A comparison of adolescent moderate-to-vigorous physical activity participation in relation to a sustained or accumulated criterion.

Contemporary guidelines for young people advocate both a sustained and accumulative approach to moderate-to-vigorous physical activity (MVPA) participation. In order to investigate the behavioural significance of applying these approaches, this study assessed if differences in adolescent MVPA occurred when either a sustained or accumulated criterion was adopted. Using heart rate thresholds indicative of intensity, the physical activity of 25 adolescents was assessed by monitoring heart rate over 3 days. Results indicated that differences in MVPA participation did exist when different approaches were used, in that the majority of adolescents were active with respect to an accumulated criterion yet inactive with respect to a sustained criterion. Such a disparity may be due to accumulative MVPA being more characteristic of young people's natural activity behaviour. Such findings have strong implications for practitioners seeking to counter young people's inactivity, in that the application of an accumulative approach may be more effective at initiating and establishing an habitual activity behaviour than that of a sustained approach.

Balancing risks and benefits of deception in assessing genetic screening utilization.

OBJECTIVE: To advocate that research using intentional deception is sometimes appropriate. METHODS: A deception paradigm created to assess utilization of genetic screening for alcoholism susceptibility is reviewed in the context of competing ethical obligations and objections to the procedure. CONCLUSIONS: The paradigm is ethically defensible, it generates useful knowledge about future utilization of alcoholism screening by college students, and it exposes participants to no more than minimal risk. The use of deception to address questions related to predictive genetic screening will require investigators to balance protection of participants with the need to advance knowledge.

Application of a bogus testing procedure to determine college students' utilization of genetic screening for alcoholism.

A convenience sample of 181 college students took part in a quasi-experimental study that tested the use of genetic screening for alcoholism--a test that does not yet exist. A questionnaire was administered before and after the students viewed a presentation that accurately explained genetic susceptibility to alcoholism but misled them by offering "a newly available" test. Alcohol-related variables were assessed before the presentation. Test-seeking intention and reasons for and against testing were assessed after the presentation. Regression analysis found that being Caucasian, female, and somewhat older than traditional college age, and having a history of early drunkenness were significant predictors of testing intention. During the week following data collection, only 7 participants (4%) attempted to schedule a test. Implications of these findings and the ethical issues related to predictive screening for alcoholism in the college population are discussed.

The role of cues, self-efficacy, level of worry, and high-risk behaviors in college student condom use.

PIP: A sample of 879 undergraduate students were recruited from a public university in western New York state during the 1993-94 academic year in order to study condom use among sexually active young people 18-24 years old. A 104-item questionnaire was administered consisting of 5 instruments and single-item measures of sexual behavior and demographics. The instruments were: the Condom Use Self-Efficacy Scale (CUSES), the Perceived Barriers to Condom Use, the Perceived Susceptibility to HIV/AIDS and other STDs, the Cues to Condom Action Scale, and the Perceived Norms scale. 92% of students reported having had sexual intercourse in the past, while 86.75 reported having sexual intercourse in the previous year. About 61% reported having 1 sex partner in the previous 12 months, whereas 35.2% reported having 3 or more partners. 22.4% reported 2 or more 1-night stands. 54.5% reported worrying about HIV/AIDS occasionally, while 23.1% reported doing so frequently. 17.2% (99) of the students were classified as non-users of condoms, 50.2% (289) as sporadic users, and 32.6% (188) as consistent users. 78 (12%) could not be classified. A multiple discriminant function analysis was also conducted to distinguish among the 3 condom user groups totalling 576 cases. The variables were age, gender, frequency of drunkenness during sexual intercourse, number of sex partners, and number of 1-night stands in the past 12 months, perceived barriers, worrying about HIV/AIDS, perceived susceptibility, condom use self-efficacy, and cues to condom action. Two significant functions emerged. Function 1 clearly separated the sporadic users from the consistent users (p 0.001), while Function 2 clearly separated the sporadic users from the non-users (p 0.001). The discriminating variables correctly classified 64.58% of the respondents into the 3 condom user groups. The variables were most effective at correctly classifying non-users (68.7%), consistent users (67.8%), and sporadic users (61.2%). Sporadic users were more diverse with respect to condom use than the other 2 groups.^ieng

Social context and sensation seeking: gender differences in college student drinking motivations.

An anonymous questionnaire was administered to students at two universities. The questionnaire contained the Social Context of Drinking Scales, the Sensation Seeking Scale, and measures of alcohol use intensity, frequency of alcohol-impaired driving, as well as frequency of riding with an impaired driver. The results revealed significant gender differences in the social context of drinking as well as sensation seeking. High intensity drinkers of each gender were more likely to drink in a context of Social Facilitation and score higher on the sensation seeking subscale--Disinhibition. High intensity men drinkers were more likely to drink in a context of Sex Seeking, whereas high intensity women drinkers tended to drink in a context of Emotional Pain. In general, the Social Context of Drinking Scales were superior to the Sensation Seeking Scales at being able to discriminate high from low intensity drinkers. The implications for targeted prevention programs on college campuses are discussed.

Health belief and self-efficacy models: their utility in explaining college student condom use.

This investigation tested the ability of the Health Belief Model (HBM), dimensions of self-efficacy, various behavioral variables (i.e., number of sex partners in the past 12 months, frequency of drunkenness during sexual intercourse, and number of diagnosed sexually transmitted diseases), and demographic measures to distinguish between three condom user groups (i.e., nonusers, sporadic users, and consistent users). The usable sample consisted of 366 college students, ages 18 to 24. The study operationalized the following HBM components: perceived susceptibility, perceived benefits, and perceived barriers. The multidimensional Condom Use Self-Efficacy Scale (CUSES) was also used in this investigation. Results from a discriminant analysis indicated that sporadic users were best distinguished from both consistent and nonusers by number of sex partners in the past year, frequency of drunkenness during sexual intercourse, perceived susceptibility to HIV/AIDS and other STDs, and a self-efficacy factor labeled Assertive. The sporadic users had significantly more sex partners, were drunk more often when engaging in sexual intercourse, perceived themselves as more susceptible to HIV/AIDS and other STDs, and were less confident in their ability to discuss and insist on condom use with a partner. It was also discovered that each condom user group was best defined by different subsets of discriminating variables. Implications of these findings for campus-based prevention programs and future research are discussed.

PIP: The ability of the health belief model and self-efficacy concept to discriminate among three condom use groups--nonusers, sporadic users, and consistent users--was assessed in a sample of 366 sexually active college students 18-24 years of age. The mean number of sex partners in the 12 months preceding the survey was 2.2. The students could be classified as follows: nonusers, 70 (19%); sporadic users (defined as having more total sex partners in the preceding year than partners with whom a condom was always used), 157 (43%); and consistent users, 107 (29%), Principal components factor analyses of the health belief model constructs indicated that perceived benefits, perceived barriers, and perceived susceptibility are multidimensional. In univariate analyses, statistically significant differences across condom use groups were found for the following measures: perceived susceptibility of partner, perceived susceptibility of self, assertiveness, partner disapproval of condoms, intoxicants, number of sex partners, and inebriation during sexual intercourse. When a multiple discriminant function analysis was conducted with these variables, they failed to differentiate significantly between nonusers and consistent users but did distinguish sporadic users. Sporadic condom users perceived themselves and their partners as at highest risk of acquired immunodeficiency syndrome and other sexually transmitted diseases, had the largest number of sex partners in the past year, reported more inebriation during sexual intercourse, and were less confident in their ability to negotiate condom use with a partner than their counterparts in the other two use groups. Out of the variable subsets, the health belief model was best at identifying sporadic users, behavioral variables were most pertinent for nonusers, and the self-efficacy measure was most relevant in the case of consistent use.

The art and science of scale development in health education research.

This conceptually-based article focuses on the value of the complementary or integrative use of qualitative and quantitative research methods in health education research. Specifically, the article describes a model for developing measurement scales using both qualitative and quantitative techniques. The qualitative methods of open-ended interviews and focus groups are used to develop questionnaire items. Quantitative methods (e.g. factor analysis) are used to test and refine questionnaire subscales. A discussion of reliability and scale validation is offered along with illustrative examples from recent health education research.

The competitive demands of elite male field hockey.

To establish the energy cost of competitive field hockey, nine international hockey players wore a modified Sport Tester PE3000 telemetric heart rate monitor during matchplay and also completed a laboratory based incremental treadmill test to establish maximal oxygen uptake (VO2max). The heart rate data from competition were compared with heart rate and oxygen uptake data measured in the laboratory. Individual regression equations were established from these data to estimate the energy penditure during competitive match-play. The mean heart rate during competition was 159 +/- 8 beats/min (mean +/- SD). The mean estimated oxygen uptake during competition was 48.2 +/- 5.2 ml/kg/min which is commensurate with 78% of the group's mean maximal oxygen uptake of 61.8 +/- 1.8 ml/kg/min. The mean estimated energy expenditure throughout an entire match was 5.19 MJ and rates of energy expenditure ranged from 83 kJ/min for the centre midfield position to 61.1 kJ/min for the left corner forward position. This study has shown the feasibility of heart rate monitoring as a means of estimating energy expenditure in elite hockey. Competitive matches place a heavy demand on the aerobic system and require players to expend energy at relatively high levels.

Social context, sensation seeking, and teen-age alcohol abuse.

An anonymous questionnaire was administered to more than 1,200 seventh to 12th grade students in four rural public schools in western New York State. The questionnaire measured alcohol use, the social contexts of drinking, and the personality trait known as "sensation seeking." A majority (57%) were drinkers, and discriminant function analyses were performed on their scores on these measures to determine if they could distinguish between different levels of alcohol use intensity, alcohol-impaired driving, and riding with an impaired driver. Results indicated social context measure were effective in distinguishing among levels on each indicant of abuse. In particular, high-intensity drinkers, impaired drivers, and riders of impaired drivers were more likely to drink in a context of social facilitation, stress control, and defiance of school and adult authority. The drinking context of peer acceptance was important only in distinguishing teen-agers who ride with drunk drivers from those who do not. Overall, the sensation seeking trait was of moderate importance in distinguishing among different alcohol abuse practices. Implications of these findings for assessment as well as school-based prevention programs are discussed.

Dimensions of self-efficacy among three distinct groups of condom users.

Condom use self-efficacy can be defined as expectations about one's ability to use condoms under a variety of circumstances. This investigation examined the factor structure of the Condom Use Self-Efficacy Scale (CUSES) in an 18- to 23-year-old college population (N = 339) and tested the ability of the factors to distinguish among three groups of condom users (nonusers, sporadic users, and ritualistic users). Emerging from a principal components analysis were four reliable factors labeled Mechanics, Partner's Disapproval, Assertive, and Intoxicants. Results from a discriminant analysis indicated that sporadic users were best distinguished from ritualistic users by number of sex partners, use of intoxicants, and intensity of alcohol use. The sporadic users had more sex partners, were less confident of their ability to use condoms when intoxicated, and were heavier drinkers than were the ritualistic users. Nonusers were best distinguished from ritualistic users by the factor labeled Assertive. Nonusers were significantly less confident in their ability to discuss condoms and to insist on their use with a sexual partner. Implications of the findings for improving campus-based programs to prevent the spread of human immunodeficiency virus infection and sexually transmitted diseases are discussed.

PIP: During January-June, 1992, 339 students, 18-23 years old, at the State University of New York in Brockport completed a 79-item questionnaire designed to assess sexual behavior and alcohol use. Researchers aimed to test the factor structure of the Condom Use Self-Efficacy Scale (CUSES), which comprised 28 items in the questionnaire, and the ability of self-efficacy, high risk behavior, and demographic factors to differentiate among consistent condom users, sporadic users, and nonusers. Sporadic users had significantly more sexual partners in the last 12 months than did consistent users (3.64 vs. 1.92; p .005). This may be because sporadic users were more likely to use alcohol (CUSES score: 9.09 vs. 7.81; p .05) and to lack confidence in their ability to use condoms when intoxicated (8.5 vs. 9.73; p .005) than were consistent users. Alcohol use had a consistent, positive correlation with number of sexual partners (p .01), indicating the need for college health education programs that promote condom use to address alcohol abuse. Nonusers were less likely to be confident of their ability to demand that their sexual partner use a condom than were consistent users (9.36 vs. 10.58; p .005). They were also more likely to fear partner's disapproval than consistent users (16.46 vs. 17.73; p .05), but this was a more moderate difference than assertiveness. Thus, nonusers tended to be insecure in their abilities to discuss and insist on condom use and to negotiate and resolve any conflict about condom use. Consistent users had better communication skills about intimate subjects than did nonusers. Any health education program promoting safer sexual practices needs to address communication and improvement of relationship skills. These findings also suggest that campus programs cannot be limited to mechanics of condom use, and that role playing would provide students opportunities to practice skills in relationships, communication, and conflict resolution.

Relationships between expectancies and adolescent dieting behaviors.

Dieting expectancies are cognitive variables pertaining to anticipated outcomes individuals expect to obtain from dieting to lose weight. This investigation examined the factor structure of dieting expectancies in an adolescent population, age 10-18, and tested the ability of factors to distinguish among types of dieter, diet pill user, and vomiter groups. Emerging from a principal components analysis were five reliable expectancy factors: Social Confidence, Social Approval, Self-Worth, Positive Performance, and Negative Consequences. Results indicate dieting expectancies and gender are important in distinguishing among adolescents who engage in different dieting practices. Gender and Self-Worth were particularly important in distinguishing frequent dieters from nondieters. Social Approval was best at separating frequent dieters from occasional dieters, diet pills users from nonusers, and vomiters from nonvomiters.

Ciliated cell remnants in peritoneal dialysis fluid.

Ciliocytophthoria are anucleate remnants of ciliated epithelial cells derived from the lower respiratory tract and female reproductive tract. We report a case of ciliocytophthoria found in the effluent dialysis fluid of a young woman undergoing long-term ambulatory peritoneal dialysis. Inability to identify these "organisms" initially led to an extensive search for parasitic contamination or infection of the peritoneum. After identifying these "organisms" as ciliocytophthoria, a prospective study showed that ciliated cell remnants occur frequently in the effluent dialysate of young women, but not in older women or men. With increasing use of peritoneal dialysis, laboratory personnel can expect to see ciliocytophthoria in peritoneal dialysate effluent and should recognize them as benign, normal findings in young women.

Extreme gestational starvation ketoacidosis: case report and review of pathophysiology.

A case of severe starvation ketoacidosis developing during pregnancy is presented. The insulinopenic/insulin-resistant state found during fasting in late gestation predisposes to ketosis. Superimposition of stress hormones, which further augment lipolysis, exacerbates the degree of ketoacidosis. In our patient, gestational diabetes, twin pregnancies, preterm labor, and occult infection were factors that contributed to severe starvation ketoacidosis. Diagnosis was delayed because starvation ketosis is not generally considered to be a cause of severe acidosis, and because the anion gap was not elevated. Improved understanding of the complex fuel metabolism during pregnancy should aid in prevention, early recognition, and appropriate therapy of this condition.

Daily energy expenditure in free-living children: comparison of heart-rate monitoring with the doubly labeled water (2H2(18)O) method.

Total energy expenditure (TEE) was measured simultaneously in 36 free-living children aged 7, 9, 12, and 15 y over 10-15 d by the doubly labeled water (DLW) method and for 2-3 separate days by heart-rate (HR) monitoring. The 95% confidence limits of agreement (mean difference +/- 2SD) were -1.99 to +1.44 MJ/d. HR TEE discrepancies ranged from -16.7% to +18.8% with 23 values lying within +/- 10% of DLW TEE estimates. Boys and girls spent 462 +/- 108 and 318 +/- 120 min/d, respectively, in total physical activity (P less than 0.01). Time spent in moderate and vigorous physical activity (MVPA) was 68 +/- 37 min/d by younger children (7-9 y) and 34 +/- 24 min/d by older children (12-15 y) (P less than 0.001). Younger boys engaged in MVPA (91 +/- 33 min/d) and vigorous physical activity (VPA) (35 +/- 15 min/d) significantly longer than younger girls (MVPA, 39 +/- 16 min/d, P less than 0.001; VPA, 10 +/- 4 min/d, P less than 0.01) as did older boys (MVPA, 52 +/- 21 min/d; VPA, 30 +/- 18 min/d) compared with older girls (MVPA, 15 +/- 10 min/d; VPA, 8 +/- 5 min/d). HR monitoring provides a close estimation of the TEE of population groups and objective assessment of associated patterns of physical activity.

Uremic encephalopathy: role of brain energy metabolism.

Uremia is associated with decreased brain oxygen consumption in humans and with decreased brain energy consumption in rodent models of acute renal failure. We measured the levels of high-energy phosphates and glycolytic intermediates in the brain of dogs with acute or chronic renal failure. We used methods of rapid brain tissue fixation that trap these labile metabolites at their in vivo levels. Creatine phosphate, ATP, and glucose were normal in the brain of animals with renal failure, indicating a normal brain energy reserve. The brain energy charge, which is the fraction of the total adenine nucleotide pool that contains high-energy phosphates, (ATP + 1/2ADP)/(ATP + ADP + AMP), was also normal despite an 8% decrease in the total adenine nucleotide pool. Mild hypoxia failed to alter the level of any of these metabolites. The brain redox state, (NAD+)/(NADH), was normal to high in acute renal failure, suggesting that oxygen supply was not limiting oxygen consumption. In the face of normal brain energy reserves, energy charge, and redox state, the decreased energy consumption of uremic brain probably results from decreased demand rather than limited supply.

Pathogenesis of dialysis encephalopathy.

Among patients with renal failure, there have been impressive modifications of both the duration and quality of life as a result of dialysis, renal transplantation, and improved medical management. However, patients who have renal failure continue to manifest a variety of neurologic disorders. Patients with chronic renal failure who have not yet received dialytic therapy may develop a symptom complex progressing from mild sensorial clouding to delirium and coma, with tremor, asterixis, multifocal myoclonus, and seizures. Even after the institution of otherwise adequate maintenance dialysis therapy, patients may continue to be afflicted with more subtle nervous system dysfunction, including impaired mentation, generalized weakness, and peripheral neuropathy. The central nervous system disorders of both untreated renal failure and that persisting despite dialysis are referred to as uremic encephalopathy. The dialytic treatment of end stage renal disease has itself been associated with the emergence of two distinct, new disorders of the central nervous system: Dialysis dysequilibrium and dialysis dementia. The dialysis disequilibrium syndrome consists of headache, nausea, muscle cramps, obtundation and seizures, and is a consequence of the initiation of dialysis therapy in some patients. Dialysis dementia is a progressive, generally fatal encephalopathy which affects patients on chronic hemodialysis. This disease also appears to be a complication of the therapy for renal failure.

Central and peripheral nervous system effects of chronic renal failure.

Although neurologic dysfunction is a major cause of disability in patients with chronic renal failure, there is little knowledge of the underlying metabolic defect(s). We used a canine model to study the effects of chronic renal failure (CRF: 4 months after 1-7/8 nephrectomy, GFR 11 +/- 2 ml/min) on the composition and function of the nervous system. We also studied the effect of acute renal failure (ARF: 3.5 days after bilateral ureteral ligation) on peripheral nerve composition and function. In dogs with CRF for 4 months intracellular pH of brain and cerebro-spinal fluid (CSF) pH remained normal, despite metabolic acidemia. Osmotic equilibrium of the brain with plasma and CSF (and thus a normal water content) was maintained by almost equivalent increases in brain of urea and idiogenic osmoles (25 mmoles/kg H2O and 23 to 26 mOsm/kg H2O, respectively). Electrolyte concentration in brain tissue water did not change significantly. Calcium content was increased in cortical gray matter and hypothalamus of dogs with CRF, but was normal in the six other regions measured. Functional changes measured by the electroencephalogram were just as severe as those previously seen in dogs with ARF. The motor nerve conduction velocity (MNCV) was normal in dogs with ARF and did not change after up to 6 months of CRF.(ABSTRACT TRUNCATED AT 250 WORDS)