Is a Picture Worth a Thousand Medical Words? A Randomized Trial of Reporting Formats for Medical Research Data

1991 ◽  
Vol 30 (02) ◽  
pp. 145-150 ◽  
Author(s):  
L. S. Elting ◽  
G. P. Bodey
Keyword(s):  
Clinical Trials ◽  
Randomized Trial ◽  
Repeated Measures ◽  
Time Dependent ◽  
Medical Settings ◽  
Repeated Measures Design ◽  
Valuable Method ◽  
The Status ◽  
The Individual ◽  
Pie Chart

AbstractMonitoring data that vary over time is an essential component of medical practice. This is doubly true in clinical trials in which the overall safety and efficacy of investigational treatments in populations must be monitored in addition to the status of the individual patients who receive them. We report the results of a randomized trial of four reporting methods for time-dependent information derived from clinical trials; narrative text, table, pie chart and icon. Multivariate analysis of variance with a repeated measures design was used to analyze the efficiency of subjects’ (physicians, research nurses and laboratory personnel) assimilation of information. Icons were found to be superior to the other reporting formats tested in both speed (p <0.0001) and accuracy (p = 0.02). The differences were most pronounced in subjects’ first exposure to the data, suggesting that icons reduce the time needed for training. We conclude that icons are a valuable method for presentation of time-dependent information in medical settings.

scholarly journals Effects of the Carrier Phrase on Word Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

2020 ◽  
Vol 31 (06) ◽  
pp. 412-441 ◽  
Author(s):  
Richard H. Wilson ◽  
Victoria A. Sanchez
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Speaker Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Test Word ◽  
Root Mean Square Amplitude ◽  
Repeated Measures Design ◽  
The Mean ◽  
The Individual

Abstract Background In the 1950s, with monitored live voice testing, the vu meter time constant and the short durations and amplitude modulation characteristics of monosyllabic words necessitated the use of the carrier phrase amplitude to monitor (indirectly) the presentation level of the words. This practice continues with recorded materials. To relieve the carrier phrase of this function, first the influence that the carrier phrase has on word recognition performance needs clarification, which is the topic of this study. Purpose Recordings of Northwestern University Auditory Test No. 6 by two female speakers were used to compare word recognition performances with and without the carrier phrases when the carrier phrase and test word were (1) in the same utterance stream with the words excised digitally from the carrier (VA-1 speaker) and (2) independent of one another (VA-2 speaker). The 50-msec segment of the vowel in the target word with the largest root mean square amplitude was used to equate the target word amplitudes. Research Design A quasi-experimental, repeated measures design was used. Study Sample Twenty-four young normal-hearing adults (YNH; M = 23.5 years; pure-tone average [PTA] = 1.3-dB HL) and 48 older hearing loss listeners (OHL; M = 71.4 years; PTA = 21.8-dB HL) participated in two, one-hour sessions. Data Collection and Analyses Each listener had 16 listening conditions (2 speakers × 2 carrier phrase conditions × 4 presentation levels) with 100 randomized words, 50 different words by each speaker. Each word was presented 8 times (2 carrier phrase conditions × 4 presentation levels [YNH, 0- to 24-dB SL; OHL, 6- to 30-dB SL]). The 200 recorded words for each condition were randomized as 8, 25-word tracks. In both test sessions, one practice track was followed by 16 tracks alternated between speakers and randomized by blocks of the four conditions. Central tendency and repeated measures analyses of variance statistics were used. Results With the VA-1 speaker, the overall mean recognition performances were 6.0% (YNH) and 8.3% (OHL) significantly better with the carrier phrase than without the carrier phrase. These differences were in part attributed to the distortion of some words caused by the excision of the words from the carrier phrases. With the VA-2 speaker, recognition performances on the with and without carrier phrase conditions by both listener groups were not significantly different, except for one condition (YNH listeners at 8-dB SL). The slopes of the mean functions were steeper for the YNH listeners (3.9%/dB to 4.8%/dB) than for the OHL listeners (2.4%/dB to 3.4%/dB) and were <1%/dB steeper for the VA-1 speaker than for the VA-2 speaker. Although the mean results were clear, the variability in performance differences between the two carrier phrase conditions for the individual participants and for the individual words was striking and was considered in detail. Conclusion The current data indicate that word recognition performances with and without the carrier phrase (1) were different when the carrier phrase and target word were produced in the same utterance with poorer performances when the target words were excised from their respective carrier phrases (VA-1 speaker), and (2) were the same when the carrier phrase and target word were produced as independent utterances (VA-2 speaker).

Time dependent changes in red blood cells during storage in the local blood banks of Khyber Pakhtunkhwa

2020 ◽  
pp. 1-16
Author(s):  
Syed Muhammad Tahir Shah ◽  
Yasar Mehmood Yousafzai ◽  
Najma Baseer
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Repeated Measures ◽  
Osmotic Fragility ◽  
Time Dependent ◽  
Prolonged Storage ◽  
Khyber Pakhtunkhwa ◽  
Repeated Measures Design ◽  
Blood Banks ◽  
Scanning Electron

Abstract Objective: This project aimed at determining time-dependent ultrastructural and hematological changes taking place in blood stored in local blood banks of Khyber Pakhtunkhwa. Methods: It was a longitudinal study with repeated measures design. Twenty healthy blood donors participated in this study. An amount of 250ml blood was collected from each donor and stored in Citrate Phosphate Dextrose Adenine-1 (CPDA-1)-containing blood bags. Within first four hours, baseline samples were taken while subsequent samples were obtained at 5 days interval till day 20 th . Structural changes in RBCs were observed under light and scanning electron microscope (SEM) at different intervals. Furthermore, hematological parameters and osmotic fragility were also determined. Results: Remarkable alterations were seen in RBCs morphology. From 5th day onwards, multiple visible spicules were observed on the RBC’s outer membrane and more than 2/3rd cells were abnormal at day 20. There was a significant reduction in RBCs count and hemoglobin concentration while the remaining parameters remained unchanged. Osmotic fragility increased significantly over time, with &lt;1% haemolysis noted in baseline samples as compared to 2.4% haemolysis on day 20th (p?0.0001). Conclusion: Prolonged storage of blood results in distorted RBCs morphology and increased fragility. Transfusion of such cells would potentially result in rapid lysis in patients with hepatosplenomegaly and conditions requiring multiple blood transfusions. Keywords: Red cells storage, scanning electron microscope, osmotic fragility, Transfusion, Blood storage, hemoglobin. Continuous...

Accuracy and Reliability of a Real-Ear-to-Coupler Difference Measurement Procedure Implemented within a Behind-the-Ear Hearing Aid

2011 ◽  
Vol 22 (09) ◽  
pp. 612-622 ◽  
Author(s):  
Susan Scollie ◽  
Marlene Bagatto ◽  
Sheila Moodie ◽  
Jeff Crukley
Keyword(s):  
Repeated Measures ◽  
Predictive Accuracy ◽  
Hearing Aid ◽  
Measurement Procedure ◽  
Convenience Sample ◽  
Retest Reliability ◽  
The Real ◽  
Repeated Measures Design ◽  
The Individual ◽  
Test Retest Reliability

Background: Measurement of the real ear response of a fitted hearing aid allows matching of the frequency response to prescriptive targets, as well as comparison of the response to both threshold and loudness discomfort level (LDL). These processes are recommended procedures for hearing aid fittings. The real ear aided response (REAR) is often predicted based on the coupler response of the device, the real-ear-to-coupler difference (RECD), and the microphone location effect (MLE). Individualized measurement of the RECD tends to increase the accuracy of this prediction. A commercial hearing aid has been developed that measures the individual RECD and incorporates the data into the software-assisted fitting process. Purpose: This study evaluated the test-retest reliability and predictive validity of this particular method for measuring the RECD. Research Design: A repeated measures design was used to evaluate differences between subsequent measures of the RECD in the same ear, and prediction differences associated with using the RECD (and other information) to predict the REAR. Study Sample: Fifteen ears, on a convenience sample of ten adults (45–86 yr) and five children (6–15 yr) were tested. All participants were hearing aid users. Data Collection and Analysis: Predicted and measured REARs were collected using normal clinical procedures, on an Audioscan Verifit VF-1 for two test signals/levels. Reliability, mean differences between predicted and measured REARs, and 95% confidence intervals of the prediction accuracy are reported. Results: The RECD procedure had test-retest reliability within 2.5 dB for 14 out of 15 ears between 500 and 4000 Hz, and had predictive accuracy within 5 dB between 500 and 4000 Hz for 14 out of 15 ears. However, errors associated with earhook misalignment were discovered. Also, the RECD values measured using this hearing-aid-specific procedure differ somewhat from the normative data available from insert earphone RECDs. Conclusions: This procedure, when measured according to recommendations, provides a reasonably accurate prediction of the REAR. Functionally, this procedure does not replace the range of measures offered by modern real ear measurement systems. However, given the inaccuracy of software-assisted fittings without a measure of individual ear canal acoustics, use of this procedure may have the potential to improve the accuracy of fittings versus fittings completed without real ear measurement.

The Words-in-Noise Test (WIN), List 3: A Practice List

2012 ◽  
Vol 23 (02) ◽  
pp. 092-096 ◽  
Author(s):  
Richard H. Wilson ◽  
Kelly L. Watts
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Repeated Measures ◽  
Word List ◽  
Normal Hearing ◽  
Sensorineural Hearing ◽  
Practice List ◽  
Repeated Measures Design ◽  
Noise Test ◽  
The Individual

Background: The Words-in-Noise Test (WIN) was developed as an instrument to quantify the ability of listeners to understand monosyllabic words in background noise using multitalker babble (Wilson, 2003). The 50% point, which is calculated with the Spearman-Kärber equation (Finney, 1952), is used as the evaluative metric with the WIN materials. Initially, the WIN was designed as a 70-word instrument that presented ten unique words at each of seven signal-to-noise ratios from 24 to 0 dB in 4 dB decrements. Subsequently, the 70-word list was parsed into two 35-word lists that achieved equivalent recognition performances (Wilson and Burks, 2005). This report involves the development of a third list (WIN List 3) that was developed to serve as a practice list to familiarize the participant with listening to words presented in background babble. Purpose: To determine—on young listeners with normal hearing and on older listeners with sensorineural hearing loss—the psychometric properties of the WIN List 3 materials. Research Design: A quasi-experimental, repeated-measures design was used. Study Sample: Twenty-four young adult listeners (M = 21.6 yr) with normal pure-tone thresholds (≤20 dB HL at 250 to 8000 Hz) and 24 older listeners (M = 65.9 yr) with sensorineural hearing loss participated. Data Collection and Analysis: The level of the babble was fixed at 80 dB SPL with the level of the words varied from 104 to 80 dB SPL in 4 dB decrements. Results: For listeners with normal hearing, the 50% points for Lists 1 and 2 were similar (4.3 and 5.1 dB S/N, respectively), both of which were lower than the 50% point for List 3 (7.4 dB S/N). A similar relation was observed with the listeners with hearing loss, 50% points for Lists 1 and 2 of 12.2 and 12.4 dB S/N, respectively, compared to 15.8 dB S/N for List 3. The differences between Lists 1 and 2 and List 3 were significant. The relations among the psychometric functions and the relations among the individual data both reflected these differences. Conclusions: The significant ˜3 dB difference between performances on WIN Lists 1 and 2 and on WIN List 3 by the listeners with normal hearing and the listeners with hearing loss dictates caution with the use of List 3. The use of WIN List 3 should be reserved for ancillary purposes in which equivalent recognition performances are not required, for example, as a practice list or a stand alone measure.

Unreliability of Difference Scores: A Clarification of the Issues

1977 ◽  
Vol 40 (3) ◽  
pp. 931-935 ◽  
Author(s):  
Stephen Leeb ◽  
Sharon Weinberg
Keyword(s):  
Repeated Measures ◽  
Experimental Situation ◽  
T Test ◽  
Specific Knowledge ◽  
Difference Scores ◽  
Repeated Measures Design ◽  
Power Of The Test ◽  
Mean And Variance ◽  
The Difference ◽  
The Individual

This paper is an attempt to clarify several recent issues that have been raised concerning the unreliability of difference scores. Articles by Overall and Woodward (1975, 1976) and Fleiss (1976) are considered. The conclusions of these articles are shown to be incomplete and to some extent misleading. We begin by noting that within the context of a repeated-measures design, when the reliability of difference scores is other than zero, there exists an interaction of subject by treatment. This interaction will imply the existence of at least one additional systematic variable which contributes to the experimental results. We argue that without specific knowledge about the mean and variance of this systematic variable the interpretation of mean changes across pretest and posttest is ambiguous. With complete knowledge of all variables affecting the experimental situation, the power of the t test on difference scores is directly related to both the individual reliabilities of the separate pretest and posttests and the reliability of the difference scores as long as interaction of subject by treatment is constant across experiments. If, on the other hand, that interaction is not constant across experiments, then the power of the test on difference scores is inversely related to the reliability of the difference scores as long as the individual reliabilities of the pretests and posttests are constant across experiments. Since it is much more reasonable to make the assumption that the interaction is constant across experiments rather than individual test reliabilities, it is more reasonable to conclude that, contrary to Overall and Woodward, power of the t test for difference scores is directly related to the reliability of the difference scores.

Effects of the Carrier Phrase on Word-Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

2020 ◽  
Author(s):  
Richard H. Wilson ◽  
Victoria A. Sanchez
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Speaker Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Test Word ◽  
Root Mean Square Amplitude ◽  
Repeated Measures Design ◽  
The Mean ◽  
The Individual

Background: In the 1950s, with monitored live voice testing, the vu meter time constant and the shortdurations and amplitude modulation characteristics of monosyllabic words necessitated the use of the carrierphrase amplitude tomonitor (indirectly) the presentation level of the words. This practice continues withrecorded materials. To relieve the carrier phrase of this function, first the influence that the carrier phrasehas on word recognition performance needs clarification, which is the topic of this study.<br />Purpose: Recordings of Northwestern University Auditory Test No. 6 by two female speakers were usedto compare word recognition performances with and without the carrier phrases when the carrier phraseand test word were (1) in the same utterance stream with the words excised digitally from the carrier (VA-1speaker) and (2) independent of one another (VA-2 speaker). The 50-msec segment of the vowel in thetarget word with the largest root mean square amplitude was used to equate the target word amplitudes.<br />Research Design: A quasi-experimental, repeated measures design was used.<br />Study Sample: Twenty-four young normal-hearing adults (YNH; M = 23.5 years; pure-tone average[PTA] = 1.3-dB HL) and 48 older hearing loss listeners (OHL; M = 71.4 years; PTA = 21.8-dB HL) participatedin two, one-hour sessions.<br />Data Collection and Analyses: Each listener had 16 listening conditions (2 speakers 3 2 carrier phraseconditions 3 4 presentation levels) with 100 randomized words, 50 different words by each speaker.Each word was presented 8 times (2 carrier phrase conditions 3 4 presentation levels [YNH, 0- to24-dB SL; OHL, 6- to 30-dB SL]). The 200 recorded words for each condition were randomized as 8,25-word tracks. In both test sessions, one practice track was followed by 16 tracks alternated betweenspeakers and randomized by blocks of the four conditions. Central tendency and repeated measuresanalyses of variance statistics were used.<br />Results: With the VA-1 speaker, the overall mean recognition performances were 6.0% (YNH) and 8.3%(OHL) significantly better with the carrier phrase than without the carrier phrase. These differences werein part attributed to the distortion of some words caused by the excision of the words from the carrierphrases. With the VA-2 speaker, recognition performances on the with and without carrier phrase conditionsby both listener groups were not significantly different, except for one condition (YNH listeners at8-dB SL). The slopes of the mean functions were steeper for the YNH listeners (3.9%/dB to 4.8%/dB) thanfor the OHL listeners (2.4%/dB to 3.4%/dB) and were <1%/dB steeper for the VA-1 speaker than for theVA-2 speaker. Although the mean results were clear, the variability in performance differences betweenthe two carrier phrase conditions for the individual participants and for the individual words was strikingand was considered in detail.<br />Conclusion: The current data indicate that word recognition performances with and without the carrierphrase (1) were different when the carrier phrase and target word were produced in the same utterancewith poorer performances when the target words were excised from their respective carrier phrases(VA-1 speaker), and (2) were the same when the carrier phrase and target word were produced as independentutterances (VA-2 speaker).<br />See the Supplementary Data tab for supplementary materials.

Do male Boana goiana (Lutz, 1968) (Anura: Hylidae) discriminate between the calls of neighbours and strangers?

Behaviour ◽  
2021 ◽  
pp. 1-18
Author(s):  
Alessandro R. Morais ◽  
Mariana N. Siqueira ◽  
Rafael Márquez ◽  
Rogério P. Bastos
Keyword(s):  
Social Factors ◽  
Repeated Measures ◽  
Dominant Frequency ◽  
Initial Position ◽  
Acoustic Properties ◽  
Agonistic Interactions ◽  
Dear Enemy ◽  
Repeated Measures Design ◽  
The Individual ◽  
Aggressive Calls

Abstract Neighbour-stranger discrimination is an important mechanism in social behaviour, as it allows the individual to avoid the high energetic costs of repeated agonistic interactions with neighbours. In some anuran species, the owners of territories respond more aggressively towards strangers than neighbours. Here, we investigated whether gladiator frog, Boana goiana, males discriminate between neighbours and strangers. This is a lek-breeding species; therefore, it does not defend fixed territories which are associated with a specific resource. We conducted a playback field experiment with a repeated-measures design, based on three treatments: (i) neighbour’s call in initial position, (ii) stranger’s call in initial position, and (iii) neighbour’s call in new position. We did not observe any systematic modification in the acoustic properties (call duration, dominant frequency, repetition rate) of the advertisement and short aggressive calls of B. goiana males given in response to our playback treatments. Our results indicate that B. goiana males do not exhibit vocally mediated ‘dear enemy’ relationships. We discuss the possible ecological and social factors that may have impeded the evolution of ‘dear enemy’ relationships in this species.

Power of Modified Brown-Forsythe and Mixed-Model Approaches in Split-Plot Designs

Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero
Keyword(s):  
Repeated Measures ◽  
Statistical Power ◽  
Mixed Model ◽  
Covariance Structure ◽  
Simulation Method ◽  
Future Research ◽  
Repeated Measures Design ◽  
Fixed And Random Effects ◽  
Split Plot ◽  
High Level

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.

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