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Missing data are a common practical problem for longitudinal designs. Time-series analysis is a longitudinal method that involves a large number of observations on a single unit. Four different missing-data methods (deletion, mean substitution, mean of adjacent observations, and maximum likelihood estimation) were evaluated. Computer-generated time-series data of length 100 were generated for 50 different conditions representing five levels of autocorrelation, two levels of slope, and five levels of proportion of missing data. Methods were compared with respect to the accuracy of estimation for four parameters (level, error variance, degree of autocorrelation, and slope). The choice of method had a major impact on the analysis. The maximum likelihood very accurately estimated all four parameters under all conditions tested. The mean of the series was the least accurate approach. Statistical methods such as the maximum likelihood procedure represent a superior approach to missing data. [ABSTRACT FROM AUTHOR]

It has been suggested that individuals with autism are more vulnerable to, and less able to cope with, the effects of stressors than the general population. However, very little work has been done to develop tools such as surveys or questionnaires that assess reactions to stressors in individuals with developmental disabilities. In the present investigation, the Stress Survey Schedule for Persons with Autism and Other Developmental Disabilities (SSS; Groden et al., 2001) was completed for 180 individuals with autism, varying in gender, verbal ability, and age. The results demonstrate that the SSS is a valid tool for identifying which dimensions of stress are perceived to be the most and least stressful for subgroups of persons with autism. [ABSTRACT FROM AUTHOR]

Despite a specific need for transfused blood among African Americans due to higher rates of sickle cell disease, African Americans donate blood significantly less frequently than their White counterparts. This study describes the development and validation of culturally adapted measures of the transtheoretical model (TTM) constructs of Stage of Change, Decisional Balance, and Self-efficacy applied to blood donation in an African American sample. Exploratory and confirmatory analyses produced one pros and two cons scales for the Decisional Balance Inventory, and one scale for the Situational Self-efficacy Measure. Expected patterns for the Decisional Balance and Self-efficacy Scales by Stage of Change were found, but only the pros and one cons scale varied significantly. Results provide support for use of the TTM applied to blood donation and have important implications for development of effective assessment and intervention tools to increase blood donation among the African American population. [ABSTRACT FROM AUTHOR]

Objective: Rates of preventive counseling remain below national guidelines. We explored physician and patient predictors of preventive counseling across multiple cancer risk behaviors in at-risk primary care patients.Methods: We surveyed 3557 patients, with at least one of four cancer risk behaviors: smoking, diet, sun exposure, and/or mammography screening, at baseline and 24 months. Patients reported receipt of 4A's (Ask, Advise, Assist, Arrange follow-up); responses were weighted and combined to reflect more thorough counseling (Ask=1, Advise=2, Assist=3, Arrange=4, score range 0-10) for each target behavior. A series of linear-regression models, controlling for office clustering, examined patient, physician and other situational predictors at 24 months.Results: Risk behavior topics were brought up more often for mammography (90%) and smoking (79%) than diet (56%) and sun protection (30%). Assisting and Arranging follow-up were reported at low frequencies across all behaviors. More thorough counseling for all behaviors was associated with multiple visits and higher satisfaction with care. Prior counseling predicted further counseling on all behaviors except smoking, which was already at high levels. Other predictors varied by risk behavior.Conclusions: More thorough risk behavior counseling can be delivered opportunistically across multiple visits; doing so is associated with more satisfaction with care. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To test the long-term efficacy of brief counseling plus a computer-based tobacco intervention for teens being seen for routine medical care. METHODS: Both smoking and nonsmoking teens, 14 to 17 years of age, who were being seen for routine visits were eligible for this 2-arm controlled trial. Staff members approached teens in waiting rooms of 7 large pediatric and family practice departments within a group-practice health maintenance organization. Of 3747 teens invited at > or =1 visits, 2526 (67%) consented and were randomized to tobacco intervention or brief dietary advice. The tobacco intervention was individually tailored on the basis of smoking status and stage of change. It included a 30-second clinician advice message, a 10-minute interactive computer program, a 5-minute motivational interview, and up to two 10-minute telephone or in-person booster sessions. The control intervention was a 5-minute motivational intervention to promote increased consumption of fruits and vegetables. Follow-up smoking status was assessed after 1 and 2 years. RESULTS: Abstinence rates after 2 years were significantly higher for the tobacco intervention arm, relative to the control group, in the combined sample of baseline smokers and nonsmokers (odds ratio [OR]: 1.23; 95% confidence interval [CI]: 1.03-1.47). Treatment effects were particularly strong among baseline self-described smokers (OR: 2.42; 95% CI: 1.40-4.16) but were not significant for baseline nonsmokers (OR: 1.25; 95% CI: 0.97-1.61) or for those who had 'experimented' in the past month at baseline (OR: 0.95; 95% CI: 0.45-1.98). CONCLUSIONS: Brief, computer-assisted, tobacco intervention during routine medical care increased the smoking cessation rate among self-described smokers but was less effective in preventing smoking onset. [ABSTRACT FROM AUTHOR]

The Transtheoretical Model of Change (TMC) postulates two sensitive mediating variables, decisional balance and self-efficacy. Four measures of condom use developed with 296 women at high risk for HIV infection or transmission representing these two constructs were cross-validated with 248 heterosexually active college men and women. Confirmatory factor analysis (CFA) procedures were conducted with structural equation modeling (SEM). Factor structures for all condom-use measures were replicated using the second independent sample and a different method of analysis, demonstrating the robustness of the scales. Model fit indices were excellent (e.g., decisional balance = .94 and .95; self-efficacy = .97 and .99), suggesting that more standardized measures can be used when assessing attitudes and behaviors toward condom use among heterosexual populations at various risk for HIV or sexually transmitted disease infection. [ABSTRACT FROM AUTHOR]