The use of the coefficient of variation in detecting sincerity of effort: a meta-analysis.

The coefficient of variation (CV) is used to determine sincerity of effort of strength measurements. However, there is a controversy in the literature concerning its validity and effectiveness. We used a meta-analytic approach and calculated the effect size between maximal and submaximal efforts for the CV of grip, elbow flexion and knee extension. We summarized findings concerning stability, sensitivity and specificity of the CV. We found large effect sizes (d > or = 0.8) for all comparisons indicating that submaximal efforts were more variable than maximal efforts. We also found large error rates and low stability of the CV. The error rates and stability values of the CV are unacceptable from both a clinical and a medico-legal standpoint. Therefore, the use of the CV for assessing sincerity of effort needs to be questioned.

Does lung transplantation improve health-related quality of life? The University of Florida experience.

BACKGROUND: Health-related quality of life (HRQoL) is an important clinical end-point in evaluating the overall success of lung transplantation. The primary purpose of this study, therefore, was to document the degree of change in HRQoL in a sample of patients evaluated before and after lung transplantation. METHODS: Sixty-six adults who underwent single or bilateral lung transplantation at the University of Florida between March 1994 and May 2001 completed assessments of HRQoL (SF-36 Health Survey, Transplant Symptom Frequency Questionnaire), both before and after transplant. Pre- and post-transplant assessments of forced expiratory volume in 1 second (FEV1) percent predicted and 6-minute walk test performance were also obtained. RESULTS: HRQoL before transplant was significantly lower than in normative samples of chronic obstructive pulmonary disease (COPD) patients and adults in the general population. However, repeated measures analyses of co-variance showed significant improvements on 7 of 8 SF-36 sub-scales, as well as the physical component summary and the mental component summary. Improvements in FEV1 percent predicted and 6-minute walk test performance were also found. Patients with longer time since transplantation reported more frequent and problematic symptoms commonly associated with immunosuppression, including depression, headaches and changes in physical appearance, among others. CONCLUSIONS: Lung transplantation appears to yield significant HRQoL benefits for patients. Many patients do, however, experience frequent symptoms associated with immunosuppression that may limit the full benefit of transplantation, and some of these symptoms appear to worsen over time. Future research efforts should focus on the development, implementation and evaluation of clinical interventions designed to optimize HRQoL both before and after lung transplantation.

Impact of body weight on long-term survival after lung transplantation.

STUDY OBJECTIVES: The purpose of this study was to determine the impact of a pretransplantation determination of body mass index (BMI) on survival after lung transplantation. DESIGN AND PATIENTS: Univariate and multivariate survival analyses of a single institution database consisting of 85 patients who had undergone lung transplantations between March 1994 and October 1998. SETTING: University of Florida Health Science Center. RESULTS: Kaplan-Meier survival curves showed that patients who were obese (ie, BMI, > or = 30) at a pretransplantation assessment had a marked decrease in posttransplantation survival time (log rank, p < 0.05; Wilcoxon, p < 0.05). The final Cox regression model revealed that the most powerful predictors of mortality after lung transplantation were higher pretransplantation BMI and the development of obliterative bronchiolitis. CONCLUSIONS: Our results suggest that the posttransplantation risk for mortality is possibly three times greater for obese patients than for nonobese patients. Additional study is needed to identify the mechanisms for such higher risk in obese patients. Our data also suggest that transplantation centers should not routinely reject underweight patients (ie, BMI, < 18.5) or overweight patients (ie, BMI, 25 to 29.9) for lung transplantation listing solely on the basis of weight, as their outcomes may not be significantly different than patients with normal BMIs.

Adherence to exercise prescriptions: effects of prescribing moderate versus higher levels of intensity and frequency.

Sedentary adults (N = 379) were randomly assigned in a 2 x 2 design to walk 30 min per day at a frequency of either 3-4 or 5-7 days per week, at an intensity of either 45%-55% or 65%-75% of maximum heart rate reserve. Analyses of exercise accumulated over 6 months showed greater amounts completed in the higher frequency (p = .0001) and moderate intensity (p = .021) conditions. Analyses of percentage of prescribed exercise completed showed greater adherence in the moderate intensity(p = .02) condition. Prescribing a higher frequency increased the accumulation of exercise without a decline in adherence, whereas prescribing a higher intensity decreased adherence and resulted in the completion of less exercise.

Are organ donation attitudes and beliefs, empathy, and life orientation related to donor registration status?

CONTEXT: The severe organ donor shortage necessitates additional research on variables that may distinguish those who register to be organ donors and those who do not. Such research has important implications for the development of educational interventions. OBJECTIVE: To examine whether registered organ donors differ significantly from nondonors on measures of organ donation beliefs and attitudes, empathy, and life orientation. DESIGN AND SETTING: Prospective participants were approached about the study while visiting a local branch of the Department of Motor Vehicles. Once consent was obtained, participants completed several questionnaires. PARTICIPANTS: Two hundred fifty community dwellers who visited the Department of Motor Vehicles office in Alachua County, Fla. MAIN OUTCOME MEASURES: Organ donor registration status, beliefs about organ donation, attitudes toward organ donation, empathy, and life orientation (ie, optimism). RESULTS: Registered organ donors reported more positive beliefs toward organ donation than did nonregistered participants or participants who were undecided about their registration status. Registered organ donors also reported more positive organ donation attitudes and more optimism than did nonregistered participants.