005-0.046] and 0.028 [CI 0.001-0.044], and SRMRs of 0.043 and 0.044, respectively. CONCLUSION: CFA demonstrated that the MAUQ presented a better fit to both models than the MUAH-16, obtaining a robust universal free instrument to assess medicine-taking behaviour and four medicine beliefs components.

A Universal Pharmacological-Based List of Drugs with Anticholinergic Activity.

Anticholinergic burden tools have relevant pharmacological gaps that may explain their limited predictive ability for clinical outcomes. The aim of this study was to provide a universal pharmacological-based list of drugs with their documented affinity for muscarinic receptors. A comprehensive literature review was performed to identify the anticholinergic burden tools. Drugs included in these instruments were searched in four pharmacological databases, and the investigation was supplemented with PubMed. The evidence regarding the potential antagonism of the five muscarinic receptors of each drug was assessed. The proportion of drugs included in the tools with an affinity for muscarinic receptors was evaluated. A universal list of drugs with anticholinergic activity was developed based on their documented affinity for the different subtypes of muscarinic receptors and their ability to cross the blood-brain barrier. A total of 23 tools were identified, including 304 different drugs. Only 48.68%, 47.70%, 48.03%, 43.75%, and 42.76% of the drugs had an affinity to the M1, M2, M3, M4, and M5 receptor, respectively, reported in any pharmacological database. The proportion of drugs with confirmed antagonism varied among the tools (36.8% to 100%). A universal pharmacological-based list of 133 drugs is presented. It should be further validated in different clinical settings.

Evaluation of a sample of Portuguese hypertensive patients' knowledge about hypertension and its influence on their beliefs and adherence to therapy.

INTRODUCTION AND OBJECTIVES: Patient knowledge about hypertension is an important patient-related determinant for poor blood pressure control and is a target for more effective interventions. We aimed to evaluate hypertensive patients' knowledge and awareness about hypertension and its influence on their beliefs about their medication and their adherence to antihypertensive therapy. METHODS: A cross-sectional study was conducted among adult patients attending one of the participating pharmacies and taking at least one antihypertensive drug. Data on personal and family history were collected, and Portuguese versions of the Hypertension Knowledge Test (HKT), Beliefs about Medicines Questionnaire (BMQ), and short version of the Maastricht Utrecht Adherence in Hypertension questionnaire (MUAH-16) were administered. RESULTS: A total of 240 patients were enrolled. The mean number of antihypertensive drugs used was 1.62±0.99, with 15.4% of patients treated with three or more drugs. More than 80% of patients knew the blood pressure therapeutic goals and identified overweight, sedentary lifestyle, and salt as risk factors for hypertension. Conversely, the majority of the patients were not aware of the asymptomatic characteristics of hypertension and believed that antihypertensive treatment had to be used for a limited time duration. Negative and significant correlations were found between the HKT and negative attitudes toward medication, but no association was found with positive attitudes. CONCLUSIONS: Hypertensive patients had good knowledge of hypertension risk factors but not of antihypertensive treatment. Increasing patient knowledge about hypertension may possibly reduce negative attitudes toward medication but will probably have no impact on positive attitudes.

Pharmacist-led medication reconciliation on admission to an acute psychiatric hospital unit.

Background: Therapy management in patients suffering from mental health disorders is complex and the risks derived from changes or interruptions of treatment should not be ignored. Medication reconciliation in psychiatry may reduce medication errors and promote patient safety during transitions of care. Objective: To identify the influence of complementary information sources in the construction of the best possible medication history, and to ascertain the potential clinical impact of discrepancies identified in a medication reconciliation service. Methods: An observational study was conducted in an acute mental hospital unit, with a further validation in an internal medicine unit. Adult patients taking at least one medicine admitted in the unit were included. Patients/caregivers were interviewed upon admission and the information gathered was compared with hospital medical and shared electronic medical records. Once the best possible medication history was gathered, therapeutic information was reconciled against the prescription on admission to identify discrepancies. Potential clinical impact of medication errors was classified using the International Safety Classification. Results: During the study period, 148 patients were admitted, 50.7% females, mean age 54.6 years (SD=16.3). Collaboration of a caregiver was a needed in 74% of the interviews. In total, 1,147 drugs were considered to obtain patients' best possible medication history. After reconciliation, 560 clinically sound intentional discrepancies were identified and 359 discrepancies required further clarification from prescribers: 84.12% "drug omission", 5.57% "drug substitution", 6.96% "dose change", and 3.34% "dosage frequency change". Potential clinical impact of these medication discrepancies was classified as: 95 mild, 100 moderate, and 29 severe medication errors. Conclusion: About 1 in three intentional discrepancies observed in a pharmacists-led medication reconciliation service required further clarification from prescribers, being 80% of them unintentional discrepancies. Results highlight the importance of the caregiver as source of information for the psychiatric patient, the relevance of analyzing shared electronic health records until 6 months before, and the need to use hospital medical records efficiently. Additionally, 29 discrepancies were classified as errors with potentially severe clinical impact. A medication reconciliation service is concluded to be feasible and necessary in a mental health unit.

Pharmacist-led medication reconciliation on admission to an acute psychiatric hospital unit

Background: Therapy management in patients suffering from mental health disorders is complex and the risks derived from changes or interruptions of treatment should not be ignored. Medication reconciliation in psychiatry may reduce medication errors and promote patient safety during transitions of care. Objective: To identify the influence of complementary information sources in the construction of the best possible medication history, and to ascertain the potential clinical impact of discrepancies identified in a medication reconciliation service. Methods: An observational study was conducted in an acute mental hospital unit, with a further validation in an internal medicine unit. Adult patients taking at least one medicine admitted in the unit were included. Patients/caregivers were interviewed upon admission and the information gathered was compared with hospital medical and shared electronic medical records. Once the best possible medication history was gathered, therapeutic information was reconciled against the prescription on admission to identify discrepancies. Potential clinical impact of medication errors was classified using the International Safety Classification. Results: During the study period, 148 patients were admitted, 50.7% females, mean age 54.6 years (SD=16.3). Collaboration of a caregiver was a needed in 74% of the interviews. In total, 1,147 drugs were considered to obtain patients’ best possible medication history. After reconciliation, 560 clinically sound intentional discrepancies were identified and 359 discrepancies required further clarification from prescribers: 84.12% “drug omission”, 5.57% “drug substitution”, 6.96% “dose change”, and 3.34% “dosage frequency change”. Potential clinical impact of these medication discrepancies was classified as: 95 mild, 100 moderate, and 29 severe medication errors. (AU)

Size of the associations between anticholinergic burden tool scores and adverse outcomes in older patients.

Background Several anticholinergic scales and equations to evaluate the anticholinergic burden have been previously created. Association of these instruments with the anticholinergic outcomes are usually estimated by means of hypothesis contrast tests, which ignore the size of the association effect. Objective To evaluate the effect size of the associations between the scores on cumulative anticholinergic burden instruments with peripheral or central anticholinergic adverse outcomes in older patients. Setting Internal medicine ward of a Tertiary University Hospital. Methods A case-control study was conducted in patients over 65 years who were admitted to two internal medicine wards of a Portuguese university hospital. The Anticholinergic Drug Scale, Anticholinergic Risk Scale, Anticholinergic Cognitive Burden scale and Drug Burden Index were used to calculate the patients' anticholinergic burden. Peripheral (dry mouth-swab technique; dry eye-Schirmer test) and central (falls and cognitive impairment-Mini-Mental State Examination) anticholinergic adverse outcomes were investigated. The Barthel Index was used to assess overall physical functionality. The Mann-Whitney test was used to evaluate probabilistic differences in the anticholinergic scores between case and control individuals. To establish the effect size of the associations, the area under the curve of the receiver operating characteristics curve was calculated. Main outcome measure Anticholinergic adverse effects. Results A total of 250 patients (mean age 81.67 years, standard deviation 7.768; 50% females) were included. In total, 148 patients (59.2%) presented with dry mouth, 85 (34%) with dry eye, 141 (56.4%) with impaired functionality, 44 (17.6%) with a history of falls and 219 (87.6%) with cognitive impairment. Significant differences (p < 0.05) were obtained for the majority of the associations between Anticholinergic Drug Scale, Anticholinergic Risk Scale, Anticholinergic Cognitive Burden and Drug Burden Index and adverse effects. Conversely, the effect sizes of these associations ranged from "fail" (area under the curve 0.5 to 0.6) to "fair" (area under the curve 0.7 to 0.8). Conclusion Although significant differences in the scores of anticholinergic burden instruments and adverse outcomes may exist, the effect sizes of these associations ranged from 'fail' to 'fair', which limits their utility in preventing anticholinergic adverse outcomes with medication review interventions.

Association between anticholinergic burden and anticholinergic adverse outcomes in the elderly: Pharmacological basis of their predictive value for adverse outcomes.

The use of anticholinergic drugs and other drugs with anticholinergic activity is highly prevalent in older people. Cumulative anticholinergic effects, known as anticholinergic burden, are associated with important peripheral and central adverse effects and outcomes. Several methods have been developed to quantify anticholinergic burden and to estimate the risk of adverse anticholinergic effects. Serum anticholinergic activity (SAA) and anticholinergic burden scoring systems are the most commonly used methods to predict the occurrence of important negative outcomes. These tools could guide clinicians in making more rational prescriptions to enhance patient safety, especially in older people. However, the literature has reported conflicting results about the predictive ability of these tools. The majority of these instruments ignore relevant pharmacologic aspects such as the doses used, differential muscarinic receptor subtype affinities, and blood-brain barrier permeability. To increase the clinical relevance of these tools, mechanistic and clinical pharmacology should collaborate. This narrative review describes the rational and pharmacological basis of anticholinergic burden tools and provides insight about their predictive value for adverse outcomes.

Patients' clinical information requirements to apply the STOPP/START criteria.

Background The STOPP/START criteria are an explicit tool to detect potentially inappropriate medications (PIMs). Patient clinical information may not be available in all settings. Objective To identify patient clinical information needed to apply the STOPP/START criteria. Setting: Four nursing homes in Portugal. Methods First, a theoretical analysis was performed to identify the patient information required to apply the STOPP/START criteria (v2), according to the following categories: patients' current medication, medication history (previous medication and duration), medical records (current and past medical conditions), and laboratory test results. A verification of the information requirements was conducted through a cross-sectional study on a nursing home population with patients over 65 years old. Patients' medical records were appraised to extract only demographic data and current medication profiles. Main outcome measure Information requirements of STOPP/START. Results For only 29 of the 81 STOPP criteria and 1 of the 34 START criteria, a judgement could be made with only the information in the patient's medication profile. 52 STOPP and 33 START criteria require additional information, (i.e. duration of therapy, previous medication, current and past medical conditions, and laboratory data). The 208 evaluated persons (87 years; 68.75% female) used 1770 medications, with 989 (55.9%) potentially involved in 1629 STOPP criteria. Sufficient information to judge STOPP criteria was available for only 529 (32.5%) potential STOPP criteria situations, with a positive identification of a STOPP PIM in 397 instances (75.0%). Conclusions Although STOPP/START criteria can be considered a high-level tool to identify PIMs, their use may be compromised in scenarios where access to patients' clinical information is limited.

Mobile-Phase Modulators as Salt Tolerance Enhancers in Phenylboronate Chromatography: Thermodynamic Evaluation of the Mechanisms Underlying the Adsorption of Monoclonal Antibodies.

Phenylboronate chromatography has been employed for bioseparation applications though details concerning the mechanisms of interaction between the ligand and macromolecules remain widely unknown. Here, the phenomena underlying the adsorption of an anti-human interleukin-8 (anti-IL8) monoclonal antibody (mAb) onto an m-aminophenylboronic acid (m-APBA) ligand in the presence of different mobile-phase modulators (NaF/MgCl 2 /(NH 4 ) 2 SO 4 ) and under different pH values (7.5/8.5/9.0) is investigated. Flow microcalorimetry (FMC) is applied to measure instantaneous heat energy transfer, providing insights about the role of specific and nonspecific interactions involved in the adsorptive process. Results show that the adsorption of anti-IL8 mAb to m-APBA is enthalpically driven, corroborating the presence of the reversible esterification reaction between boronic acid or boronates and cis-diol-containing molecules. Nevertheless, for all mobile-phase modulators studied, changes in thermogram profiles are observed as well as reductions in the net heat of adsorption when increasing the pH. Overall, FMC and parallel chromatographic experiments data suggest that ligand salt tolerance could be enhanced using mobile-phase modulators, with all salts studied promoting the specific cis-diol interactions and reducing nonspecific interactions. The last feature is more noticeable at pH values above ligand's pK a , mainly due to the ability of NaF and (NH 4 ) 2 SO 4 to diminish electrostatic interactions when compared to the commonly used NaCl.

Antibody Binding Heterogeneity of Protein A Resins.

Protein A affinity chromatography is a core unit operation in antibody manufacturing. Nevertheless, there is not enough understanding of in-column antibody adsorption in the Protein A capture step. This work aims to investigate in situ the establishment of an antibody (trastuzumab) layer during Protein A chromatography both in terms of energetic contributions and uptake kinetics. Flow microcalorimetry is employed as a technique with an in situ operating detector, which provides an understanding of the thermodynamics of the adsorption process. In addition, the antibody uptake rate is also investigated in order to establish a correlation between its diffusion on the stationary phase and the associated thermodynamics. Two resins with different particle size, intraparticle porosity, and a Protein A ligand structure are studied: the synthetically engineered B-domain tetrameric MabSelect SuRe and the synthetically engineered C-domain hexameric TOYOPEARL AF-rProtein A HC. The uptake rate follows a pore diffusion model at low equilibrium time, showing a slower diffusivity after a certain time because of the heterogeneous binding nature of these two resins. In addition, the microcalorimetric studies show that adsorption enthalpy is highly favourable at low isotherm concentrations and evolves toward an equilibrium with increasing surface concentration. These data suggest that the relationship between adsorption enthalpy and the establishment of the antibody layer in the Protein A chain is consistent with heterogeneous adsorption.

Consequences of ignoring patient diagnoses when using the 2015 Updated Beers Criteria.

BACKGROUND: Beers Criteria are one of the best known explicit criteria to identify inappropriate medication in elderly that can be used in medication review. The access to patients' medical records may be different among healthcare professionals and settings and, subsequently, the identification of patients' diagnoses may be compromised. OBJECTIVE: To assess the consequences of ignoring patient diagnoses when applying 2015 Beers Criteria to identify potentially inappropriate medication (PIM). SETTING: Three nursing homes in Central Portugal. METHOD: Medical records of nursing home residents over 65 years old were appraised to identify medication profile and medical conditions. 2015 Beers Criteria were used with and without considering patients' diagnoses. To compare the number of PIM and PIM-qualifying criteria complied in these two judgements, Wilcoxon signed-rank tests were performed. MAIN OUTCOME MEASURE: Number of PIMs and number of PIM-qualifying criteria. RESULTS: A total of 185 patients with a mean age of 86.7 years (SD = 7.8) with a majority of female (70.3%) were studied. When assessing the patients with full access to the diagnoses, median number of PIMs was 4 (IQR 0-10) and number of PIM-qualifying criteria was 5 (IQR 0-15). When evaluating only patient current medication, median number of PIMs was 4 (IQR 0-10) and PIM-qualifying criteria was 4 (IQR 0-12). Statistical difference was found in the number of PIM-qualifying criteria identified (p < 0.001), but not in the number of PIMs per patient (p = 0.090). In 171 patients (92.4%) PIMs identified were identical when using or ignoring their medical diagnoses. However, in 80 patients (43.2%) the PIM-qualifying criteria complied were different with and without access to patient diagnoses. CONCLUSION: Although restricted access to patients' diagnoses may limit the judgement of Beers PIM-qualifying criteria, this limitation had no effect on the number of PIM identified.

The pearl necklace model in protein A chromatography: Molecular mechanisms at the resin interface.

Staphylococcal protein A chromatography is an established core technology for monoclonal antibody purification and capture in the downstream processing. MabSelect SuRe involves a tetrameric chain of a recombinant form of the B domain of staphylococcal protein A, called the Z-domain. Little is known about the stoichiometry, binding orientation, or preferred binding. We analyzed small-angle X-ray scattering data of the antibody-protein A complex immobilized in an industrial highly relevant chromatographic resin at different antibody concentrations. From scattering data, we computed the normalized radial density distributions. We designed three-dimensional (3D) models with protein data bank crystallographic structures of an IgG1 (the isoform of trastuzumab, used here; Protein Data Bank: 1HZH) and the staphylococcal protein A B domain (the native form of the recombinant structure contained in MabSelect SuRe resin; Protein Data Bank: 1BDD). We computed different binding conformations for different antibody to protein A stoichiometries (1:1, 2:1, and 3:1) and compared the normalized radial density distributions computed from 3D models with those obtained from the experimental data. In the linear range of the isotherm we favor a 1:1 ratio, with the antibody binding to the outer domains in the protein A chain at very low and high concentrations. In the saturation region, a 2:1 ratio is more likely to occur. A 3:1 stoichiometry is excluded because of steric effects.

Cross-cultural adaptation and validation of a European Portuguese version of the 8-item Morisky medication adherence scale.

INTRODUCTION AND OBJECTIVE: The 8-Item Morisky Medication Adherence Scale (MMAS-8) is one of the most widely used instruments to assess medication adherence, but a validated European Portuguese version of MMAS-8 does not exist. Our aim was to develop and validate a European Portuguese version of the MMAS-8. METHODS: A process of translation and back-translation of the original MMAS-8 was performed. The questionnaire was administered in nine community pharmacies and one public hospital between March 2014 and September 2015. Adult patients taking at least one antihypertensive drug were invited to participate. A confirmatory factor analysis was performed and internal consistency, convergent validity and concurrent validity were examined. RESULTS: A total of 472 patients were enrolled in the study. The mean MMAS-8 score obtained was 6.74±1.39. One hundred and thirty-two patients were classified as low adherers (28%), 181 (38.3%) as medium adherers and 159 (33.7%) as high adherers. For the factorial structure of the Portuguese version of the MMAS-8, the fit indices of the final model (chi-square [18] 48.465, p<0.001) are suggestive of very good fit, with comparative fit index 0.95, root mean square error of approximation 0.06 (90% confidence interval 0.04-0.08), and standardized root mean square residual 0.04, confirming that the construct tested was unidimensional. The Cronbach's alpha for all items was 0.60, and the translated version presents convergent validity and concurrent validity. CONCLUSION: A European Portuguese version of the MMAS-8 was created that maintained a similar structure to the original MMAS-8 and good psychometric properties.

Developing an adherence in hypertension questionnaire short version: MUAH-16.

The Maastricht Utrecht Adherence in Hypertension (MUAH) questionnaire provides clinicians with information about the causes of a patient's poor adherence to antihypertensive drugs. In this study, the authors aimed to develop and validate a short version of the MUAH questionnaire. After an exploratory factor analysis, the number of MUAH items was reduced. The original MUAH questionnaire (model 1) was compared with the 16-item MUAH short version (model 2). Next, this short version of MUAH (MUAH-16) with all factors correlated (model 2a) was compared with the short version of MUAH with four subscales that contribute to a global factor of adherence (model 2b). Model 1 had a poor fit to the data (χ2 269 = 663.41, P < .001, comparative fit index = 0.695, root mean square error of approximation = 0.06), and model 2 had a very good fit to the data (χ2 100 = 171.07, P < .001, comparative fit index = 0.92, root mean square error of approximation = 0.04). When comparing model 2a with model 2b, the chi-square difference of the model (Δχ2 2 = 4.06; P = .067) revealed that the fits of both models were not significantly different. These findings suggest that MUAH-16 better represents a patient's adherence to antihypertensive medication than the original MUAH questionnaire.

Influence of the mode of administration on the results of medication adherence questionnaires.

INTRODUCTION AND OBJECTIVES: Adherence to medication regimen is commonly assessed through questionnaires, some of which are validated via self-administration. The inadequate health literacy of elderly people pushes researchers to the use of interviews as a method of administration. The aims of this study were to compare the results obtained with an interviewer-administered and a self-administered medication adherence questionnaire and to evaluate the consequences of the adherence status classification of individuals. METHODS: A cross-sectional study was performed in which the Medida de Adesão aos Tratamentos adherence questionnaire was administered to adult patients who were taking at least 1 antihypertensive drug. The data were collected in 7 community pharmacies in central Portugal between March 2014 and September 2015 in 2 different phases: in the first phase, the questionnaire was applied during a healthcare professional interview, and the second phase involved a self-report administration. A confirmatory factor analysis was conducted, and the measurement and structural invariances across the application methods were examined. RESULTS: A sample of 425 patients with a mean age of 68.21 ± 10.56 years participated in the study. The confirmatory factor analysis revealed that both the interview and self-report had a good fit with the original model, although the self-report results exhibited a better fit. In the interview administration, we obtained lower values for skewness and higher levels of kurtosis. The patients subjected to the interview administration presented with a 9.7% higher tendency to answer "never" when compared with the self-administered application, which overestimated adherence. CONCLUSIONS: The interview administration method induced bias that led to a higher percentage of "never" answers and a subsequent overestimation of adherence levels. Self-report administration should be preferred in the application of medication adherence questionnaires.

Cross-cultural adaptation of Hypertension Knowledge Test into European Portuguese

ABSTRACT We aim to validate a European-Portuguese version of the Hypertension Knowledge Test (HKT) questionnaire and examine its factorial structure with a confirmatory factor analysis (CFA). A process of translation and back-translation was performed. A cross-sectional study was developed in which all adult patients taking at least one antihypertensive drug were invited to participate. Data on personal and family history were collected, and the HKT, Strelec, and the Batalla questionnaires were administered. We enrolled 304 patients with a mean age of 68.12±10.83 years. The mean score of HKT was 15.33±2.79. CFA indicated that the construct being tested was unidimensional, and Cronbach's alpha (α=0.65) showed that the instrument had an acceptable internal consistency. When evaluating concurrent validity, HKT was significantly correlated with the Batalla and Strelec scores. Thus, the Portuguese version of HKT (HKT-pt-PT) can be used either in research or in clinical practice. With this version, a potential standard exists to evaluate knowledge about hypertension, which could avoid the practice of using non-validated questionnaires in Portugal and allow the cross-sectional and longitudinal comparability of studies.

Association of the transcobalamin II gene 776C → G polymorphism with Alzheimer's type dementia: dependence on the 5, 10-methylenetetrahydrofolate reductase 1298A → C polymorphism genotype.

BACKGROUND: Decreased serum concentrations of vitamin B12 are associated with Alzheimer's type dementia. The transcobalamin II gene (TCN2) 776C → G polymorphism affects transcobalamin II function as a carrier of vitamin B12 and might modify its availability. The association of the TCN2 776C → G polymorphism with Alzheimer's type dementia is unclear and was investigated in the present study. METHODS: Case-control study including 27 individuals diagnosed with Alzheimer's type dementia and 28 healthy controls. Serum concentrations of vitamin B12, homocysteine and other analytes were determined and the presence of TCN2 776C → G and 5, 10-methylenetetrahydrofolate reductase 1298A → C polymorphisms genotypes was ascertained by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Serum concentrations of vitamin B12 were lower while those of homocysteine were higher in patients than in controls (P < 0.05). The frequency of individuals carrying at least one 5, 10-methylenetetrahydrofolate reductase 1298C allele was higher (59% versus 32%) while frequency of individuals harbouring at least one TCN2 776G allele was lower (58% versus 86%) in patients than in controls (P < 0.05). Univariate logistic regression showed negative association of TCN2 776CG genotype with Alzheimer's type dementia (OR = 0.17 versus CC genotype, P < 0.02). Multivariate logistic regression identified TCN2 776C → G polymorphism as independent predictor of Alzheimer's type dementia together with higher concentrations of homocysteine, cholesterol and uric acid and lower concentrations of oestradiol. Association of TCN2 776C → G polymorphism with Alzheimer's type dementia was observed for individuals carrying the 5,10-methylenetetrahydrofolate reductase 1298AA genotype but not the AC or CC genotypes, indicating interaction between the two polymorphisms. CONCLUSIONS: The TCN2 776C → G polymorphism is negatively associated with Alzheimer's type dementia, suggesting a protective role against the disease in subjects with the 5, 10-methylenetetrahydrofolate reductase 1298AA genotype.