ABSTRACT
Interrupted time-series (ITS) is a quasi-experimental design which evaluates the effectiveness of an intervention based on time-series outcome variables. Compared with the single group of ITS, the two groups of ITS can better control the influence of pre-interventional confounding factors and evaluate the effectiveness of the intervention. This paper summarizes the principles and statistical methods of two groups of ITS by an example of evaluating vaccine effect on the incidence of a disease in two cities. The regression model is fitted by Prais-Winsten method and Newey-West method and the results are explained and compared in detail. When the intervention is performed with other confounding interventions at the same time, the two groups of ITS can be more effective to balance the existing trends before the intervention, and evaluate the effectiveness of intervention. The method of two groups of ITS has important practical significance, providing new insights in program evaluation.
ABSTRACT
OBJECTIVES: Most children and adolescents have low levels of cancer knowledge and awareness, and infrequently engage in preventive behaviors. This study examined the effects of a short classroom-based intervention for cancer prevention on knowledge, attitude toward cancer preventability, self-efficacy, and behavioral intentions of fifth-grade elementary school students. METHODS: The study was based on a pre-post-follow-up, 2-group, quasi-experimental design. Participants in the intervention group attended two 40-minute sessions on cancer prevention education and watched a music video about cancer prevention, while participants in the control group were only exposed to the music video. Self-reported knowledge, attitude toward cancer preventability, self-efficacy, and behavioral intentions were assessed 1 week pre-intervention and post-intervention, as well as 3 months post-intervention. RESULTS: The 3-month post-intervention results revealed partial effects, indicating that the education intervention improved knowledge and attitudes toward cancer preventability; however, no effects were observed on self-efficacy and behavioral intentions 3 months after the intervention. CONCLUSIONS: Long-term regular booster sessions are required to improve not only social-cognitive factors, but also behavioral intentions, which could result in behavior changes promoting cancer prevention.
Subject(s)
Adolescent , Child , Humans , Education , Intention , Korea , Music , Program EvaluationABSTRACT
OBJECTIVES: Most children and adolescents have low levels of cancer knowledge and awareness, and infrequently engage in preventive behaviors. This study examined the effects of a short classroom-based intervention for cancer prevention on knowledge, attitude toward cancer preventability, self-efficacy, and behavioral intentions of fifth-grade elementary school students.METHODS: The study was based on a pre-post-follow-up, 2-group, quasi-experimental design. Participants in the intervention group attended two 40-minute sessions on cancer prevention education and watched a music video about cancer prevention, while participants in the control group were only exposed to the music video. Self-reported knowledge, attitude toward cancer preventability, self-efficacy, and behavioral intentions were assessed 1 week pre-intervention and post-intervention, as well as 3 months post-intervention.RESULTS: The 3-month post-intervention results revealed partial effects, indicating that the education intervention improved knowledge and attitudes toward cancer preventability; however, no effects were observed on self-efficacy and behavioral intentions 3 months after the intervention.CONCLUSIONS: Long-term regular booster sessions are required to improve not only social-cognitive factors, but also behavioral intentions, which could result in behavior changes promoting cancer prevention.
Subject(s)
Adolescent , Child , Humans , Education , Intention , Korea , Music , Program EvaluationABSTRACT
The Randomized Control Trial (RCT) design is typically seen as the gold standard in psychological research. As it is not always possible to conform to RCT specifications, many studies are conducted in the quasi-experimental framework. Although quasi-experimental designs are considered less preferable to RCTs, with guidance they can produce inferences which are just as valid. In this paper, the authors present 3 quasi-experimental designs which are viable alternatives to RCT designs. These designs are Regression Point Displacement (RPD), Regression Discontinuity (RD), and Propensity Score Matching (PSM). Additionally, the authors outline several notable methodological improvements to use with these designs.
Los diseños de Pruebas Controladas Aleatorizadas (PCA) son típicamente vistas como el mejor diseño en la investigación en psicología. Como tal, no es siempre posible cumplir con las especificaciones de las PCA y por ello muchos estudios son realizados en un marco cuasi experimental. Aunque los diseños cuasi experimentales son considerados menos convenientes que los diseños PCA, con directrices estos pueden producir inferencias igualmente válidas. En este artículo presentamos tres diseños cuasi experimentales que son formas alternativas a los diseños PCA. Estos diseños son Regresión de Punto de Desplazamiento (RPD), Regresión Discontinua (RD), Pareamiento por Puntaje de Propensión (PPP). Adicionalmente, describimos varias mejorías metodológicas para usar con este tipo de diseños.
ABSTRACT
Este estudo avaliou a eficácia de uma intervenção com foco nas práticas de socialização com 13 mães e um pai de crianças entre três e seis anos, com perfil internalizante, divididos em dois grupos: intervenção e comparação. O BCL/1½-5 anos e o CBCL/6-18 anos foram utilizados para avaliar os problemas internalizantes e indicaram somente uma redução significativa nas queixas somáticas do grupo intervenção do pré para o pós-teste. Essa redução pode estar associada aos seguintes fatores: (a) aumento da previsibilidade das contingências da relação pais-criança, diminuindo seu caráter aversivo e levando à extinção respondente das respostas fisiológicas que estariam relacionadas às queixas somáticas; e (b) substituição de práticas superprotetoras e coercitivas por práticas facilitadoras do desenvolvimento socioemocional, que levaria à extinção respondente de respostas fisiológicas ligadas a emoções eliciadas pelas práticas coercitivas e superprotetoras. Discutem-se as limitações da intervenção e de aspectos metodológicos comuns a estudos realizados em contexto clínico.
This study evaluated the efficacy of an intervention focused on socialization practices with 13 mothers and one father of children between three and six years with internalizing profile, divided into two groups: intervention and comparison. The CBCL/1½-5 years and CBCL/6-18 years were used for assess internalizing problems, indicating only a significant reduction in somatic complaints in the intervention group from pre to post-test. This reduction may be associated with the following factors: (a) increase of the predictability of contingencies parent-child relationship, decreasing its aversive character and leading to respondent extinction of physiological responses that are related to somatic complaints and (b) replacement of overprotective and coercive practices by facilitating socioemotional development leading to the extinction of respondent physiological responses related to emotions elicited by coercive practices and overprotection. The limitations of intervention and methodological aspects common in studies conducted in clinical settings are discussed.
Subject(s)
Humans , Male , Female , Adult , Behavioral Symptoms , Child , Parents , Psychotherapy, Group , SocializationABSTRACT
En este estudio se evaluó la eficacia de la hipnosis en la modificación de un conjunto de variables psicológicas y fisiológicas durante la realización de pruebas de esfuerzo. Se utilizaron un total de 24 participantes ciclistas. El procedimiento consistió en enviar al azar a los participantes a un grupo experimental con hipnosis o al grupo control. En ambos grupos se midieron variables psicológicas y fisiológicas relacionadas con el deporte. Los resultados no mostraron diferencias estadísticamente significativas entre-grupos en las variables evaluadas. Sí se observó una tendencia en el grupo experimental a puntuar más positivamente en varias variables psicológicas analizadas. Se concluye que sería de interés desarrollar futuras investigaciones ampliando el tamaño de la muestra y aplicar el procedimiento en diferentes modalidades deportivas.
In this paper evaluated the efficiency of hypnosis on modification of a set of psychological and physiological variables during the performance of a task force. There were in use a total of 24 cycle participants. The procedure consisted of sending at random to the participants to an experimental group with hypnosis and group control. In both groups there measured up psychological and physiological variables related to the sport. Results indicate that there was not a statistically significant difference between the two groups. However, a tendency more positively in a set of psychological variables was observed in the experimental group. It is concluded that it would be of interest to develop future researches extending the size of the sample and to apply the procedure in different sports modalities.
Subject(s)
Psychology, SportsABSTRACT
La actitudes negativas hacia las personas con discapacidad imperantes en la sociedad plantean la necesidad de intervenciones que modifiquen tales actitudes. Con este objetivo se ha desarrollado un programa de cambio de actitudes hacia personas con discapacidad en alumnos de educación primaria, 100 niños y niñas, entre 7 y 10 años, asignados 39 al grupo experimental y 61 al grupo control. Se utilizaron como técnicas de cambio la información y el contacto. También se efectuó un seguimiento de dos años y medio, durante el que se realizaron actividades recordatorio. El instrumento de evaluación utilizado fue la Escala de Actitudes hacia Personas con Discapacidad (Verdugo, Arias & Jenaro, 1994). Los resultados alcanzados abogan por la eficacia de estas técnicas, al encontrase entre las medidas pretratamiento y postratamiento diferencias estadísticamente significativas para estas últimas a favor del grupo experimental. Tales cambios se mantienen en el seguimiento.
The negative attitudes toward people with disabilities prevailing in our society suggest the need for interventions to modify those attitudes. With this aim a program in changing attitudes towards people with disabilities in primary school children has been developed. 100 children between 7 and 10 years old took part in the study, 39 were assigned to the experimental group and 61 to the control group. Information and contact have been used as change techniques. It has also been followed up for two years and a half. During this time, activities reminders have been made. The assessment instrument used was the Scale of Attitudes toward People with Disabilities (Verdugo, Arias & Jenaro, 1994). The results obtained argue for the effectiveness of these techniques. There are statistically significant differences between pretreatment and posttreatment measures in favor of the experimental group. Also, these changes at follow up have been maintained.
Subject(s)
Psychology, Educational , Intellectual DisabilityABSTRACT
Objective: To examine the effectiveness of a drug abuse prevention program focusing on social influences for drug education classes in high school. Methods: The social influence program in the experimental group used role-playing led by a pharmacist, a police officer and a teacher. The intervention evaluation used a quasi-experimental design. The subjects were first-year students from 10 high schools assigned to the experimental group (6 schools, 828 students) and the control group (4 schools, 408 students). In the control group, a pharmacist used a conventional information program in a lecture format. Results: Regarding knowledge about drug abuse, in both the experimental and control groups, and for both males and females, a long-term effect was observed immediately after the program and lasted up to 15 months. For three other measures, attitudes toward drug abuse problem, self-efficacy regarding drug abuse prevention, and perception of social support for preventing drug abuse, a short-term effect was generally observed in the experimental group beginning immediately after the program and lasting for 3 months. A long-term effect was evident in high-risk students with positive opinions regarding drugs. In the control group and for both males and females, although an effect was generally evident immediately after the program, neither a short- nor a long-term effect was observed in males, suggesting the difficulty in achieving lasting effects. Conclusions: The social influence program in the experimental group showed remarkable effectiveness. Thus, the program may be useful for preventing drug abuse among high school students in Japan.
Subject(s)
Substance-Related Disorders , Control GroupsABSTRACT
<p><b>OBJECTIVE</b>To examine the effectiveness of a drug abuse prevention program focusing on social influences for drug education classes in high school.</p><p><b>METHODS</b>The social influence program in the experimental group used role-playing led by a pharmacist, a police officer and a teacher. The intervention evaluation used a quasi-experimental design. The subjects were first-year students from 10 high schools assigned to the experimental group (6 schools, 828 students) and the control group (4 schools, 408 students). In the control group, a pharmacist used a conventional information program in a lecture format.</p><p><b>RESULTS</b>Regarding knowledge about drug abuse, in both the experimental and control groups, and for both males and females, a long-term effect was observed immediately after the program and lasted up to 15 months. For three other measures, attitudes toward drug abuse problem, self-efficacy regarding drug abuse prevention, and perception of social support for preventing drug abuse, a short-term effect was generally observed in the experimental group beginning immediately after the program and lasting for 3 months. A long-term effect was evident in high-risk students with positive opinions regarding drugs. In the control group and for both males and females, although an effect was generally evident immediately after the program, neither a short-nor a long-term effect was observed in males, suggesting the difficulty in achieving lasting effects.</p><p><b>CONCLUSIONS</b>The social influence program in the experimental group showed remarkable effectiveness. Thus, the program may be useful for preventing drug abuse among high school students in Japan.</p>