Validity and systematic error in measuring carotenoid consumption with dietary self-report instruments

Vegetables and fruits are rich in carotenoids, a group of compounds thought to protect against cancer. Studies of diet-disease associations need valid and reliable instruments for measuring dietary intake. The authors present a measurement error model to estimate the validity (defined as correlation between self-reported intake and "true" intake), systematic error, and reliability of two self-report dietary assessment methods. Carotenoid exposure is measured by repeated 24-hour recalls, a food frequency questionnaire (FFQ), and a plasma marker. The model is applied to 1,013 participants assigned between 1995 and 2000 to the nonintervention arm of the Women's Healthy Eating and Living Study, a randomized trial assessing the impact of a low-fat, high-vegetable/fruit/fiber diet on preventing new breast cancer events. Diagnostics including graphs are used to assess the goodness of fit. The validity of the instruments was 0.44 for the 24-hour recalls and 0.39 for the FFQ. Systematic error accounted for over 22% and 50% of measurement error variance for the 24-hour recalls and FFQ, respectively. The use of either self-report method alone in diet-disease studies could lead to substantial bias and error. Multiple methods of dietary assessment may provide more accurate estimates of true dietary intake.     

Perceived adverse effects of antiretroviral therapy

Adverse effects from antiretroviral therapy (ARV) for HIV are associated with medication nonadherence. The purposes of this study were to explore group differences in the reporting of adverse effects, identify individual adverse effects that are linked to nonadherence, and to explore the role of coping in the relationship between adverse effects and adherence. Cross-sectional interviews of 2,765 HIV-positive adults on ARV therapies in four U.S. cities were performed using a computerized assessment of self-reported adverse effects, coping self-efficacy, and adherence. There were no gender differences in the rate or severity of adverse effects reported. Latino respondents reported more adverse effects than either White or African Americans. Those taking a protease inhibitor (PI) reported a higher rate and greater severity of adverse effects. Older participants reported fewer adverse effects despite being more likely to be on a regimen containing a PI. Respondents with less than 90% adherence reported greater numbers and severity of adverse effects overall. In multivariate analyses, nausea, skin problems, vomiting, and memory adverse effects were independently related to less than 90% adherence over the prior three days. Coping moderated the relationship between nausea and adherence such that individuals who reported lower coping self-efficacy and experienced nausea were at increased risk for nonadherence, regardless of the length of time on the current ARV regimen. Women and men are similar in their overall reports of adverse effects, and Latinos report more adverse effects to ARVs than White or African American patients. Specific adverse effects (skin problems, memory problems, vomiting, and nausea) are more likely than others to be associated with missing ARV medications. Increasing adaptive coping self-efficacy among patients experiencing nausea may be a particularly effective strategy in increasing medication adherence.     

Translating diabetes prevention programs: implications for dissemination and policy

Numerous studies have translated the Diabetes Prevention Program (DPP) for community-based settings, and the results are encouraging. This commentary discusses one community-based DPP translational study, Healthy Living Partnerships to Prevent Diabetes, in detail, as well as the implications of DPP translational studies for public policy.     

A randomized controlled trial of pretransplant antiviral therapy to prevent recurrence of hepatitis C after liver transplantation

Hepatitis C virus (HCV) infection recurs in liver recipients who are viremic at transplantation. We conducted a randomized, controlled trial to test the efficacy and safety of pretransplant pegylated interferon alpha-2b plus ribavirin (Peg-IFN-α2b/RBV) for prevention of post-transplant HCV recurrence. Enrollees had HCV and were listed for liver transplantation, with either potential living donors or Model for End-Stage Liver Disease upgrade for hepatocellular carcinoma. Patients with HCV genotypes (G) 1/4/6 (n = 44/2/1) were randomized 2:1 to treatment (n = 31) or untreated control (n = 16); HCV G2/3 (n=32) were assigned to treatment. Overall, 59 were treated and 20 were not. Peg-IFN-α2b, starting at 0.75 μg/kg/week, and RBV, starting at 600 mg/day, were escalated as tolerated. Patients assigned to treatment versus control had similar baseline characteristics. Combined virologic response (CVR) included pretransplant sustained virologic response and post-transplant virologic response (pTVR), defined as undetectable HCV RNA 12 weeks after end of treatment or transplant, respectively. In intent-to-treat analyses, 12 (19%) assigned to treatment and 1 (6%) assigned to control achieved CVR (P = 0.29); per-protocol values were 13 (22%) and 0 (0%) (P = 0.03). Among treated G1/4/6 patients, 23 of 30 received transplant, of whom 22% had pTVR; among treated G2/3 patients 21 of 29 received transplant, of whom 29% had pTVR. pTVR was 0%, 18%, and 50% in patients treated for <8, 8-16, and >16 weeks, respectively (P = 0.01). Serious adverse events (SAEs) occurred with similar frequency in treated versus untreated patients (68% versus 55%; P = 0.30), but the number of SAEs per patient was higher in the treated group (2.7 versus 1.3; P = 0.003). Conclusion: Pretransplant treatment with Peg-IFN-α2b/RBV prevents post-transplant recurrence of HCV in selected patients. Efficacy is higher with >16 weeks of treatment, but treatment is associated with increased risk of potentially serious complications.     

The relative importance of specific risk factors for insomnia in women treated for early-stage breast cancer

BACKGROUND: Many individual risk factors for insomnia have been identified for women with a history of breast cancer. We assessed the relative importance of a wide range of risk factors for insomnia in this population. METHODS: Two thousand six hundred and forty-five women < or =4 years post-treatment for Stage I (> or =1 cm)-IIIA breast cancer provided data on cancer-related variables, personal characteristics, health behaviors, physical health/symptoms, psychosocial variables, and the Women's Health Initiative-Insomnia Rating Scale (WHI-IRS; scores > or =9 indicate clinically significant insomnia). RESULTS: Thirty-nine per cent had elevated WHI-IRS scores. In binary logistic regression, the variance in high/low insomnia group status accounted for by each risk factor category was: cancer-specific variables, 0.4% (n.s.); personal characteristics, 0.9% (n.s.); health behaviors, 0.6% (n.s.); physical health/symptoms, 13.4% (p<0.001); and, psychosocial factors, 11.4% (p<0.001). Insomnia was associated with worse depressive (OR = 1.32) and vasomotor symptoms (particularly night sweats) (OR = 1.57). CONCLUSION: Various cancer-specific, demographic, health behavior, physical health, and psychosocial factors have been previously reported as risk factors for insomnia in breast cancer. In our study (which was powered for simultaneous examination of a variety of variables), cancer-specific, health behavior, and other patient variables were not significant risk factors when in the presence of physical health and psychosocial variables. Only worse depressive and vasomotor symptoms were meaningful predictors.     

Healthy active living: Physical activity guidelines for children and adolescents

The epidemic of childhood obesity is rising globally. Although the risk factors for obesity are multifactorial, many are related to lifestyle and may be amenable to intervention. These factors include sedentary time and non-exercise activity thermogenesis, as well as the frequency, intensity, amounts and types of physical activity. Front-line health care practitioners are ideally suited to monitor children, adolescents and their families’ physical activity levels, to evaluate lifestyle choices and to offer appropriate counselling.This statement presents guidelines for reducing sedentary time and for increasing the level of physical activity in the paediatric population. Developmentally appropriate physical activity recommendations for infants, toddlers, preschoolers, children and adolescents are provided. Advocacy strategies for promoting healthy active living at the local, municipal, provincial/territorial and federal levels are included.     

Workshop on personal motion technologies for healthy independent living: executive summary

The objective of the June 2010 "Workshop on Personal Motions Technologies for Healthy Independent Living" was to discuss personal motion technologies that might enable older adults and individuals with disability to live independently for longer periods. The 60 participants included clinicians, academic researchers, engineers, patient advocates, caregivers, members of the public, and federal representatives. The workshop was divided into 6 sessions that addressed the following: (1) use of technologies in identifying early indicators of disease or adverse events; (2) monitoring daily activities; (3) coping with impairment; (4) managing mild cognitive impairment; (5) rehabilitation and exercise in the home; and (6) caregiver support. Presentations and discussion focused on clinical needs, the health impact of addressing those needs, state-of-the-art technologies, and challenges to adoption of those technologies. Conclusions included the following: (1) Involvement of end-users in research and development will increase the likelihood that technologies will be adopted. (2) Integration of differing types of technology into a system that includes clinical measures is required for independent living. (3) Seniors are willing to sacrifice some privacy for an effective technology that keeps them in their homes as long as they control who receives their data. (4) Multilevel and multiscale models are needed to understand motion in the context of the environment and to design effective systems.     

Positive provider interactions, adherence self-efficacy, and adherence to antiretroviral medications among HIV-infected adults: A mediation model

Adherence to antiretroviral (ARV) therapy for HIV infection is critical for maximum benefit from treatment and for the prevention of HIV-related complications. There is evidence that many factors determine medication adherence, including adherence self-efficacy (confidence in one's ability to adhere) and relations with health care providers. However, there are no studies that examine how these two factors relate to each other and their subsequent influence on HIV medication adherence. The goal of the current analysis was to explore a model of medication adherence in which the relationship between positive provider interactions and adherence is mediated by adherence self-efficacy. Computerized self-administered and interviewer-administered self reported measures of medication adherence, demographic and treatment variables, provider interactions, and adherence self-efficacy were administered to 2765 HIV-infected adults on ARV. Criteria for mediation were met, supporting a model in which adherence self-efficacy is the mechanism for the relationship between positive provider interactions and adherence. The finding was consistent when the sample was stratified by gender, race, injection drug use history, and whether the participant reported receipt of HIV specialty care. Positive provider interactions may foster greater adherence self-efficacy, which is associated with better adherence to medications. Results suggest implications for improving provider interactions in clinical care, and future directions for clarifying interrelationships among provider interactions, adherence self-efficacy, and medication adherence are supported.     

Expression of iNOS in early injury in a rat model of small-for-size liver transplantation

BACKGROUND:Living donor liver transplantation has been widely accepted as the treatment of choice for end-stage liver disease.Large amounts of nitric oxide generated by inducible nitric oxide synthase(iNOS)have been shown to play an important role in many inflammatory and immune reactions,but expression of iNOS in small-for-size liver transplantation is unknown.The aims of this study were to determine the time course of iNOS mRNA and protein as well as the redox state of liver biopsies in a rat model of sma...