Objective. This study was conducted to identify some factors (beliefs and norms) which are related to fast food consumption among high school students in Isfahan, Iran. We used the framework of the theory planned behavior (TPB) to predict this behavior. Subjects & Methods. Cross-sectional data were available from high school students (n = 521) who were recruited by cluster randomized sampling. All of the students completed a questionnaire assessing variables of standard TPB model including attitude, subjective norms, perceived behavior control (PBC), and the additional variables past behavior, actual behavior control (ABC). Results. The TPB variables explained 25.7% of the variance in intentions with positive attitude as the strongest (β = 0.31, P < 0.001) and subjective norms as the weakest (β = 0.29, P < 0.001) determinant. Concurrently, intentions accounted for 6% of the variance for fast food consumption. Past behavior and ABC accounted for an additional amount of 20.4% of the variance in fast food consumption. Conclusion. Overall, the present study suggests that the TPB model is useful in predicting related beliefs and norms to the fast food consumption among adolescents. Subjective norms in TPB model and past behavior in TPB model with additional variables (past behavior and actual behavior control) were the most powerful predictors of fast food consumption. Therefore, TPB model may be a useful framework for planning intervention programs to reduce fast food consumption by students.
This study provided a simultaneous, confirmatory test of the theory of planned behavior (TPB) in predicting heavy episodic drinking (HED) among college students. It was hypothesized that past HED, drinking attitudes, subjective norms and drinking refusal self-efficacy would predict intention, which would in turn predict future HED. Participants consisted of 131 college drinkers (63% female) who reported having engaged in HED in the previous two weeks. Participants were recruited and completed questionnaires within the context of a larger intervention study (see Collins & Carey, 2005). Latent factor structural equation modeling was used to test the ability of the TPB to predict HED. Chi-square tests and fit indices indicated good fit for the final structural models. Self-efficacy and attitudes but not subjective norms significantly predicted baseline intention, and intention and past HED predicted future HED. Contrary to hypotheses, however, a structural model excluding past HED provided a better fit than a model including it. Although further studies must be conducted before a definitive conclusion is reached, a TPB model excluding past behavior, which is arguably more parsimonious and theory driven, may provide better prediction of HED among college drinkers than a model including past behavior.
college drinking; alcohol use; theory of planned behavior; heavy episodic drinking; college students
Practice guidelines recommend a multifaceted approach for managing concussions, but a relatively small percentage of athletic trainers (ATs) follow these recommendations. Understanding ATs' beliefs toward the recommended concussion practice guidelines is the first step in identifying interventions that could increase compliance. The theory of planned behavior (TPB) allows us to measure ATs' beliefs toward the recommended concussion practice guidelines.
To examine the influence of ATs' beliefs toward the current recommended concussion guidelines on concussion-management practice through an application of the TPB.
A Web link with a survey was e-mailed to 1000 randomly selected members of the National Athletic Trainers' Association (NATA).
Patients or Other Participants:
A total of 221 certified ATs working in secondary school/clinic, high school, and college/university settings.
Main Outcome Measure(s):
A 66-item survey reflecting the current recommended concussion guidelines of the NATA and International Conference on Concussion in Sport was created to measure beliefs using the TPB constructs attitude toward the behavior (BA), subjective norms (SN), perceived behavioral control (PBC), and behavioral intention (BI) of ATs. We used a linear multiple regression to determine if the TPB constructs BA, SN, and PBC predicted BI and if PBC and BI predicted behavior according to the TPB model.
We found that BA, SN, and PBC predicted BI (R = 0.683, R2 = 0.466, F3,202 = 58.78, P < .001). The BA (t202 = 5.53, P < .001) and PBC (t202 = 9.64, P < .001) contributed to the model, whereas SN (t202 = −0.84, P = .402) did not. The PBC and BI predicted behavior (R = 0.661, R2 = 0.437, F2,203 = 78.902, P < .001).
In this sample, the TPB constructs predicted BI and behavior of ATs' compliance with recommended concussion-management guidelines. The BA and PBC were the most influential constructs, indicating that those with positive attitudes toward concussion-management recommendations are more likely to implement them, and ATs are less likely to implement them when they do not believe they have the power to do so. We theorize that interventions targeting ATs' attitudes and control perceptions will lead to improved compliance.
concussion management; traumatic brain injuries; practice guidelines
Abstinence from smoking on the morning of surgery may improve outcomes. This study examined the explicatory power of the Theory of Planned Behavior (TPB) to predict smoking behavior on the morning of surgery, testing the hypothesis that the constructs of attitude, subjective norm, and perceived behavioral control (PBC) will predict intent to abstain from smoking the morning of surgery, and that intent will predict behavior. TPB constructs were assessed in 169 pre-surgical patients. Smoking behavior on the morning of surgery was assessed by self-report and CO monitoring. Correlations and structural equation modeling (SEM) were used to determine associations between measures and behavior. All TPB measures, including intent as predicted by the TPB, were correlated with both a lower rate of self-reported smoking on the morning of surgery and lower CO levels. The SEM showed a good fit to the data. In the SEM, attitude and PBC, but not subjective norm, were significantly associated with intent to abstain, explaining 46% of variance. The effect of PBC on CO levels was partially mediated by intent. The amount of variance in behavior explained by these TPB constructs was modest (10% for CO levels). Thus, attitude and perceived behavioral control explain a substantial portion of the intent to maintain preoperative abstinence on the morning of elective surgery, and intent and perceived behavioral control explain a more modest but significant amount of the variance in actual smoking behavior.
Trial Registration: Clinical Trials.gov registration: NCT01014455
Voluntary HIV Counseling and Testing (VCT) forms one of the cornerstones of HIV prevention strategies. It is imperative to understand HIV testing correlates and their theoretical underpinnings in order to promote VCT uptake. The aim of this study was to predict the intention to VCT and associated factors among health professionals in Jimma zone, Ethiopia using the theory of planned behavior.
An institution based cross-sectional quantitative study among a sample of 336 health professionals in 12 selected districts of Jimma, Ethiopia was conducted in 2012. The constructs and principles of the theory of planned behavior (TPB) were measured. Data were collected using structured questionnaire on self administered basis. A multivariable linear regression model was used to predict the role of independent variables/TPB constructs on the intention to use VCT using SPSS version 16.0.
The components of TPB independently explained the variance in intention to VCT by 30.3%. Both components of TPB and socio-demographic characteristic in the final model explained 32.7% of variance in the intention to use VCT services. Significant proportions (33.0%) of the respondents have never been tested for HIV. The respective indirect components of the TPB predicted the direct components. The strongest predictors of intention to VCT were subjective norm (β=0.39, p<0.001) and attitude (β= 0.19, p<0.001) whereas, none of the socio-demographic variables were significantly predicted the intention to use VCT. Past VCT experience did not have significant statistical association with VCT use intention.
Behavioral intention to use VCT was a function of attitude and perceived social pressure. Demographic related social determinants were not barriers for VCT use intention. Most health workers test their blood by themselves. Strategies to empower health professionals on social pressure resistance and programs targeted at changing negative attitude on VCT use can enhance intention of health professionals to use VCT.
HIV/AIDS; VCT; HCT; Health professionals; Intention; TPB; Jimma zone; Ethiopia
Despite research indicating that effective parenting plays an important protective role in adolescent risk behaviors, few studies have applied theory to examine this link with marijuana use, especially with national data. In the current study (N=2,141), we hypothesized that parental knowledge (of adolescent activities and whereabouts) and parental warmth are antecedents of adolescents’ marijuana beliefs—attitudes, subjective norms, and perceived behavioral control—as posited by the Theory of Planned Behavior (TPB; Ajzen 1991). These three types of beliefs were hypothesized to predict marijuana intention, which in turn was hypothesized to predict marijuana consumption. Results of confirmatory factor analyses corroborated the psychometric properties of the two-factor parenting structure as well as the five-factor structure of the TPB. Further, the proposed integrative predictive framework, estimated with a latent structural equation model, was largely supported. Parental knowledge inversely predicted pro-marijuana attitudes, subjective norms, and perceived behavioral control; parental warmth inversely predicted pro-marijuana attitudes and subjective norms, ps<.001. Marijuana intention (p<.001), but not perceived behavioral control, predicted marijuana use 1 year later. In households with high parental knowledge, parental warmth also was perceived to be high (r=.54, p<.001). Owing to the analysis of nationally representative data, results are generalizable to the United States population of adolescents 12–18 years of age.
Parental knowledge; Parental warmth; Theory of planned behavior; Marijuana; Adolescents
Background: Regular physical activity is ranked as a leading health indicator. Despite the extensive benefits of physical activity, elder people are much less active than desired. Using Theory of Planned Behavior (TPB) and the self-efficacy construct, this study examined the prediction of physical activity intention and behavior in a sample of elderly male resident of a nursing home.
Methods: In a cross-sectional study of the residents of Kahrizak Nursing Home in Tehran, Iran, elderly men who were 60 years or older, capable of independent living, mobility, and verbal communication were asked to complete measures of the TPB, self-efficacy and physical activity behavior.
Results: A hierarchical step-wise multiple regression analysis indicated that affective/instrumental attitude, subjective norm, and perceived behavioral control (PBC) explained 32.8% of the variance in physical activity intention, and self-efficacy provided an additional 2.7%. In a reverse step regression, the TPB variables explained an additional 12.2% of physical activity intention. In a multiple regression analysis on physical activity behavior, affective/instrumental attitude, subjective norm, perceived behavioral control (PBC) and intention explained 15.7% of the variance in physical activity behavior while self-efficacy contributed an additional 5.6%. In the reverse step regression, TPB predictors contributed an additional 3.0% in explaining the variance in physical activity behavior.
Conclusion: The results indicate that in addition to the TPB, self-efficacy may also play an important role in the prediction of behavior, and should be included in the design of physical activity programs for elderly men of nursing home residents.
Attitude; intention; elderly; self-efficacy
To examine if the theory of planned behavior (TPB) predicts smoking behavior, 35 data sets (N = 267,977) have been synthesized, containing 219 effect sizes between the model variables, using a meta-analytic structural equation modeling approach (MASEM). Consistent with the TPB’s predictions, 1) smoking behavior was related to smoking intentions (weighted mean r = 0.30), 2) intentions were based on attitudes (weighted mean r = 0.16), and subjective norms (weighted mean r = 0.20). Consistent with TPB’s hypotheses, perceived behavioral control was related to smoking intentions (weighted mean r = −0.24) and behaviors (weighted mean r = −0.20) and it contributes significantly to cigarette consumption. The strength of the associations, however, was influenced by the characteristics of the studies and participants.
theory of planned behavior; smoking; meta-analysis; structural equation modeling
To describe sugar-sweetened beverage (SSB) consumption, establish psychometric properties and utility of a Theory of Planned Behavior (TPB) instrument for SSB consumption.
This cross-sectional survey included 119 southwest Virginia participants. Respondents were majority female (66%), white (89%), ≤ high school education (79%), and averaged 41.4 (±13.5) years. A validated beverage questionnaire was used to measure SSB. Eleven TPB constructs were assessed with a 56-item instrument. Analyses included descriptive statistics, one-way ANOVAs, Cronbach alphas, and multiple regressions.
Sugar-sweetened beverage intake averaged 457 (±430) kilocalories/day. The TPB model provided a moderate explanation of SSB intake (R2=0.38; F=13.10, P<0.01). Behavioral intentions had the strongest relationships with SSB consumption, followed by attitudes, perceived behavioral control, and subjective norms. The six belief constructs did not predict significant variance in the models.
Conclusions and Implications
Future efforts to comprehensively develop and implement interventions guided by the TPB hold promise for reducing SSB intake.
beverages; health behavior; psychometrics
Transitioning to parenthood is a major life event that may impact parents’ personal lifestyles, yet there is an absence of theory-based research examining the impact of parenthood on motives for dietary behaviour. As a result, we are unaware of the social cognitive variables that predict eating behaviour among those transitioning to parenthood. The purpose of the study was to examine eating behaviour motives across 12 months within the framework of the theory of planned behavior (TPB) and compare these across groups of new parents, non-parents, and established parents.
Non-parents (n = 92), new parents (n = 135), and established parents (n = 71) completed TPB questionnaires assessing attitudes, subjective norms, perceived behavioral control (PBC), and intentions and three day food records at baseline, and 6- and 12-months post-delivery (for parents) and 6- and 12-months post-baseline (for non-parents).
Repeated measures ANOVAs revealed that among men, new- and established-parents had greater intentions to eat healthy compared to non-parents, F(2) = 3.59, p = .03. Among women, established parents had greater intentions than new- and non-parents, F(2) = 5.33, p = .01. Among both men and women during the first 6-months post-delivery, new-parents experienced decreased PBC, whereas established parents experienced increased PBC. Overall, affective attitudes were the strongest predictor of intentions for men (β = 0.55, p < .001) and women (β = 0.38, p < .01). PBC predicted changes in fruit and vegetable consumption for men (β = 0.45, p = .02), and changes in fat consumption for men (β = −0.25, p = .03) and women (β = −.24, p < .05), regardless of parent status.
The transition to parenthood for new and established parents may impact motivation for healthy eating, especially PBC within the framework of TPB. However, regardless of parental status, affective attitudes and PBC are critical antecedents of intentions and eating behaviour. Interventions should target affective attitudes and PBC to motivate healthy eating and may need to be intensified during parenthood.
Theory of planned behaviour; Nutrition; Dietary behaviour; Parenthood
The authors examined the relation between Greek students’ perceptions of alcohol consumption in their pledge classes (descriptive norms) and acceptability of drinking (injunctive norms) and the ability of these normative influences to predict drinking behavior, alcohol-related negative consequences, and symptoms of alcohol dependence concurrently and prospectively over 1 year. Participants were 279 men and 303 women recruited from incoming pledge classes of 12 fraternities and 6 sororities, who completed measures of descriptive and injunctive norms, alcohol use, and consequences. Results revealed that descriptive norms significantly predicted concurrent drinking. After controlling for baseline drinking, injunctive norms significantly predicted drinking 1 year later and predicted alcohol-related consequences and dependency symptoms at baseline and follow-up. The potential to incorporate injunctive norms into preventive interventions is discussed.
Over half of kidney cancer survivors (KCS) are completely inactive and only a quarter are meeting physical activity (PA) guidelines. This highlights the need to identify and understand the determinants of PA in this understudied population. The purpose of this study is to determine the social cognitive correlates of PA intention and behavior in KCS using the Theory of Planned Behavior (TPB).
All 1,985 KCS diagnosed between 1996 and 2010 in Alberta, Canada were mailed a self-report survey that consisted of the Godin Leisure Time Exercise Questionnaire and standard TPB items for intention, planning, perceived behavioral control (PBC), affective and instrumental attitudes, and descriptive and injunctive norms. Standard demographic and medical variables were also collected.
Completed surveys were received from 703 of 1,654 (43%) eligible KCS. The TPB was tested using structural equation modelling and demonstrated an adequate-to-good fit to the data [χ² = 256.88, p < .001; TLI = 0.97; CFI = 0.98; RMSEA = 0.06, 90% CI = 0.05-0.06].
There were significant pathways to PA from PBC (ß = 0.18, p = 0.02), planning (ß = 0.22, p < 0.01), and intention (ß = 0.31, p < 0.01); and to planning from intention (ß = 0.81, p < 0.01). In addition, there were significant model pathways to intention from instrumental attitude (ß = 0.28, p = 0.03), descriptive norm (ß = 0.09, p = 0.01), and PBC (ß = 0.52, p < 0.01). Overall, the TPB accounted for 69%, 63%, and 42% of the variance in intention, planning and PA, respectively.
The TPB appears to be a useful model for explaining PA in KCS. All TPB constructs except injunctive norm and affective attitude were useful for explaining intention with PBC emerging as the largest correlate. Developing PA interventions based on the TPB may be effective in promoting PA in KCS and may lead to important improvements in health.
Exercise; Motivation; Social cognitive models; Correlates
This study aimed to determine the factors associated with exercise behavior based on the theory of planned behavior (TPB) among the sarcopenic elderly people in Cheras, Kuala Lumpur. A total of 65 subjects with mean ages of 67.5±5.2 (men) and 66.1±5.1 (women) years participated in this study. Subjects were divided into two groups: 1) exercise group (n=34; 25 men, nine women); and 2) the control group (n=31; 22 men, nine women). Structural equation modeling, based on TPB components, was applied to determine specific factors that most contribute to and predict actual behavior toward exercise. Based on the TPB’s model, attitude (β=0.60) and perceived behavioral control (β=0.24) were the major predictors of intention to exercise among men at the baseline. Among women, the subjective norm (β=0.82) was the major predictor of intention to perform the exercise at the baseline. After 12 weeks, attitude (men’s, β=0.68; women’s, β=0.24) and subjective norm (men’s, β=0.12; women’s, β=0.87) were the predictors of the intention to perform the exercise. “Feels healthier with exercise” was the specific factor to improve the intention to perform and to maintain exercise behavior in men (β=0.36) and women (β=0.49). “Not motivated to perform exercise” was the main barrier among men’s intention to exercise. The intention to perform the exercise was able to predict actual behavior regarding exercise at the baseline and at 12 weeks of an intervention program. As a conclusion, TPB is a useful model to determine and to predict maintenance of exercise in the sarcopenic elderly.
theory planned behavior; aging; elderly; sarcopenic; exercise
To endorse involvement in voluntary HIV counseling and testing (VCT), it is essential to recognize factors that influence people in deciding whether to access VCT services and their underlying route factors. Theory of planned behavior (TPB) constitutes a proficient framework for predicting behaviors and intentions.
The aim of the study reported here was to assess the predicting ability of TPB in determining the intended use of VCT services among health professionals in Jimma, southwest Ethiopia.
This was an institution-based cross-sectional quantitative study of a sample of 336 health professionals in 12 selected districts of Jimma, southwest Ethiopia between February 5 to March 28, 2012. Data were collected using structured questionnaire self-administered by the study participants. A hierarchal multivariable linear regression model was used to predict the role of TPB constructs that can influence the intention to use VCT services.
The constructs of TPB explained the variability in intention to use VCT by 27% (R2 adjusted = 0.27). The standardized regression coefficients showed that the strongest predictor of intention to use VCT was subjective norms (β = 0.32, P < 0.0005) followed by attitude (β = 0.21, P < 0.002). Perceived behavioral control was not a significant predictor of intention to use VCT among the study group (P = 0.12).
The study revealed the possibility of describing the intention to use VCT among health professionals using TPB, with perceived social pressure being the leading predictor. In light of this, health intervention programs should be designed to develop health professionals’ ability to resist norms that oppose the use of VCT and to change community-held norms against VCT use, provided they help individuals develop a positive attitude toward the services.
HIV/AIDS; VCT; health professionals; intention; TPB
The HIV epidemic poses significant challenges to the low income countries in sub Saharan Africa (SSA), affecting the attrition rate among health care workers, their level of motivation, and absenteeism from work. Little is known about how to deal with deterioration of human resources in the health care systems. This study aimed to predict the intention to provide surgical treatment to HIV infected patients among medical- and dental students in Tanzania and Sudan using an extended version of the Theory of Planned Behaviour (TPB).
Four hundred and seventy five medical- and dental students at the University of Dar es Salaam (mean age, 25 yr) and 642 dental students attending 6 public and private dental faculties in Khartoum (mean age 21.7 yr) completed self-administered TPB questionnaires in 2005 and 2007, respectively.
Both Tanzanian and Sudanese students demonstrated strong intentions to provide care for people with HIV and AIDS. Stepwise linear regression revealed that the TPB accounted for 51% (43% in Tanzania and Sudan) of the variance in intention across study sites. After having controlled for country and past behaviour, the TPB in terms of attitudes, subjective norms and perceived behavioural control accounted for 34% and moral norms for an additional 2,3% of the explainable variance in intention. Across both study sites, attitudes were the strongest predictor of intention followed in descending order by subjective norms, moral norms and perceived behavioural control.
The TPB is applicable to students' care delivery intentions in the context of HIV and AIDS across the two SSA countries investigated. It is suggested that attitudes, subjective norms, moral norms and perceived behavioural control are key factors in students' willingness to treat AIDS and HIV infected patients and should be targets of interventions aimed at improving the quality of health care delivery in this context.
This study aimed to resolve the direction of the relation between Greek affiliation and substance use by taking advantage of the quasi-experimental nature of change in college fraternity/sorority affiliation. Precollege individual differences and college substance use were examined as a function of time-varying Greek status to characterize self-selection (by which heavy substance users opt into Greek systems) and socialization (by which Greek systems foster heavy substance use). Prospective data on continuously enrolled college students (N = 2,376), assessed at precollege and in the first 6 semesters of college, were used. Latent class analysis indicated 4 discrete groups of status: constant Greek members (30%), constant nonmembers (64%), late joiners (2%), and droppers (4%). Random coefficient models demonstrated disaffiliation with Greek systems is associated with decreases in risky drinking and alcohol-conducive environmental factors (peer norms and alcohol availability), whereas affiliation is associated with increases, indicating Greek socialization via sociocognitive and physical environments. Future Greeks differed from nonmembers in diverse individual characteristics and heavier substance use at precollege, suggesting multiple selection paths into Greek systems. Findings suggest a reciprocal relation between Greek environment and individuals in determining the trajectories of college drinking and heterogeneity in drinking as functions of changes in Greek affiliation.
substance use; alcohol use; fraternity and sorority; college environment
The theory of planned behavior (TPB) was integrated within the theory of self-care (SCT) to explore the predictive value of extending TPB to measure attitudes and beliefs regarding a behavioral goal, and determine the ability of goal beliefs to predict engagement in the combined, multiple behaviors necessary to control BP. The hypothesized model was evaluated in a sample of 306 community-dwelling African Americans between 21 and 65 years of age. Scales developed for the study achieved acceptable reliability (α=.68–95). Structural equation modeling analysis resulted in a second-order factor structure with attitude, subjective norm, perceived behavioral control, and intention modeled as indicators of a construct representing goal beliefs related to keeping BP within normal limits. This latent construct was conceptualized within the theory of self-care as “self-care motivation,” and predicted 18% of the variance in self-care behaviors necessary for BP control. The model achieved acceptable fit (CMIN/df = 2.32; CFI = .95; RMSEA = .066). Final assessment of fit was done using multi-group SEM and bootstrapping techniques. In this extension of the TPB attitudes and beliefs regarding the goal of keeping BP within normal limits were found to determine one's motivation to engage in the multiple behaviors necessary for BP control.
Blood pressure; self-care; self-care agency; self-care motivation; theory of planned behavior; structural equation modeling
Psychological models can be used to understand and predict behaviour in a wide range of settings. However, they have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. The aim of this study was to explore the usefulness of a range of psychological theories to predict health professional behaviour relating to management of upper respiratory tract infections (URTIs) without antibiotics.
Psychological measures were collected by postal questionnaire survey from a random sample of general practitioners (GPs) in Scotland. The outcome measures were clinical behaviour (using antibiotic prescription rates as a proxy indicator), behavioural simulation (scenario-based decisions to managing URTI with or without antibiotics) and behavioural intention (general intention to managing URTI without antibiotics). Explanatory variables were the constructs within the following theories: Theory of Planned Behaviour (TPB), Social Cognitive Theory (SCT), Common Sense Self-Regulation Model (CS-SRM), Operant Learning Theory (OLT), Implementation Intention (II), Stage Model (SM), and knowledge (a non-theoretical construct). For each outcome measure, multiple regression analysis was used to examine the predictive value of each theoretical model individually. Following this 'theory level' analysis, a 'cross theory' analysis was conducted to investigate the combined predictive value of all significant individual constructs across theories.
All theories were tested, but only significant results are presented. When predicting behaviour, at the theory level, OLT explained 6% of the variance and, in a cross theory analysis, OLT 'evidence of habitual behaviour' also explained 6%. When predicting behavioural simulation, at the theory level, the proportion of variance explained was: TPB, 31%; SCT, 26%; II, 6%; OLT, 24%. GPs who reported having already decided to change their management to try to avoid the use of antibiotics made significantly fewer scenario-based decisions to prescribe. In the cross theory analysis, perceived behavioural control (TPB), evidence of habitual behaviour (OLT), CS-SRM cause (chance/bad luck), and intention entered the equation, together explaining 36% of the variance. When predicting intention, at the theory level, the proportion of variance explained was: TPB, 30%; SCT, 29%; CS-SRM 27%; OLT, 43%. GPs who reported that they had already decided to change their management to try to avoid the use of antibiotics had a significantly higher intention to manage URTIs without prescribing antibiotics. In the cross theory analysis, OLT evidence of habitual behaviour, TPB attitudes, risk perception, CS-SRM control by doctor, TPB perceived behavioural control and CS-SRM control by treatment entered the equation, together explaining 49% of the variance in intention.
The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for identifying factors that predict clinical behaviour. However, a number of conceptual and methodological challenges remain.
Introduction: The implementation of complex medical interventions in daily practice is often fraught with difficulties. According to the iterative phase model proposed by the British Medical Research Council (MRC), the development, implementation and evaluation of complex interventions should be theory-driven. A conceptual model that seems to be a promising framework is the Theory of planned behaviour (TPB). In our study we aimed to develop and validate a generic and multifaceted questionnaire based on the TPB to detect physicians’ willingness to implement complex medical interventions and the factors influencing this willingness.
Methods: The questionnaire was developed according to the literature and was informed by previous qualitative research of our department. It was validated on the example of an electronic library of decision aids, arriba-lib. The sample consisted of 181 General Practitioners (GPs) who received a training regarding arriba-lib and subsequently filled in the questionnaire, assessing the TPB variables attitude, subjective norm, perceived behaviour control and intention. Follow-up assessments were conducted after two (assessing retest reliability) and eight weeks (assessing target behaviour). We performed a confirmatory factor analysis investigating the factorial structure of our questionnaire according to the TPB. Beside the calculation of the questionnaire’s psychometric properties we conducted a structural equation model and an ordinal regression to predict actual behaviour regarding the installation and application of arriba-lib.
Results: The postulated three factorial model (attitude, subjective norm, perceived behaviour control) of our questionnaire based on the TPB was rejected. A two factorial model with a combined factor subjective norm/perceived behaviour control was accepted. The explained variance in the ordinal regression was low (Nagelkerke’s R2=.12). Neither attitude nor intention were able to predict the use or non-use of arriba-lib (attitude: p=.68, intention: p=.44). For the combined factor subjective norm/perceived behaviour control a significant, but small effect (p=.03) was shown.
Conclusions: The TPB is not an adequate theoretical framework to guide the development of a generic questionnaire in the context of the implementation of complex interventions. To enable the successful implementation of complex medical interventions evaluators have to go through the whole development and evaluation process according to the MRC-model, without short cuts. Further, it has to be discussed if a generic instrument can be valid and useful. Regarding the TPB a publication bias regarding the theory’s applicability might have to be considered.
implementation; questionnaires; primary health care; theory of planned behaviour
This study examines the ability of the theory of reasoned action (TRA) and the theory of planned behavior (TPB) to predict whether or not pediatricians encourage parents to get their adolescent daughters vaccinated against the human papillomavirus (HPV). Four-hundred and six pediatricians completed a mail survey measuring attitudes, subjective norms, perceived behavioral control, intentions, and behavior. Results indicate that pediatricians have positive attitudes, subjective norms, and perceived behavioral control toward encouraging parents to get their daughters vaccinated, that they intend to regularly encourage parents to get their daughters vaccinated against HPV in the next 30 days, and that they had regularly encouraged parents to get their daughters vaccinated against HPV in the past 30 days (behavior). Though the data were consistent with both the TRA and TPB models, results indicate that perceived behavioral control adds only slightly to the overall predictive power of the TRA, suggesting that attitudes and norms may be more important targets for interventions dealing with this topic and audience. No gender differences were observed for any of the individual variables or the overall fit of either model. These findings have important theoretical and practical implications for the development of health communication messages targeting health care providers in general, and for those designed to influence pediatricians’ communication with parents regarding the HPV vaccine in particular.
Drop-out from 12-step groups is notoriously high, yet the field lacks strong models and scales for addressing this problem. We aim to determine whether the theory of planned behavior (TPB) can be applied to 12-step involvement, and to develop and validate a scale of 12-step readiness based on that theory: the Alcoholics Anonymous Intention Measure (AAIM).
Data were from a longitudinal trial of a manual-guided 12-step facilitation intervention called Making AA Easier (MAAEZ) involving 2 treatment programs in California (N=508). Participants completed surveys at baseline, 7 weeks, 6 months, and 12 months. Surveys included the preliminary AAIM, a 12-step involvement measure, other readiness measures, and substance use outcomes.
The final, 17-item AAIM measured attitudes (5-item α's=.75-.83), subjective norms (4-item α's=.56-.81), perceived control (5 item α's=.78-.85), and intentions (3-item α's=.80-.95) regarding attendance at 12-step groups. Components were correlated with each other and other readiness measures as expected, supporting the AAIM's validity. Scale components predicted 31% of the variance in Intention to attend 12-step groups at 6 months and 41% of the variance in 12-step involvement at 12 months. Social factors were among the strongest predictors of 12-step involvement. Results did not support the expectancy-value formulation of the TPB, as unweighted (vs. weighted) belief items performed optimally.
Results generally support the TPB as a model of 12-step involvement and suggest specific targets for 12-step facilitation interventions within attitude, norm, and control components. Findings also support the AAIM as a tool for identifying drop-out risks and tailoring individual interventions.
Alcoholics Anonymous; 12-step; treatment readiness; drop-out; theory of planned behavior; scale
To control the latent social risk of disease, the government usually spreads accurate information and attempts to improve the public’s attitude toward adopting prevention. However, these methods with the Knowledge, Attitudes, and Practices (KAP) model do not always work. Therefore, we used the theory of planned behavior (TPB) to understand dog owners’ behavior and distinguished the knowledge effect as objective knowledge (OK) and subjective knowledge (SK). A total of 310 dog owners completed a questionnaire based on our model. We employed structural equation modeling to verify the structural relationships and found three main results. First, our model was fit, and each path was significant. People with better attitudes, stronger subjective norms, and more perceptive behavioral control have stronger behavioral intention. Second, perceived behavioral control, not attitude, was the best predictive index in this model. Finally, on perceived behavioral control, subjective knowledge showed more influence than objective knowledge. We successfully extended TPB to explain the behavioral intention of dog owners and presented more workable recommendations. To reduce the latent social risk of disease, the government should not only address dog owners’ attitudes, but also their subjective norms and perceptive behavioral control. Indeed, perceptive behavioral control and SK showed the most influence in this model. It is implied that the self-efficacy of dog owners is the most important factor in such a behavior. Therefore, the government should focus on enhancing dog owners’ self-efficacy first while devoted to prevention activities.
social risk; rabies; vaccination; the theory of planned behavior
Women diagnosed with early breast cancer (stage I or II) can be offered the choice between mastectomy or breast conservation surgery with radiotherapy due to equivalence in survival rates. A wide variation in the surgical management of breast cancer and a lack of theoretically guided research on this issue highlight the need for further research into the factors influencing women’s choices. An extended Theory of Planned Behaviour (TPB) could provide a basis to understand and predict women’s surgery choices. The aims of this study were to understand and predict the surgery intentions and choices of women newly diagnosed with early breast cancer, examining the predictive utility of an extended TPB.
Sixty-two women recruited from three UK breast clinics participated in the study; 48 women, newly diagnosed with early breast cancer, completed online questionnaires both before their surgery and after accessing an online decision support intervention (BresDex). Questionnaires assessed views about breast cancer and the available treatment options using items designed to measure constructs of an extended TPB (i.e., attitudes, subjective norms, perceived behavioural control, and anticipated regret), and women’s intentions to choose mastectomy or BCS. Objective data were collected on women’s choice of surgery via the clinical breast teams. Multiple and logistic regression analyses examined predictors of surgery intentions and subsequent choice of surgery.
The extended TPB accounted for 69.9% of the variance in intentions (p <.001); attitudes and subjective norms were significant predictors. Including additional variables revealed anticipated regret to be a more important predictor than subjective norms. Surgery intentions significantly predicted surgery choices (p <.01).
These findings demonstrate the utility of an extended TPB in predicting and understanding women’s surgery intentions and choices for early breast cancer. Understanding these factors should help to identify key components of interventions to support women while considering their surgery options.
Breast cancer; Mastectomy; Breast conserving surgery; Decision making; Theory of planned behaviour
Temptation and restraint have long been associated with problematic drinking. Among college students, social norms are one of the strongest predictors of problematic drinking. To date, no studies have examined the association between temptation and restraint and perceived descriptive norms on drinking and alcohol-related problems among college students. The purpose of this study was to examine whether perceived descriptive norms moderated the relationship between temptation and restraint and drinking outcomes among college students. Participants were 1,095 college students from a large, public, culturally-diverse, southern university who completed an online survey about drinking behaviors and related attitudes. Drinks per week and alcohol-related problems were examined as a function of perceived descriptive norms, Cognitive Emotional Preoccupation (CEP) (temptation), and Cognitive Behavioral Control (CBC) (restraint). Additionally, drinking outcomes were examined as a function of the two-way interactions between CEP and perceived descriptive norms and CBC and perceived descriptive norms. Results indicated that CEP and perceived descriptive norms were associated with drinking outcomes. CBC was not associated with drinking outcomes. Additionally, perceived descriptive norms moderated the association between CEP and drinks per week and CEP and alcohol-related problems. There was a positive association between CEP and drinks per week and CEP and alcohol-related problems, especially for those higher on perceived descriptive norms. College students who are very tempted to drink may drink more heavily and experience alcohol-related problems more frequently if they have greater perceptions that the typical student at their university/college drinks a lot.
college; drinking; alcohol-related problems; temptation; restraint; perceived descriptive norms
Study objective: To examine associations between social capital and individual risk for alcohol abuse and harms and identify protective effect mechanisms.
Design: Multilevel multivariate analysis with individual level data from a national panel survey of drinking and a contextual measure of social capital reflecting college mean aggregate reports of student volunteerism. Outcomes include heavy episodic (binge) drinking, frequent drinking, frequent drunkenness, diagnosable alcohol abuse, intentional drunkenness, acquisition of binge drinking, harms, secondhand effects from others' drinking.
Setting: United States, 119 four year colleges.
Participants: Representative samples of youth ages 18–24 surveyed in 1997 and 1999 using an anonymous mailed questionnaire (total n = 27 687).
Main results: Students from colleges with higher levels of social capital reported reduced risks for binge drinking (adjusted OR 0.38, 95% CI 0.20 to 0.69, p = 0.002), frequent drunkenness (adjusted OR 0.58, 95% CI 0.34 to 0.98, p = 0.04), acquisition of binge drinking in college (adjusted OR 0.48, 95% CI 0.24 to 0.95, p = 0.03), and alcohol abuse (adjusted OR 0.55, 95% CI 0.34 to 0.91, p = 0.02) in multilevel multivariate analyses that controlled for individual volunteering, the measure on which social capital was based. Higher levels of social capital protected against multiple drinking related harms (adjusted OR 0.51, 95% CI 0.29 to 0.90, p = 0.02) and secondhand drinking effects (adjusted OR, 0.30, 95% CI 0.16 to 0.58, p = 0.0003). Significant cross level interactions exist between fraternity/sorority membership and social capital for measures of risky drinking. Harm reduction primarily reflects consumption modification.
Conclusions: Social capital exerts strong protective effects on alcohol abuse and harm in college including among high risk students.