APPetite: Validation of a smartphone app-based tool for the remote measure of free-living subjective appetite

Abstract This study determined the validity, reproducibility and usability of a smartphone app – APPetite – for the measure of free-living, subjective appetite. Validity was assessed compared with the criterion tool of pen-and-paper visual analogue scale (VAS) (n=22). Appetite was recorded using APPetite and VAS, one immediately after the other, upon waking and every hour thereafter for twelve hours. This was repeated the next day with the order of tool reversed. Agreement between tools was assessed using Bland-Altman analysis. Reproducibility and usability were assessed in a separate experiment (n=22) of two trials (APPetite vs. VAS), separated by seven days. Appetite was recorded in duplicate upon waking and every hour for twelve hours using APPetite or VAS. Agreement between duplicate measures was assessed using Bland-Altman analysis and coefficient of variation (CV) was compared between tools. Usability was assessed by comparing compliance and by qualitative evaluation. APPetite demonstrated good criterion validity with trivial bias of 1.65 units/mm·hr−1 between APPetite- and VAS-derived AUC appetite scores. Limits of agreement were within a maximum allowed difference of 10%. However, proportional bias was observed. APPetite demonstrated high reproducibility, with minimal bias (-0.578 units·hr−1) and no difference in CV between APPetite and VAS (1.29±1.42% vs 1.54±2.36%, p = 0.64). Compliance was high with APPetite (92.7±8.0%) and VAS (91.6±20.4%, p = 0.81). Ninety percent of participants preferred APPetite, citing greater accessibility, simplified process and easier/quicker use. While proportional bias precludes using APPetite and VAS interchangeably, APPetite appears a valid, reproducible and highly usable tool for measuring free-living appetite in young-to-middle-aged adults.

Download Full-text

A Comparison of Three Minimally Invasive Cardiac Output Devices with Thermodilution in Elective Cardiac Surgery

Anaesthesia and Intensive Care ◽

10.1177/0310057x1103900606 ◽

2011 ◽

Vol 39 (6) ◽

pp. 1014-1021 ◽

Cited By ~ 22

Author(s):

T. D. Phan ◽

R. Kluger ◽

C. Wan ◽

D. Wong ◽

A. Padayachee

Keyword(s):

Cardiac Output ◽

Minimally Invasive ◽

Kappa Statistic ◽

Altman Analysis ◽

Limits Of Agreement ◽

Fluid Bolus ◽

Elective Cardiac Surgery ◽

Measured Change ◽

Minimal Bias ◽

Oesophageal Doppler Monitor

This study compared the cardiac output responses to haemodynamic interventions as measured by three minimally invasive monitors (Oesophageal Doppler Monitor, the VigileoFlotrac and the LiDCOrapid) to the responses measured concurrently using thermodilution, in cardiac surgical patients. The study also assessed the precision and bias of these monitors in relation to thermodilution measurements. After a fluid bolus of at least 250 ml, the measured change in cardiac output was different among the devices, showing an increase with thermodilution in 82% of measurements, Oesophageal Doppler Monitor 68%, VigileoFlotrac 57% and LiDCOrapid 41%. When comparing the test devices to thermodilution, the kappa statistic showed at best only fair agreement, Oesophageal Doppler Monitor 0.34, LiDCOrapid 0.28 and VigileoFlotrac -0.03. After vasopressor administration, there was also significant variation in the change in cardiac output measured by the devices. Using Bland-Altman analysis, the precision of the devices in comparison to thermodilution showed minimal bias, but wide limits of agreement with percentage errors of Oesophageal Doppler Monitor 64.5%, VigileoFlotrac 47.6% and LiDCOrapid 54.2%. These findings indicate that these three devices differ in their responses, do not always provide the same information as thermodilution and should not be used interchangeably to track cardiac output changes.

Download Full-text

Comparison of two methods for measurement of equine adrenocorticotropin

Journal of Veterinary Diagnostic Investigation ◽

10.1177/1040638717752216 ◽

2017 ◽

Vol 30 (2) ◽

pp. 233-237 ◽

Cited By ~ 6

Author(s):

Heidi E. Banse ◽

Nichol Schultz ◽

Molly McCue ◽

Ray Geor ◽

Dianne McFarlane

Keyword(s):

Pars Intermedia ◽

Plasma Samples ◽

Altman Analysis ◽

Poor Agreement ◽

Limits Of Agreement ◽

Cutoff Value ◽

Bland Altman Analysis ◽

Acth Concentration

Accurate measurement of equine adrenocorticotropin (ACTH) is important for the diagnosis of equine pituitary pars intermedia dysfunction (PPID). Several radioimmunoassays (RIAs) and chemiluminescent immunoassays (CIAs) are used for measurement of ACTH concentration in horses; whether these methods yield similar results across a range of concentrations is not determined. We evaluated agreement between a commercial RIA and CIA. Archived plasma samples ( n = 633) were measured with both assays. Correlation between the 2 methods was moderate ( r = 0.49, p < 0.001). Bland–Altman analysis revealed poor agreement, with a proportional bias and widening limits of agreement with increasing values. Poor agreement between assays was also observed when evaluating plasma samples with concentrations at or below the recommended diagnostic cutoff value for PPID testing. The lack of agreement suggests that measurements obtained should not be considered interchangeable between methods.

Download Full-text

COMPARISON BETWEEN RECTAL AND BODY SURFACE TEMPERATURES OBTAINED BY DIGITAL AND NON-CONTACT INFRARED THERMOMETER IN SOME LARGE ANIMAL SPECIES

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v7.i8.2019.639 ◽

2019 ◽

Vol 7 (8) ◽

pp. 62-68

Author(s):

Mera Usman Muhammed ◽

Mayaki Abubakar Musa ◽

Gambo Abdulrahman Abdullahi

Keyword(s):

Animal Species ◽

Large Animal ◽

Altman Analysis ◽

Limits Of Agreement ◽

Infrared Thermometer ◽

Bland Altman Analysis ◽

The Face ◽

Body Temperature Measurement ◽

The Mean ◽

The Moment

This study was carried out to compare the digital rectal (DR) thermometer with non-contact infrared thermometer (IRT) measurements at two locations on the face in some large animal species. Two hundred and forty (240) animals comprising of equal numbers of three species (cattle, camel and horses) of varying age and either sex was used. The IR temperature was taken from two sites [frontal (FIRT) and temporal (TIRT) region] on the animal face. The mean IR temperatures (FIRT and TIRT) were higher than the RT in all the animal species. The two thermometers correlate poorly in all the animal species. Bland-Altman analysis showed high biases and limits of agreement not acceptable for clinical purposes. In conclusion, IRT seems to offer a quick and easy way to determine the animal temperature but clinically it cannot be used interchangeably with DR thermometer at the moment for body temperature measurement in these animal species.

Download Full-text

Better Performance of Flow-FISH in Comparison to qPCR As a Diagnostic Test for Telomere Diseases

Blood ◽

10.1182/blood.v124.21.1605.1605 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1605-1605

Author(s):

Fernanda Gutierrez-Rodrigues ◽

Bárbara A Santana-Lemos ◽

Priscila Santos Scheucher ◽

Raquel M Alves-Paiva ◽

Rodrigo T. Calado

Keyword(s):

Telomere Length ◽

Diagnostic Test ◽

Quantitative Pcr ◽

Measurement Techniques ◽

Healthy Individuals ◽

Altman Analysis ◽

Poor Agreement ◽

Limits Of Agreement ◽

Gold Standard Method ◽

Bland Altman Analysis

Abstract Excessive telomere erosion is the molecular etiology of a group of disorders (dyskeratosis congenita, aplastic anemia, idiopathic pulmonary fibrosis) collectively called telomeropathies. Telomere length measurement is an essential diagnostic test for these diseases. The most commonly used methods are terminal restriction fragment (TRF) analysis by Southern blotting (the gold-standard method), flow cytometry combined with fluorescence in situ hybridization (flow-FISH), and quantitative PCR (qPCR). Although the clinical use of these methods has been reported, their utility and characteristics have not been widely compared. Measurement techniques and coefficients of variations often differ among diagnostic services. Here, we directly compared the accuracy, reproducibility, sensitivity, and specificity of flow-FISH and qPCR in comparison to TRF to measure peripheral blood leukocyte’s telomere length in healthy individuals and patients with telomeropathies. TRF analyses and flow-FISH showed good correlation in the analysis of samples from healthy subjects (R2=0.60; p<0.0001) and patients (R2=0.51; p<0.0001). Bland-Altman analyses also displayed a very good agreement between these methods for both healthy individuals (bias±SD = 0.17±1.03; limits of agreement ranging from 2.24 to -1.88) and patients (bias±SD = 0.0±1.21; limits of agreement ranging from 2.41 to -2.41). In contrast, the comparison between TRF and qPCR yielded modest correlation for the analysis of samples of healthy individuals (R2=0.35; p<0.0001) and low correlation for patients (R2=0.20; p=0.001). Bland-Altman analysis indicated poor agreement between the two methods for both patients and controls. The differences averages were very different from zero and standard deviation was wide. For patients, the bias±SD was 0.78±1.34 with limits of agreement ranging from 3.47 to -1.90, and for controls, the bias±SD was 1.15±1.49 with limits of agreement ranging from 4.14 to -1.84. Finally, qPCR and flow-FISH also modestly correlated in the analysis of healthy individual samples (R2=0.33; p<0.0001) and did not correlate in the comparison of patients’ samples (R2=0.1, p=0.08). Bland-Altman analysis corroborate this finding. For controls, the bias±SD were very similar to the one found by comparison between qPCR and TRF analysis (-0.6±1.27; limits of agreement ranging from 1.94 to -3.16). For patients, bias ± SD were -1.15 ± 1.65 with limits of agreement ranging from 2.15 to -4.45, which evidenced a poor agreement between flow-FISH and qPCR in these samples. Intra-assay coefficient of variation (CV) was 10.8±7.1% for flow-FISH and 9.5±7.4% for qPCR (p=0.35). The inter-assay CV was lower for flow-FISH (9.6±7.6%) in comparison to qPCR (16±19.5%; p=0.02). Flow-FISH and qPCR were sensitive (both 100%) and specific (93% and 89%, respectively) to distinguish very short telomeres. However, qPCR sensitivity (40%) and specificity (63%) to detect telomere length below tenth percentile were lower in comparison to flow-FISH (80% sensitivity and 85% specificity). Taken together, these findings indicate that, in the clinical setting, flow-FISH is more accurate and reproducible in the measurement of human leukocyte’s telomere length in comparison to qPCR. Quantitative PCR exhibited low accuracy in the analysis of samples of patients with short telomeres. In conclusion, flow-FISH appears to be a more appropriate method for diagnostic purposes. Studies that compare methodologies are helpful in the selection of standard methods and to narrow the differences among laboratories. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Inter-Operator Reliability of an Onsite Machine Learning-Based Prototype to Estimate Ct Angiography-Derived Fractional Flow Reserve

10.21203/rs.3.rs-741234/v1 ◽

2021 ◽

Author(s):

Yushui Han ◽

Ahmed Ibrahim Ahmed ◽

Chris Schwemmer ◽

Myra Cocker ◽

Talal S Alnabelsi ◽

...

Keyword(s):

Machine Learning ◽

Sensitivity Analysis ◽

Ct Angiography ◽

Coronary Ct Angiography ◽

Altman Analysis ◽

Fractional Flow ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Coronary Ct ◽

Flow Reserve

Abstract Background: Advances in computed tomography (CT) and machine learning have enabled on-site non-invasive assessment of fractional flow reserve (FFRCT). Purpose: To assess the inter-operator variability of Coronary CT Angiography–derived FFRCT using a machine learning based post-processing prototype.Materials and Methods: We included 60 symptomatic patients who underwent coronary CT angiography. FFRCT was calculated by 2 independent operators after training using a machine learning based on-site prototype. FFRCT was measured 1 cm distal to the coronary plaque or in the middle of the segments if no coronary lesions were present. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to evaluate inter-operator variability effect in FFRCT estimates. Sensitivity analysis was done by cardiac risk factors, degree of stenosis and image quality. Results: A total of 535 coronary segments in 60 patients were assessed. The overall ICC was 0.986 per patient (95% CI: 0.977 - 0.992) and 0.972 per segment (95% CI: 0.967 - 0.977). The absolute mean difference in FFRCT estimates was 0.012 per patient (95% CI for limits of agreement: -0.035 - 0.039) and 0.02 per segment (95% CI for limits of agreement: -0.077 - 0.080). Tight limits of agreement were seen on Bland-Altman analysis. Distal segments had greater variability compared to proximal/mid segments (absolute mean difference 0.011 vs 0.025, p<0.001). Results were similar on sensitivity analysis. Conclusion: A high degree of inter-operator reproducibility can be achieved by onsite machine learning based FFRCT assessment. Future research is required to evaluate the physiological relevance and prognostic value of FFRCT.

Download Full-text

‘My Meal Mate’ (MMM): validation of the diet measures captured on a smartphone application to facilitate weight loss

British Journal Of Nutrition ◽

10.1017/s0007114512001353 ◽

2012 ◽

Vol 109 (3) ◽

pp. 539-546 ◽

Cited By ~ 73

Author(s):

Michelle C. Carter ◽

V. J. Burley ◽

C. Nykjaer ◽

J. E. Cade

Keyword(s):

Weight Loss ◽

Assessment Tool ◽

Dietary Assessment ◽

Smartphone Application ◽

Assessment Process ◽

Nutritional Epidemiology ◽

Altman Analysis ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Individual Level

Accurate dietary assessment is an essential foundation of research in nutritional epidemiology. Due to the weaknesses in current methodology, attention is turning to strategies that automate the dietary assessment process to improve accuracy and reduce the costs and burden to participants and researchers. ‘My Meal Mate’ (MMM) is a smartphone application designed to support weight loss. The present study aimed to validate the diet measures recorded on MMM against a reference measure of 24 h dietary recalls. A sample of fifty volunteers recorded their food and drink intake on MMM for 7 d. During this period, they were contacted twice at random to conduct 24 h telephone recalls. Daily totals for energy (kJ) and macronutrients recorded on MMM were compared against the corresponding day of recall using t tests for group means and Pearson's correlations. Bland–Altman analysis was used to assess the agreement between the methods. Energy (kJ) recorded on MMM correlated well with the recalls (day 1: r 0·77 (95 % CI 0·62, 0·86), day 2: r 0·85 (95 % CI 0·74, 0·91)) and had a small mean difference (day 1 (MMM − recall): − 68 kJ/d (95 % CI − 553, 418 kJ) ( − 16 kcal/d, 95 % CI − 127, 100 kcal); day 2 (MMM − recall): − 441 kJ/d (95 % CI − 854, − 29 kJ) ( − 105 kcal/d, 95 % CI − 204, − 7 kcal)). Bland–Altman analysis showed wide limits of agreement between the methods: − 3378 to 3243 kJ/d ( − 807 to 775 kcal/d) on day 1. At the individual level, the limits of agreement between MMM and the 24 h recall were wide; however, at the group level, MMM appears to have potential as a dietary assessment tool.

Download Full-text

VALIDITY OF THE RETROSPECTIVE APPLICATION OF OXFORD HIP AND KNEE SCORES

Journal of Musculoskeletal Research ◽

10.1142/s0218957715500037 ◽

2015 ◽

Vol 18 (01) ◽

pp. 1550003

Author(s):

Travis M. Falconer ◽

Julie Headford ◽

Stephen Edmondston ◽

Piers J. Yates

Keyword(s):

Positive Relationship ◽

Oxford Knee Score ◽

Knee Score ◽

Altman Analysis ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Oxford Hip Score ◽

The Mean ◽

Mean Time

The Oxford Hip Score (OHS) and Oxford Knee Score (OKS) are validated, reliable and reproducible outcome measures, however their use retrospectively has not been examined. The aim of this prospective cohort study was to examine the accuracy and reliability of patients' ability to recall their OHS and OKS in a retrospective manner. A total of 137 patients undergoing primary hip (40) or primary knee (97) arthroplasty with a mean age of 70.8 years (range, 47–88) and a mean time to follow up of 27.2 months (range, 6–46) were included in the study. The mean retrospective OHS and OKS decreased compared to the pre-operative score (OHS = 1.6 ± SD, p = 0.36, OKS = 4.7 ± SD, p < 0.001). There was only a weak positive relationship between the actual pre-operative scores and the retrospective scores (OHS: r2 = 0.30, OKS: r2 = 0.19). Bland–Altman analysis demonstrated 95% limits of agreement between scores of -19.9 to 23.1 for the OHS and -15.3 to 24.8 for the OKS. This study shows that patients are poor at retrospectively recalling their pre-operative OHS and OKS and therefore these scores should not be used in a retrospective manner.

Download Full-text

Comparison between radial artery tonometry pulse analyzer and pulsed-Doppler echocardiography derived hemodynamic parameters in cardiac surgery patients: a pilot study

PeerJ ◽

10.7717/peerj.4132 ◽

2017 ◽

Vol 5 ◽

pp. e4132 ◽

Cited By ~ 9

Author(s):

Rashad Zayat ◽

Andreas Goetzenich ◽

Ju-Yeon Lee ◽

HeeJung Kang ◽

So-Hyun Jansen-Park ◽

...

Keyword(s):

Pilot Study ◽

Radial Artery ◽

Pearson Correlation ◽

Hemodynamic Parameters ◽

Altman Analysis ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Number Of Patients ◽

The Mean ◽

Lower Limits

BackgroundBedside non-invasive techniques, such as radial artery tonometry, to estimate hemodynamic parameters have gained increased relevance as an attractive alternative and efficient method to measure hemodynamics in outpatient departments. For our pilot study, we sought to compare cardiac output (CO), and stroke volume (SV) estimated from a radial artery tonometry blood pressure pulse analyzer (BPPA) (DMP-Life, DAEYOMEDI Co., Gyeonggi-do, South Korea) to pulsed-wave Doppler (PWD) echocardiography derived parameters.MethodsFrom January 2015 to December 2016, all patients scheduled for coronary artery bypass (CABG) surgery at our department were screened. Exclusion criteria were, inter alia, moderate to severe aortic- or Mitral valve disease and peripheral arterial disease (PAD) > stage II. One hundred and seven patients were included (mean age 66.1 ± 9.9, 15 females, mean BMI 27.2 ± 4.1 kg/m2). All patients had pre-operative transthoracic echocardiography (TTE). We measured the hemodynamic parameters with the BPPA from the radial artery, randomly before or after TTE. For the comparison between the measurement methods we used the Bland-Altman test and Pearson correlation.ResultsMean TTE-CO was 5.1 ± 0.96 L/min, and the mean BPPA-CO was 5.2 ± 0.85 L/min. The Bland-Altman analysis for CO revealed a bias of −0.13 L/min and SD of 0.90 L/min with upper and lower limits of agreement of −1.91 and +1.64 L/min. The correlation of CO measurements between DMP-life and TTE was poor (r = 0.501,p < 0.0001). The mean TTE-SV was 71.3 ± 16.2 mL and the mean BPPA-SV was 73.8 ± 19.2 mL. SV measurements correlated very well between the two methods (r = 0.900,p < 0.0001). The Bland-Altman analysis for SV revealed a bias of −2.54 mL and SD of ±8.42 mL and upper and lower limits of agreement of −19.05 and +13.96 mL, respectively.ConclusionOur study shows for the first time that the DMP-life tonometry device measures SV and CO with reasonable accuracy and precision of agreement compared with TTE in preoperative cardiothoracic surgery patients. Tonometry BPPA are relatively quick and simple measuring devices, which facilitate the collection of cardiac and hemodynamic information. Further studies with a larger number of patients and with repeated measurements are in progress to test the reliability and repeatability of DMP-Life system.

Download Full-text

Whatman FTA® cards versus plasma specimens for the quantitation of HIV-1 RNA using two Real-Time PCR assays

10.1101/748061 ◽

2019 ◽

Author(s):

Abdourahamane Yacouba ◽

Malika Congo ◽

Gérard Komonsira Dioma ◽

Hermann Somlaré ◽

David Coulidiaty ◽

...

Keyword(s):

Viral Load ◽

Filter Paper ◽

Load Testing ◽

Altman Analysis ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Viral Loads ◽

Fta Cards ◽

Pcr Assays ◽

Hiv 1

AbstractBackgroundSeveral studies have been conducted to compare the use DBS as alternative to plasma specimens, but mainly using Whatman 903® cards as filter paper. The aim of this study was to evaluate Whatman FTA® cards (FTA cards) specimens for HIV-1 viral load testing by comparing it to plasma specimens, using 2 real-Time PCR assays.MethodologyA cross-sectional study was conducted between April 2017 and September 2017, in HIV-1 patients admitted at Yalgado Ouédraogo teaching hospital. Paired FTA cards and plasma specimens were collected and analyzed using Abbott RealTime HIV-1 assay (Abbott) and COBAS® AmpliPrep/COBAS® TaqMan v2.0 (Roche), following manufacturers’ protocol.ResultsA total of 107 patients were included. No Statistical differences (p-value > 0.05) were observed between the mean viral loads obtained from FTA cards and plasma specimens with Roche and Abbott assays. Twenty-nine samples with Roche and 15 samples with Abbott assay showed discrepant results. At viral loads of ≤1000 copies/mL, the sensitivity and specificity of FTA cards were 78.6%, and 100% with Roche, and 92.3% and 95.9% with Abbott. Strong correlation was found between FTA cards and plasma specimens with both assays. With Roche, Bland-Altman analysis showed bias of −0.3 and 95% limits of agreement of −2.6 to 1.8 log10, with 97/99 cases (97.9%) within agreement limits. With Abbott, Bland-Altman analysis showed bias of −0.1 and 95% limits of agreement of −2.3 to 2.1 log10, with 96/99 cases (96.9%) within agreement limits.ConclusionOur study demonstrated the feasibility of using FTA cards filter paper for HIV-1 viral load testing. However, further studies are required for FTA cards filter paper validation in HIV-1 treatment monitoring.

Download Full-text

Energy expenditure in critically ill surgical patients. Comparative analysis of predictive equation and indirect calorimetry

Acta Cirurgica Brasileira ◽

10.1590/s0102-86502011000800010 ◽

2011 ◽

Vol 26 (suppl 2) ◽

pp. 51-56 ◽

Cited By ~ 6

Author(s):

Maria Auxiliadora Martins ◽

Mayra Gonçalves Menegueti ◽

Edson Antônio Nicolini ◽

Michele Ferreira Picolo ◽

Alessandra Fabiane Lago ◽

...

Keyword(s):

Mechanical Ventilation ◽

Energy Expenditure ◽

Critically Ill ◽

Indirect Calorimetry ◽

Resting Energy Expenditure ◽

Surgical Patients ◽

Altman Analysis ◽

Limits Of Agreement ◽

Bland Altman Analysis ◽

Critically Ill Surgical Patients

PURPOSE: The aim of this investigation was to compare the resting energy expenditure (REE) calculated by the Harris-Benedict equation (REE HB) with the REE measured by indirect calorimetry (REE IC) in critically ill surgical patients under mechanical ventilation. METHODS: Thirty patients were included in this work. REE was calculated by the Harris-Benedict equation (REE HB) using real body weight, and it was also measured by indirect calorimetry (REE IC), which was performed for 30 minutes. RESULTS: REE HB had significant (p < 0.0005) but low correlation (Spearman r = 0.57) with REE IC, with a mean bias of 12 kcal.d-1 and limits of agreement ranging from - 599.7 to 623.7 kcal.d-1 as detected by the Bland-Altman analysis. CONCLUSION: These findings suggest that REE IC seems to be more appropriate than REE HB for accurate measurement of REE in critically ill surgical patients under mechanical ventilation.

Download Full-text