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Biomedical subjects

R Desharnais

Publications and source records attributed to R Desharnais.

9 recordsLinked to original sources
PubMed1998

Hypercholesterolemia screening. Does knowledge of blood cholesterol level affect dietary fat intake?

OBJECTIVE: To assess whether knowing blood cholesterol test results influences people's intention to lower their dietary fat intake and to assess changes in diet after 3 months. DESIGN: Randomized clinical study. SETTING: Two hospital-based family medicine centres. PARTICIPANTS: A total of 526 patients aged 18 to 65, without prior knowledge of their blood cholesterol levels, were recruited. Seventy did not appear for their appointments, and 37 did not meet study criteria, leaving 419 participants. From that group, 391 completed the study. INTERVENTIONS: Patients submitted to cholesterol screening were randomly assigned to one of two groups, completing the study questionnaires either before (control group) or after (experimental group) being informed of their screening test results. All participants were called 3 months after transmission of test results to assess their dietary fat intake at that time. MAIN OUTCOME MEASURES: Differences in intention to adopt a low-fat diet reported between the experimental and control groups and differences in dietary fat intake modification after 3 months between patients with normal and abnormal blood cholesterol test results. RESULTS: Knowledge of test results influenced patients' intentions to adopt low-fat diets (F1,417 = 5.4, P = .02). Patients reported lower mean dietary fat intake after 3 months than at baseline (P < .0001). The reduction was greater in patients with abnormal screening results (F2,388 = 3.6, P = .03). CONCLUSIONS: Being informed of personal blood cholesterol levels effects an immediate change in eating habits that translates into reduced dietary fat intake.

Adolescent↗
PubMed1992

Predictors of smoking behaviour: an application of Ajzen's theory of planned behaviour.

The aim of the present paper was to verify the basic assumptions underlying the theory of planned behaviour for the prediction of cigarette smoking intentions and behaviour among adults of the general population (study 1) and a group of pregnant women (study 2). Each study was developed based upon Ajzen's theory of planned behaviour. In both studies, baseline data was collected at home with trained interviewers and with the use of paper and pencil questionnaires. The self-report on behaviour was obtained 6 months (study 1) and between 8 and 9 months (study 2) after baseline data collection. In study 1, for smokers, perceived behavioural control, attitudes and subjective norm were explaining intention, whereas perceived behavioural control and habit were the most important predictors of behaviour. In study 2, smoker's intentions was mainly under the influence of perceived behavioural control and attitude, whereas behaviour was predicted by perceived behavioural control only. The present studies suggest that promotional programmes should help smokers to know and develop their will-power regarding non-smoking of cigarettes and should be informed of the effort required in order to modify smoking behaviour.

Adult↗
PubMed1990

Optimism and health-relevant cognitions after a myocardial infarction.

The relationship between dispositional optimism (LOT) and health-relevant cognitions after a myocardial infarction was examined with 158 patients (mean age = 52.7 +/- 8.1 yr.). Patients above the median on optimism (i.e., optimists) scored significantly lower on perceived susceptibility, perceived severity, and experienced fear than did pessimists. However, no difference on perceived self-efficacy was reported between optimists and pessimists. It is concluded that these results provide further evidence for the LOT's construct validity.

Adaptation, Psychological↗
PubMed1988

A comparison of the Fishbein and Ajzen and the Triandis attitudinal models for the prediction of exercise intention and behavior.

The main purpose of the study was to compare the efficiency of the Fishbein and Ajzen and the Triandis models to predict (1) the intention to participate regularly in some physical activities during free time within a 3-week period and (2) the exercise behavior within these 3 weeks among a group of 166 subjects, aged 22 to 65 years. Our results show that the Triandis model was as efficient as the Fishbein and Ajzen model in predicting the exercise behavior. However, the results obtained from the Triandis model demonstrate the importance of the habit of exercising in predicting the exercise behavior. Moreover, the Triandis model was superior to the Fishbein and Ajzen model in explaining behavioral intention. Of particular interest was the salience of the affective, social, and personal belief components of the Triandis model. In addition, from a practical perspective, this comparative study showed that (1) to exercise regularly is perceived as hard work, and (2) individuals believe that it is their own responsibility to exercise or not to exercise.

Adult↗
PubMed1987

Prediction of leisure-time exercise behavior: a path analysis (LISREL V) model.

In an attempt to understand the inherent process underlying the regular practice of physical activity, the relationships among subjective norm, attitude, habit, intention, and future behaviors have been investigated in a random sample of 136 University of Toronto employees. For this purpose, leisure-time exercise behavior was measured on two occasions after a statement of intentions had been obtained: 3 weeks later (proximal behavior) and 2 months later (distal behavior). The results of a path analysis (LISREL) suggest that intention is directly influenced by habit and attitude, proximal behavior is the result of habit only, and distal behavior can be explained by a combination of intention and proximal behavior. Subjective norm was not a significant predictor of intention, proximal behavior, or distal behavior. This modeling approach offers a clearer understanding of the dynamics of exercise intention and behavior, strongly supporting the role of habit as a determinant of exercise behavior.

Adult↗
PubMed1987

The impact of physical fitness and health-age appraisal upon exercise intentions and behavior.

This study investigated the relative and combined effectiveness of the Canadian Home Fitness Test (CHFT) and Health Hazard Appraisal (HHA) to modify (1) intention to exercise with and without knowledge of the results and (2) intention and behavior to exercise over 3 months. The 200 subjects were randomly attributed to groups, either (1) physical-fitness evaluation (PF), (2) appraised health age (HA), (3) physical-fitness evaluation and health-hazard appraisal (PF-HA), or (4) control (C). The immediate impact on the intention to exercise of passing one and/or the other tests, without knowledge of the results, was not significant. With knowledge of the results, the intentions of the PF and PF-HA groups differed from those of the C group. This effect disappeared after 3 months. There was no significant impact on exercise behavior over 3 months. The results indicated a short-term motivational effect from being informed of CHFT results. Maintaining this effect might require intervention on a long-term basis.

Adult↗
PubMedDate not supplied

Aerobic exercise and the placebo effect: a controlled study.

An experiment was conducted with 48 healthy young adults engaged in a supervised 10-week exercise program to determine whether a placebo effect is involved within the exercise-psychological enhancement connection. Based on an expectancy modification procedure, one-half of the subjects were led to believe that their program was specifically designed to improve psychological well-being (experimental condition) whereas no such intervention was made with the second half (control condition). Expectations for psychological benefits and aerobic capacity (VO2max) were measured before and after completion of the program. Self-esteem, as the indicator of psychological well-being, was measured on four specific occasions: at the beginning, after the fourth and seventh weeks, and upon completion of the training program. The results showed similar significant increases in fitness levels in both conditions. Moreover, self-esteem was significantly improved over time in the experimental but not in the control condition. These findings provide evidence to support the notion that exercise may enhance psychological well-being via a strong placebo effect. Implications of the results with regard to exercise prescription are discussed.

Adult↗