Validity of age at menarche self-reported in adulthood.

OBJECTIVE: To test the validity of age at menarche self-reported in adulthood and examine whether socioeconomic position, education, experience of gynaecological events and psychological symptoms influence the accuracy of recall. DESIGN: Prospective birth cohort study. SETTING: England, Scotland and Wales. PARTICIPANTS: 1050 women from the Medical Research Council National Survey of Health and Development, with two measures of age at menarche, one recorded in adolescence and the other self-reported at age 48 years. RESULTS: By calculating the limits of agreement, kappa statistic and Pearson's correlation coefficients (r), we found that the validity of age at menarche self-reported in middle age compared with that recorded in adolescence was moderate (kappa = 0.35, r = 0.66, n = 1050). Validity was improved by categorising age at menarche into three groups: early, normal and late (kappa = 0.43). Agreement was influenced by educational level and having had a stillbirth or miscarriage. CONCLUSIONS: The level of validity shown in this study throws some doubt on whether it is justifiable to use age at menarche self-reported in middle age. It is likely to introduce error and bias, and researchers should be aware of these limitations and use such measures with caution.

Motives underlying healthy eating: using the Food Choice Questionnaire to explain variation in dietary intake.

The Food Choice Questionnaire (FCQ), which measures the reported importance to a given individual of nine factors underlying food choice, and a food frequency questionnaire, were administered to 241 participants, who were also required to classify their diet as either 'standard', 'low in red meat' or 'vegetarian'. Respondents describing their diet as low in red meat attributed greater importance to health, natural content, weight control and ethical concern in their food choice than did those who described their diets as standard, whereas vegetarians differed significantly from those with a standard diet only on the score for ethical concern. Differences between men and women and between students and non-students in the frequency of consumption of a number of foods were shown to be mediated by differences in the importance attached to FCQ factors. Thus the generally healthier diets of women compared to men appeared to be accounted for by the greater importance attributed by women to weight control, natural content and ethical concerns.

Physiological consequences of everyday psychosocial stress.

A large body of data has been accumulated concerning physiological responses in people exposed to stressors in laboratories. Adrenaline and cortisol have become known as "stress hormones" because, in men, levels of both hormones consistently rise in response to stress in laboratory-based investigations. If chronically repeated, elevation of adrenaline and cortisol is likely to have long-term consequences for health, especially cardiovascular health, partly via the effects of the hormones on blood pressure and serum cholesterol levels. Research on people conducting their everyday lives is necessary to establish whether the same responses are shown on a day to day basis. Such research requires new methodologies and careful data collection. So far, it has been shown that adrenaline and blood pressure do seem to vary in expected ways. Other responses in everyday life, including those of cholesterol, cortisol and the immune system, are less well characterised.

Epinephrine and cortisol responses to work: a test of the models of Frankenhaeuser and Karasek.

Both Frankenhaeuser and Karasek have put forward models describing how job demand and control influence epinephrine and cortisol levels. These models were tested in a sample of 53 women and 51 men in a variety of occupations. They were studied over one rest day and two working days. Subjects reported their perceived demand and control and their mood on each day, as well as providing urine for assessment of urinary excretion rates of epinephrine and cortisol. In men, but not women, epinephrine levels were higher on the working days than on the rest day, and demand was found to covary positively with epinephrine, supporting Frankenhaeuser's model with respect to epinephrine variation in men. However, cortisol levels were not elevated on working days compared to the rest day, and no relationship between job control and cortisol was seen which is in contradiction of Frankenhaeuser's model with respect to cortisol variation. There was some suggestion that demand was most strongly associated with elevated epinephrine in men when job control was low in accordance with Karasek's model, but there was no evidence for such an effect with respect to cortisol.

Stress, social support and health-related behavior: a study of smoking, alcohol consumption and physical exercise.

The effects of academic examination stress on health behavior was assessed in university students. It was hypothesized that the anticipation of examinations would lead to increases in cigarette smoking and alcohol consumption, and to decreases in physical activity, and that effects would be particularly salient in students with low social supports. One hundred eighty students were divided into exam-stress (51 women, 64 men) and control (49 women, 16 men) groups, and were assessed at baseline and then within 2 weeks of exams, or an equivalent point for the control group. Perceived stress, emotional well-being and health behaviors were assessed by questionnaire and interview. The exam-stress group reported significant increases in perceived stress and emotional distress between baseline and exam sessions, but responses were not affected by social support availability. The controls showed no systematic changes in health behaviors. In the exam-stress group, smoking increased by an average of 54.7% between sessions in women with few social supports, but remained stable in men. There was a decrease in alcohol consumption of 17.5% in students with high social support between sessions, while those with low social supports showed an average increase of 18.5%. Physical activity decreased between baseline and exam sessions in the exam-stress group, but was not affected by social support. The results are discussed in relation to the effects of naturally occurring episodic stress on health behaviors, and the role of social support in moderating responses.

Development of a measure of the motives underlying the selection of food: the food choice questionnaire.

A number of factors are thought to influence people's dietary choices, including health, cost, convenience and taste, but there are no measures that address health-related and non-health-related factors in a systematic fashion. This paper describes the development of a multidimensional measure of motives related to food choice. The Food Choice Questionnaire (FCQ) was developed through factor analysis of responses from a sample of 358 adults ranging in age from 18 to 87 years. Nine factors emerged, and were labelled health, mood, convenience, sensory appeal, natural content, price, weight control, familiarity and ethical concern. The questionnaire structure was verified using confirmatory factor analysis in a second sample (n = 358), and test-retest reliability over a 2- to 3-week period was satisfactory. Convergent validity was investigated by testing associations between FCQ scales and measures of dietary restraint, eating style, the value of health, health locus of control and personality factors. Differences in motives for food choice associated with sex, age and income were found. The potential uses of this measure in health psychology and other areas are discussed.

Effects of academic examination stress on eating behavior and blood lipid levels.

The influence of academic examination stress on eating behavior and lipid profiles and the moderating effect of dietary restraint, trait anxiety, and social support availability was assessed in university students. One hundred and seventy-nine students were divided into exam-stress groups (51 women, 64 men) and control groups (48 women, 16 men) and were assessed at baseline and then within 2 weeks of exams or an equivalent point for the control group. Perceived stress, emotional well-being, and fasting lipid profiles were measured, and dietary information was collected by interview. The exam-stress group reported significant increases in perceived stress and deterioration in emotional well-being at the exam sessions compared with baseline sessions. No general effects of exam stress on food intake were observed, and there was no interaction between stress and dietary restraint. However, students in the exam-stress group with high trait anxiety and low social support showed significant increases in total energy intake between baseline and exam sessions, whereas individuals with low trait anxiety and high social support showed a reduction in energy intake. Students with high trait anxiety and low social support showed increases between baseline and exam sessions in the amount of fat and saturated fat consumed. Women in the exam-stress group taking oral contraceptives showed a significant increase in total cholesterol between baseline and exam sessions. The results are discussed in relation to the effects of naturally occurring episodic stress on health behavior and on lipid profiles.

Geographic distributions of within-population variability in blood pressure.

Data on mean blood pressure with standard deviation were extracted from the medical and anthropologic literature for as many populations as possible. The populations were classified as traditional, transitional, or modern. Both mean and within-population variability were found to be higher in more modern populations, confirming the prediction that variability of a character of low heritability is higher in an adverse environment, where it is more difficult to maintain homeostasis. In addition, variability increases with age, indicating a breakdown in homeostasis with aging. On average, males had higher diastolic blood pressure than females, and on average, females had greater variability in systolic blood pressure than males. There was a highly significant negative relationship between latitude and within-population variability in blood pressure.