A two-stage approach for joint modeling of longitudinal measurements and competing risks data.

Joint modeling of longitudinal measurements and time-to-event data is used in many practical studies of medical sciences. Most of the time, particularly in clinical studies and health inquiry, there are more than one event and they compete for failing an individual. In this situation, assessing the competing risk failure time is important. In most cases, implementation of joint modeling involves complex calculations. Therefore, we propose a two-stage method for joint modeling of longitudinal measurements and competing risks (JMLC) data based on the full likelihood approach via the conditional EM (CEM) algorithm. In the first stage, a linear mixed effect model is used to estimate the parameters of the longitudinal sub-model. In the second stage, we consider a cause-specific sub-model to construct competing risks data and describe an approximation for the joint log-likelihood that uses the estimated parameters of the first stage. We express the results of a simulation study and perform this method on the "standard and new anti-epileptic drugs" trial to check the effect of drug assaying on the treatment effects of lamotrigine and carbamazepine through treatment failure.

Investigation of new indole derivatives of bovine serum albumin using spectroscopic and molecular docking techniques.

We investigated the interaction of two derivatives of bis (indolyl) methane with bovine serum albumin (BSA) using spectroscopic and molecular docking calculations. Fluorescence quenching measurements revealed that the quenching mechanism was static. FÓ§rster energy transfer measurements, synchronous fluorescence spectroscopy and docking studies demonstrated that both bis(indolyl)methanes bound to the Trp residues of BSA. The docking study confirmed that both bis(indolyl)methanes form hydrogen bonds and van der Waals interactions with BSA. Our molecular docking study indicated that the compounds are located within the binding pocket of subdomains IIB and IB of BSA. Fourier transform infrared spectroscopy demonstrated that both bis(indolyl)methane derivatives can interact with BSA and can affect the secondary structure of BSA.

Lost productivity among military personnel with cardiovascular disease.

OBJECTIVE: Cardiovascular disease (CVD) is associated with significant productivity loss among all occupational groups. However, the increased occupational requirements of military personnel pose physical and psychological demands that could lead to greater lost productivity of CVD. The aim of this study was to determine the economic cost of lost productivity of military patients with CVD. METHODS: A prospective cross-sectional study was undertaken on all military patients attending a specialist CVD clinic in Tehran, Iran. All participants were interviewed using face-to-face questioning using a Valuation of Lost Productivity questionnaire. Data captured included paid and unpaid time lost due to CVD, military job characteristics and their work environment. Ordered logistic regression was used to examine the determinants of lost productivity. RESULTS: The mean time of lost productivity was 118 hours over a 3-month period, of which 70 and 48 hours were paid and unpaid work, respectively. The average cost per patient of total lost productivity was estimated to be US$303 over a 3-month period. CONCLUSIONS: CVDs are associated with significant lost productivity among military personnel. There is a statistically significant relation between some military occupation characteristics and lost productivity from CVD. Level of income, teamwork and physical activity have the greatest effects on lost productivity. Military workers who were suffering from other chronic conditions (in addition to CVD) were four times more likely to lose productivity. A supportive work environment should be created for military personnel with emphasis on developing teamwork, improving worker's attitudes towards disease and giving priority to workers with comorbidities.