Polypharmacy and the Progression of Chronic Kidney Disease: Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease

<b><i>Introduction:</i></b> The renal hazard of polypharmacy has never been evaluated in predialysis chronic kidney disease (CKD) patients. <b><i>Objective:</i></b> We aimed to analyze the renal hazard of polypharmacy in predialysis CKD patients with stage 1–5. <b><i>Method:</i></b> The data of 2,238 patients from a large-scale multicenter prospective Korean study (2011–2016), excluding 325 patients with various missing data, were reviewed. Polypharmacy was defined as taking 6 or more medications at the time of enrollment; renal events were defined as a ≥50% decrease in kidney function from baseline values, doubling of the serum creatinine levels, or initiation of renal replacement treatment. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using Cox proportional-hazard regression analysis. <b><i>Results:</i></b> Of the 1,913 patients, the mean estimated glomerular filtration rate was 53.6 mL/min/1.73 m². The mean medication count was 4.1, and the prevalence of polypharmacy was 27.1%. During the average period of 3.6 years, 520 patients developed renal events (27.2%). Although increased medication counts were associated with increased renal hazard with HR (95% CI) of 1.056 (1.007–1.107, <i>p</i> = 0.025), even after adjusting for various confounders, adding comorbidity score and kidney function nullified the statistical significance. In mediation analysis, 55.6% (<i>p</i> = 0.016) of renal hazard in increased medication counts was mediated by the kidney function, and there was no direct effect of medication counts on renal event development. In subgroup analysis, the renal hazard of the medication counts was evident only in stage 1–3 of CKD patients (<i>p</i> for interaction = 0.014). <b><i>Conclusions:</i></b> We cannot identify the direct renal hazard of multiple medications, and most of the potential renal hazard was derived from intimate relationship with disease burden and kidney function.

Adaptive Single-Pole Auto-Reclosing Scheme Based on Secondary Arc Voltage Harmonic Signatures

This paper presents an advanced adaptive single-pole auto-reclosing (ASPAR) scheme based on harmonic characteristics of the secondary arc voltage. For analysis of the harmonics, short-time Fourier transform (STFT), which is a universal signal processing tool for transforming a signal from the time domain to the frequency domain, is utilized. STFT is applied to extract the abnormal harmonic signature from the voltage waveform of a faulted phase when a transient or permanent fault occurs on a power transmission line. The proposed scheme uses the total harmonic distortion (THD) factor to determine the fault type based on the variation and distortion characteristics of the harmonics. Harmonic components in the order of odd/even are also utilized to detect the secondary arc extinction time and guide the reclosing operation. Based on these factors, two coordinated algorithms are proposed to reduce the unnecessary dead time in conventional auto-reclosing methods and enable an optimal reclosing operation in the event of a single-pole to ground fault. The proposed ASPAR scheme is implemented using the electromagnetic transient program (EMTP), and various simulations are conducted for actual 345 and 765 kV Korean study systems.

Evaluation of Serious Adverse Event Reporting Forms for Clinical Trials: A Comparative Korean Study

Safety surveillance, using appropriately consistent review criteria, could improve human participants’ well-being in clinical trials. To establish a globally consistent framework, the quality of the current content for review by institutional review boards (IRBs), as mandatory oversight entities, requires evaluation. This study collected and analyzed forms reporting serious adverse events (SAEs) to IRBs/ Research Ethics Committees(RECs) to compare them with the well-structured form presented in the literature using completeness and accuracy scores. We found sub-optimal completeness and accuracy scores when compared with perfect scores ( p < .05). Less than half of the retrieved forms had queries on causality assessment (≤43.1%). Thus, contents of SAE forms require improvement for IRB oversight and, further, there is a need to develop a well-structured form that could improve international consistency.