Validity of scales measuring the psychosocial determinants of HIV/STD-related risk behavior in adolescents.
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We examined the content, construct and concurrent validity of scales to assess beliefs and self-efficacy related to adolescents' sexual risk behavior. We addressed content validity in the scale development process by drawing on literature and theory, and by pre-testing items with focus groups. We used confirmatory factor analysis of two models, an intercourse involvement model and a condom use model, to assess construct validity. The final intercourse involvement model included three scales: norms about sexual intercourse, attitudes about sexual intercourse and self-efficacy in refusing sex. The final condom use model included five scales: norms about condoms, attitudes about condom use, self-efficacy in communicating about condoms, self-efficacy in buying/using condoms and barriers to condom use. After two alterations to the models, the chi 2 and other indices indicated that the data fit the models well. Supporting the concurrent validity of the scales, high school students who had never had sexual intercourse had more negative attitudes toward sexual intercourse among teenagers, perceived norms toward sexual intercourse among teenagers to be more negative and expressed greater self-efficacy in refusing sex than did those who had experienced sexual intercourse. Consistent condom users had more positive attitudes and norms about condoms, had higher self-efficacy in communicating about and buying/using condoms, and perceived fewer barriers to condom purchase and use than did inconsistent condom users. (+info)
Primary schoolchildrens' perceptions of smoking: implications for health education.
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This paper suggests that there is a need, as early as Reception, to implement smoking intervention programmes in the local school curriculum. Findings from a cross-sectional study have shown that primary schoolchildren (4-8 years old) possess negative attitudes and beliefs about smoking, have as yet to establish regular patterns of smoking behaviour, and have a broad understanding of the nature of smoking. Health educators need to capitalize on this negative disposition toward smoking via early intervention; however, to date, there are no smoking-specific health education measures for this age group. The implementation of proactive programmes, before the habit manifests itself, has many supporters but little research has been conducted. This study was devised to fill this significant gap in the literature on smoking. Data was collected on a representative sample of primary schoolchildren in the city of Liverpool. A triangular methodology was adopted consisting of questionnaires (N = 1701), the Draw and Write investigative technique (N = 976), and semi-structured interviews (N = 50). The results highlight the need to implement smoking intervention programmes from Reception onward, the importance of developing a model that is more than just knowledge based and the necessity of involving the family in any school-based health education strategies. (+info)
Photopic temporal processing in retinitis pigmentosa.
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PURPOSE: The relation between early changes in the photopic flicker electroretinogram (ERG) and photopic psychophysical changes in retinitis pigmentosa (RP) is poorly understood. Here, abnormalities in foveal and extrafoveal temporal contrast sensitivity functions (TCSFs) were studied in a group of carefully selected patients with RP who had relatively preserved macular function. The psychophysical results were compared with changes in the timing of the multifocal ERG. METHODS: Subjects were patients with RP who had acuity > or =20/32 and no visual field defects within 6 degrees from the fovea. Maxwellian-view and direct-view optical systems were used to obtain foveal and extrafoveal TCSFs under a range of test conditions, including high retinal illuminances that yielded temporal contrast sensitivity independent of mean retinal illuminance. TCSFs were described using log sensitivity and corner frequency parameters. RESULTS: Foveal TCSFs in these patients showed overall reductions in sensitivity but no frequency-dependent defects. Also, no macular defects were found in the timing of the multifocal ERG. TCSFs from extrafoveal locations in moderate field defects, obtained at retinal illuminances that were sufficient to render flicker sensitivity independent of effective mean luminance, showed reductions in overall sensitivity as well as changes in temporal tuning. The multifocal ERGs from these extrafoveal locations showed signs of temporal slowing. CONCLUSIONS: Changes in temporal tuning (both psychophysical and electroretinographic) were found only within visual field scotomas, whereas changes of the log sensitivity parameter were found also in the relatively preserved foveas of this group of patients with early stage RP. (+info)
Quality-of-life measurement in advanced cancer: assessing the individual.
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PURPOSE: Despite the increasing importance of assessing quality of life (QoL) in patients with advanced cancer, relatively little is known about individual patient's perceptions of the issues contributing to their QoL. The Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and the shorter SEIQoL-Direct Weighting (SEIQoL-DW) assess individualized QoL using a semistructured interview technique. Here we report findings from the first administration of the SEIQoL and SEIQoL-DW to patients with advanced incurable cancer. PATIENTS AND METHODS: QoL was assessed on a single occasion using the SEIQoL and SEIQoL-DW in 80 patients with advanced incurable cancer. RESULTS: All patients were able to complete the SEIQoL-DW, and 78% completed the SEIQoL. Of a possible score of 100, the median QoL global score was as follows: SEIQoL, 61 (range, 24 to 94); SEIQoL-DW, 60.5 (range, 6 to 95). Psychometric data for SEIQoL indicated very high levels of internal consistency (median r =.90) and internal validity (median R(2) = 0.88). Patients' judgments of their QoL were unique to the individual. Family concerns were almost universally rated as more important than health, the difference being significant when measured using the SEIQoL-DW (P =.002). CONCLUSION: Patients with advanced incurable cancer were very good judges of their QoL, and many patients rated their QoL as good. Judgments were highly individual, with very high levels of consistency and validity. The primacy given to health in many QoL questionnaires may be questioned in this population. The implications of these findings are discussed with regard to clinical assessment and advance directives. (+info)
The Adolescent Sexual Activity Index (ASAI): a standardized strategy for measuring interpersonal heterosexual behaviors among youth.
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This study reports on the properties of a standardized measure that is used to index the spectrum of sexual behaviors typical of adolescents. Prior work has shown sexual behaviors to be ordered and progressive. Using pre-coitus sexual behaviors that did not refer to sex organs and self-reports of sexual intercourse, a 13-item index was developed. The index was standardized with values ranging from 0.0 to 10.0. Measures were administered to 1493 female and 1073 male black and white adolescents aged 12-19 years in community settings. Analyses reveal the index to have high internal consistency and to perform as a psychometrically sound dependent variable. Because the index uses conservative language, its use may avoid the controversy common to much of the research on adolescent sexuality. The Adolescent Sexual Activity Index will provide researchers and practitioners with an interpretable tool for examining developmental patterns that precede sexual intercourse. (+info)
A cardiovascular extension of the Health Measurement Questionnaire.
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OBJECTIVE: To investigate the psychometric properties of a cardiovascular extension of an existing utility-based quality of life questionnaire (Health Measurement Questionnaire). The new instrument has been named the Utility Based Quality of life--Heart questionnaire, or UBQ-H. DESIGN: Explored the test-retest reliability, construct validity, and responsiveness of the UBQ-H. PATIENTS: A sample of 322 patients attending cardiac outpatient clinics were recruited from two large metropolitan teaching hospitals. A second sample of 1112 patients taking part in the LIPID trial was also used to investigate the validity and responsiveness of the UBQ-H. RESULTS: Ninety per cent of all UBQ-H questionnaires were returned, and item completion rates were high (median of less than 1% missing or N/A answers). Cronbach's alpha measure of internal consistency for the scales ranged between 0.79-0.91, and each item was also most strongly correlated with its hypothesised domain than alternative domains. The intra-class test-retest reliability of the UBQ-H scales ranged from 0.65 to 0.81 for patients with stable health. Results supported the construct validity of the UBQ-H. The UBQ-H was significantly correlated with other information on quality of life (for example, General Health Questionnaire) as anticipated. The instrument was able to distinguish between contrasted groups of patients (for example, with versus without symptoms of dyspnoea, prior myocardial infarction versus none, etc), and was responsive to changes in health associated with adverse events requiring hospitalisation. CONCLUSIONS: The modifications made to the Health Measurement Questionnaire has resulted in an assessment designed for cardiovascular patients that has proved to be both reliable and valid. (+info)
Use of the functional assessment measure (FIM+FAM) in head injury rehabilitation: a psychometric analysis.
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OBJECTIVES: The drive to measure outcome during rehabilitation after brain injury has led to the increased use of the functional assessment measure (FIM+FAM), a 30 item, seven level ordinal scale. The objectives of the study were to determine the psychometric structure, internal consistency, and other characteristics of the measure. METHODS: Psychometric analyses including both traditional principal components analysis and Rasch analysis were carried out on FIM+FAM data from 2268 assessments in 965 patients from 11 brain injury rehabilitation programmes. RESULTS: Two emergent principal components were characterised as representing physical and cognitive functioning respectively. Subscales based on these components were shown to have high internal consistency and reliability. These subscales and the full scale conformed only partially to a Rasch model. Use of raw item ratings, as opposed to transformed ratings, to produce summary scores for the two subscales and the full scale did not introduce serious distortion. CONCLUSION: The full FIM+FAM scale and two derived subscales have high internal reliability and the use of untransformed ratings should be adequate for most clinical and research purposes in comparable samples of patients with head injury. (+info)
Review article: economic issues in Crohn's disease--assessing the effects of new treatments on health-related quality of life.
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The advent of highly effective yet costly new treatments for Crohn's disease will force clinicians, patients, and society to make important choices regarding the allocation of resources. Pharmacoeconomic analyses can be useful in deciding whether new technologies are of good value in comparison to established treatment regimens. In Crohn's disease conventional cost-effectiveness analyses are of limited use because surgery, death, and disease-related complications occur relatively infrequently. Alternatively, cost-utility models relate the incremental cost of new treatments to improvements in health-related quality of life. These analyses require the collection of valid cost and utility inputs that have only recently become available. Ultimately, cost-utility models should allow decision makers to make sensible choices for patients and society. This article describes the techniques of pharmacoeconomic analysis and reviews existing data on the measurement of costs and quality-of-life outcomes in Crohn's disease. (+info)