Distinguishing among perceived control, perceived difficulty, and self-efficacy as determinants of intentions and behaviours

Perceptions of control hold a dominant position in social cognitive theories yet there is a lack of conceptual and empirical clarity regarding what kind of control is most associated with particular behaviours. Three prominent types of control are perceived control (PC), perceived difficulty (PD), and perceived confidence or self-efficacy (SE) for performing the desired behaviour. Three studies are presented with a primary goal of distinguishing PC, PD, and SE from each other, and a secondary goal of determining which of the three is the superior predictor of health-related intentions and behaviours. The first study replicates earlier work by Trafimow et al. (2002) distinguishing the three constructs for reading 1, 30, and 100 pages, and extends it to exercising one, two, four, and six times per week and also to predicting intentions to exercise 4 days per week and behaviour 1 week later. The second study examines the predictive capability of the three constructs for intentions to floss one's teeth everyday and to eat 5-10 servings of fruits and vegetables everyday and subsequently on behaviour assessed 7 days later. The third study reports a meta-analysis of the relative influence of PC, PD, and SE on behaviours when defined in conceptually consistent ways. The results of all three studies support the conceptual and empirical distinction of PC, PD, and SE and the superiority of SE as a predictor of health behaviours and intentions.

Extracellular loops and ligand binding to a subfamily of Family A G-protein-coupled receptors

GPCRs (G-protein-coupled receptors) are a large family of structurally related proteins which mediate their effects by coupling to G-proteins. The V(1a)R (V(1a) vasopressin receptor) is a member of a family of related GPCRs that are activated by vasopressin {AVP ([Arg(8)]vasopressin)}, OT (oxytocin) and related peptides. These receptors are members of a subfamily of Family A GPCRs called the neurohypophysial peptide hormone receptor family. GPCRs exhibit a conserved tertiary structure comprising a bundle of seven TM (transmembrane) helices linked by alternating ECLs (extracellular loops) and ICLs (intracellular loops). The cluster of TM helices is functionally important for ligand binding, and, furthermore, activation of GPCRs involves movement of these TM helices. Consequently, it might be assumed that the extracellular face of GPCRs is composed of peptide linkers that merely connect important TM helices. However, using a systematic mutagenesis approach and focusing on the N-terminus and the second ECL of the V(1a)R, we have established that these extracellular domains fulfil a range of important roles with respect to GPCR signalling, including agonist binding, ligand selectivity and receptor activation.

Can the theory of planned behaviour predict maintenance of a frequently repeated behaviour?

The present study used the theory of planned behaviour to predict self-monitoring of blood glucose in patients with type 1 diabetes. Sixty-four adult patients with type 1 diabetes completed a questionnaire assessing the variables of the TPB in addition to demographic variables and a measure of conscientiousness. Self-report measures of daily self-monitoring behaviour were obtained for a two-week period. The extended model predicted 46% of the variance in behavioural intention and 57% of variance in self-monitoring behaviour, suggesting that the TPB is able to predict useful levels of variance, comparable to initiation, even in familiar and frequently repeated maintenance behaviours. Implications of these results are discussed.

Spontaneously Occurring Fibroid Tumors of the Laying Hen Oviduct

Spontaneously occurring benign uterine leiomyomas (fibroids) are the most common tumors of reproductive-age women. It is estimated that more than 70% of all women will develop uterine fibroids, and the presence of these tumors is a primary cause of hysterectomies. Research into the causes and treatment of uterine fibroids is hampered by a lack of reliable animal models for the disease. Leiomyomas that appear to be outwardly similar to human uterine fibroid tumors are known to occur on the oviducts of laying hens over 2 yr of age. The objective of this study was to characterize these tumors and compare them to human uterine fibroids to determine the suitability of the aging hen as a model system for the study of the disease. In this study, hens at 5 yr of age were examined for the presence of oviduct-associated fibroid tumors. Tumors were found attached to the internal surface of the oviduct, embedded in the oviduct wall, or attached to the exterior of the magnum and isthmus. Tumor and normal oviduct samples were frozen or fixed in formalin for histological analyses or immunohistochemistry for estrogen and progesterone receptors, proliferating cell nuclear antigen and Bcl-2 protein expression. Human uterine fibroid samples were acquired and evaluated compared with hen oviduct fibroids. The results indicate that laying hen fibroid tumors are similar to human fibroid tumors with respect to estrogen and progesterone receptors, localized cellular proliferation, and expression of the Bcl-2 protein.

Factors explaining the intention to give blood among the general population

BACKGROUND AND OBJECTIVES

The aim of this study was to identify factors explaining the intention to donate blood.

MATERIALS AND METHODS

A random sample of 4000 respondents drawn from the general population received a questionnaire by mail. This questionnaire assessed variables as defined by the most prominent social cognitive theories.

RESULTS

Overall, the respondents expressed a neutral mean level of intention to give blood in the next 6 months (2.84 on a five-point scale); 56.2% had never given blood in the past. The variables explaining 74% of the variance of intention were: perceived behavioural control (beta = 0.39; P < 0.001); factors facilitating taking action (beta = 0.25; P < 0.001); anticipated regret (beta = 0.16; P < 0.001); moral norm (beta = 0.11; P < 0.001); attitude (beta = 0.08; P < 0.01); level of education (beta = -0.03; P < 0.05); and past experience in giving blood (beta = 0.09; P < 0.001). Nonetheless, the predictive power of perceived behavioural control and moral norm was higher among the ever donors (both at P < 0.01) compared to the never donors, whereas the reverse was observed for attitude (P < 0.05).

CONCLUSIONS

People's intentions are mainly determined by perceived barriers and obstacles regarding blood donations. This suggests that promotional strategies should focus on the elimination of barriers to action as well as the development of a higher perception of control. Also, messages should be adapted to the targeted population, based on their previous blood donation behaviour (i.e. never donors vs. ever donors).

Increasing daily fruit and vegetable consumption: what changes do cardiac patients make?

BACKGROUND

Interventions targeting fruit and vegetable consumption report significant increases in consumption but do not detail how increases are achieved. This prospective study explored (i) the changes in daily fruit and daily vegetable consumption of cardiac patients participating in an intervention study and (ii) how participants made these changes.

METHODS

A total of 120 cardiac patients were asked to increase their daily fruit and vegetable consumption by two portions and to maintain this over 3 months. They were telephoned at 7-, 28- and 90-day follow-up to record daily consumption using a dietary questionnaire; 94 participants completed all parts of the study.

RESULTS

Mean reported daily fruit and daily vegetable consumption increased by 1.07 (SD = 1.26) and 0.34 (SD = 0.96) portions, respectively, over 3 months. These increases were statistically significant (P < 0.001) and greatest for participants who reported eating low levels of fruit and vegetables at recruitment. Eating fresh fruit as a snack and at mealtimes were preferred choices for participants.

CONCLUSIONS

Providing information and telephone follow-up could be used by busy healthcare professionals instead of face-to-face contact. Interventions to increase total fruit and vegetable consumption could usefully focus on eating fruit. Interventions to increase vegetable consumption need further investigation.

Ambivalence about health-related behaviours: an exploration in the domain of food choice

OBJECTIVES

Interest in attitudes and ambivalence has highlighted problems with the adequacy of conceptualizing attitudes as unitary, unidimensional, evaluations. In this paper, we report an application of the Theory of Planned Behaviour (Ajzen, 1991) in the domain of dietary choice which investigates the hypothesis that ambivalence will attenuate observed attitude-intention relationships (since the evaluations influencing the expression of attitudes are more likely to differ from the evaluations influencing the expression of intentions for people who are more ambivalent.

DESIGN

Participants completed a postal questionnaire which contained, inter alia, measures assessing the components of the Theory of Planned Behaviour and a measure of ambivalence.

METHODS

Participants (N = 296) were recruited via advertisements placed in local newspapers, asking for volunteers to assist in a research project. Participants were randomly assigned to complete a questionnaire about either their chocolate consumption or their meat consumption. Participants were paid 4.

RESULTS

The findings show considerable support for the hypothesis: there was a tendency for attitude-intention relationships to be attenuated among participants with higher levels of ambivalence, compared to participants with lower levels of ambivalence.

CONCLUSIONS

The research supports the widespread view that ambivalence is an important issue, both for those involved in basic attitude research and for those who seek to use attitude theories in applied research. In particular, the findings indicate that ambivalence may often have implications for the predictive ability of attitude-intention-behaviour models, especially when applied to health-related behaviours that are characterized by motivational conflicts.

Developing network-based services in the NHS

Networks, based upon informal relationships, have ensured that care was delivered to patients for many years. This informal organisation of care, based upon personal relationships, ensures that where the bureaucratic organisation fails the patient, health professionals' work together to network the resources the patient needs. Networks are not new. Formalising networks and recognising their potential to deliver seamless care is new. The NHS must ensure that networks are developed, allowing them freedom from bureaucracy to reach their potential. The Northern and Yorkshire Learning Alliance (NYLA) was established as part of the Northern and Yorkshire health community's efforts to radically improve care. The NYLA operates as a network with a small team of change experts working to develop change management and service improvement capacity across 10,000 square miles. As a network based organisation the team has learned many lessons, which may inform the development of clinical networks in England.

Disseminated peritoneal tuberculosis mimicking metastatic ovarian cancer

A 41-year-old woman had a 2-week history of low-grade fever, associated with gradually increasing abdominal pain and girth. Ultrasonography showed a complex cystic right adnexal mass. Diffuse nodules (0.1 to 0.5 cm) were found at exploratory laparotomy involving the serosal surfaces of the uterus, fallopian tubes, and ovaries. She had a total abdominal hysterectomy, with bilateral salpingo-oophorectomy and omentectomy for presumed stage IIIC ovarian carcinoma. Histopathologic examination showed chronic granulomatous inflammation with no evidence of neoplasm. Special stains on tissue sections and ascitic fluid were negative for fungi and mycobacteria. Additional history indicated a recently positive PPD skin test (within 6 months), followed by isoniazid therapy for 4 months. Polymerase chain reaction (PCR) done on paraffin-embedded tissues produced evidence of Mycobacterium tuberculosis. Ascitic fluid cultures became positive for M. tuberculosis at 6 weeks. The patient was placed on four-drug antituberculous therapy and had a complete recovery.

Efficacy of the Theory of Planned Behaviour: a meta-analytic review

The Theory of Planned Behaviour (TPB) has received considerable attention in the literature. The present study is a quantitative integration and review of that research. From a database of 185 independent studies published up to the end of 1997, the TPB accounted for 27% and 39% of the variance in behaviour and intention, respectively. The perceived behavioural control (PBC) construct accounted for significant amounts of variance in intention and behaviour, independent of theory of reasoned action variables. When behaviour measures were self-reports, the TPB accounted for 11% more of the variance in behaviour than when behaviour measures were objective or observed (R2s = .31 and .21, respectively). Attitude, subjective norm and PBC account for significantly more of the variance in individuals' desires than intentions or self-predictions, but intentions and self-predictions were better predictors of behaviour. The subjective norm construct is generally found to be a weak predictor of intentions. This is partly attributable to a combination of poor measurement and the need for expansion of the normative component. The discussion focuses on ways in which current TPB research can be taken forward in the light of the present review.

Attitudes towards following meat, vegetarian and vegan diets: an examination of the role of ambivalence

Vegetarianism within the U.K. is growing in popularity, with the current estimate of 7% of the population eating a vegetarian diet. This study examined differences between the attitudes and beliefs of four dietary groups (meat eaters, meat avoiders, vegetarians and vegans) and the extent to which attitudes influenced intentions to follow each diet. In addition, the role of attitudinal ambivalence as a moderator variable was examined. Completed questionnaires were obtained from 111 respondents (25 meat eaters, 26 meat avoiders, 34 vegetarians, 26 vegans). In general, predictions were supported, in that respondents displayed most positive attitudes and beliefs towards their own diets, and most negative attitudes and beliefs towards the diet most different form their own. Regression analyses showed that, as predicted by the Theory of Planned Behaviour, attitudes, subjective norm and perceived behavioural control were significant predictors of intention to follow each diet (apart from the vegetarian diet, where subjective norm was non-significant). In each case, attitudinal ambivalence was found to moderate the attitude-intention relationship, such that attitudes were found to be stronger predictors at lower levels of ambivalence. The results not only highlight the extent to which such alternative diets are an interesting focus for psychological research, but also lend further support to the argument that ambivalence in an important influence on attitude strength.

Efficacy of a minimal intervention to reduce fat intake

Effective dietary interventions must be developed to reduce fat intake in whole populations, rather than clinical subgroups. This study tested the effects of personalised feedback on fat intake in a general population. Hospital workers (n = 801) were randomised to receive personalised feedback or no personalised feedback. Personalised feedback consisted of one sentence expressing current fat intake as a percentage of total calorific intake. Changes in fat intake from baseline to five months post-intervention were evaluated. The personalised intervention produced significant decreases in total and saturated fat intake, compared with the control group. Total-fat decreased by 8.6% (versus 0.2% in the control group); saturated fat decreased by 9.3% (versus 1.7% in the control group). Fat intake as a proportion of total calorific intake did not decrease significantly in either condition. Findings also revealed differential effects of feedback on high- versus low-fat consumer groups. Personalised feedback significantly reduced fat intake in high-fat consumers, and prevented low-fat consumers from increasing their fat intake. Personalised fat feedback therefore represents an efficacious and low-intensity approach to the reduction of fat intake in the general population.

Why do women use dietary supplements? The use of the theory of planned behaviour to explore beliefs about their use

Dietary supplements use is increasing, despite the lack of evidence to suggest they are needed to meet dietary deficiency in the majority of people. Reasons for consuming dietary supplements are likely to be complex, combining social, psychological, knowledge and economic factors. The Theory of Planned Behaviour (TPB) is a widely used model of social cognition, which has recently been applied to the nutrition field. It was used in a questionnaire, along with a number of additional measures, to explore dietary supplement use in a cohort of women. Data from 303 questionnaires were included in the analysis. The results showed that intentions were the major predictor of dietary supplement use. Health value and susceptibility to illness were also significant predictors of dietary supplement use (total of 82.9% of respondents correctly classified as users or non-users). Intentions themselves were most strongly predicted by attitude, with 70% of variance explained by attitude, subjective norms and perceived behavioural control. Other significant predictors of intentions were control beliefs, normative beliefs and health value. Beliefs underlying dietary supplement use revealed differences between supplement users and non-users in relation to the notion that taking dietary supplements acts as an insurance against possible ill-health, with supplement users believing more strongly than non-users that taking dietary supplements would stop them getting ill and help them to be healthy. Both users and non-users of supplements also perceived the media, in the form of books and magazines, to be a powerful influence on a person's decision to use supplements. The findings of this study highlight the potential of the TPB in exploring supplement-taking behaviour, while throwing light on the factors influencing an individual's motivations to use dietary supplements.

Can the theory of planned behavior explain patterns of health behavior change?

This article tested the ability of the theory of planned behavior (TPB) to predict patterns of behavior change associated with health screening. Attitudes, subjective norms, perceived behavioral control, and intentions were used to predict objective measures of attendance 1 month and 13 months later among participants who had never previously been screened (N = 389). Findings showed that the TPB predicted attendance on each occasion and also predicted frequency of attendance. However, the model was unable to reliably distinguish among consistent attendees, participants who delayed attending, and participants who initially attended but relapsed. Thus, the TPB needs to be extended to understand behaviors that must be performed promptly and repeatedly for health benefits to accrue.

Temporal stability as a moderator of relationships in the Theory of Planned Behaviour

Temporal stability of behavioural intentions and perceived behavioural control (PBC) within the Theory of Planned Behaviour were examined as moderators of the cognition-behaviour relationships in two studies. Study 1 (N = 201) examined attendance at health screening appointment (infrequently performed behaviour) using an objective measure of attendance. The impact of intentions and past behaviour on behaviour was moderated by intention stability. In addition, stable intentions were more strongly related to attitudes and past behaviour. Study 2 (N = 407) examined eating a low-fat diet (frequently performed behaviour) using a self-report measure of behaviour. The impact of intentions on behaviour was moderated by intention stability, while the impact of PBC and past behaviour on behaviour was moderated by PBC stability. Stable intentions were more strongly related to attitudes, subjective norms and PBC. Stable PBC was more strongly related to attitudes and past behaviour. The discussion considers the implications of the findings for furthering the understanding of the proximal determinants of behaviour and emphasizes the importance of temporal stability as a key measure of the strength of intentions and PBC.

Validation of a questionnaire measuring patient satisfaction with general practitioner services

BACKGROUND

In order that patient satisfaction may be assessed in a meaningful way, measures that are valid and reliable are required. This study was undertaken to assess the construct validity and internal reliability of the previously developed Patient Satisfaction Questionnaire (PSQ).

METHOD

A total of 1390 patients from five practices in the North of England, the Midlands, and Scotland completed the questionnaire. Responses were checked for construct validity (including confirmatory factor analysis to check the factor structure of the scale) and internal reliability.

RESULTS

Confirmatory factor analysis showed that items loaded on the appropriate factors in a five factor model (doctors, nurses, access, appointments, and facilities). Scores on the specific subscales showed highly significant positive correlations with general satisfaction subscale scores suggesting construct validity. Also, the prediction (derived from past research) that older people would be more satisfied with the service was borne out by the results (F (4, 1312) = 57.10; p < 0.0001), providing further construct validation. The five specific subscales (doctors, nurses, access, appointments, and facilities), the general satisfaction subscale, and the questionnaire as a whole were found to have high internal reliability (Cronbach's alpha = 0.74-0.95).

CONCLUSION

The results suggest that the PSQ is a valid and internally reliable tool for assessing patient satisfaction with general practitioner services.

Understanding choice of milk and bread for breakfast among Swedish children aged 11-15 years: an application of the Theory of Planned Behaviour

The present study examined the influences of attitudes, social norms, perceived control and underlying beliefs on 11 to 15-year-olds' breakfast choices of milk with different fat content and high-fibre bread. All pupils in the 5th, 7th and 9th grades in Mölndal community (N=1730), Sweden, were asked to complete a questionnaire based on the Theory of Planned Behaviour. Two weeks later, they were asked to fill in a 7-day record of food consumed for breakfast. Consumption of milk and high-fibre bread was predicted from intentions, and for milk also by perceived behavioural control. Intentions were influenced by attitudes, perceptions of significant others' preferences, and perceived control. In addition, perception of the parents' consumption (descriptive norm) of the specific food played an important role. Attitudes, norms and perceived control predicted intentions to a similar extent in each age group. Attitudes to the consumption of milk and high fibre bread were influenced by beliefs about their sensory and health aspects. Females and the oldest children had greater knowledge about the healthier alternatives and the oldest children had a tendency to choose healthier options.

A critical examination of the application of the Transtheoretical Model's stages of change to dietary behaviours

This paper proposes that the application of the Transtheoretical Model's stages of change to dietary behaviours may be fundamentally problematic due to the difference in nature between dietary behaviours and the addictive behaviours upon which the model was originally based. It was considered that specific problems associated with stage categorization for dietary change would include: problems due to the potential mismatch between a person's perceived and actual dietary behaviour; and problems due to the use of specific time periods to distinguish between different stages. A total of 541 volunteers completed questionnaires that measured their stage of change with respect to one of three dietary behaviours (healthy eating, eating a low-fat diet, and eating five portions of fruit and vegetables per day). Results indicate that people who were actively making a change (actors) or maintaining a change (maintainers) had done so for a range of different periods of time, with no specific cut-off point being evident. Also, more realistic stage categorizations were evident for the most specific dietary behaviours where there was least likelihood of a mismatch between perceived and actual dietary behaviour. Problems associated with issues of operationalization of the model and the application of the stage model to dietary change are discussed.

The persistence of mood disorders following traumatic brain injury: a 1 year follow-up

The study investigated whether the frequency of mood disorders following traumatic brain injury (TBI) increased with time. Consecutive hospital admissions completed the Wimbledon Self-Report Scale at 6 and 12 months post-injury. Scores in the 'borderline/case' range were deemed clinically significant. Seventy-seven of those assessed at 6 months completed the 12 month follow-up. Those lost to follow-up (22) were not more likely to have been classified 'borderline/case' at 6 months. They were more likely to have been 'unoccupied' pre-injury (p=0.002). The frequency of clinically significant disorders did not change significantly, being 39% at 6 months and 35% 1 year post-injury. The majority of subjects (58) maintained the same clinical classification at both assessments. Eight of the 47 (17%) classified 'normal' at 6 months changed to 'borderline/case' at 12 months. However, 11 of the 30 (37%) classified 'borderline/case' at 6 months were 'normal' at 12 months. The direction of change was not statistically significant (p=0.5). These findings are consistent with previous research. However, the present study examined a larger sample and included a wider range of injury severity, thereby increasing the generalizability of the findings. Also, a broader spectrum of mood disorders was investigated which adds to previous work specifically on depression.

Interaction effects in the theory of planned behaviour: studying cannabis use

This study employed the theory of planned behaviour (TPB) to investigate the factors underlying intentions and frequency of use of cannabis over a three-month period in a population of students (N = 249). In addition, several hypotheses in relation to the TPB were investigated. The TPB provided good predictions of both intentions (R2 = 0.653; attitude, injunctive norms and perceived behavioural control significant) and behaviour (R2 = 0.711; intentions significant). Other norm measures (descriptive and moral norms) explained additional variance in intentions (p < .01). In addition, habit strength and self-identity explained significant additional portions of the variance in intentions (p < .001), but not behaviour, over and above the TPB variables. Several interactions among these variables were also tested. Attitude moderated the impact of perceived behavioural control (PBC) on intentions (p < .001). Moral norms moderated the impact of attitudes on intentions (p < .001). Habit strength moderated the impact of self-identity on intentions (p < .001). PBC was found to moderate the impact of intentions on behaviour (p < .05). The findings are discussed in relation to how interaction effects further our understanding of the social processes by which variables are related in the TPB.

The theory of planned behavior and smoking cessation

A sample of 84 smokers attending health promotion clinics in a primary care setting completed questionnaires that assessed the main constructs of the theory of planned behavior, perceived susceptibility, and past cessation attempts. Regression analyses revealed that intention to quit smoking was primarily predicted by perceived behavioral control and perceived susceptibility. At 6-month follow-up, the making of a quit attempt was predicted by intention and the number of previous quit attempts, whereas the length of the quit attempt was predicted solely by the length of the longest recent quit attempt. The results suggest that interventions should focus on perceptions of susceptibility and control to increase smokers' motivation to quit. However, further work is required to identify the social cognitive variables that ensure that initial quit attempts are translated into longer term abstinence.

Analysis of illicit ecstasy tablets: implications for clinical management in the accident and emergency department

OBJECTIVE

To examine the composition of illicitly manufactured "ecstasy" tablets sold on the UK drugs market.

METHODS

Analysis by gas chromatography of 25 illicit ecstasy tablets handed in under amnesty to Leeds Addiction Unit.

RESULTS

Illicitly manufactured ecstasy tablets contain a range of ingredients, of widely differing concentrations, and even tablets with the same brand name have variable concentrations of active ingredients. Concentrations of 3,4-methylenedioxymethamphetamine (MDMA) more popularly known as ecstasy, varied 70-fold between tablets. Nine tablets contained neither MDMA nor related analogues.

CONCLUSIONS

These results have implications for emergency workers attending to those who have become casualties of the drug ecstasy. Those claiming to have ingested ecstasy may actually have taken other agents that require different clinical management.

Diet and lifestyle characteristics associated with dietary supplement use in women

OBJECTIVES

To describe the characteristics of dietary supplement users in a large cohort of women and test the hypothesis that supplement users would be more likely to have a healthier lifestyle than non-users.

DESIGN

Comparison of nutrient intakes from food frequency questionnaire (FFQ) data for 8409 supplement users and 5413 non-users. Use of logistic regression modelling to determine predictors of supplement use in this cohort.

SUBJECTS

13,822 subjects from the UK Women's Cohort Study (UKWCS) for whom data on supplement use was available.

RESULTS

Significant differences in nutrient intakes from FFQ were seen between the two groups, with supplement users having higher intakes of all nutrients, except for fat and vitamin B12. Use of dietary supplements was associated with being vegetarian, vegan or fish-eating, consuming more fruit and vegetables, being more physically active and having a lower alcohol intake. Supplement use was less likely in those with a body mass index above 25 and those who reported smoking regularly.

CONCLUSIONS

The findings are consistent with the hypothesis that supplement use is associated with a healthier lifestyle profile and an adequate nutritional intake, suggesting that supplement users do not need to take supplements to meet a nutrient deficiency.

The theory of planned behavior and smoking cessation

A sample of 84 smokers attending health promotion clinics in a primary care setting completed questionnaires that assessed the main constructs of the theory of planned behavior, perceived susceptibility, and past cessation attempts. Regression analyses revealed that intention to quit smoking was primarily predicted by perceived behavioral control and perceived susceptibility. At 6-month follow-up, the making of a quit attempt was predicted by intention and the number of previous quit attempts, whereas the length of the quit attempt was predicted solely by the length of the longest recent quit attempt. The results suggest that interventions should focus on perceptions of susceptibility and control to increase smokers' motivation to quit. However, further work is required to identify the social cognitive variables that ensure that initial quit attempts are translated into longer term abstinence.

Measuring support for tobacco control policy in selected areas of six countries

OBJECTIVE

To explore the validity, reliability, and applicability of using a short, psychometrically sound survey instrument to measure population attitudes toward tobacco control policies.

DESIGN

Surveys.

SUBJECTS AND SETTING

Student respondents attending university in Australia (n = 403), Hong Kong (n = 336), the Netherlands (n = 351), South Africa (n = 291), the United Kingdom (n = 164) and the United States (n = 241); total n = 1786.

MAIN OUTCOME MEASURE

The Smoking Policy Inventory (SPI), a 35-item scale. SPI scores were adjusted for age, income, gender, and smoking status. Estimates of internal consistency and tests of factorial invariance were conducted in each sample.

RESULTS

Across all six countries, the SPI was found to be highly reliable and to have a consistent factor structure, indicating that the SPI scale represents a higher order construct that assesses general attitudes about tobacco control policy with five dimensions. In general, the degree of endorsement of anti-tobacco policies as measured by the SPI reflected the extent and strength of tobacco control legislation in those countries. Dutch students were the least likely, and Australian and Hong Kong students the most likely, to support tobacco control policies.

CONCLUSIONS

It is possible to develop appropriate and meaningful measurement tools for assessing support of tobacco control policies. Strong evidence was found for internal reliability and structural invariance of the SPI. The SPI may be a useful mechanism for monitoring ongoing policy initiatives, making cross-cultural comparisons, and evaluating population receptiveness to proposed policy approaches.

Interpretations of healthy and unhealthy eating, and implications for dietary change

Central to many considerations of health-related dietary change is the interpretation given to 'healthy' and 'unhealthy' eating. Results are reported from two studies which investigated people's understanding of these concepts. The first study involved structured interviews with 48 respondents: a wide range of interpretations of healthy and unhealthy eating was found using content analysis techniques. The second study (n = 242) used questionnaires to assess the extent to which different interpretations were endorsed. The extent to which different eating behaviours were perceived as healthy or unhealthy varied greatly. A principal components analysis of perceptions of healthy and unhealthy eating produced five separate factors. Some differences in perceptions were found for people of different age, gender and educational level. Objectively assessed dietary intake and perceived intake were found to be two distinct quantities. 'Healthy' eaters were found to perceive 'healthy eating' slightly differently to 'unhealthy' eaters. The results suggest that lay understanding of healthy eating does generally conform with dietary guidelines, and therefore health promotion priorities should focus on physical and psychological constraints to healthy eating, rather than attempting to increase the public's knowledge as a whole.

Mood disorders following traumatic brain injury: identifying the extent of the problem and the people at risk

The extent of mood disorders following traumatic brain injury (TBI), and the possible risk factors, are investigated. New data are presented from a prospective study of consecutive hospital admissions. Six months post-TBI, 99 adults completed a standardized assessment of emotional state, the Wimbledon Self-Report Scale. Cognitive performance and the impact of the injury on everyday functioning were also assessed. The rate of clinically significant mood disorders (caseness) was 38%. Of the demographic or injury characteristics, only pre-injury occupational status predicted post-injury caseness. Those unoccupied pre-injury were more likely to report mood disturbance post-injury. In contrast, post-injury occupational status was not related to caseness either for the whole group or the subgroup of those previously occupied, despite the adverse effects on occupational functioning for a significant proportion of subjects. Associations were found between emotional state and cognitive and everyday functioning 6 months post-injury. Psychosocial disabilities appeared more strongly associated to mood disorders than did physical disabilities. A significant level of unmet need has been highlighted, and possible risk factors identified, which may inform the purchase and provision of TBI rehabilitation services. Follow-up data on these subjects are available and will be reported separately.

Assessing food choice in school children: reliability and construct validity of a method stacking food photographs

A method utilizing pictures was used to assess food choice with 44 school boys in three different age groups (10, 13 and 16 years old). The aim of the study was to test reliability and construct validity (i.e. inter-instrument agreement) of food choice assessed when the boys were asked to compose breakfasts. The focus was on choices of milk, margarine, bread and breakfast cereals, as in these food groups it is possible to choose between low-fat/high-fat and low-fibre/high-fibre products. Subjects were asked to repeat their composing of breakfasts after eight weeks, and to complete a four-day food record on breakfasts after the second interview occasion. For comparisons between food choices a new non-parametric statistical method was used. Both reliability and construct validity were good for choices of milk and margarine. The unreliability could be explained as random in nature or in terms of healthier choices in the second interview.

Eating sweet snacks: gender differences in attitudes and behaviour

This paper reports a study of gender differences in the components of the Theory of Reasoned Action in relation to eating sweet snacks, and the role of these components in predicting sweet-snacking in women and men. Totals of 65 women and 64 men completed questionnaires assessing attitudes and behaviours towards eating sweet snacks. Women were more ambivalent towards eating sweet snacks than men, perceiving eating sweet snacks to be significantly less healthy (t(127) = - 2.43, p < 0.02), and more pleasant (t(127) = 2.52, p < 0.01). There were no statistically significant gender differences in outcome beliefs x evaluations, subjective norms, normative belief x motivation to comply, or in behavioural intention, although some gender differences were found within components. Women scored significantly higher (t(127) = 5.54, p < 0.0005) on restraint items from the Dutch Eating Behaviour Questionnaire, including those on snacking (t(127) = 5.04; p < 0.0005), but did not differ significantly from men on reported frequency of eating sweet snacks. There were gender differences in the predictive power of components of the Theory of Reasoned Action. Women's intentions to eat sweet snacks were predicted by perceived social pressure and attitudes towards sweet snacks. Men's intentions were only predicted significantly by attitudes. It is concluded that men's sweet-snacking is less influenced by social pressure than is women's.

Body weight and shape control: examining component behaviours

Relationship between body weight and the performance of five weight-related behaviours (limiting amount of food and drink at meals, avoid unnecessary fat, taking regular exercise, drinking little or no alcohol, avoiding calories in snacks) is examined in a sample of 165 normal-weight individuals. Each of these behaviours was commonly performed, particularly when trying to control body weight and shape. Avoiding alcohol, while being viewed as the least effective means of controlling weight, is found to be the only behaviour significantly related to lower current body weight. None of the five behaviours significantly correlate with amount lost in last effort to reduce weight. Self-reported intentions and previous performance of each behaviour are significantly predicted by components of the Theory of Planned Behaviour. The results are discussed in relation to implications for body weight and shape control and the prediction of behaviours and goal achievement.

Identification and purification of a distinct dihydrolipoamide dehydrogenase from pea chloroplasts

Two distinct dihydrolipoamide dehydrogenases (E3s, EC 1.8.1.4) have been detected in pea (Pisum sativum L. cv. Little Marvel) leaf extracts and purified to at or near homogeneity. The major enzyme, a homodimer with an apparent subunit M(r) value 56,000 (80-90% of overall activity), corresponded to the mitochondrial isoform studied previously, as confirmed by electrospray mass spectrometry and N-terminal sequence analysis. The minor activity (10-20%), which also behaved as a homodimer, copurified with chloroplasts, and displayed a lower subunit M(r) value of 52,000 which was close to the M(r) value of 52,614 +/- 9.89 Da determined by electrospray mass spectrometry. The plastidic enzyme was also present at low levels in root extracts where it represented only 1-2% of total E3 activity. The specific activity of the chloroplast enzyme was three- to fourfold lower than its mitochondrial counterpart. In addition, it displayed a markedly higher affinity for NAD+ and was more sensitive to product inhibition by NADH. It exhibited no activity with NADP+ as cofactor nor was it inhibited by the presence of high concentrations of NADP+ or NADPH. Antibodies to the mitochondrial enzyme displayed little or no cross-reactivity with its plastidic counterpart and available amino acid sequence data were also suggestive of only limited sequence similarity between the two enzymes. In view of the dual location of the pyruvate dehydrogenase multienzyme complex (PDC) in plant mitochondria and chloroplasts, it is likely that the distinct chloroplastic E3 is an integral component of plastidic PDC, thus representing the first component of this complex to be isolated and characterised to date.

Development of a questionnaire to measure patients' satisfaction with general practitioners' services

BACKGROUND

It is now a requirement that patients' satisfaction with the services obtained from their general practitioner should be surveyed.

AIM

The aim of the study was to produce a reliable and valid multidimensional patient satisfaction questionnaire that could be used in general practice.

METHOD

Items were originally derived from patients' responses to open-ended questions. The resulting 148-item Likert-scale questionnaire was completed by 1193 patients. General satisfaction items were removed from the set, and responses to remaining items underwent factor analysis. Subscales were produced from items representing each factor. Reliability and validity of each subscale were examined.

RESULTS

Five subscales with a total of 40 items resulted from the factor analysis: doctors, access, nurses, appointments and facilities. Each subscale was internally reliable (Cronbach's alpha coefficient between 0.73 and 0.95), and initial tests of validity suggested that all subscales were valid.

CONCLUSION

The study has resulted in a 40-item scale that has been found to be reliable and valid after initial tests. Further work to test the reliability and validity of the final version of the patient satisfaction questionnaire is described.

Patterns of patient-controlled analgesia and intramuscular analgesia

Effective management of acute pain is a major nursing goal. The purpose of this study was to identify patient patterns in intravenous patient-controlled analgesia (PCA) and intramuscular (IM) analgesia for patients after surgery. The patients who received analgesia via PCA had shorter lengths of stay. The morphine PCA patients used more medication than the IM group; the meperidine IM patients used more medication than the PCA patients. Patterns of the use of PCA and IM analgesia were identified. These provide additional information for the development of pain management protocols.

You are your ethics

The true extent of nurses' moral agency is to be found in their everyday encounters with clients. Yet, in today's procedure-bound health care institutions they have little freedom to exercise this morality.