An international study of the quality of national-level guidelines on driving with medical illness

BACKGROUND

Medical illnesses are associated with a modest increase in crash risk, although many individuals with acute or chronic conditions may remain safe to drive, or pose only temporary risks. Despite the extensive use of national guidelines about driving with medical illness, the quality of these guidelines has not been formally appraised.

AIM

To systematically evaluate the quality of selected national guidelines about driving with medical illness.

DESIGN

A literature search of bibliographic databases and Internet resources was conducted to identify the guidelines, each of which was formally appraised.

METHODS

Eighteen physicians or researchers from Canada, Australia, Ireland, USA and UK appraised nine national guidelines, applying the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

RESULTS

Relative strengths were found in AGREE II scores for the domains of scope and purpose, stakeholder involvement and clarity of presentation. However, all guidelines were given low ratings on rigour of development, applicability and documentation of editorial independence. Overall quality ratings ranged from 2.25 to 5.00 out of 7.00, with modifications recommended for 7 of the guidelines. Intra-class coefficients demonstrated fair to excellent appraiser agreement (0.57-0.79).

CONCLUSIONS

This study represents the first systematic evaluation of national-level guidelines for determining medical fitness to drive. There is substantive variability in the quality of these guidelines, and rigour of development was a relative weakness. There is a need for rigorous, empirically derived guidance for physicians and licensing authorities when assessing driving in the medically ill.

Left ventricular hypertrophy and arterial stiffness in essential hypertension

AIM

The aim of this study was to evaluate the association between an increase in arterial stiffness and the development of left ventricular hypertrophy in essential hypertension patients.

MATERIALS AND METHODS

One hundred forty essential hypertension patients were included in the study. Patients were divided into two groups based on echocardiographic measurements; with left ventricular hypertrophy (n=70) and without left ventricular hypertrophy (n=70). The criterion for hypertrophy was accepted as an intraventricular septum and posterior wall thickness in diastole of 11 mm or above. Aortic stiffness values of the patients groups were measured noninvasively by arteriography through the brachial artery. Pulse wave velocity (PWV) measurements were used as indicators of arterial stiffness.

RESULTS

When compared to the group without left ventricular hypertrophy, elevated systolic blood pressure, mean blood pressure, and pulse pressure were located in the left ventricular hypertrophy group at a significant level (p > 0.01). A statistically significant difference was not observed in the diastolic blood pressure and pulse measurements of the groups. Pulse wave velocity, the indicator of arterial stiffness, was elevated to a significant degree in the left ventricular hypertrophy group (p > 0.01). While a positive correlation was found between pulse wave velocity and left ventricle mass index, microalbuminuria, high sensitive C-reactive protein (Hs-CRP), and left ventricle end-diastolic volume, a negative correlation was found between pulse wave propagation velocity and left ventricle E/A.

CONCLUSIONS

In conclusion, pulse wave analysis is a valuable method for predicting cardiac hypertrophy in essential hypertension (Tab. 6, Ref. 25).

Influence on the mechanisms of generation of distortion product otoacoustic emissions of mobile phone exposure

Mobile phones have become very commonly used throughout the world within a short period of time. Although there is no clear evidence to show harmful physiological effects of electromagnetic fields (EMF) at the levels used by mobile phones, there is widespread public concern that there may be potential for harm. Because mobile phones are usually held close to the ear, it is appropriate to study effects on hearing. In this study, the outer hair cell function of 15 subjects was assessed by DPOAE recording before and after a controlled EMF exposure. To increase the sensitivity of DPOAE recording to identify even small changes in hearing function, an inverse fast Fourier transform (IFFT) analysis and time-domain windowing was applied to separate the two generation mechanisms of DPOAE, the so-called place-fixed and wave-fixed mechanisms, in order to verify if EMF can affects the two DPOAE emission mechanisms. Statistical analysis of the data showed that 10 min of EMF exposure at the maximum power (2 W at 900 MHz or 1 W at 1800 MHz) does not induce any changes in either DPOAE generation mechanism.

The role of intersection topography in bond selectivity of cis-trans photoisomerization

Ab initio methods are used to characterize the ground and first excited state of the chromophore in the rhodopsin family of proteins: retinal protonated Schiff base. Retinal protonated Schiff base has five double bonds capable of undergoing isomerization. Upon absorption of light, the chromophore isomerizes and the character of the photoproducts (e.g., 13-cis and 11-cis) depends on the environment, protein vs. solution. Our ab initio calculations show that, in the absence of any specific interactions with the environment (e.g., discrete ordered charges in a protein), energetic considerations cannot explain the observed bond selectivity. We instead attribute the origin of bond selectivity to the shape (topography) of the potential energy surfaces in the vicinity of points of true degeneracy (conical intersections) between the ground and first excited electronic states. This provides a molecular example where a competition between two distinct but nearly isoenergetic photochemical reaction pathways is resolved by a topographical difference between two conical intersections.

Quantum dynamics of the femtosecond photoisomerization of retinal in bacteriorhodopsin

The membrane protein bacteriorhodopsin contains all-trans-retinal in a binding site lined by amino acid side groups and water molecules that guide the photodynamics of retinal. Upon absorption of light, retinal undergoes a subpicosecond all-trans-->13-cis phototransformation involving torsion around a double bond. The main reaction product triggers later events in the protein that induce pumping of a proton through bacteriorhodopsin. Quantum-chemical calculations suggest that three coupled electronic states, the ground state and two closely lying excited states, are involved in the motion along the torsional reaction coordinate phi. The evolution of the protein-retinal system on these three electronic surfaces has been modelled using the multiple spawning method for non-adiabatic dynamics. We find that, although most of the population transfer occurs on a timescale of 300 fs, some population transfer occurs on a longer timescale, occasionally extending well beyond 1 ps.