Mobile, Remote, and Individual Focused: Comparing Breath Carbon Monoxide Readings and Abstinence Between Smartphone-Enabled and Stand-Alone Monitors

Abstract Introduction Newly available, smartphone-enabled carbon monoxide (CO) monitors are lower in cost than traditional stand-alone monitors and represent a marked advancement for smoking research. New products are promising, but data are needed to compare breath CO readings between smartphone-enabled and stand-alone monitors. The purpose of this study was to (1) determine the agreement between the mobile iCO (Bedfont Scientific Ltd) with two other monitors from the same manufacturer (Micro+ pro and Micro+ basic) and (2) determine optimal, monitor-specific, cotinine-confirmed abstinence cutoff values. Methods Adult (≥18) smokers (n = 26) and nonsmokers (n = 21) provided three breath CO samples (using three different monitors) in each of 10 sessions, and urine cotinine was measured for gold standard determination of abstinence. CO comparisons (N = 437) were analyzed using regression-based Bland–Altman Analysis of Agreement; receiver operating characteristics curves were used to determine optimal abstinence cutoffs. Results Bland–Altman analyses indicated that the iCO monitor provided higher CO results than both Micro+ monitors. Sensitivity and specificity analyses showed that the optimal CO cutoff for determining abstinence was <3 ppm for the Micro+ pro (88% sensitivity, 93% specificity) and Micro+ basic (83% sensitivity, 98% specificity), but was higher for the iCO (<6 ppm; 73% sensitivity, 100% specificity). Conclusions Relative to both Micro+ monitors, the smartphone-enabled iCO provided systematically higher CO values and required a higher cutoff to reliably determine smoking abstinence. This does not indicate that CO values obtained using the iCO are not valid; instead, these results suggest that monitor-specific abstinence cutoffs are needed to ensure accurate bioverification of smoking status. Implications Results from this study indicate that CO values from the smartphone-enabled iCO should not be used interchangeably with the stand-alone Micro+ pro and Micro+ basic, particularly when lower CO values (<10 ppm) are critical (ie, determination of abstinence vs confirming smoking status for study inclusion). Optimal CO cutoffs recommended for determining abstinence on Micro+ and iCO monitors are at <3 and <6 ppm, respectively.

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Evaluation of automated microvascular flow analysis software AVA 4: a validation study

Intensive Care Medicine Experimental ◽

10.1186/s40635-021-00380-0 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Christian S. Guay ◽

Mariam Khebir ◽

T. Shiva Shahiri ◽

Ariana Szilagyi ◽

Erin Elizabeth Cole ◽

...

Keyword(s):

General Anesthesia ◽

Validation Study ◽

Validation Studies ◽

Gold Standard ◽

Flow Analysis ◽

Automated Analysis ◽

Altman Analysis ◽

Analysis Software ◽

Bland Altman Analysis ◽

Microvascular Flow

Abstract Background Real-time automated analysis of videos of the microvasculature is an essential step in the development of research protocols and clinical algorithms that incorporate point-of-care microvascular analysis. In response to the call for validation studies of available automated analysis software by the European Society of Intensive Care Medicine, and building on a previous validation study in sheep, we report the first human validation study of AVA 4. Methods Two retrospective perioperative datasets of human microcirculation videos (P1 and P2) and one prospective healthy volunteer dataset (V1) were used in this validation study. Video quality was assessed using the modified Microcirculation Image Quality Selection (MIQS) score. Videos were initially analyzed with (1) AVA software 3.2 by two experienced investigators using the gold standard semi-automated method, followed by an analysis with (2) AVA automated software 4.1. Microvascular variables measured were perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV). Bland–Altman analysis and intraclass correlation coefficients (ICC) were used to measure agreement between the two methods. Each method’s ability to discriminate between microcirculatory states before and after induction of general anesthesia was assessed using paired t-tests. Results Fifty-two videos from P1, 128 videos from P2 and 26 videos from V1 met inclusion criteria for analysis. Correlational analysis and Bland–Altman analysis revealed poor agreement and no correlation between AVA 4.1 and AVA 3.2. Following the induction of general anesthesia, TVD and PVD measured using AVA 3.2 increased significantly for P1 (p < 0.05) and P2 (p < 0.05). However, these changes could not be replicated with the data generated by AVA 4.1. Conclusions AVA 4.1 is not a suitable tool for research or clinical purposes at this time. Future validation studies of automated microvascular flow analysis software should aim to measure the new software’s agreement with the gold standard, its ability to discriminate between clinical states and the quality thresholds at which its performance becomes unacceptable.

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Comparing School-Aged Refraction Measurements Using the 2WIN-S Portable Refractor in Relation to Cycloplegic Retinoscopy: A Cross-Sectional Study

Journal of Ophthalmology ◽

10.1155/2021/6612476 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Ziming Liu ◽

Emmanuel Eric Pazo ◽

Hong Ye ◽

Cui Yu ◽

Ling Xu ◽

...

Keyword(s):

Gold Standard ◽

Intraclass Correlation ◽

Cross Sectional Study ◽

Mean Value ◽

Spherical Equivalent ◽

Sectional Study ◽

Altman Analysis ◽

Cross Sectional ◽

Bland Altman Analysis ◽

The Mean

Purpose. To assess the repeatability and agreement of refractive measurements using 2WIN-S photoscreening with the gold-standard cycloplegic retinoscope refraction. Design. Single centre, cross-sectional study. Methods. Spherical, cylindrical, axis, and spherical equivalent of 194 bilateral eyes of 97 children were assessed using a retinoscope and 2WIN-S. One week later, another operator repeated the 2WIN-S measurements. The primary outcome measures were to assess the repeatability and agreement between spherical equivalent, J0, and J45 readings of 2WIN-S. The repeatability of measurements was assessed by the within-subject standard deviation (2.77 Sw) and intraclass correlation coefficient (ICC). The agreement between devices was assessed using 95% limits of agreement. The extent of the agreement between cycloplegic retinoscopy and noncycloplegic 2WIN-S measurements was assessed using Bland–Altman analysis. Results. The mean age ± SD was 10.3 ± 2.46 year (range, 4–14 years). The sphere, cylinder, and spherical equivalent measurements were found to be consistent with both apparatus (r value >0.86). ICC for SE, J0, and J45 was 0.900, 0.666, and 0.639, respectively; Sw for SE, J0, and J45 was 0.61D, 0.30D, and 0.31D, respectively; Bland–Altman analysis of retinoscopy with cycloplegia and 2WIN-S for SE was 184/194 (95%) in 95% confidence interval, and the mean value was 0.46. J0 was 184/194 (95%), and the mean value is −0.04. J45 was 181/194 (93%), and the mean value is −0.15. Conclusion. The objective refractive measurement of 2WIN-S had good reliability and high agreement with the gold-standard retinoscopy refraction in children and adolescents. While consistency was observed, it is essential to take into consideration that it is a screening tool.

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Comparison of Three Carbon Monoxide Monitors for Determination of Smoking Status in Smokers and Nonsmokers with and without COPD

Journal of Aerosol Medicine ◽

10.1089/jam.2007.0606 ◽

2007 ◽

Vol 20 (4) ◽

pp. 475-483 ◽

Cited By ~ 17

Author(s):

Lieke Christenhusz ◽

Frans de Jongh ◽

Paul van der Valk ◽

Marcel Pieterse ◽

Erwin Seydel ◽

...

Keyword(s):

Carbon Monoxide ◽

Smoking Status

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Validation of Self-Reported Smoker and Second Hand Smoke Exposure by Urinary Cotinine within The Malaysian Cohort Project

Journal of Biomedicine and Translational Research ◽

10.14710/jbtr.v5i1.3971 ◽

2019 ◽

Vol 5 (1) ◽

pp. 15

Author(s):

Noraidatulakma Abdullah

Keyword(s):

High Performance ◽

Smoking Status ◽

Smoke Exposure ◽

Misclassification Rate ◽

Second Hand Smoke ◽

Urinary Cotinine ◽

Urine Cotinine ◽

Second Hand Smoke Exposure ◽

Former Smokers

Background: Validation of self-reported questionnaire is very crucial in ensuring the quality and reliability of data collection. Objective: The aim of this study were i) to validate the questionnaire on tobacco smoke intake and second hand smoke exposure among The Malaysian Cohort (TMC) subjects through the determination of urinary cotinine levels, ii) to determine the optimal cut-off point of urine cotinine that discriminates smokers from non-smokers and iii) to estimate misclassification rate between self-reported smoking and urinary cotinine level.Methods: Urine samples from a total of 775 The Malaysian Cohort subjects (104 smokers, 102 former smokers and 569 non-smokers) were obtained and urinary cotinine levels were determined by high-performance liquid chromatography (HPLC). Differences between groups were compared using Kruskal Wallis and Mann-Whitney tests. The Receiver Operating Characteristic (ROC) curved was performed to define the optimal urinary cotinine cut-off point.Results: Urinary cotinine concentration significantly (p<0.001) correlated with smoking status (r=0.46), the average number of cigarettes smoked per day (r=0.53), duration of smoking (r=0.33) and number of cigarettes packed per year (r=0.47). Smokers and second hand smokers have significantly higher median cotinine levels (978.40 and 21.31 respectively) compared to non-smokers (15.52) and non-exposed (13.60) subjects. Cotinine level at cut-off value of 1.51 ng/mg creatinine is able to distinguish smokers and non-smokers with a sensitivity of 84.62% and specificity of 81.97%.Conclusion: The Malaysian Cohort self-reported smoking questionnaire is a reliable tool in assessing the use of tobacco and second hand smoke exposure among the subjects.

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Validation of Non-Smoking Status by Spouse Following a Cessation Intervention

The Journal of Smoking Cessation ◽

10.1017/jsc.2015.11 ◽

2015 ◽

Vol 12 (1) ◽

pp. 38-42 ◽

Cited By ~ 4

Author(s):

Raul M. Mejia ◽

Sandra Braun ◽

Lorena Peña ◽

Steven E. Gregorich ◽

Eliseo J. Pérez-Stable

Keyword(s):

Gold Standard ◽

Smoking Status ◽

Medical Advice ◽

Self Report ◽

Smoking Abstinence ◽

Community Studies ◽

Cessation Intervention ◽

Quit Attempts ◽

The Mean ◽

Reported Data

Background: Following cessation interventions, self-reported smoking abstinence with biochemical verification is the “gold standard” for defining outcomes. Because obtaining biochemical verification is challenging in community studies, we compared self-reported cessation among smokers completing treatment to the smoking status reported by each participant's spouse or proxy.Method: Participants were smokers who had reported quitting 12 months after a cessation intervention. Participants had either attended a smoking cessation clinic or they were patients seen by physicians who had recently participated in a cessation-training program. Proxies living with these participants were interviewed by telephone to ask about their partner's smoking status. We compared the participants' responses to those from their spouses.Results: At 12 months, 346 of 1423 baseline smokers had quit; 161/346 reported non-smokers were called and 140 proxies were interviewed. The participants averaged 51 years of age, 69% were women. At baseline, the mean number of cigarettes smoked per day was 20.1 (SD = 9.9) and the average number of quit attempts was 2.4 (SD = 1.2). Cessation methods used were medical advice (21%) and/or pharmacotherapy (79%). Of the 140 spouses interviewed, only 10 (7.1%) reported that their partners were currently smoking.Conclusions: Proxy-reported data on smoking status could be used to validate self-report.

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Comparison of variables measured with a Scheimpflug device for evaluation of progression and detection of keratoconus

Scientific Reports ◽

10.1038/s41598-020-76020-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Sophie Neuhann ◽

Anna Schuh ◽

Daniel Krause ◽

Raffael Liegl ◽

Valerie Schmelter ◽

...

Keyword(s):

Regression Analysis ◽

Visual Impairment ◽

Classification System ◽

Staging System ◽

Altman Analysis ◽

Bland Altman Analysis ◽

Intraclass Correlations ◽

High Repeatability ◽

Corneal Disorder

Abstract Keratoconus is a progressive ectatic corneal disorder, which can result in severe visual impairment. The new ABCD keratoconus classification system allows differentiated description of the disease. Aim of the study was to evaluate the components of this novel staging system (ARC, PRC, thinnest pachymetry) as well as topometric indices, deviation of normality indices, and other parameters in terms of repeatability and reliability. 317 eyes with keratoconus were examined twice with a Scheimpflug device (Pentacam, Oculus). Bland Altman analysis and intraclass correlations were carried out to evaluate the parameters repeatability and reliability. Apart from IHA (ICC = 0.730), all parameters showed excellent reliability (ICC > 0.900). ARC, PRC, thinnest pachymetry, Kmax, CKI, KI, Rmin, and Progression Avg were the best repeatable parameters with relative repeatability values < 2.5%. Other parameters performing well in terms of repeatability were IHD, ISV, IVA, and final D (RR < 13%). Regression analysis revealed consistently high repeatability along all stages of keratoconus for PRC, thinnest pachymetry, and CKI. All parameters of the ABCD staging system showed excellent reliability and repeatability, PRC and thinnest pachymetry even at all stages of keratoconus and can consequently be reliably used in the determination of keratoconus progression.

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Evaluation of Automated Microvascular Flow Analysis Software AVA 4: A Validation Study

10.21203/rs.3.rs-71474/v2 ◽

2021 ◽

Author(s):

Christian S. Guay ◽

Mariam Khebir ◽

Shiva Shahiri ◽

Ariana Szilagyi ◽

Erin Elizabeth Cole ◽

...

Keyword(s):

General Anesthesia ◽

Validation Study ◽

Validation Studies ◽

Gold Standard ◽

Flow Analysis ◽

Automated Analysis ◽

Altman Analysis ◽

Analysis Software ◽

Bland Altman Analysis ◽

Microvascular Flow

Abstract BACKGROUND: Real-time automated analysis of videos of the microvasculature is an essential step in the development of research protocols and clinical algorithms that incorporate point-of-care microvascular analysis. In response to the call for validation studies of available automated analysis software by the European Society of Intensive Care Medicine, and building on a previous validation study in sheep, we report the first human validation study of AVA 4.METHODS:Two retrospective perioperative datasets of human microcirculation videos (P1 and P2) and one prospective healthy volunteer dataset (V1) were used in this validation study. Video quality was assessed using the modified Microcirculation Image Quality Selection (MIQS) score. Videos were initially analyzed with (1) AVA software 3.2 by two experienced investigators using the gold standard semi-automated method, followed by an analysis with (2) AVA automated software 4.1. Microvascular variables measured were perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV). Bland-Altman analysis and intraclass correlation coefficients (ICC) were used to measure agreement between the two methods. Each method’s ability to discriminate between microcirculatory states before and after induction of general anesthesia was assessed using paired t-tests. RESULTS: Fifty-two videos from P1, 128 videos from P2 and 26 videos from V1 met inclusion criteria for analysis. Correlational analysis and Bland Altman analysis revealed poor agreement and no correlation between AVA 4.1 and AVA 3.2. Following the induction of general anesthesia, TVD and PVD measured using AVA 3.2 increased significantly for P1 (p < 0.05) and P2 (p < 0.05). However, these changes could not be replicated with the data generated by AVA 4.1. CONCLUSIONS: AVA 4.1 is not a suitable tool for research or clinical purposes at this time. Future validation studies of automated microvascular flow analysis software should aim to measure the new software’s agreement with the gold standard, its ability to discriminate between clinical states and the quality thresholds at which its performance becomes unacceptable.

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