Prevalence and factors associated with chronic use of levothyroxine: A cohort study

Importance Levothyroxine prescriptions are rising worldwide. However, there are few data on factors associated with chronic use. Objective To assess the prevalence of chronic levothyroxine use, its rank among other chronic drugs and factors associated with chronic use. To assess the proportion of users outside the therapeutic range of thyroid-stimulating hormone (TSH). Design Cohort study (CoLaus|PsyCoLaus) with recruitment from 2003 to 2006. Follow-ups occurred 5 and 10 years after baseline. Participants A random sample of Lausanne (Switzerland) inhabitants aged 35-75 years. Main outcomes We evaluated the prevalence of chronic levothyroxine use and we then ranked it among the other most used chronic drugs. The ranking was compared to data from health insurance across the country. We assessed the association between each factor and chronic levothyroxine use in multivariable logistic regression models. The proportion of chronic levothyroxine users outside the usual TSH therapeutic range was assessed. Results 4,334 participants were included in the analysis (mean±SD age 62.8±10.4 years, 54.9% women). 166 (3.8%) participants were chronic levothyroxine users. Levothyroxine was the second most prescribed chronic drug after aspirin in the cohort (8.2%) and the third most prescribed when using Swiss-wide insurance data. In multivariable analysis, chronic levothyroxine use was associated with increasing age [odds ratio 1.03, 95% confidence interval 1.01-1.05 per 1-year increase]; female sex [11.87 (5.24-26.89)]; BMI [1.06 (1.02- 1.09) per 1-kg/m2 increase]; number of concomitant drugs [1.22 (1.16-1.29) per 1-drug increase]; and family history of thyroid pathologies [2.18 (1.37-3.48)]. Among chronic levothyroxine users with thyroid hormones assessment (n = 157), 42 (27%) were outside the TSH therapeutic range (17% overtreated and 10% undertreated). Conclusions In this population-based study, levothyroxine ranked second among chronic drugs. Age, female sex, BMI, number of drugs and family history of thyroid pathologies were associated with chronic levothyroxine use. More than one in four chronic users were over- or undertreated

Nanoscale depth-resolved coherent femtosecond motion in laser-excited bismuth

We employ grazing-incidence femtosecond x-ray diffraction to characterize the coherent, femtosecond laser-induced lattice motion of a bismuth crystal as a function of depth from the surface with a temporal resolution of 193 +/- 8 fs. The data show direct consequences on the lattice motion from carrier diffusion and electron-hole interaction, allowing us to estimate an effective diffusion rate of D=2.3 +/- 0.3 cm(2)/s for the highly excited carriers and an electron-hole interaction time of 260 +/- 20 fs

Comparison between B.R.A.H.M.S PCT direct, a new sensitive point-of-care testing device for rapid quantification of procalcitonin in emergency department patients and established reference methods - a prospective multinational trial

BACKGROUND: Procalcitonin (PCT) is increasingly being used for the diagnostic and prognostic work up of patients with suspected infections in the emergency department (ED). Recently, B.R.A.H.M.S PCT direct, the first high sensitive point-of-care test (POCT), has been developed for fast PCT measurement on capillary or venous blood samples. METHODS: This is a prospective, international comparison study conducted in three European EDs. Consecutive patients with suspicion of bacterial infection were included. Duplicate determination of PCT was performed in capillary (fingertip) and venous whole blood (EDTA), and compared to the reference method. The diagnostic accuracy was evaluated by correlation and concordance analyses. RESULTS: Three hundred and three patients were included over a 6-month period (60.4% male, median age 65.2 years). The correlation between capillary or venous whole blood and the reference method was excellent: r2=0.96 and 0.97, sensitivity 88.1% and 93.0%, specificity 96.5% and 96.8%, concordance 93% and 95%, respectively at a 0.25 mug/L threshold. No significant bias was observed (-0.04 and -0.02 for capillary and venous whole blood) although there were 6.8% and 5.1% outliers, respectively. B.R.A.H.M.S PCT direct had a shorter time to result as compared to the reference method (25 vs. 144 min, difference 119 min, 95% CI 110-134 min, p>0.0001). CONCLUSIONS: This study found a high diagnostic accuracy and a faster time to result of B.R.A.H.M.S PCT direct in the ED setting, allowing shortening time to therapy and a more wide-spread use of PCT

Relatively higher norms of blood flow velocity of major intracranial arteries in North-West Iran

<p>Abstract</p> <p>Background</p> <p>Transcranial Doppler (TCD) is a noninvasive, less expensive and harmless hemodynamic study of main intracranial arteries. The aim of this study was to assess normal population values of cerebral blood flow velocity and its variation over age and gender in a given population.</p> <p>Findings</p> <p>Eighty healthy volunteers including 40 people with an age range of 25-40 years (group1) and 40 persons with an age range of 41-55 years (group2) were studied. In each group 20 males and 20 females were enrolled. Peak systolic, end diastolic and mean velocities of nine main intracranial arteries were determined using TCD. Mean age of the studied volunteers was 31.6 ± 4.50 years in group one and 47.2 ± 4.3 years in group two. Mean age among males was 40 years and among females it was 39. Mean blood flow velocity in middle, anterior and posterior cerebral arteries, vertebral and basilar arteries was 60 ± 8, 52 ± 9, 42 ± 6, 39 ± 8 and 48 ± 8 cm/sec respectively. Cerebral blood flow velocities among females were relatively higher than males. Cerebral blood flow velocity of left side was relatively higher than right side.</p> <p>Conclusion</p> <p>Compared to previous studies, cerebral blood flow velocity in this population was relatively higher.</p

Reproducibility of Transcranial Doppler ultrasound in the middle cerebral artery

Abstract Background Transcranial Doppler ultrasound remains the only imaging modality that is capable of real-time measurements of blood flow velocity and microembolic signals in the cerebral circulation. We here assessed the repeatability and reproducibility of transcranial Doppler ultrasound in healthy volunteers and patients with symptomatic carotid artery stenosis. Methods Between March and August 2017, we recruited 20 healthy volunteers and 20 patients with symptomatic carotid artery stenosis. In a quiet temperature-controlled room, two 1-h transcranial Doppler measurements of blood flow velocities and microembolic signals were performed sequentially on the same day (within-day repeatability) and a third 7–14 days later (between-day reproducibility). Levels of agreement were assessed by interclass correlation co-efficient. Results In healthy volunteers (31±9 years, 11 male), within-day repeatability of Doppler measurements were 0.880 (95% CI 0.726–0.950) for peak velocity, 0.867 (95% CI 0.700–0.945) for mean velocity, and 0.887 (95% CI 0.741–0.953) for end-diastolic velocity. Between-day reproducibility was similar but lower: 0.777 (95% CI 0.526–0.905), 0.795 (95% CI 0.558–0.913), and 0.674 (95% CI 0.349–0.856) respectively. In patients (72±11 years, 11 male), within-day repeatability of Doppler measurements were higher: 0.926 (95% CI 0.826–0.970) for peak velocity, 0.922 (95% CI 0.817–0.968) for mean velocity, and 0.868 (95% CI 0.701–0.945) for end-diastolic velocity. Similarly, between-day reproducibility revealed lower values: 0.800 (95% CI 0.567–0.915), 0.786 (95% CI 0.542–0.909), and 0.778 (95% CI 0.527–0.905) respectively. In both cohorts, the intra-observer Bland Altman analysis demonstrated acceptable mean measurement differences and limits of agreement between series of middle cerebral artery velocity measurements with very few outliers. In patients, the carotid stenoses were 30–40% (n = 9), 40–50% (n = 6), 50–70% (n = 3) and > 70% (n = 2). No spontaneous embolisation was detected in either of the groups. Conclusions Transcranial Doppler generates reproducible data regarding the middle cerebral artery velocities. However, larger studies are needed to validate its clinical applicability. Trial registration ClinicalTrial.gov (ID NCT 03050567), retrospectively registered on 15/05/2017