Development of a rating scale for measuring resistance to persuasive health messages

BACKGROUND@#Pretesting is the key to understanding how the intended audience will react to the message. Resistant reactions affect message processing or can lead to undesirable boomerang effects. The objective of this study was to develop a rating scale for measuring active (reactance) and passive (disengagement) resistance to persuasive health messages.@*METHODS@#Six candidate items (3 items for disengagement and 3 items for reactance) were generated based on literature review. A web-based survey was conducted among Japanese adults aged 25-64 years to verify the reliability and validity of the 6-item resistance scale. Participants were asked to rate one of the advance care planning (ACP) promotion messages. All scale items were scored on a 1-to-5 point Likert scale and they were averaged to produce the resistance score.@*RESULTS@#Explanatory factor analysis revealed a two-factor solution that agreed with the disengagement and reactance domains, respectively. Correlation coefficients between each set of items ranged between 0.30-0.69. Cronbach alpha (0.86) indicated satisfactory internal consistency of the set of items. Confirmatory factor analysis showed a good fit of the two-factor model with CFI = 0.998, SRMR = 0.011, and RMSEA = 0.041. The resistance score showed a moderate positive correlation with negative emotional responses (displeasure γ = 0.55, anger γ = 0.53) and was significantly inversely related to the persuasiveness score (γ = -0.50). Multivariable logistic regression analysis showed that the odds ratio for ACP intention per 1-point increase in the resistance score was 0.47 (95% confidence interval 0.40-0.56) with adjustment for the persuasiveness score.@*CONCLUSION@#The 6-item resistance scale exhibited adequate reliability and validity for measuring audience resistance when applied to the ACP promotion messages in Japanese people. The scale will be useful for pretesting health messages to make them more acceptable to the intended audience.@*TRIAL REGISTRATION@#Not applicable; this is not a report of intervention trial.

Role of Impulse Oscillometry in Assessing Asthma Control in Children

Background: Impulse oscillometry is an effort-independenttechnique of assessment of airway resistance and reactance, andcan be performed in children unable to complete spirometry.Objective: To evaluate the utility of impulse oscillometry andspirometry for assessing asthma control in children.Study design: Prospective cohort study.Participants: Children aged 5-15 years, with mild to severepersistent asthma.Intervention: On each 3-monthly follow-up visit, clinicalassessment, classification of control of asthma, impulseoscillometry and spirometry were performed.Outcome: Utility of impulse oscillometry parameters [impedance(Z5), resistance (R5), reactance (X5) at 5 Hz, and R5-20(resistance at 20Hz -5Hz) (% predicted), and area of reactance(AX, actual values)] and FEV1 (% predicted) to discriminatebetween controlled and uncontrolled asthma was assessed byreceiver operating characteristic (ROC) curve. Association ofFEV1 and impulse oscillometry parameters over time withcontrolled asthma was evaluated by generalized estimatingequation model.Results: Number of visits in 256 children [mean (SD) age, 100(41.6) mo; boys: 198 (77.3%)], where both impulse oscillometryand spirometry were performed was 2616; symptoms werecontrolled in 48.9% visits. Area under the curve fordiscrimination between controlled and uncontrolled asthma byFEV1, AX, R5-20, Z5, R5, and X5 were 0.58, 0.55, 0.55, 0.52,0.52 and 0.52, respectively. FEV1 [OR (95% CI): 1.02 (1.01-1.03)]and AX [OR (95% CI): 0.88 (0.81-0.97)] measured over theduration of follow-up were significantly associated withcontrolled asthma.Conclusion: Spirometry and impulse oscillometry parametersare comparable in ascertaining controlled asthma. Impulseoscillometry being less effort-dependent may be performed formonitoring control of childhood asthma, especially in youngerchildren.

Forced oscillation technique as a predictor for loss of control in asthmatic children

BACKGROUND: A reliable objective tool using as a predictor of asthma control status could assist asthma management.OBJECTIVE: To find the parameters of forced oscillation technique (FOT) as predictors for the future loss of asthma symptom control.METHODS: Children with well-controlled asthma symptom, aged 6–12 years, were recruited for a 12-week prospective study. FOT and spirometer measures and their bronchodilator response were evaluated at baseline. The level of asthma symptom control was evaluated according to Global Initiative for Asthma.RESULTS: Among 68 recruited children, 41 children (60.3%) maintain their asthma control between 2 visits (group C-C), and 27 children (39.7%) lost their asthma control on the follow-up visit (group C-LC). Baseline FOT parameters, including the values of respiratory resistance at 5 Hz (R5), respiratory resistance at 20 Hz (R20), respiratory reactance at 5 Hz, area of reactance, %predicted of R5 and percentage of bronchodilator response (%∆) of R5 and R20 were significantly different between C-C and C-LC groups. In contrast, only %∆ of forced vital capacity, forced expiratory volume in 1 second (FEV₁), and FEF25%–75% (forced expiratory flow 25%–75%) were significantly different between groups. Multiple logistic regression analysis revealed that %predicted of R5, %∆R5, %predicted of FEV₁ and %∆FEV₁ were the predictive factors for predicting the future loss of asthma control. The following cutoff values demonstrated the best sensitivity and specificity for predicting loss of asthma control: %predicted of R5=91.28, %∆R5=21.2, %predicted of FEV₁=89.5, and %∆FEV₁=7.8. The combination of these parameters predicted the risk of loss of asthma control with area under the curve of 0.924, accuracy of 83.8%.CONCLUSION: Resistance FOT measures have an additive role to spirometric parameter in predicting future loss of asthma control.

Estandarización de la oscilometría de impulso y generación de ecuaciones piloto para generar valores de referencia en el Hospital Central Militar / Standardization of impulse oscillometry and the generation of pilot equations to generate reference values in the Central Military Hospital

Resumen Introducción La oscilometría de impulso es una prueba que evalúa la mecánica respiratoria a través de la aplicación de pequeños pulsos de presión que producen oscilaciones de flujo a una frecuencia determinada. Su aplicación relevante es en el estudio de las enfermedades de la vía aérea pequeña. El software integrado al equipo que ejecuta esta prueba genera cálculos de valores predictivos para cada uno de los parámetros oscilométricos, los cuales se basan en datos de población alemana. Objetivo Estandarizar la prueba de oscilometría de impulso y obtener ecuaciones piloto para valores de referencia. Material y métodos Se realizó un estudio experimental, analítico, prospectivo y longitudinal con sujetos voluntarios sanos. Se llevaron a cabo pruebas de espirometría y oscilometría de impulso basales y, tras broncodilatador, se registraron las impedancias, resistencias y reactancias del sistema respiratorio a 5, 10, 15 y 20 Hz. Los resultados se analizaron por sexo, edad, talla y peso. Se de 127 participantes sanos ingresaron al estudio, 51.5% del sexo efectuó un modelo de regresión lineal múltiple. Resultados Un total masculino (68) y 48.5% (64) del femenino, con edad promedio de 39.65 ± 15.26 años; la talla tuvo un promedio de 1.63 ± 0.09 m. Se demostró que el sexo influye en los valores de la oscilometría en el volumen corriente (VT), la impedancia, las resistencias y el área de reactancia (p < 0.05), y no afecta las reactancias (XRs) (p > 0.05); este parámetro está mayormente asociado a la talla (r = 0.727, r2 = 0.528). La edad incide en los valores de la oscilometría, ya que las resistencias (Rrs) son menores en los grupos más jóvenes; el IMC y el peso no comprometieron los valores de IOS. Conclusiones Este estudio proporciona ecuaciones piloto de referencia para los índices comunes de oscilometría de impulso en sujetos mexicanos. Así, integra una prueba de función pulmonar para facilitar la detección de alteraciones funcionales en vía aérea pequeña. Sugerimos realizar más trabajos en población mexicana, sobre todo de edad avanzada, para confirmar nuestros resultados y proporcionar una base más sólida a las ecuaciones de referencia para IOS, con un fin clínico y epidemiológico.

Abstract Introduction Impulse oscillometry is a test that evaluates the respiratory mechanics by the application of small pulses of pressure, which produce flow oscillations to a certain frequency. Its main application is in the study of the illnesses of the small airline. The integrated software of the test equipment generates predictive values for each of the oscillometric parameters, based on German population data. Objective To standardize the impulse oscillometry test in order to design pilot equations for reference values in our population. Material and methods We performed a pilot, experimental, analytical, longitudinal study with healthy volunteer subjects. Spirometry and impulse oscillometry tests were performed, both basal impedances, resistances, and reactances of the respiratory system to and after bronchodilator application; we measured and registered the 5, 10, 15, and 20 Hz. The results were analyzed by sex, age, height, and weight. The analysis was performed using a model of multiple linear retrogression. Results A total of 127 healthy participants were recruited, 51.5% men (68) and 48.5% (64) women, with an average age of 39.65 ± 15.26 years; their height was an average of 1.63 ± 0.09 m. It was proved that the gender influences the oscillometry values of tidal volume (VT), the impedance, the resistances and reactance area (p < 0.05), but not the reactances (XRs) (p > 0.05); this parameter is mainly associated with the size (r = 0.727, r2 = 0.528). The age influences the oscillometry values since the resistances (Rrs) are lower in the youngest groups; the BMI and the weight had no influence on the values of IOS. Conclusions This study provides pilot reference equations for the common indexes of impulse oscillometry in Mexican subjects, in order to integrate this test of pulmonary function to facilitate the detection of functional alterations in the small airline. We suggest more studies should be done on Mexican population, and especially on people of advanced age, to confirm our results and to provide a more solid base for the equations of reference to IOS, with clinical and epidemiologic purposes.

Preferencias por las decisiones compartidas en pacientes con depresión / Depressive patients' preferences in shared decision-making / Preferências pelas decisões compartilhadas em pacientes com depressão

This study analyzed the role of psychological processes predicting depressed patients' preferences in clinical decision-making about psychiatric treatment. 462 patients diagnosed with depressive disorders, acute or recurrent, participated in a crosssectional survey. Most participants preferred collaborative-passive or totally passive roles. Results showed no significant differences between acute and recurrent patients in their preference of participation in decision-making, but longer treatment duration was associated with a more passive style. MANCOVA, controlling age, educational level and treatment duration variables, showed that collaborative and passive patients had a greater locus of control focused on their psychiatrist than active patients. Gender differences were found. Men showed greater internal locus of control and psychological reactance, while women showed greater external locus of control focused on chance. Regression analysis indicated that, for men, passive preferred role was explained by external locus centered on their psychiatrist. However, age registered the highest weight for women' passive decision-making, followed by the locus focused on chance, locus focused on the psychiatrist and lower self-efficacy. Our findings suggest the need to study shared decision-making from a differential perspective that involves psychological processes and the impact of these processes in adherence to medical treatments.

En el presente estudio se analizaron los procesos psicológicos asociados con las preferencias de los pacientes con depresión en la toma de decisión sobre su tratamiento psiquiátrico. Participaron 462 pacientes diagnosticados con un trastorno depresivo agudo o recurrente. La mayor parte prefirió asumir un rol colaborativo-pasivo o totalmente pasivo. Los resultados no mostraron diferencias significativas entre pacientes en función de su cronicidad en la preferencia por la toma de decisiones, aunque un mayor tiempo de tratamiento se asoció con un estilo más pasivo. El MANCOVA aplicado al total de participantes, controlando la edad, el nivel educativo y el tiempo de tratamiento, indicó que los pacientes colaborativos y pasivos mostraron mayor locus de control centrado en la confianza en el psiquiatra que los activos. Se encontraron diferencias de género mostrando en los hombres mayor locus de control interno y reactancia psicológica, y en las mujeres, mayor locus centrado en el azar. Los análisis de regresión indicaron que en el caso de los hombres, la preferencia pasiva por la toma de decisión es explicada por el locus centrado en el psiquiatra. Sin embargo, en las mujeres tuvo mayor peso la edad, seguida del locus centrado en el azar, el locus centrado en el psiquiatra y una percepción de menor autoeficacia. Los hallazgos señalan la necesidad de estudiar desde una perspectiva diferencial la participación de los pacientes en la toma de decisión de acuerdo con los procesos psicológicos, así como la repercusión que esta tiene en la adherencia al tratamiento médico.

Neste estudo, analisaram-se os processos psicológicos associados com as preferências dos pacientes com depressão na tomada de decisão sobre seu tratamento psiquiátrico. Participaram 462 pacientes diagnosticados com um transtorno depressivo agudo ou recorrente. A maior parte preferiu assumir um papel colaborativo-passivo ou totalmente passivo. Os resultados não mostraram diferenças significativas entre pacientes em função de sua cronicidade na preferência por tomada de decisões, embora um maior tempo de tratamento tenha sido associado com um estilo mais passivo. O MANCOVA aplicado ao total de participantes, controlando a idade, o nível educativo e o tempo de tratamento, indicou que os pacientes colaborativos e passivos mostraram maior lócus de controle centralizado na confiança no psiquiatra do que os ativos. Constataram-se diferenças de gênero que mostraram nos homens maior lócus de controle interno e reatância psicológica, e, nas mulheres, maior lócus centralizado no aleatório, o lócus centralizado no psiquiatra e uma percepção de menor autoeficácia. Os achados indicam a necessidade de estudar, sob uma perspectiva diferencial, a participação dos pacientes na tomada de decisão de acordo com os processos psicológicos e a repercussão que esta tem na aderência ao tratamento médico.

Ichthyometry and electrical bioimpedance analysis to estimate the body composition of tambatinga / Ictiometria e bioimpedância elétrica para estimativa da composição corporal do tambatinga

Body composition analysis is relevant to characterize the nutritional requirements and finishing phase of fish. The aim of this study was to investigate the relationship between ichthyometric (weight, total and standard length, density and yields), bromatological (fat, protein, ash and water content) and bioelectrical-impedance-analysis (BIA) (resistance, reactance, phase angle and composition indexes) variables in the hybrid tambatinga (Colossoma macropomum × Piaractus brachypomus). In a non-fertilized vivarium, 520 juveniles were housed and fed commercial rations. Then, 136 days after hatching (DAH), 15 fish with an average weight of 37.69 g and average total length of 12.96 cm were randomly chosen, anesthetized (eugenol) and subjected to the first of fourteen fortnightly assessments (BIA and biometry). After euthanasia, the following parts were weighed: whole carcass with the head, fillet, and skin (WC); fillet with skin (FS); and the remainder of the carcass with the head (CH). Together, FS and CH were ground and homogenized for the bromatological analyses. Estimates of the body composition and yields of tambatinga, with models including ichthyometric and BIA variables, showed correlation coefficients ranging from 0.81 (for the FS yield) to 1,00 (for the total ash). Similarly, models that included only BIA variables had correlation coefficients ranging from 0.81 (FS and CH yields) to 0.98 (for the total ash). Therefore, in tambatinga, the BIA technique allows the estimation of the yield of the fillet with skin and the body composition (water content, fat, ash, and protein). The best models combine ichthyometric and BIA variables.

Analisar composição corporal é relevante para caracterizar necessidades nutricionais e fase de terminação de peixes. Objetivou-se estudar a relação entre variáveis ictiométricas (peso, comprimentos total e padrão, densidade e rendimentos), bromatológicas (gordura, proteína, cinza e umidade) e aquelas da análise por bioimpedância ou BIA (resistência, reatância, ângulo de fase e índices de composição), no híbrido tambatinga (Colossoma macropomum x Piaractus brachypomus). Em um viveiro não fertilizado, 520 juvenis foram cultivados com ração comercial. Com idade de 136 dias após a eclosão dos ovos, 37,69 g de peso, 12,96 cm de comprimento total, 15 peixes, colhidos ao acaso, foram anestesiados (eugenol) e submetidos à primeira de quatorze avaliações quinzenais (BIA e biometria). Após eutanásia foram dissecados e pesados: carcaça inteira com cabeça, filé e pele (CICFP), filé com pele (FCP) e resto da carcaça com cabeça (CCC). Juntos, FCP e CCC foram moídos e homogeneizados para análise bromatológica. Estimativas da composição corporal e de rendimentos do tambatinga, com modelos incluindo variáveis ictiométricas e da BIA, apresentaram coeficientes de correlação entre 0,81 (para o rendimento do FCP) e 1,00 (para cinzas totais). Analogamente, modelos com a inclusão apenas de variáveis da BIA mostram coeficientes de correlação entre 0,81 (rendimento do FCP e do CCC) e 0,98 (para cinzas totais). Portanto, no tambatinga, a técnica da BIA possibilita a estimativa do rendimento de filé com pele e composição corporal (umidade, gordura, cinza e proteína). Os melhores modelos agregam variáveis ictiométricas e da BIA.

Vectores de impedancia bioeléctrica para la composición corporal en población mexicana / Bioimpedance vector analysis for body composition in Mexican population

Objective. To construct bivariate tolerance ellipses from impedance values normalized for height, which can be used in Mexican population for the assessment of body composition and compare them with others made in different populations. Methods. Body composition was assessed by bioelectrical impedance analysis (BIA) in 439 subjects (204 men and 235 women), 18 to 82 years old, with a BMI between 18-31, using an impedanciometer Quadscan 4000. Resistance, reactance and phase angle were used to calculate bioelectrical impedance vectors and construct bivariate tolerance ellipses. Results. Mean age in men was 47.1 ± 16 years and 42.4 ± 13 for women, mean weight (73.4 ± 9 vs. 60.1 ± 8 kg) and height (1.68 vs. 1.55 m) were significant greater in men than in women (p < 0.002). Women in comparison with men, had greater values of impedance (622.96 ± 66.16 Ω vs. 523.59 ± 56.56 Ω) and resistance (618.96 ± 66.10 Ω 61.97 vs. 521.73 ± 61.97Ω), as well as of resistance and reactance standardized by height (398.24 ± 46.30 Ω/m vs. 308.66 ± 38.44) (44.32 ± 7.14 Ω/m vs. 39.75 ± 6.29) respectively, with a significant difference in all of them (p < 0.0001). Similarly, the reactance was greater in females, nevertheless this difference did not reach statistical significance (68.96 ± 11.17 vs. 67.18 ± 10.3; p = 0.0861). The phase angle was greater in men than in women, with a statistically significant difference (7.33° ± 0.88 vs. 6.36° ± 0.97; p < 0.0001). Bivariate tolerance ellipses (50%, 75% y 95%) derived from Mexican subjects showed a significant upward deviation (p < 0.05) from previously published references from Mexican American and Italian populations. New ellipses of tolerance were therefore constructed for the Mexican population. Conclusions. Bioimpedance vectors in Mexican subjects are significantly different from the existing ones, supporting the need of population specific bivariate tolerance ellipses for the evaluation of body composition.

Objetivo. Realizar intervalos bivariados (elipses) de tolerancia a partir de las variables de impedancia estandarizadas por la estatura, las cuales pueden ser utilizadas en la población mexicana para determinar la composición corporal y comparar dichas elipses con las de otras elipses realizadas en otras poblaciones. Material y métodos. Se evaluó la composición corporal por impedancia bioeléctrica (IBE) en 439 sujetos (204 hombres y 235 mujeres), de 18 a 82 años de edad, con un IMC entre 18-31, utilizando un impedanciómetro Quadscan 4000. A partir de las mediciones de resistencia, reactancia y ángulo de fase se obtuvieron vectores de impedancia bioeléctrica para realizar elipses de tolerancia. Resultados. La edad promedio de los hombres fue de 47.1 ± 16 años y 42.4 ± 13 para las mujeres, el peso promedio (73.4 ± 9 vs. 60.1 ± 8) y la estatura (1.68 vs. 1.55 m) fueron significativamente mayores en hombres que en mujeres (p < 0.002). Las mujeres en comparación con los hombres, presentaron valores mayores de impedancia (622.96 ± 66.16 Ω vs. 523.59 ± 56.56 Ω) y resistencia (618.96 ± 66.10 Ω vs. 521.73 ± 61.97 Ω), así como de resistencia y reactancia estandarizadas por la estatura (398.24 ± 46.30 Ω/m vs. 308.66 ± 38.44 Ω/m) (44.32 ± 7.14 Ω/m vs. 39.75 ± 6.29 Ω/m), respectivamente, presentando en todas éstas una diferencia significativa (p < 0.0001). De igual manera, la reactancia fue mayor en el grupo femenino; sin embargo, esta diferencia no alcanzó significancia estadística (68.96 ± 11.17 vs. 67.18 ± 10.3; p = 0.0861). El ángulo de fase fue mayor en los hombres que en las mujeres, con una diferencia estadísticamente significativa (7.33° ± 0.88 vs. 6.36° ± 0.97; p < 0.0001). Las elipses de tolerancia (50%, 75% y 95%) elaboradas en población italiana sana fueron probadas para la población mexicana, encontrando que éstas tienden a situarse en el extremo superior de las elipses de poblaciones mexicoamericanas e italianas de referencia con una diferencia significativa p < 0.05, por lo que se realizaron nuevas elipses de tolerancia para población mexicana. Conclusiones. Los vectores de la población mexicana fueron significativamente diferentes al ser comparados con las existentes, apoyando la necesidad de realizar elipses de tolerancia específicas para cada población para la evaluación de la composición corporal.