Background:The visual analog scale (VAS) is a validated, subjective measure for acute and chronic pain. Scores are recorded by making a handwritten mark on a 10-cm line that represents a continuum between “no pain” and “worst pain.”Methods:One hundred consecutive patients aged ≥18 years who presented with a chief complaint of pain were asked to record pain scores via a paper VAS and digitally via both the laptop computer and mobile phone. Ninety-eight subjects, 51 men (age, 44 ± 16 years) and 47 women (age, 46 ± 15 years), were included. A mixed-model analysis of covariance with the Bonferroni post hoc test was used to detect differences between the paper and digital VAS scores. A Bland–Altman analysis was used to test for instrument agreement between the platforms. The minimal clinically important difference was set at 1.4 cm (14% of total scale length) for detecting clinical relevance between the three VAS platforms. A paired one-tailed Student t-test was used to determine whether differences between the digital and paper measurement platforms exceeded 14% (P < 0.05).Results:A significant difference in scores was found between the mobile phone–based (32.9% ± 0.4%) and both the laptop computer– and paper-based platforms (31.0% ± 0.4%, P < 0.01 for both). These differences were not clinically relevant (minimal clinically important difference <1.4 cm). No statistically significant difference was observed between the paper and laptop computer platforms. Measurement agreement was found between the paper- and laptop computer–based platforms (mean difference, 0.0% ± 0.5%; no proportional bias detected) but not between the paper- and mobile phone–based platforms (mean difference, 1.9% ± 0.5%; proportional bias detected).Conclusion:No clinically relevant difference exists between the traditional paper-based VAS assessment and VAS scores obtained from laptop computer– and mobile phone–based platforms.

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Thermally conductive polymer crystals are of both fundamental and practical interest for their high thermal conductivity that exceeds that of many metals. In particular, polyethylene fibers and oriented films with uniaxial thermal conductivity exceeding 50 W⋅m−1⋅K−1 have been reported recently, stimulating interest into the underlying microscopic thermal transport processes. While ab initio calculations have provided insight into microscopic phonon properties for perfect crystals, such properties of actual samples have remained experimentally inaccessible. Here, we report the direct observation of thermal phonons with mean free paths up to 200 nm in semicrystalline polyethylene films using transient grating spectroscopy. Many of the mean free paths substantially exceed the crystalline domain sizes measured using small-angle X-ray scattering, indicating that thermal phonons propagate ballistically within and across the nanocrystalline domains; those transmitting across domain boundaries contribute nearly one-third of the thermal conductivity. Our work provides a direct determination of thermal phonon propagation lengths in molecular solids, yielding insights into the microscopic origins of their high thermal conductivity.