DIETFITS study (diet intervention examining the factors interacting with treatment success) - Study design and methods.

Numerous studies have attempted to identify successful dietary strategies for weight loss, and many have focused on Low-Fat vs. Low-Carbohydrate comparisons. Despite relatively small between-group differences in weight loss found in most previous studies, researchers have consistently observed relatively large between-subject differences in weight loss within any given diet group (e.g., ~25kg weight loss to ~5kg weight gain). The primary objective of this study was to identify predisposing individual factors at baseline that help explain differential weight loss achieved by individuals assigned to the same diet, particularly a pre-determined multi-locus genotype pattern and insulin resistance status. Secondary objectives included discovery strategies for further identifying potential genetic risk scores. Exploratory objectives included investigation of an extensive set of physiological, psychosocial, dietary, and behavioral variables as moderating and/or mediating variables and/or secondary outcomes. The target population was generally healthy, free-living adults with BMI 28-40kg/m2 (n=600). The intervention consisted of a 12-month protocol of 22 one-hour evening instructional sessions led by registered dietitians, with ~15-20 participants/class. Key objectives of dietary instruction included focusing on maximizing the dietary quality of both Low-Fat and Low-Carbohydrate diets (i.e., Healthy Low-Fat vs. Healthy Low-Carbohydrate), and maximally differentiating the two diets from one another. Rather than seeking to determine if one dietary approach was better than the other for the general population, this study sought to examine whether greater overall weight loss success could be achieved by matching different people to different diets. Here we present the design and methods of the study.

Risk and protective factors of adolescent exclusive snus users compared to non-users of tobacco, exclusive smokers and dual users of snus and cigarettes.

The use of snus is increasing in Norway. In this study we examined differences between adolescents who were exclusive snus users, and adolescent non-users, smokers and dual users of snus and cigarettes on a number of psychosocial factors, categorized as risk variables and protective variables associated with involvement in health compromising behavior. We applied separate logistic regression models, where exclusive snus users (n=740) were compared with non-users (n=904), smokers (n=219), and dual users (n=367). Compared to non-users, the group of exclusive snus users was associated with variables traditionally predicting health risk behavior, such as smoking friends (OR=1.74, SD 1.27-2.38) and truancy (OR=2.12, SD 1.65-2.78). Compared to smokers, exclusive snus users were related to variables traditionally associated with protection against involvement in health risk behavior, e.g. higher academic orientation (OR=1.66, SD 1.12-2.45). Associations with protective factors were also observed when exclusive snus users were compared with dual users. While the group of exclusive snus users was associated with a pattern of psychosocial risk compared to non-users, they showed a more conventional pattern when compared to smokers and dual users. The group of exclusive snus users may be described on a continuum varying from psychosocial risk factors to protective factors of risk involvement depending on the group of comparison.

Dutch and Norwegian support of alcohol policy measures to prevent young people from problematic drinking: a cross-national comparison.

AIMS: To examine whether Dutch and Norwegian adults differ in their opinion on policy measures that may prevent young people from problematic drinking. METHODS: Data were derived from a web-based cross-sectional study. In this study, only Dutch and Norwegian adults (aged ≥24 years) were included (n(NL) = 5023, n(NO) = 1916). Opinions on policy items concerning restrictive and educational measures were examined together with alcohol consumption. RESULTS: Differences between the opinions of the Dutch and Norwegians concerning the restrictive and educational measures were small. In both countries, the support for restrictive measures was predicted by female gender, higher age and less own alcohol consumption. For the educational measures, the explained variance in the Norwegian and Dutch sample was relatively low; this indicates that opinion was more strongly predicted by other factors. CONCLUSION: This study indicates that, despite the differences between the Dutch and Norwegian alcohol policy, differences in opinion are small between Dutch and Norwegian respondents, especially regarding restrictive measures that may prevent young people from drinking.

Predicting the intention to quit smoking and quitting behaviour: extending the theory of planned behaviour.

OBJECTIVES: The present study examined the ability of the TPB to predict the intention to quit smoking and quitting behaviour. In addition, the predictive power of future orientation, number of cigarettes smoked, planning, past behaviour and the interactions between intention and other predictors was examined. MATERIAL AND METHODS: The data were derived from a longitudinal survey among 103 daily smoking students at the University of Oslo (mean age 24.6 years, mean number of years of smoking = 8 years). These data were collected by means of self-administered questionnaires at T1 (October 2003) and at T2 (February 2004) in terms of recording actual quitting. RESULTS: The TPB components accounted for 30% of the variance in quitting intentions, and affective attitude and descriptive norm emerged as the strongest predictors of quitting intention. Ordinal regression analysis showed that intention was a borderline significant predictor of subsequent quitting behaviour, while the impact of PBC was non-significant (model 1). The inclusion of the additional variables improved the fit of the model, with number of cigarettes and planning appearing as significant predictors of behaviour (model 2). As predicted, there was a significant interaction between perceived control and intentions on quitting (model 3). Nagelkerke R(2) increased from .07 in model 1 to .54 in model 2, and finally to .58 in model 3. CONCLUSIONS: The results indicate that affective attitude and descriptive norm play a more crucial role than the other TPB predictors in motivating smokers to quit. The results also indicate that self-regulatory strategies are important in relation to addictive behaviours.

Socio-economic differences in patterns of health and oral health behaviour in 25 year old Norwegians.

The purpose of this study was to test the hypothesis of multidimensionality of oral and general health behaviour. To evaluate the proposed behavioural dimensions, relationships with individual beliefs and socio-economic factors were explored. A simple random sample of 1190 residents born in 1972 was drawn from the populations of three counties in western Norway in February 1997. A questionnaire was mailed to the eligible sample. After one reminder, 735 subjects (58% women) replied. Principal component analysis (PCA) provided two factors, which accounted for 32.5% of the variance among the behavioural variables. One-way analysis of variance revealed significant, inverse relationships between two sum scores of health enhancing and health detrimental behaviour derived from the factors; socioeconomic variables and perceived vulnerability. Controlling for gender, multiple logistic regression analyses revealed significant relationships between health enhancing behaviour and occupational status (non-manual versus student, OR=0.6, 95% CI 0.4-0.8) and perceived vulnerability (OR=2.2, 95% CI 1.5-3.0). Occupational status (manual versus student OR=1.8 95% CI 1.2-2.6 and non-manual versus student OR=1.4 95% CI 1.0-2.1) turned out to be the strongest predictor of health detrimental behaviour. The present results indicate that oral and general health behaviour reflects two distinct behavioural domains. This appears to imply that oral and general health behaviour should be approached jointly in health promotion lifestyle programmes and that the lower socio-economic status groups should be targeted.

Dimensionality of psychosocial responses to marital disruption.

The purpose of the study was to assess whether psychosocial responses to marital disruption were best arranged along one single dimension ranging from maximum positive to maximum negative responses, or whether positive and negative responses constituted two separate and distinct dimensions. Participants were 658 recently divorced individuals. A confirmatory factor analysis revealed that a two-factor model provided a better fit to the data than a one-factor model. Moreover, a number of external variables differentiated between positive and negative responses, indicating that such responses reflect two separate domains. Thus, the findings support the notion that psychosocial responses after marital disruption comprise a bidimensional rather than a unidimensional pattern. The findings are discussed within the general framework of positive-negative asymmetry and the idea that positive and negative evaluations belong to different psychological system.

Outcome of clinical mastitis in dairy heifers assessed by reexamination of cases one month after treatment.

Heifers that were treated for clinical mastitis prior to parturition or within 14 d postpartum were reexamined approximately 1 mo after treatment. Clinical examination of the heifers and microbiological examination of quarter milk samples were carried out on both occasions. Of the 1000 heifers included in the study, 10.9% were culled within 28 d after treatment. Udder damage caused by mastitis was the only or main reason for culling in 96% of those heifers. In comparison, 4.5% of nonmastitic heifers from the same herds were culled within 30 d postpartum. Twenty-five percent of those heifers that were not culled at d 28 after treatment had at least one nonfunctional quarter at that time. One thousand one hundred twenty-two quarters that were clinically affected at the time of treatment were reexamined; 22% were nonfunctional, 14% were still affected by clinical mastitis, 12% had subclinical mastitis, 5% had a latent infection with coagulase-positive staphylococci or Streptococcus dysgalactiae, and 46% were bacteriologically negative and had a normal cell count at the time of reexamination. High percentages of nonfunctional quarters were observed among those quarters that were infected with Arcanobacterium pyogenes or with coagulase-positive staphylococci at treatment. When all quarters that were clinically affected at treatment were considered, 40% of quarters were cured and were still in lactation at reexamination. Quarters infected with coagulase-negative staphylococci had a higher cure rate than quarters infected with other organisms. At reexamination, clinical signs of thelitis were observed in many of those quarters that were nonfunctional following the episode of clinical mastitis and also in 25% of lactating quarters in which clinical mastitis persisted.

Predicting Intended Condom Use among Tanzanian Students using the Theory of Planned Behaviour.

This study examined whether perceived behavioural control predicted the intention to use condoms at next sexual intercourse above the components of the theory of reasoned action, as well as the sufficiency of the theory of planned behaviour (TPB) as a theory of intention among Tanzanian adolescents. Five hundred and twenty-eight students who were sexually active, from seven secondary schools in Arusha, Northern Tanzania, completed a questionnaire designed to measure the components of the TPB. Behavioural intentions were significantly predictable from attitudes (.11), subjective norms (.22) and perceived behavioural control (.48). The inclusion of past behaviour into the regression equation increased R(2) only marginally (2 percent) but significantly, suggesting that the TPB provides a fairly accurate explanation of intention to use condoms among Tanzanian adolescents. The implications of this finding in relation to theoretical and practical issues are discussed.

Noncoital sexual interactions and problem behaviour among young adolescents: the Norwegian Longitudinal Health Behaviour Study.

This paper focuses on whether early onset of noncoital sexual interactions is best considered in the same paradigm as adolescent problem behaviour. Among adolescents (n = 927) followed longitudinally from age 13 to 15, the interrelationships between noncoital sexual interactions and various problem and conventional behaviours were examined. Early onset of noncoital sexual interactions was related to problem behaviour, and the higher ordered the noncoital sexual interaction was, the more strongly it correlated with measures of problem behaviour. This study provides support for the usefulness of the notion of an underlying factor of proneness to problem behaviours, which is relevant when studying developmental change in terms of accumulation of early noncoital sexual experience. It is suggested that in the construction of countermeasures to prevent the negative consequences of early sexual activities among adolescents, it may be useful to target broader correlates of behaviour.

Adolescents' Knowledge about HIV/AIDS: One Dimensional or Two Dimensional? A Confirmatory Factor Analysis.

This article sets out to study the dimensionality of adolescents' knowledge of HIV transmission by contrasting a two-factor and a one-factor model using confirmatory factor analysis (LISREL). The empirical data stem from a longitudinal study on health behaviour in Norway. This study uses cross-sectional data of the same subjects in 1990 with mean age 13.3 (n = 927) and 1992 ( n = 974). The respondents were confronted with 12 items describing different types of risky situations and asked whether HIV could be transmitted in these situations. The two-factor model provided a significantly better fit to the empirical data than did the one-factor model, suggesting that knowledge of how HIV is transmitted is distinct from knowledge of how HIV is not transmitted. Several explanations for this difference are suggested, and implications for constructing health- education messages are discussed.

Analysis of adolescents' beliefs about the outcome of using dental floss and drinking non-sugared mineral water.

Using an expectancy value approach, personal and normative beliefs about the outcome of using dental floss and drinking non-sugared mineral water were studied in a sample of 970 15-year-old adolescents in the county of Hordaland in Norway. The data stem from a survey performed in October 1992. A detailed analysis of these beliefs provides information about which of them should be targeted in a persuasive communication directed at changing behavior. The adolescents evaluated six outcomes of each behavior in terms of how much they wanted or feared them, and rated the probability of each outcomes happening. The adolescents also rated the probability that four significant referents would approve the performance of each behavior and how much they valued the approval of each referent. Subjects with relatively strong and relatively weak intentions to use dental floss and to drink non-sugared mineral water (intenders and non-intenders) were compared with respect to their scores on each measure. A one-way analysis of variance showed consistent differences between intenders and non-intenders. Intenders were more likely to believe that the specified behaviors would result in positive outcomes and they evaluated these outcomes as more desirable than non-intenders. Intenders believed their referens, in particular dentists and parents, to be more concerned about whether or not to perform the specified behaviors than non-intenders. The most promising candidates for persuasive communication among behavioral beliefs with respect to the specified behaviors appeared to be reduced tooth decay and several non, health beliefs in terms of immediate social and sensory concerns.

Expectancy-value approach to drinking non-sugared mineral water among adolescents.

This study set out to predict the intention to drink non-sugared mineral water and the performance of this behavior in a group of Norwegian adolescents using the theories of reasoned action and planned behavior. The empirical data stem from The Norwegian Longitudinal Health Behavior Study, and a comprehensive questionnaire survey was performed in September and October 1992. The study group comprised 970, 15-yr-old adolescents, considered to be representative of this age group in the county of Hordaland. After a 4-week period actual behavior was assessed in a subgroup (n=170). The theories posit that a person will probably perform a behavior if she/he intends to perform the behavior and has actual control with its performance. Behavioral intention is in turn governed by three types of predictors: attitudes, subjective norms and perceived behavioral control. Multiple regression analysis showed that the intention to drink non-sugared mineral water was primarily governed by perceived behavioral control and attitudes while subjective norms had less impact. Intention alone turned out to be the immediate determinant of drinking of non-sugared mineral water, which implies that performance of this behavior presents few problems regarding actual control.

Relationship between sexual experience and non-sexual behaviours among secondary school students in Arusha, Tanzania.

A sexual behaviour study was conducted among 655 secondary school students to assess the association between sexual experience and non-sexual behaviours. Among students aged 15-19 years, the prevalence of nonvirginity increased with age, from 58.8% to 85.6% for males, and from 21.9% to 44.9% for females. Sexual experience correlated positively with measures of problem behaviours (r = .31) and negatively with a measure of church or mosque attendance (r = -.09). Overall, the relationship between sexual experience and non-sexual behaviours demonstrated the conventionality-unconventionality polarity suggested by problem behavior theory. The observed relationships were relatively stronger at young ages and declined with increasing age, suggesting the developmental functions of these behaviours. Hence, the relations between sexual experience and non-sexual behaviours provided empirical support of the potential utility of the theory of problem behaviour in HIV/AIDS prevention and control among students in Arusha, Tanzania.

Organization of HIV/AIDS related attitudes and predictors of attitudes.

The purpose of this study was to investigate the psychological organization of attitudes towards public measures instituted to combat AIDS; secondly, to study the cognitive information about HIV transmission upon which these attitudes are based; and thirdly, to study whether education plans and gender also predicted negative attitudes. The study subjects were 229 students attending a Norwegian high-school (median age = 19), and the data were collected using a self-administered questionnaire. Confirmatory factor analysis confirmed the existence of two separate attitudinal dimensions: "Restrictive" and "Supportive". The hypothesis was confirmed that beliefs about uncontrollable contact predicted "Restrictive" attitudes, while beliefs about controllable contracts did not. Educational plans, gender and "Uncontrolable contact" beliefs each predicted "Restrictive" attitudes. This suggests that beliefs and attitudes have instrumental as well as symbolic bases. Implications for public health strategies are discussed.

Prediction of attitudes towards restrictive AIDS policies: a structural equation modelling approach.

The purpose of the study was to test a prehypothesized structural equation model of predictors of attitudes towards restrictive AIDS policies. It was assumed that such attitudes ae under influence of both cognitive processes and more general attitudinal structures. The hypothesized model was tested against empirical data from a nation-wide survey of Norwegian adults, including 543 males and 577 females. The proposed model fit the data reasonably well. As expressed by total effect education was the most important predictor of AIS policy attitudes. However, the most notable findings appeared to be the strong direct effect exerted by attitudes towards minorities. Misinformation about AIDS transmission and sexual attitudes also exerted significant direct effects upon AIDS policy attitudes. The results clearly demonstrate that AIDS policy attitudes are not cognitively based alone but also reflect more general attitudinal structures. Thus choosing a strategy which is primarily based on increasing the flow of factual AIDS information in order to remedy casual contact beliefs, will not be sufficient to prevent stigmatized and negative AIDS attitudes. This is more evident in that beliefs about modes of AIDS transmission, as reported in this study, seem themselves to have a symbolic component. A perspective which includes the idea of the value expressive functions of AIDS related attitudes seem relevant. Consequently, educational strategies which directly address prejudiced attitudes towards minority groups may prove particularly appropriate in the prevention of stigmatized and restrictive AIDS attitudes.

Promoting safer sexual practices among young adults: a survey of health workers in Moshi Rural District, Tanzania.

As part of the national effort to prevent further spread of HIV/AIDS, rural health workers in Tanzania are asked to promote safer sex practices among the sexually active population. We conducted a survey among health workers in Moshi Rural District, Kilimanjaro, designed to assess their attitudes, perceived norms and self-efficacy with respect to the promotion of safer sexual practices among young adults 15-35 years old. Health workers at all private and governmental health facilities were included (n = 342; participation rate of 68.4%). We observed relatively strong associations between the frequency and quality of reported counselling behaviour and perceived norms, attitudes and self-efficacy (standardized regression coefficients (beta) of 0.329, 0.252 and 0.159 respectively). In addition, exposure to behaviour change strategies during formal training and marital status of the health workers were associated with counselling behaviour (beta of 0.133 and 0.118 respectively). Overall, these factors accounted for 40.8% of the observed variance in reported counselling behaviour. It is recommended that continued education for health workers focus on providing normative support for promoting safer sex, provide information which may help foster positive attitudes and teach practical counselling skills to further increase the self-efficacy regarding counselling young people.

PIP: As part of the national effort to prevent further spread of HIV/AIDS, rural health workers in Tanzania were asked to promote safer sex practices among the sexually active population. A survey was conducted September-October 1993 among all registered health workers in Moshi Rural District, Kilimanjaro. It was designed to assess the attitudes, perceived norms, and self efficacy with respect to the promotion of safer sexual practices of young adults 15-35 years old. Of 500 eligible health workers at all private and governmental health facilities 342 were included (participation rate of 68.4%). The study was guided by the Theory of Reasoned Action (Fishbein, 1969) and Social Learning Theory (Bandura, 1992). Counseling behavior was assessed by combining 4 items addressing frequency of safer sex promotion into a sum score. Participating health workers were classified as clinicians, nurses, prevention personnel, and laboratory personnel. Prevention personnel had significantly more positive attitudes toward counseling compared to the other professionals (28.6 compared to 25.0). Prevention personnel also reported having counseled more clients the previous month with respect to reducing the number of sexual partners than did laboratory personnel (16.0 vs. 6.1). Relatively strong associations were observed between the frequency and quality of reported counseling behavior and perceived norms, attitudes, and self efficacy (standardized regression coefficients (beta) of 0.329, 0.252, and 0.159, respectively). Subjects who had received behavior change training were more likely to report counseling young people on safer sex practices than were their colleagues without such training (beta = 0.133). Married health workers were also more likely to offer such counseling compared to unmarried workers (beta = 0.118). Overall, these factors accounted for 40.8% of the observed variance in reported counseling behavior. It is recommended that continued education for health workers focus on providing normative support for promoting safer sex, disseminate information to help foster positive attitudes, and teach practical counseling skills.

Concordance of parental and adolescent health behaviors.

This paper reports upon an empirical study of health behaviors in adolescents and their parents. The study aimed at assessing: effects of parental health behaviors on that of their adolescent child; whether mother's and father's health behaviors have additive effects on the respective health behaviors of their child; and whether eventual effects of parental health behaviors decrease with increasing age of the child. The data stemmed from the Norwegian national Health Survey in 1985 and comprised separate interviews with two parents and an adolescent child in 337 families. Results from logistic regression analyses showed that the strongest association found between parental and adolescent health behaviors was for fat intake, and the probability of having a low fat intake was 5 times higher if the mother had a low fat intake than if she did not. With the exception of mother's frequency of exercise, all other parental health behaviors were positively and statistically significantly associated with the corresponding health behavior of their adolescent child. Parental fat intake, smoking behavior and alcohol consumption appeared to have additive effects on the corresponding behaviors of their children. No statistically significant interaction between any of the parental health behaviors and age of the adolescent was found. Hence, the effect of parental health behaviors on that of their adolescent child does not seem to decrease with increasing age of the adolescent. The results are discussed with reference to the functions of modeling.

Young adolescents' intention to use seat belts: the role of attitudinal and normative beliefs.

In this study, the Theory of Reasoned Action was applied for two different purposes: (i) to explain and predict seat-belt usage among young adolescents, and (ii) to investigate the specific cognitions underlying the decision to use seat belts. A detailed analysis of these cognitions may provide clues as to which beliefs one should try to change in order to improve seat-belt usage among young adolescents. The decision to wear seat belts was under attitudinal control in the front seat, while it was under both attitudinal and normative control in the back seat. However, prior use of seat belts was the single most powerful predictor of intention. There was a striking consistency in the difference between high intenders and low intenders with regard to the specific underlying cognitions. The most promising 'messages' for persuasive communication appears to be that use of seat belts has an injury reducing effect and makes one feel safe when driving.

[What do Norwegians know about sexually transmitted diseases? Results from a survey on Norwegians' knowledge about sexually transmitted diseases]. / Hva vet nordmenn om seksuelt overførbare sykdommer? Resultater fra en undersøkelse av nordmenns kunnskaper om seksuelt overførbare sykdommer.

This paper reports on knowledge about sexually transmitted diseases in Norwegian adults. The sample (572 males and 601 females) was representative of Norwegians aged 15 and above. Data were collected by means of personal interviews and self-completed questionnaires. Out of ten respondents, seven did not know that sexually diseases are not transmitted via toilet seats; six that syphilis is not the most prevalent of the sexually transmitted diseases in Norway; five that both males and females can be infected by chlamydia; four that contraceptive pills do not protect against chlamydia infection; three that condoms protect against all sexually transmitted diseases; and two that condoms protect against gonorrhoea and that females infected by sexually transmitted diseases run higher risk of infertility. Knowledge about sexually transmitted diseases was lowest in the youngest and oldest age groups, and increased monotonously with increased education.

Norwegian adults' perceived need for coping skills to adjust to dental and non-dental life events.

Limited attention has been paid to the importance which adults attach to dental, as opposed to other, life events. Consequently, the purpose of the present study was to determine how Norwegian adults rate the need for adjustment to cope with losing teeth or getting dentures, relative to some other life events, and to study effects of age, gender, level of education, place of residence, smoking, drinking and exercise habits. A representative, simple random sample of 400 residents of the County of Hordaland aged 20-69 yr received a mail questionnaire plus one reminder requesting demographic information and completion of a 48-item Social Readjustment Rating Questionnaire (SRRQ) in May 1990. The mean age of the 284 who responded (71%) was 41.1 yr (SD = 13.5 yr). The replies to the SRRQ were given on a graphic rating scale with end points "not difficult at all" (0 cm) and "more difficult than anything" (20 cm). Mean values were calculated and used to rank the life events. "Losing one or more teeth" was ranked 30 (mean = 11.8; SD = 5.6) and "getting dentures" 33 (mean = 13.8; SD = 5.5). "Losing one or more teeth" was on a par with life events like "trouble with other relatives" (mean = 11.7). "Getting dentures" occupied a position between "trouble with wife/husband" (mean = 14.3) and "wife/husband stopping work" (mean = 13.8). Multiple Classification Analysis revealed significant effects of education on "losing one or more teeth"; and of age, sex and education on "getting dentures" (P < 0.05). Furthermore, it was found that these two dental life events required an above average degree of readjustment according to the Social Readjustment Rating Questionnaire.