Cost-effectiveness of computed tomography versus ultrasound-based surveillance following endovascular aortic repair of intact infrarenal abdominal aortic aneurysms.

BACKGROUND: While Society for Vascular Surgery guidelines recommend computed tomography angiography (CTA) or ultrasound for surveillance following infrarenal endovascular aortic repair (EVAR), there is a lack of consensus regarding optimal timing and modalities. We hypothesized that ultrasound-based approaches would be more cost-effective and developed a cost-effectiveness analysis to estimate the lifetime costs and outcomes of various strategies. METHODS: We developed a decision tree with nested Markov models to compare five surveillance strategies: yearly CTA, yearly CDU, yearly CEU, CTA at first year followed by CDU, and CTA at first year followed by CEU. The model accounted for differential sensitivity, specificity, and risk of acute kidney injury after CTA, and was implemented on a monthly cycle with a willingness-to-pay threshold of $50,000 per quality-adjusted life year (QALY) and 3% annual discounting. RESULTS: Under base case assumptions, the CTA-CDU strategy was cost effective with a lifetime cost of $77950 for 7.74 QALYs. In sensitivity analysis, the CTA-CDU approach remained cost-effective when CEU specificity was less than 95%, and risk of acute kidney injury following CTA was less than 20%. At diagnostic sensitivities below 75% for CEU and 55% for CDU, a yearly CTA strategy maximized QALYs. CONCLUSIONS: A hybrid strategy in which CTA is performed in the first year and CDU is performed annually thereafter is the most cost-effective strategy for infrarenal EVAR surveillance in patients with less than a 20% risk of contrast-induced nephropathy. If the sensitivity of CEU and CDU are at the lower end of plausible estimates, a yearly CTA strategy is reasonable. Further research should aim to identify patients who may benefit from alternative surveillance strategies.

Abnormal beta and gamma frequency neural oscillations mediate auditory sensory gating deficit in schizophrenia.

BACKGROUND: Sensory gating is a process in which the brain's response to irrelevant and repetitive stimuli is inhibited. The sensory gating deficit in schizophrenia (SZ) is typically measured by the ratio or difference score of the P50 event-related potential (ERP) amplitudes in response to a paired click paradigm. While the P50 gating effect has usually been measured in relation to the peak amplitude of the S1 and S2 P50 ERPs, there is increasing evidence that inhibitory processes may be reflected by evoked or induced oscillatory activity during the inter-click interval in the beta (20-30 Hz) and gamma (30-50 Hz) frequency bands. We therefore examined the relationship between frequency specific activity in the inter-click interval with gating effects in the time and frequency domains. METHOD: Paired-auditory stimuli were presented to 131 participants with schizophrenia and 196 healthy controls (HC). P50 ERP amplitudes to S1 and S2as well as averaged- and single-trial beta (20-30 Hz) and gamma (30-50 Hz) frequency power during the inter-click interval were measured from the CZ electrode site. RESULTS: In the time domain, P50 gating deficits were apparent in both ratio and difference scores. This effect was mainly due to smaller S1 amplitudes in the patient group. SZ patients exhibited less evoked beta and gamma power, particularly at the 0-100 ms time point, in response to S1. Early (0-100 ms) evoked beta and gamma responses were critical in determining the S1 amplitude and extent of P50 gating across the delay interval for both HC and SZ. CONCLUSION: Our findings support a disruption in initial sensory registration in those with SZ, and do not support an active mechanism throughout the delay interval. The degree of response to S1 and early beta and gamma frequency oscillations in the delay interval provides information about the mechanisms supporting auditory sensory gating, and may provide a framework for studying the mechanisms that support sensory inhibition.

Impact of pharmacist interventions on cost avoidance in an ambulatory cancer center.

Objective To provide a foundation to justify the presence of a full-time clinical pharmacist in the ambulatory cancer center in addition to an existing centralized pharmacist through cost avoidance calculation and patient and staff satisfaction surveys. Methods The prospective, pilot study took place in an ambulatory cancer center over four weeks in 2014. Cost avoidance values were assigned to interventions performed by a pharmacy resident, who was present in the ambulatory cancer center during clinic hours, along with a centralized oncology pharmacist routinely working with the cancer center. Anonymous patient and staff satisfaction surveys based on a 5-point Likert scale were distributed to assess the perceived benefit of a pharmacist located in the ambulatory cancer center. Results Data collection took place over approximately one month. After evaluation of 962 interventions from both pharmacists, the estimated cost avoidance was US$282,741 per pharmacist per year, yielding a net benefit of US$138,441. The most common interventions made by the resident included chemotherapy regimen review (n = 290, 69%) and patient counseling (n = 102, 24%), while the majority of the centralized pharmacist's interventions was chemotherapy regimen review (n = 525, 97%). Results from the anonymous patient and staff surveys revealed an overall positive perception of the pharmacy resident while in the ambulatory cancer center. Conclusion A full-time clinical pharmacist in an ambulatory cancer center is both financially beneficial and positively perceived by patients and staff.

An evaluation of hyperkalemia and serum creatinine elevation associated with different dosage levels of outpatient trimethoprim-sulfamethoxazole with and without concomitant medications.

BACKGROUND: Adverse events associated with high-dose trimethoprim-sulfamethoxazole (TMP-SMX) for outpatient infections, particularly those likely caused by community-acquired methicillin-resistant Staphylococcus aureus, have not been adequately characterized. OBJECTIVE: Describe hyperkalemia and acute renal injury associated with high-dose TMP-SMX. METHODS: An electronic medical record database retrospective study was conducted of outpatients receiving high-dose or low-dose TMP-SMX, comparing the incidences of hyperkalemia and acute renal injury. RESULTS: Of 6162 patients, more developed hyperkalemia (3.06% vs 1.05%, P < .0001) or acute renal injury (1.99% vs 0.700%, P = .0001) in the high-dose TMP-SMX group. Variables independently associated with hyperkalemia included age >58 years (odds ratio [OR] = 3.44; 95% CI = 1.86-7.0; P < .0001), concomitant receipt of an NSAID (OR = 1.71; 95% CI = 1.02-2.79; P = .044) or an ACE inhibitor (OR = 3.27; 95% CI = 2.06-5.14; P < .0001), high-dose TMP-SMX prescribed (OR = 2.92; 95% CI = 1.85-4.60; P < .0001), and baseline elevated serum creatinine (OR = 45.1; 95% CI = 21.7-93.2; P < .0001). Variables independently associated with acute renal injury included concomitant receipt of an ACE inhibitor (OR = 2.36; 95% CI = 1.01-5.24; P = .048) or a potassium supplement (OR = 4.10; 95% CI = 1.45-10.1; P = .010), high-dose TMP-SMX prescribed (OR = 3.70; 95% CI = 1.70-8.12; P = .0012), and baseline elevated serum creatinine (OR = 2110; 95% CI = 724-7980; P < .0001). CONCLUSIONS: Serum creatinine and potassium concentrations should be monitored in outpatients receiving high-dose TMP-SMX.

A comparison of adverse drug reactions between high- and standard-dose trimethoprim-sulfamethoxazole in the ambulatory setting.

BACKGROUND: High-dose trimethoprim-sulfamethoxazole (TMP-SMX) for the empiric treatment of community-acquired methicillin-resistant Staphylococcus aureus skin and soft tissue infections has been evaluated for efficacy, but characterization of adverse reactions is lacking. METHODS: To describe adverse reactions associated with high-dose TMP-SMX therapy, a retrospective medical record review of outpatients receiving TMP-SMX was conducted. Each episode (case) of a patient receiving high-dose TMP-SMX (at least 4 double-strength tablets per day) was matched by next closest prescription number with a patient (control) receiving standard-dose TMP-SMX. RESULTS: 982 cases were reviewed; 491 in each arm. At least one adverse drug reaction (ADR) occurred in 9.1% of patients. There was a significant difference in the incidence for any ADR between high-dose and standard-dose groups (13.0% vs 5.09%, respectively; p<0.0001). More patients taking high-dose TMP-SMX developed hyperkalemia (3.46% vs 0.81%, p=0.0066), acute renal injury (3.67% vs 1.63%, p=0.044), and rash (1.83% vs 0.20%, p=0.021). Patients receiving high-dose TMP-SMX had significantly higher rates of electrolyte abnormality ADR (5.09% vs 1.63%, p=0.0021), gastrointestinal ADR (5.30% vs 2.24%, p=0.011), renal ADR (3.67% vs 1.63%, p=0.044), central nervous system ADR (2.65% vs 0.81%, p=0.047), and hypersensitivity (2.24% vs 0.41%, p=0.022). Concomitant receipt of an angiotensin-converting enzyme (ACE) inhibitor was a univariate variable associated with hyperkalemia, and advanced age and receipt of high-dose TMP-SMX were independent variables. CONCLUSION: ADRs such as hyperkalemia are more likely to be associated with the use of high-dose TMP-SMX in the ambulatory setting. Clinicians should use caution when initiating high-dose TMP-SMX and consider laboratory monitoring in patients of advanced age or those receiving concomitant ACE inhibitor therapy.