scholarly journals Smartphone Movement Sensors for Remote Monitoring of Respiratory Rate: Observational Study

2021 ◽  
Author(s):  
Sophie Valentine ◽  
Benjamin Klasmer ◽  
Mohammad Dabbah ◽  
Marko Balabanovic ◽  
David Plans
Keyword(s):  
Respiratory Rate ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Absolute Error ◽  
Smartphone Application ◽  
Healthcare Systems ◽  
In The Wild ◽  
Smartphone Sensors ◽  
Movement Sensors

AbstractBackgroundMobile health offers potential benefits to patients and healthcare systems alike. Existing remote technologies to measure respiratory rate (RR) have limitations, such as cost, accessibility and reliability. Using smartphone sensors to measure RR may offer a potential solution.ObjectiveThe aim of this study was to conduct a comprehensive assessment of a novel mHealth smartphone application designed to measure RR using movement sensors.MethodsIn Study 1, 15 participants simultaneously measured their RR with the app, and an FDA cleared reference device. A novel reference method to allow the app to be evaluated ‘in the wild’ was also developed. In Study 2, 165 participants measured their RR using the app, and these measures were compared to the novel reference. Usability of the app was also assessed in both studies.ResultsThe app, when compared to the FDA-cleared and novel references, respectively, showed a mean absolute error (MAE) of 1.65 (SD=1.49) and 1.14 (1.44), relative MAE of 12.2 (9.23) and 9.5 (18.70) and bias of 0.81 (limits of agreement (LoA) =-3.27-4.89) and 0.08 (−3.68-3.51). Pearson correlation coefficients were 0.700 and 0.885. 93% of participants successfully operated the app on their first use.ConclusionsThe accuracy and usability of the app demonstrated here show promise for the use of mHealth solutions employing smartphone sensors to remotely monitor RR. Further research should validate the benefits that this technology may offer patients and healthcare systems.

Smartphone Movement Sensors for Remote Monitoring of Respiratory Rate: Observational Study (Preprint)

2021 ◽  
Author(s):  
Sophie Valentine ◽  
Benjamin Klasmer ◽  
Mohammad Dabbah ◽  
Marko Balabanovic ◽  
DAVID PLANS
Keyword(s):  
Respiratory Rate ◽  
Reference Method ◽  
Absolute Error ◽  
Smartphone Application ◽  
Healthcare Systems ◽  
Economic Benefits ◽  
Preliminary Evaluation ◽  
The Novel ◽  
In The Wild ◽  
Movement Sensors

BACKGROUND Mobile health (mHealth) offers notable potential clinical and economic benefits to patients and healthcare systems alike. Although respiratory rate (RR) is of great clinical significance, existing remote technologies to measure RR suffer from limitations, such as cost, accessibility and reliability. Using smartphone movement sensors to measure RR may offer a potential solution to these shortcomings. OBJECTIVE The aim of this study was to conduct a comprehensive and ecologically valid assessment of a novel mHealth smartphone application designed to measure RR using movement sensors. METHODS Study 1 offered a preliminary evaluation, in which RR measurements from 15 participants generated via the mHealth app were compared to simultaneous measurements from a reference device cleared by the US Food and Drug Administration (FDA). Participants’ ability to successfully operate the app was also determined. Finally, a novel reference method, that would allow accuracy of the mHealth app to be investigated ‘in the wild’, was assessed for validity against the FDA-cleared reference. In Study 2, 165 participants of balanced demographics remotely downloaded the mHealth app and measured their RR. Measures from the mHealth app were compared to the novel reference that was assessed in Study 1. Usability was quantified based on the proportion of participants that were able to successfully use the app to measure their RR and standardised usability scales. RESULTS Outcomes from Study 1 supported further assessment of the mHealth app, including as assessed by the novel reference. The mHealth app, when compared to the FDA-cleared and novel references, respectively, showed a mean absolute error (MAE) of 1.65 (standard deviation (SD) = 1.49) and 1.14 (1.44), relative MAE of 12.2 (9.23) and 9.5 (18.70) and bias of 0.81 (limits of agreement (LoA) = -3.27-4.89) and 0.08 (-3.68-3.51). Pearson Product Moment Correlation (PPMC) coefficients were 0.700 and 0.885. 93% of participants could successfully operate the device on their first use and standardised usability scores were above industry averages. CONCLUSIONS The accuracy and usability of the mHealth app demonstrated in this research hold promise for the use of mHealth solutions employing smartphone movement sensors to remotely monitor RR. Considering methodological limitations, further research should be undertaken to more holistically validate the benefits that this technology may offer patients and healthcare systems.

scholarly journals Reproducibility and validity of a food-frequency questionnaire for use among low-income Brazilian workers

2003 ◽  
Vol 6 (8) ◽  
pp. 821-827 ◽  
Author(s):  
Nélida Schmid Fornés ◽  
Maria Luiza Ferreira Stringhini ◽  
Berenice Müller Elias
Keyword(s):  
Vitamin C ◽  
Total Energy ◽  
Low Income ◽  
Food Frequency Questionnaire ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Nutrient Intakes ◽  
Low Literacy ◽  
Food Frequency

AbstractObjectives:To assess the reproducibility and validity a 127-item, habitual intake, food-frequency questionnaire (FFQ), developed for low-income and low-literacy Brazilian workers, by comparison with a 24-hour dietary recall (24-HDR).Design:The FFQ and 24-HDR were interviewer-administered at the local workplace to each subject twice, with a period of 6 months between estimates; and four 24-HDRs were conducted during the 4-month period between the two FFQs (FFQ1 and FFQ2). Reproducibility was tested by comparing mean nutrient intakes from the two FFQs. Validity was determined by comparing the mean nutrient intakes from the FFQs with the corresponding averages of the six 24-HDRs (reference method).Setting:Goiânia City, in Central West Brazil.Subjects:The study was based on 104 (62 women and 42 men) subjects, aged 18 to 60 years, who were randomly selected.Results:Dietary intake from the FFQ was higher than from the 24-HDR. Reproducibility was assessed by Pearson correlation coefficients for nutrients from FFQ1 and FFQ2, and ranged from 0.23 for retinol to 0.69 for total energy (mean 0.52). Intra-class coefficients for nutrients averaged by the 24-HDRs ranged from 0.29 for vitamin C to 0.76 for total energy; retinol was not significant. In the validation study, correlation between the FFQ and the 24-HDR ranged between 0.21 for vitamin C and 0.70 for total energy (mean 0.50). Adjusting for total energy lowered the coefficients, except for calcium, retinol and vitamin C. Coefficients increased with attenuation, ranging from 0.35 for carbohydrate to 0.65 for calcium.Conclusions:Results indicate that this questionnaire had satisfactory reproducibility and reasonable validity.

scholarly journals Does exclusion of extreme reporters of energy intake (the “Goldberg cutoffs”) reliably reduce or eliminate bias in nutrition studies? Analysis with illustrative associations of energy intake with health outcomes

2019 ◽  
Vol 110 (5) ◽  
pp. 1231-1239 ◽  
Author(s):  
Keisuke Ejima ◽  
Andrew W Brown ◽  
Dale A Schoeller ◽  
Steven B Heymsfield ◽  
Erik J Nelson ◽  
...  
Keyword(s):  
Health Outcomes ◽  
Energy Intake ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Long Term Effects ◽  
Nutrition Survey ◽  
Behavioral Measures ◽  
Data Set ◽  
Method Bias

ABSTRACT Background The Goldberg cutoffs are used to decrease bias in self-reported estimates of energy intake (EISR). Whether the cutoffs reduce and eliminate bias when used in regressions of health outcomes has not been assessed. Objective We examined whether applying the Goldberg cutoffs to data used in nutrition studies could reliably reduce or eliminate bias. Methods We used data from the Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE), the Interactive Diet and Activity Tracking in American Association of Retired Persons (IDATA) study, and the National Diet and Nutrition Survey (NDNS). Each data set included EISR, energy intake estimated from doubly labeled water (EIDLW) as a reference method, and health outcomes including baseline anthropometric, biomarker, and behavioral measures and fitness test results. We conducted 3 linear regression analyses using EISR, a plausible EISR based on the Goldberg cutoffs (EIG), and EIDLW as an explanatory variable for each analysis. Regression coefficients were denoted ${\hat{\beta }_{\rm SR}}$, ${\hat{\beta }_{\rm G}}$, and ${\hat{\beta }_{\rm DLW}}$, respectively. Using the jackknife method, bias from ${\hat{\beta }_{\rm SR}}$ compared with ${\hat{\beta }_{\rm DLW}}$ and remaining bias from ${\hat{\beta }_{\rm G}}$ compared with ${\hat{\beta }_{\rm DLW}}$ were estimated. Analyses were repeated using Pearson correlation coefficients. Results The analyses from CALERIE, IDATA, and NDNS included 218, 349, and 317 individuals, respectively. Using EIG significantly decreased the bias only for a subset of those variables with significant bias: weight (56.1%; 95% CI: 28.5%, 83.7%) and waist circumference (WC) (59.8%; 95% CI: 33.2%, 86.5%) with CALERIE, weight (20.8%; 95% CI: −6.4%, 48.1%) and WC (17.3%; 95% CI: −20.8%, 55.4%) with IDATA, and WC (−9.5%; 95% CI: −72.2%, 53.1%) with NDNS. Furthermore, bias significantly remained even after excluding implausible data for various outcomes. Results obtained with Pearson correlation coefficient analyses were qualitatively consistent. Conclusions Some associations between EIG and outcomes remained biased compared with associations between EIDLW and outcomes. Use of the Goldberg cutoffs was not a reliable method for eliminating bias.

scholarly journals Accuracy-Based Vitamin D Survey: Six Years of Quality Improvement Guided by Proficiency Testing

2019 ◽  
Vol 143 (12) ◽  
pp. 1531-1538 ◽  
Author(s):  
Patrick Erdman ◽  
Darryl E. Palmer-Toy ◽  
Gary Horowitz ◽  
Andrew Hoofnagle
Keyword(s):  
Vitamin D ◽  
Proficiency Testing ◽  
Clinical Laboratory ◽  
Matrix Effects ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Serum Samples ◽  
Testing Program ◽  
Target Values

Context.— The goal of the College of American Pathologists Accuracy-Based Proficiency Testing Program is to promote the quality, standardization, and harmonization of clinical laboratory results through proficiency testing specimens that are free from matrix effects, have target values that are traceable to reference methods, and that probe the limitations of current methods. Objective.— To summarize the first 6 years of the Accuracy-Based Vitamin D Survey and highlight key insights from the data generated as it relates to assay performance. Design.— Accuracy-based challenges were created by using pooled human serum samples. Certain samples were derived from participants in an institutional review board–approved protocol in which vitamin D–deficient participants were treated with ergocalciferol (vitamin D2). Reference targets for the survey were set by the Centers for Disease Control and Prevention using isotope-dilution liquid chromatography–tandem mass spectrometry. Each method was compared with the reference method procedure over the course of the program (n = 43 proficiency testing samples). Results.— Linear regression versus the reference method procedure revealed proportional biases across the methods, ranging from 0.0% to 16.7%. Pearson correlation coefficients (r2) ranged from 0.902 to 0.996. Results were influenced by the concentration of 25-hydroxyvitamin D2 as well as the C-3 epimer of 25-hydroxyvitamin D3. During the 6 years, 2 manufacturers altered their assays to match the reference method procedure more closely. Conclusions.— There is considerable bias, both proportional bias and sample-specific matrix effects, affecting many assays. This ongoing accuracy-based proficiency testing program for vitamin D will provide the data needed for laboratories and manufacturers to improve their assays and thereby patient care.

scholarly journals Assessment of a Rapid Semi-Quantitative Immunochromatographic Test for the Evaluation of Transfer of Passive Immunity in Calves

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1641
Author(s):  
Pauline Delhez ◽  
Elise Meurette ◽  
Emilie Knapp ◽  
Léonard Theron ◽  
Georges Daube ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Weighted Kappa ◽  
Passive Immunity ◽  
Quick Test ◽  
Test Characteristics ◽  
Serum Igg ◽  
Classification Agreement ◽  
On Farm

Calves are born agammaglobulinemic and they rely on transfer of passive immunity (TPI) through ingestion of colostrum from the dam. Ensuring the effectiveness of TPI through blood serum immunoglobulins (IgG) quantification is of critical importance for the prevention of calf diseases. The main objective of this study was to assess the performance of a novel on-farm immunochromatographic quick assay (SmartStripsTM, Bio-X Diagnostics, Rochefort, Belgium) compared to the ELISA reference method to directly measure serum IgG concentration and assess TPI status in beef and dairy calves. Additional comparison was made with the commonly used Brix refractometer. Jugular blood samples were collected from beef (n = 71) and dairy (n = 26) calves in Belgium within 7 days post-birth. Quantitative (Pearson correlation coefficients, Bland-Altman plots) and qualitative (diagnostic test characteristics, weighted kappa for classification into 4 categories of TPI) analyses were performed to evaluate the performances of the quick test and the refractometer compared to ELISA. The quick test showed a correlation of 0.83 and a classification agreement (weighted kappa) of 0.79 with the reference method (average values for two types of blood anticoagulants). Performances were better for low IgG concentrations and the assessment of poor TPI status and they outperformed those of the Brix refractometer. Results suggested that the immunochromatographic quick test can be considered as a suitable on-farm method for direct serum IgG measurement and the assessment of TPI status in calves, contributing to timely interventions in the management of calves with inadequate TPI.

scholarly journals Diaphragm shear modulus reflects transdiaphragmatic pressure during isovolumetric inspiratory efforts and ventilation against inspiratory loading

2019 ◽  
Vol 126 (3) ◽  
pp. 699-707 ◽  
Author(s):  
Damien Bachasson ◽  
Martin Dres ◽  
Marie-Cécile Niérat ◽  
Jean-Luc Gennisson ◽  
Jean-Yves Hogrel ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Confidence Intervals ◽  
Shear Wave ◽  
Repeated Measures ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Shear Wave Elastography ◽  
Transdiaphragmatic Pressure ◽  
Diaphragm Function

The reference method for the assessment of diaphragm function relies on the measurement of transdiaphragmatic pressure (Pdi). Local muscle stiffness measured using ultrafast shear wave elastography (SWE) provides reliable estimates of muscle force in locomotor muscles. This study aimed at investigating whether SWE could be used as a surrogate of Pdi to evaluate diaphragm function. Fifteen healthy volunteers underwent a randomized stepwise inspiratory loading protocol of 0–60% of maximal isovolumetric inspiratory pressure during closed-airways maneuvers and 0–50% during ventilation against an external inspiratory threshold load. During all tasks, Pdi was measured and SWE was used to assess shear modulus of the right hemidiaphragm (SMdi) at the zone of apposition. Pearson correlation coefficients ( r) and repeated-measures correlation coefficients ( R) were computed to determine within-individual and overall relationships between Pdi and SMdi, respectively. During closed-airways maneuvers, mean Pdi correlated to mean SMdi in all participants [ r ranged from 0.77 to 0.96, all P < 0.01; R = 0.82, 95% confidence intervals (0.76, 0.86), P < 0.01]. During ventilation against inspiratory threshold loading, Pdi swing correlated to maximal SMdi in all participants [ r ranged from 0.40 to 0.90, all P < 0.01; R = 0.70, 95% confidence intervals (0.66, 0.73), P < 0.001]. Changes in diaphragm stiffness as assessed by SWE reflect changes in transdiaphragmatic pressure. SWE provides a new opportunity for direct and noninvasive assessment of diaphragm function. NEW & NOTEWORTHY Accurate and specific estimation of diaphragm effort is critical for evaluating and monitoring diaphragm dysfunction. The measurement of transdiaphragmatic pressure requires the use of invasive gastric and esophageal probes. In the present work, we demonstrate that changes in diaphragm stiffness assessed with ultrasound shear wave elastography reflect changes in transdiaphragmatic pressure, therefore offering a new noninvasive method for gauging diaphragm effort.

scholarly journals The reliability and reproducibility of an Android cephalometric smartphone application in comparison with the conventional method

2020 ◽  
Author(s):  
Obada M. Zamrik ◽  
Haluk İşeri
Keyword(s):  
Conventional Method ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Smartphone Application ◽  
Linear Measurement ◽  
Significant Difference ◽  
The Difference ◽  
Clinically Significant ◽  
Mean Differences ◽  
Tracing Techniques

ABSTRACT Objectives To assess the reliability and reproducibility of linear and angular measurements of the cephalometric smartphone Android application OneCeph in comparison with the conventional method. Materials and Methods A total number of 22 landmarks were registered, and 26 skeletal and dental cephalometric parameters were measured on 30 pretreatment cephalograms. The measurements for both digital (OneCeph) and conventional tracings were performed twice with a 4-week interval. The reliability (intraexaminer error) was evaluated by using the Pearson correlation coefficient. The variation in measurements between the tracing techniques (reproducibility) was determined by paired t-test. Results The Pearson correlation coefficients of all cephalometric measurements for each tracing technique were ≥ 0.95. Significant differences between the two tracing techniques were detected in five measurements (SNB angle, N I to Pog linear measurement, U1-Apoint linear measurement, U lip to S line, and nasiolabial angle; P &lt; .05). Conclusions Using 26 measurements to compare both tracing methods, all mean differences between the digital (OneCeph) and conventional methods were below 1 degree/1 mm, indicating that differences between the tracing methods were clinically insignificant. The U1-A point measurement was an exception for the digital method (OneCeph) with a clinically significant difference of 1.25 mm (P &lt; .01); the difference was a result of wrongly measuring the distance from the A line to the incisor edge of the upper central incisor rather than the facial surface of the upper incisor. This leads to the conclusion that both tracing methods were reliable for daily clinical practice.

Development and Validation of a Semiquantitative Food Frequency Questionnaire to Assess Dietary Intake in 40–65-Year-Old Mexican Women

2020 ◽  
Vol 76 (1) ◽  
pp. 73-82
Author(s):  
Alexandra Tijerina ◽  
Josep A. Tur
Keyword(s):  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Epidemiological Studies ◽  
Test Method ◽  
Mexican Women ◽  
Food Groups ◽  
Nutrient Intakes ◽  
Food Frequency

Background and Aims: Food frequency questionnaires (FFQ) have been widely used in epidemiologic studies since 1990s, but instruments need to be validated. The aim of this work was to create and assess the validity and reproducibility of an interview administered FFQ to be used in a Mexican women’s bone health cohort study, located in Monterrey city, Mexico. Methods: Validation of FFQ formed by 11 food groups and 136 food and beverage items was performed on 40–65-year-old Mexican women (n = 200) by applying 2 FFQ (test method) and six 24-h dietary recalls (24hR, reference method; 1 per season on weekdays and 2 on weekends). Pearson correlation coefficient was calculated of both logs, transformed intakes and energy-adjusted nutrient intakes based on the residual method, and intraclass correlation coefficients were calculated. Results: The relative validity of FFQ against the average of six 24hR for intakes of energy, macronutrients, cholesterol, water, vitamins and minerals required for bone metabolism such as vitamin D, calcium, magnesium, phosphorus were obtained. Pearson coefficients of correlation show significance (p < 0.05) for the validity, 0.244–0.820 and 0.258–0.794, for energy-unadjusted and adjusted data, respectively. Reproducibility coefficients range 0.186–0.810 for energy-unadjusted data and 0.174–0.597 for energy-adjusted data. Most nutrients showed lower than 5% of misclassification. Conclusion: The designed 136-item FFQ shows acceptable validity and reproducibility, and it is useful to be applied on 40–65-year-old Mexican women for the estimation of nutrient intakes in epidemiological studies.

scholarly journals Validation of a food frequency questionnaire designed for adolescents in Salvador, Bahia, Brazil

2016 ◽  
Vol 29 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Jean Márcia Oliveira MASCARENHAS ◽  
Rita de Cássia Ribeiro SILVA ◽  
Maria Ester Pereira Conceição MACHADO ◽  
Carlos Antonio de Souza Teles SANTOS ◽  
Dirce Maria Lobo MARCHIONI ◽  
...  
Keyword(s):  
Public Schools ◽  
Food Frequency Questionnaire ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Kappa Statistics ◽  
Food Record ◽  
Food Frequency ◽  
Good Ability ◽  
The Mean

Objective: This study assessed the validity of a Food Frequency Questionnaire used to assess food intake in adolescents in Salvador, Bahia, Brazil. Methods: Seventy adolescents enrolled in public schools aged 11 to 17 years participated in this study. The dietary intake of the adolescents was assessed using the Food Frequency Questionnaire and the mean value of three-day food record, used as the reference method. The mean (and standard deviation) energy and nutrient intakes estimated from the Food Frequency Questionnaire and food records were calculated. The paired Student's t test was used to determine differences between the data. Results: Pearson's correlation coefficient and Kappa statistics were used to measure the strength of the association between the two instruments. There was variation in the crude unadjusted (r=0.61-0.73) and deattenuated (r=0.33-0.99) Pearson correlation coefficients. After adjusting for energy, the crude and deattenuated coefficients ranged from r=0.53-0.81 and r=0.27-0.99, respectively. The intake of energy and most nutrients were found to be adequate, except for fiber (r=0.27) and calcium (r=0.33), which showed a weak correlation. Kappa statistics showed good correlation between all values varying from r=0.47 to 0.73. Conclusion: It is considered that an average r value greater than 0.40 indicates a good correlation, the results obtained indicate the good ability of the Food Frequency Questionnaire to assess individuals according to their usual intake of most nutrients.

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

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