Ninety-day mortality after radiotherapy for head and neck cancer: Population-based comparison between rural and urban patients.

BACKGROUND: This study assesses whether 90-day mortality differs between patients living in rural and urban areas, as lower access to supportive care services in rural areas could result in higher mortality. METHODS: All patients with head and neck cancer (HNC) treated between 1998 and 2014 with radiotherapy in British Columbia were included. Patients were divided into rurality areas according to the Modified Statistics Canada (mSC) definition, which classifies a population <30 000 as rural and ≥30 000 as urban. RESULTS: Five thousand five hundred and fifty-four patients were included in this study, of which 68% lived in urban centers. The 90-day mortality for rural versus urban patients were 3.0% and 3.9% (p = 0.09), respectively. Univariate and multivariate analyses showed no association with 90-day mortality and rurality. CONCLUSION: After controlling for potentially confounding factors, we did not find a significant association between 90-day mortality and rurality in patients who were treated with radiotherapy for HNC in British Columbia.

Pressure-Corrected Carotid Stiffness and Young's Modulus: Evaluation in an Outpatient Clinic Setting.

BACKGROUND: Conventional measures for assessing arterial stiffness are inherently pressure dependent. Whereas statistical pressure adjustment is feasible in (larger) populations, it is unsuited for the evaluation of an individual patient. Moreover, statistical "correction" for blood pressure may actually correct for: (i) the acute dependence of arterial stiffness on blood pressure at the time of measurement; and/or (ii) the remodeling effect that blood pressure (hypertension) may have on arterial stiffness, but it cannot distinguish between these processes. METHODS: We derived-assuming a single-exponential pressure-diameter relationship-3 theoretically pressure-independent carotid stiffness measures suited for individual patient evaluation: (i) stiffness index ß0, (ii) pressure-corrected carotid pulse wave velocity (cPWVcorr), and (iii) pressure-corrected Young's modulus (Ecorr). Using linear regression analysis, we evaluated in a sample of the CATOD study cohort changes in mean arterial pressure (ΔMAP) and comparatively the changes in the novel (Δß0, ΔcPWVcorr, and ΔEcorr) as well as conventional (ΔcPWV and ΔE) stiffness measures after a 2.9 ± 1.0-year follow-up. RESULTS: We found no association between ΔMAP and Δß0, ΔcPWVcorr, or ΔEcorr. In contrast, we did find a significant association between ΔMAP and conventional measures ΔcPWV and ΔE. Additional adjustments for biomechanical confounders and traditional risk factors did neither materially change these associations nor the lack thereof. CONCLUSIONS: Our newly proposed pressure-independent carotid stiffness measures avoid the need for statistical correction. Hence, these measures (ß0, cPWVcorr, and Ecorr) can be used in a clinical setting for (i) patient-specific risk assessment and (ii) investigation of potential remodeling effects of (changes in) blood pressure on intrinsic arterial stiffness.