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1.
Psychol Methods ; 2021 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-34383531

RESUMEN

To prevent mistakes in psychological assessment, the precision of test norms is important. This can be achieved by drawing a large normative sample and using regression-based norming. Based on that norming method, a procedure for sample size planning to make inference on Z-scores and percentile rank scores is proposed. Sampling variance formulas for these norm statistics are derived and used to obtain the optimal design, that is, the optimal predictor distribution, for the normative sample, thereby maximizing precision of estimation. This is done under five regression models with a quantitative and a categorical predictor, differing in whether they allow for interaction and nonlinearity. Efficient robust designs are given in case of uncertainty about the regression model. Furthermore, formulas are provided to compute the normative sample size such that individuals' positions relative to the derived norms can be assessed with prespecified power and precision. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

2.
Tob Control ; 2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-34226262

RESUMEN

BACKGROUND: Studies demonstrated that adolescent e-cigarette use is associated with subsequent tobacco smoking, commonly referred to as the gateway effect. However, most studies only investigated gateways from e-cigarettes to tobacco smoking. This study replicates a cornerstone study revealing a positive association between both adolescent e-cigarette use and subsequent tobacco use; and tobacco and subsequent e-cigarette use in the Netherlands and Flanders. DESIGN: The longitudinal design included baseline (n=2839) and 6-month (n=1276) and 12-month (n=1025) follow-up surveys among a school-based cohort (mean age: 13.62). Ten high schools were recruited as a convenience sample. The analyses involved (1) associations of baseline e-cigarette use and subsequent tobacco smoking among never smokers; (2) associations of e-cigarette use frequency at baseline and tobacco smoking frequency at follow-up; and (3) the association of baseline tobacco smoking and subsequent e-cigarette use among non-users of e-cigarettes. FINDINGS: Consistent with prior findings, baseline e-cigarette use was associated with higher odds of tobacco smoking at 6-month (OR=1.89; 95% CI 1.05 to 3.37) and 12-month (OR=5.63; 95% CI 3.04 to 10.42) follow-ups. More frequent use of e-cigarettes at baseline was associated with more frequent smoking at follow-ups. Baseline tobacco smoking was associated with subsequent e-cigarette use (OR=3.10; 95% CI 1.58 to 6.06 at both follow-ups). CONCLUSION: Our study replicated the positive relation between e-cigarette use and tobacco smoking in both directions for adolescents. This may mean that the gateway works in two directions, that e-cigarette and tobacco use share common risk factors, or that both mechanisms apply.

3.
Biom J ; 63(7): 1444-1463, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34247406

RESUMEN

Cluster randomized trials evaluate the effect of a treatment on persons nested within clusters, with clusters being randomly assigned to treatment. The optimal sample size at the cluster and person level depends on the study cost per cluster and per person, and the outcome variance at the cluster and the person level. The variances are unknown in the design stage and can differ between treatment arms. As a solution, this paper presents a Maximin design that maximizes the minimum relative efficiency (relative to the optimal design) over the variance parameter space, for trials with two treatment arms and a quantitative outcome. This maximin relative efficiency design (MMRED) is compared with a published Maximin design which maximizes the minimum efficiency (MMED). Both designs are also compared with the optimal designs for homogeneous costs and variances (balanced design) and heterogeneous costs and homogeneous variances (cost-conscious design), for a range of variances based upon three published trials. Whereas the MMED is balanced under high uncertainty about the treatment-to-control variance ratio, the MMRED then tends towards a balanced budget allocation between arms, leading to an unbalanced sample size allocation if costs are heterogeneous, similar to the cost-conscious design. Further, the MMRED corresponds to an optimal design for an intraclass correlation (ICC) in the lower half of the assumed ICC range (optimistic), whereas the MMED is the optimal design for the maximum ICC within the ICC range (pessimistic). Attention is given to the effect of the Welch-Satterthwaite degrees of freedom for treatment effect testing on the design efficiencies.


Asunto(s)
Modelos Estadísticos , Proyectos de Investigación , Análisis por Conglomerados , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Tamaño de la Muestra , Incertidumbre
4.
BMC Med Ethics ; 22(1): 73, 2021 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-34139997

RESUMEN

BACKGROUND: The COVID-19 pandemic has created ethical challenges for intensive care unit (ICU) professionals, potentially causing moral distress. This study explored the levels and causes of moral distress and the ethical climate in Dutch ICUs during COVID-19. METHODS: An extended version of the Measurement of Moral Distress for Healthcare Professionals (MMD-HP) and Ethical Decision Making Climate Questionnaire (EDMCQ) were online distributed among all 84 ICUs. Moral distress scores in nurses and intensivists were compared with the historical control group one year before COVID-19. RESULTS: Three hundred forty-five nurses (70.7%), 40 intensivists (8.2%), and 103 supporting staff (21.1%) completed the survey. Moral distress levels were higher for nurses than supporting staff. Moral distress levels in intensivists did not differ significantly from those of nurses and supporting staff. "Inadequate emotional support for patients and their families" was the highest-ranked cause of moral distress for all groups of professionals. Of all factors, all professions rated the ethical climate most positively regarding the culture of mutual respect,  ethical awareness and support. "Culture of not avoiding end-of-life-decisions" and "Self-reflective and empowering leadership" received the lowest mean scores. Moral distress scores during COVID-19 were significantly lower for ICU nurses (p < 0.001) and intensivists (p < 0.05) compared to one year prior. CONCLUSION: Levels and causes of moral distress vary between ICU professionals and differ from the historical control group. Targeted interventions that address moral distress during a crisis are desirable to improve the mental health and retention of ICU professionals and the quality of patient care.


Asunto(s)
COVID-19 , Actitud del Personal de Salud , Cuidados Críticos , Humanos , Unidades de Cuidados Intensivos , Principios Morales , Pandemias , SARS-CoV-2 , Estrés Psicológico , Encuestas y Cuestionarios
5.
Subst Abus ; : 1-9, 2021 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-33849396

RESUMEN

Background: Screening for unhealthy alcohol use in routine consultations can aid primary health care (PHC) providers in detecting patients with hazardous or harmful consumption and providing them with appropriate care. As part of larger trial testing strategies to improve implementation of alcohol screening in PHC, this study investigated the motivational (role security, therapeutic commitment, self-efficacy) and organizational context (leadership, work culture, resources, monitoring, community engagement) factors that were associated with the proportion of adult patients screened with AUDIT-C by PHC providers in Colombia, Mexico and Peru. Additionally, the study investigated whether the effect of the factors interacted with implementation strategies and the country. Methods: Pen-and-paper questionnaires were completed by 386 providers at the start of their study participation (79% female, Mage = 39.5, 37.6% doctors, 15.0% nurses, 9.6% psychologists, 37.8% other professional roles). They were allocated to one of four intervention arms: control group; short training only; short training in presence of municipal support; and standard (long) training in presence of municipal support. Providers documented their screening practice during the five-month implementation period. Data were collected between April 2019 and March 2020. Results: Negative binomial regression analysis found an inverse relationship of role security with the proportion of screened patients. Self-efficacy was associated with an increase in the proportion of screened patients only amongst Mexican providers. Support from leadership (formal leader in organization) was the only significant organizational context factor, but only in non-control arms. Conclusion: Higher self-efficacy is a relevant factor in settings where screening practice is already ongoing. Leadership support can enhance effects of implementation strategies.

6.
Nicotine Tob Res ; 23(1): 99-106, 2021 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-31993637

RESUMEN

INTRODUCTION: Financial incentives effectively increase smoking cessation rates, but it is unclear via which psychological mechanisms incentives influence quit behavior. The current study examines how receiving financial incentives for smoking cessation leads to quitting smoking and investigates several mediators and moderators of that relationship. AIMS AND METHODS: The study sample consisted of 604 tobacco-smoking employees from 61 companies in the Netherlands who completed a baseline and follow-up questionnaire. The current study is a secondary analysis from a cluster randomized trial where employees received smoking cessation group counseling at the workplace. Participants in the intervention group additionally received financial incentives of €350 in total for 12-month continuous smoking abstinence. We used a two-level path analysis to test a model that assesses the effects of financial incentives through smoking cessation program evaluation, medication use, nicotine replacement use, attitudes, self-efficacy, and social influences on quit success. We additionally tested whether an individual's reward responsiveness moderated the influence of incentives on quit success. RESULTS: The effect of financial incentives on quit success was mediated by a higher self-efficacy. Financial incentives were also associated with a higher use of cessation medication. A more positive program evaluation was related to higher self-efficacy, more social influence to quit, and more positive attitudes about quitting. The results did not differ significantly by individual reward responsiveness. CONCLUSIONS: The results of the current study suggest that financial incentives may be used to increase medication use and self-efficacy for quitting smoking, which offers an indirect way to increase successful smoking cessation. IMPLICATIONS: (1) This is the first study investigating via which psychological pathways financial incentives for quitting smoking can lead to long-term quit success. (2) The results showed a path between financial incentives and a higher likelihood of medication use. Incentives may encourage smokers to use medication in order to increase their chance of quitting smoking and receive the reward. (3) There was a path from financial incentives to quit success via a higher self-efficacy. (4) The effects of financial incentives did not depend on individual reward responsiveness.


Asunto(s)
Terapia Conductista/economía , Motivación , Fumadores/psicología , Cese del Hábito de Fumar/economía , Fumar/terapia , Dispositivos para Dejar de Fumar Tabaco/estadística & datos numéricos , Terapia Conductista/métodos , Femenino , Promoción de la Salud , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Fumar/epidemiología , Fumar/psicología , Cese del Hábito de Fumar/métodos , Cese del Hábito de Fumar/psicología , Lugar de Trabajo
7.
Health Psychol Behav Med ; 8(1): 73-95, 2020 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-34040863

RESUMEN

Background: Despite nutritional benefits, a high consumption of red meat is not without risks as it is linked to the development of certain types of cancer as well as to other non-communicable diseases, such as type II diabetes or cardiovascular diseases. Moreover, the production of meat has negative effects on the environment. Therefore, a transition to a less meat-based diet could be beneficial. It is unclear how explicit cognitions towards red meat consumption and implicit attitudes jointly influence intention and consumption. We tested the additive pattern (both types of cognitions explain unique variance) and interactive pattern (both types interact in the prediction). Method: At baseline (T0; N = 1790) and one (T1; n = 980) and three months thereafter (T2; n = 556), explicit cognitions, red meat consumption, and implicit attitudes were assessed among a Dutch sample. Results: Only explicit cognitions were associated with red meat consumption. Implicit attitudes moderated the effect of self-efficacy on T0-RMC; negative implicit attitudes strengthened this effect. T0-intention was associated with explicit cognitions and implicit attitudes. Additionally, negative implicit attitudes strengthened the effect of social norms on T0 and T2-intention. Regarding red meat consumption, support for the interactive pattern was found. For intention there was support for the interactive and additive pattern. Conclusion: Interventions aiming to reduce red meat consumption in the general public might profit from changing implicit attitudes in addition to explicit cognitions.

8.
Trials ; 20(1): 643, 2019 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-31752975

RESUMEN

BACKGROUND: Organ donation registration rates remain low, especially among people with lower educational levels. An interactive educational intervention was developed to prepare lower-educated students in the Netherlands for making a well-informed decision about organ donation. This article reports on the effects of this intervention on the intention to register (i.e., the primary outcome in the study at hand) and beliefs regarding organ donation. MATERIALS AND METHODS: The effectiveness was investigated in a post-test-only cluster randomized controlled trial, in which the intervention was offered to the experimental group and after measurement also to the control group. Randomization to the experimental and control groups took place at a class level. Teachers of schools for Intermediate Vocational Education who taught a course on Citizenship delivered three intervention elements (i.e., video fragments and discussion, quizzes with tailored feedback and exercise filling out a registration form) to their students during two 50-min lessons. RESULTS: A total of 1170 students participated in the trial and filled out a questionnaire (45 experimental and 43 control classes). Compared to the control group, students in the experimental group had higher odds of having positive registration intentions (OR = 1.81; 95%CI [1.10-2.96]), their perceived knowledge was higher (B = 0.62; 95%CI [0.23-1.01]) and they had higher intentions to talk to family members (B = 0.68; 95%CI [0.28-1.08]) and friends (B = 0.36; 95%CI [0.07-0.66]) about organ donation. There were no effects on the choice students intended to register (OR = 1.08; 95%CI [0.67-1.73]). CONCLUSIONS: Providing education in a classroom setting is an effective tool in increasing registration intentions. Despite uncertainties about the effects on actual registration behavior, a larger-scale dissemination of this intervention is recommended. Providing clear information and opening the discussion about organ donation is an important and promising first step towards higher registration rates. TRIAL REGISTRATION: The Dutch Trial Register, ID: NTR6771. Registered on 24 October 2017. https://www.trialregister.nl/trial/6557.


Asunto(s)
Escolaridad , Conocimientos, Actitudes y Práctica en Salud , Estudiantes/psicología , Donantes de Tejidos/educación , Donantes de Tejidos/psicología , Obtención de Tejidos y Órganos , Educación Vocacional , Adolescente , Altruismo , Actitud Frente a la Muerte , Conducta de Elección , Características Culturales , Femenino , Conocimientos, Actitudes y Práctica en Salud/etnología , Humanos , Consentimiento Informado , Masculino , Países Bajos , Evaluación de Programas y Proyectos de Salud , Adulto Joven
9.
Artículo en Inglés | MEDLINE | ID: mdl-31684033

RESUMEN

In 2016, the Netherlands was required to introduce new European Union (EU)'s (pictorial) tobacco health warnings. Our objective was to describe the pathways through which the new EU tobacco health warnings may influence quit attempts and smoking cessation among Dutch smokers. Longitudinal data from 2016 and 2017 from the International Tobacco Control (ITC) Netherlands Survey were used. Smokers who participated in both surveys were included (N = 1017). Structural equation modeling was applied to examine the hypothesized pathways. Health warning salience was positively associated with more health worries (ß = 0.301, p < 0.001) and a more positive attitude towards quitting (ß = 0.180, p < 0.001), which, in turn, were associated with a stronger quit intention (health worries: ß = 0.304, p < 0.001; attitude: ß = 0.340, p < 0.001). Quit intention was a strong predictor of quit attempts (ß = 0.336, p = 0.001). Health warning salience was also associated with stronger perceived social norms towards quitting (ß = 0.166, p < 0.001), which directly predicted quit attempts (ß = 0.141, p = 0.048). Quit attempts were positively associated with smoking cessation (ß = 0.453, p = 0.043). Based on these findings, we posit that the effect of the EU's tobacco health warnings on quit attempts and smoking cessation is mediated by increased health worries and a more positive attitude and perceived social norms towards quitting. Making tobacco health warnings more salient (e.g., by using plain packaging) may increase their potential to stimulate quitting among smokers.


Asunto(s)
Cese del Hábito de Fumar/estadística & datos numéricos , Prevención del Hábito de Fumar/métodos , Fumar Tabaco/prevención & control , Adolescente , Adulto , Unión Europea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos , Etiquetado de Productos , Cese del Hábito de Fumar/psicología , Encuestas y Cuestionarios , Tabaco , Fumar Tabaco/psicología , Adulto Joven
10.
BMC Psychol ; 7(1): 52, 2019 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-31391101

RESUMEN

BACKGROUND: Explicit attitudes as well as implicit attitudes have been shown to be associated with physical activity (PA). These two types of attitudes can, however, be discrepant towards the same object or behavior. This study investigated whether there is a discrepancy between explicit and implicit attitudes (IED) regarding physical activity (PA), and whether IED moderates the relationship between explicit attitude and PA, and explicit attitude and PA intention. METHODS: At baseline (T0) and one (T1) and three months (T2) thereafter, students' (N = 340) PA levels, intention, explicit attitudes, further PA determinants, e.g. self-efficacy, were assessed. Implicit attitudes towards PA were assessed by means of a tailored Single-Category Implicit Association task. RESULTS: IED was present but weak. Multiple hierarchical regressions revealed that IED did not moderate the relationship between explicit attitudes and PA or intention. Yet, IED was negatively associated with T0-PA and T1-PA. CONCLUSION: The study revealed the important insight that IED is detrimental for PA. Interventions targeting attitudes to increase PA, should ensure that implicit and explicit attitudes regarding PA are concordant.


Asunto(s)
Actitud , Ejercicio Físico/psicología , Femenino , Humanos , Intención , Masculino , Autoeficacia , Estudiantes , Adulto Joven
11.
Stat Med ; 38(10): 1817-1834, 2019 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-30575062

RESUMEN

In multilevel populations, there are two types of population means of an outcome variable ie, the average of all individual outcomes ignoring cluster membership and the average of cluster-specific means. To estimate the first mean, individuals can be sampled directly with simple random sampling or with two-stage sampling (TSS), that is, sampling clusters first, and then individuals within the sampled clusters. When cluster size varies in the population, three TSS schemes can be considered, ie, sampling clusters with probability proportional to cluster size and then sampling the same number of individuals per cluster; sampling clusters with equal probability and then sampling the same percentage of individuals per cluster; and sampling clusters with equal probability and then sampling the same number of individuals per cluster. Unbiased estimation of the average of all individual outcomes is discussed under each sampling scheme assuming cluster size to be informative. Furthermore, the three TSS schemes are compared in terms of efficiency with each other and with simple random sampling under the constraint of a fixed total sample size. The relative efficiency of the sampling schemes is shown to vary across different cluster size distributions. However, sampling clusters with probability proportional to size is the most efficient TSS scheme for many cluster size distributions. Model-based and design-based inference are compared and are shown to give similar results. The results are applied to the distribution of high school size in Italy and the distribution of patient list size for general practices in England.


Asunto(s)
Análisis por Conglomerados , Tamaño de la Muestra , Consumo de Bebidas Alcohólicas/epidemiología , Simulación por Computador , Inglaterra , Medicina General/estadística & datos numéricos , Hospitalización/estadística & datos numéricos , Humanos , Italia/epidemiología , Densidad de Población , Proyectos de Investigación , Instituciones Académicas/estadística & datos numéricos
12.
Comput Math Methods Med ; 2018: 8025827, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30402138

RESUMEN

If there are no carryover effects, AB/BA crossover designs are more efficient than parallel (A/B) and extended parallel (AA/BB) group designs. This study extends these results in that (a) optimal instead of equal treatment allocation is examined, (b) allowance for treatment-dependent outcome variances is made, and (c) next to treatment effects, also treatment by period interaction effects are examined. Starting from a linear mixed model analysis, the optimal allocation requires knowledge on intraclass correlations in A and B, which typically is rather vague. To solve this, maximin versions of the designs are derived, which guarantee a power level across plausible ranges of the intraclass correlations at the lowest research costs. For the treatment effect, an extensive numerical evaluation shows that if the treatment costs of A and B are equal, or if the sum of the costs of one treatment and measurement per person is less than the remaining subject-specific costs (e.g., recruitment costs), the maximin crossover design is most efficient for ranges of intraclass correlations starting at 0.15 or higher. For other cost scenarios, the maximin parallel or extended parallel design can also become most efficient. For the treatment by period interaction, the maximin AA/BB design can be proven to be the most efficient. A simulation study supports these asymptotic results for small samples.


Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Análisis de Varianza , Simulación por Computador , Estudios Cruzados , Costos de la Atención en Salud , Humanos , Modelos Lineales , Conceptos Matemáticos , Modelos Estadísticos , Método de Montecarlo , Ensayos Clínicos Controlados Aleatorios como Asunto/economía , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Tamaño de la Muestra , Resultado del Tratamiento
13.
Trials ; 19(1): 532, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30285823

RESUMEN

BACKGROUND: The gap between the supply and demand of organ donors is substantial, causing patients to suffer from long waiting times. Moreover, the lack of registrations places a burden on family members and medical professionals when an unregistered individual dies. This article describes a cluster randomized controlled trial (CRCT) study to assess the effectiveness and quality of implementation of a web-based program aimed at encouraging lower-educated adolescents to register a well-informed choice about organ donation, regardless of it being as a donor or not. METHODS/DESIGN: The program will be delivered by teachers at schools for Intermediate Vocational Education in the Netherlands. The effectiveness will be assessed in a CRCT design with post-test only using self-administered questionnaires for the primary outcome (i.e. intention to register). Classes will be matched to improve equivalence of groups. From each pair of matched classes, one class will be randomly assigned to the experimental condition, and the other assigned to the control condition. Students in the control groups will fill in the questionnaire before receiving the program, while the experimental groups will do this afterwards. A post-test design prevents the risk of testing bias. The required sample size is 14 schools, with 10 classes per school and 13 unregistered students per class. The questionnaire assesses demographics, behavioural determinants (attitude, self-efficacy, knowledge and social outcomes), intention to register (as a donor) and registration status. Six months after delivery, registration status will be assessed again. Additionally, a process evaluation will be conducted to evaluate the quality of implementation using both qualitative (i.e. semi-structured interviews) and quantitative (i.e. logbooks, questionnaires, Google Analytics to track user behaviour at the website) methods. DISCUSSION: Findings of the study can help to further improve the program and serve as a basis for a solid dissemination plan. Moreover, the study will provide insight into (change in) determinants of registration and donorship and the translation of research into practice of school-based health promotion interventions, which can serve as an example for others. TRIAL REGISTRATION: The Dutch Trial Register, NTR6771 . Registered on 24 October 2017. This is version 2 of the protocol (5 November 2017).


Asunto(s)
Conducta del Adolescente , Escolaridad , Conductas Relacionadas con la Salud , Educación en Salud/métodos , Conocimientos, Actitudes y Práctica en Salud , Servicios de Salud Escolar , Donantes de Tejidos/educación , Obtención de Tejidos y Órganos , Adolescente , Conducta de Elección , Femenino , Humanos , Internet , Masculino , Países Bajos , Ensayos Clínicos Controlados Aleatorios como Asunto , Donantes de Tejidos/psicología , Donantes de Tejidos/provisión & distribución
15.
Stat Med ; 37(21): 3027-3046, 2018 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-29888393

RESUMEN

Cluster randomized trials evaluate the effect of a treatment on persons nested within clusters, where treatment is randomly assigned to clusters. Current equations for the optimal sample size at the cluster and person level assume that the outcome variances and/or the study costs are known and homogeneous between treatment arms. This paper presents efficient yet robust designs for cluster randomized trials with treatment-dependent costs and treatment-dependent unknown variances, and compares these with 2 practical designs. First, the maximin design (MMD) is derived, which maximizes the minimum efficiency (minimizes the maximum sampling variance) of the treatment effect estimator over a range of treatment-to-control variance ratios. The MMD is then compared with the optimal design for homogeneous variances and costs (balanced design), and with that for homogeneous variances and treatment-dependent costs (cost-considered design). The results show that the balanced design is the MMD if the treatment-to control cost ratio is the same at both design levels (cluster, person) and within the range for the treatment-to-control variance ratio. It still is highly efficient and better than the cost-considered design if the cost ratio is within the range for the squared variance ratio. Outside that range, the cost-considered design is better and highly efficient, but it is not the MMD. An example shows sample size calculation for the MMD, and the computer code (SPSS and R) is provided as supplementary material. The MMD is recommended for trial planning if the study costs are treatment-dependent and homogeneity of variances cannot be assumed.


Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Análisis por Conglomerados , Humanos , Modelos Estadísticos , Tamaño de la Muestra
16.
BMC Public Health ; 18(1): 740, 2018 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-29902984

RESUMEN

BACKGROUND: Displaying tobacco products at point-of-sale (PoS) has become an important marketing strategy for the tobacco industry. This study was designed to (1) examine how support for a PoS cigarette display ban changed among Dutch smokers between 2010 and 2015 and (2) identify the variables that predict support among smokers for a PoS cigarette display ban. METHODS: Longitudinal data from six annual survey waves (2010-2015) from the International Tobacco Control (ITC) Netherlands Survey were analyzed. The sample consisted of between 1279 and 1800 smokers per year. Smokers were asked whether they supported a complete ban on displays of cigarettes inside shops and stores. RESULTS: Support for a PoS cigarette display ban increased from 28.9% in 2010 to 42.5% in 2015 (OR = 1.40, p < 0.001). A multiple logistic regression analysis revealed that support for a PoS display ban of cigarettes was more likely among smokers who had more knowledge about the health risks of smoking (OR = 3.97, p < 0.001), believed smoking-related health risks to be severe (OR = 1.39, p < 0.001), had a more positive attitude towards quitting smoking (OR = 1.44, p = 0.006), reported stronger social norms to quit smoking (OR = 1.29, p = 0.035), had a higher self-efficacy for quitting smoking (OR = 1.31, p = 0.001), and had stronger intentions to quit smoking (OR = 1.23, p = 0.006). CONCLUSIONS: This paper showed that support for a PoS display ban of cigarettes increased among smokers in the Netherlands over the years. To further increase support, educational campaigns about the dangers of smoking, and campaigns that encourage quitting may be needed.


Asunto(s)
Comercio/legislación & jurisprudencia , Mercadotecnía/legislación & jurisprudencia , Mercadotecnía/métodos , Opinión Pública , Fumadores/psicología , Productos de Tabaco , Adolescente , Adulto , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Países Bajos , Fumadores/estadística & datos numéricos , Encuestas y Cuestionarios , Industria del Tabaco , Adulto Joven
17.
BMC Psychol ; 6(1): 18, 2018 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-29699574

RESUMEN

BACKGROUND: Strategies to promote physical activity (PA) focus mainly on changing or fostering explicit cognitions and are only modestly effective. Contemporary studies suggest that, as well as explicit cognitions, implicit cognitions influence health behavior, such as PA, and that implicit processes interact with the intention to be active. Relatively little is known about whether implicit processes interact with other explicit cognitions which determine PA intention and behavior, i.e. self-efficacy. The aim of the current study was to investigate the direct effects of explicit cognitions and implicit attitudes on PA behavior as well as interactions between them regarding intention and behavior prediction. METHODS: In a longitudinal study, participants (N = 340) completed self-report measures of explicit cognitions (perceived pros, perceived cons, social norms, social modeling, self-efficacy, intention) and activity levels, as well as a Single-Category Implicit Association Task to measure implicit attitudes towards PA at baseline (T0), and at one (T1) and 3 months thereafter (T2). RESULTS: Hierarchical multiple regressions revealed that T0-positive implicit attitudes moderated the relationship between T0 self-efficacy and T1 PA. Similarly, T0-neutral implicit attitudes were associated with the relationship between T0 intention and T1 PA. Negative implicit attitudes strengthened the negative relationship between perceived cons and intention at baseline; neutral or positive implicit attitudes strengthened the positive relationship between self-efficacy and intention. At the follow-ups, the relationship between social modeling and intention was strengthened by negative implicit attitudes. CONCLUSION: This study revealed important insights into how implicit attitudes and explicit cognitions synergistically predict PA intention and behavior. As well as targeting explicit cognitions, steering a person's implicit attitude towards a more positive one, i.e. by implicit cognitive trainings, could help to increase both PA intention and behavior.


Asunto(s)
Ejercicio Físico , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Intención , Adulto , Ejercicio Físico/psicología , Femenino , Humanos , Estudios Longitudinales , Masculino , Adulto Joven
18.
Stat Med ; 37(1): 12-27, 2018 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-28948651

RESUMEN

At the design stage of a study, it is crucial to compute the sample size needed for treatment effect estimation with maximum precision and power. The optimal design depends on the costs, which may be known at the design stage, and on the outcome variances, which are unknown. A balanced design, optimal for homogeneous costs and variances, is typically used. An alternative to the balanced design is a design optimal for the known and possibly heterogeneous costs, and homogeneous variances, called costs considering design. Both designs suffer from loss of efficiency, compared with optimal designs for heterogeneous costs and variances. For 2 × 2 multicenter trials, we compute the relative efficiency of the balanced and the costs considering designs, relative to the optimal designs. We consider 2 heterogeneous costs and variance scenarios (in 1 scenario, 2 treatment conditions have small and 2 have large costs and variances; in the other scenario, 1 treatment condition has small, 2 have intermediate, and 1 has large costs and variances). Within these scenarios, we examine the relative efficiency of the balanced design and of the costs considering design as a function of the extents of heterogeneity of the costs and of the variances and of their congruence (congruent when the cheapest treatment has the smallest variance, incongruent when the cheapest treatment has the largest variance). We find that the costs considering design is generally more efficient than the balanced design, and we illustrate this theory on a 2 × 2 multicenter trial on lifestyle improvement of patients in general practices.


Asunto(s)
Ensayos Clínicos como Asunto/métodos , Bioestadística , Ensayos Clínicos como Asunto/economía , Ensayos Clínicos como Asunto/estadística & datos numéricos , Medicina General , Costos de la Atención en Salud , Promoción de la Salud , Humanos , Estilo de Vida , Modelos Lineales , Modelos Estadísticos , Estudios Multicéntricos como Asunto/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Tamaño de la Muestra , Resultado del Tratamiento
19.
Nicotine Tob Res ; 20(9): 1101-1108, 2018 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-28472427

RESUMEN

Introduction: The aim of the study was to compare the construct validity and the predictive validity of three instruments to measure intention to quit smoking: a Stages of Change measure, the Motivation To Stop Scale (MTSS), and a Likert scale. We used the Theory of Planned Behavior as theoretical framework. Methods: We used data from the International Tobacco Control Netherlands Survey. We included smokers who participated in three consecutive survey waves (n = 980). We measured attitude, subjective norm, and perceived behavioral control in 2012, intention to quit with three instruments in 2013, and having made a quit attempt in the last year in 2014. We conducted Structural Equation Modeling with three models for the instruments of intention separately and with one model that included the three instruments simultaneously. Results: All three instruments of intention were significantly and positively related to attitude and perceived behavioral control but none was related to subjective norm. All three instruments were significantly and positively related to making a quit attempt. The relation of the Likert scale with making a quit attempt (ß = 0.38) was somewhat stronger than that of the Stages of Change measure (ß = 0.35) and the MTSS (ß = 0.22). When entering the three instruments together into one model, only the Likert scale was significantly related to making a quit attempt. Conclusions: All three instruments showed reasonable construct validity and comparable predictive validity. Under the studied conditions, the Likert scale performed slightly better than the Stages of Change measure and the MTSS. Implications: An assessment of the Stages of Change, the Motivation To Stop Scale, and a Likert scale showed comparable predictive and construct validity as measures for intention to quit smoking. All three instruments can be used in future research; however, under the studied theoretical framework, that is, the Theory of Planned Behavior, the Likert scale performed slightly better than the other two instruments.


Asunto(s)
Intención , Fumadores/psicología , Cese del Hábito de Fumar/psicología , Encuestas y Cuestionarios/normas , Fumar Tabaco/psicología , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Motivación , Países Bajos/epidemiología , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Cese del Hábito de Fumar/métodos , Fumar Tabaco/epidemiología , Fumar Tabaco/terapia , Tabaquismo/epidemiología , Tabaquismo/psicología , Tabaquismo/terapia , Adulto Joven
20.
J Psychoactive Drugs ; 49(5): 363-372, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28548619

RESUMEN

Previously, a Dutch randomized controlled trial evaluating an intervention aimed at changing adolescents' cannabis use, called Moti-4, has shown its efficacy. A secondary analysis of the Moti-4 data investigated the process of change specified by the Stage of Change (SOC) model in cannabis use during the trial. Seventy-one Moti-4 participants and 60 controls were recruited for the study with a pre-test, post-test (T1), and six-month follow-up (T2). All participants showed signs of problematic cannabis use. No contribution of the Moti-4 intervention to a change in SOC between T1 and T2 was found. Although motivation for treatment and motivation for change can be conceived as independent predictors of treatment outcome, the SOC a person is in does not mediate the effect of the intervention on change in cannabis use. However, a reduction in cannabis use was associated with a positive change in "action willingness," in line with the SOC model. In contrast to model expectations, a higher score on "contemplation" is associated with a higher cannabis consumption. Results highlight both the limitations and usefulness of the SOC model. Future interventions may focus more on the stage of "action willingness," as well as on perceived social norms.


Asunto(s)
Conducta del Adolescente , Conducta Adictiva , Conductas Relacionadas con la Salud , Abuso de Marihuana/prevención & control , Fumar Marihuana/prevención & control , Entrevista Motivacional , Adolescente , Factores de Edad , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Abuso de Marihuana/diagnóstico , Abuso de Marihuana/psicología , Fumar Marihuana/psicología , Modelos Psicológicos , Países Bajos , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
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