Category: Statistics

J Speech Lang Hear Res. 2022 Jul 19:1-12. doi: 10.1044/2022_JSLHR-20-00722. Online ahead of print.

ABSTRACT

PURPOSE: Core lexicon measures have received growing attention in research. They are intended to provide clinicians with a clinician-friendly means to quantify word retrieval ability in discourse based on normal expectations of discourse production for specific discourse elicitation tasks. To date, different criteria have been used to develop core lexicon measures by groups of researchers. The need for statistical guidance in pursuit of the psychologically robust measure has been recognized.

AIMS: This study was to investigate the best criterion for accurate measurement. Specifically, we focused on two criteria (frequency vs. percentage) that have previously been used for the development of core lexicon measures.

METHOD: Core lexicon measures consisting of five different checklists by word class (verbs, nouns, adjectives, adverbs, and function words) and developed by the two criteria were applied to language samples produced by 470 cognitively healthy adults. Performance in word retrieval ability at the discourse level was modeled as a latent variable based on the observed proportions of the production of core lexicon items in two different sets of core lexicon measures using structural equation modeling.

RESULTS: Results indicated that both criterion for core lexicon measures capture word retrieval ability in discourse. Greater residual variances were found in the core lexicon measure established by the percentage criterion compared to the one established by the frequency criterion. This indicates that the measure based on the percentage criterion is more affected by measurement errors.

CONCLUSIONS: The findings provide evidence that the frequency criterion is better to use for the development of core lexicon measures for core nouns, verbs, adjectives, and adverbs, but not for function words. However, our findings are limited to core lexicon measures based on language samples elicited by wordless picture books. This may not be easily applied to other core lexicon measures that use different discourse elicitation tasks due to the difference in quality and quantity of language samples. Ideally, the same approach should be replicated to evaluate the appropriateness of respective criteria in the development of core lexicon measures.

SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.20304144.

PMID:35858271 | DOI:10.1044/2022_JSLHR-20-00722

Am J Speech Lang Pathol. 2022 Jul 12;31(4):1845-1853. doi: 10.1044/2022_AJSLP-21-00385. Epub 2022 Jul 7.

ABSTRACT

PURPOSE: The tongue plays a key role in bolus propulsion during swallowing, with reduced lingual pressure generation representing a risk factor for impaired swallowing safety and efficiency. We compared lingual pressure generation capacity in people with Parkinson disease (PwPD), people with amyotrophic lateral sclerosis (PwALS), and healthy older adults. We hypothesized that both patient cohorts would demonstrate reduced maximum anterior isometric pressure (MAIP) and regular effort saliva swallow (RESS) pressures compared with healthy controls, with the greatest reductions expected in the ALS cohort.

METHOD: We enrolled 20 PwPD, 18 PwALS, and 20 healthy adults over 60 years of age. The Iowa Oral Performance Instrument was used to measure MAIP, RESS, and lingual functional reserve (LFR, i.e., MAIP – RESS). Descriptive statistics were calculated; between-groups differences were explored using univariate analyses of variance and post hoc Sidak tests with alpha set at .05.

RESULTS: Mean MAIPs for the PD, ALS, and heathy cohorts were 54.7, 33.5, and 47.4 kPa, respectively. Significantly lower MAIP was found in PwALS compared with PwPD and healthy controls. RESS values did not differ significantly across groups. LFR was significantly higher in PwPD versus PwALS and healthy controls.

CONCLUSIONS: Lingual pressure generation capacity and functional reserve were reduced in PwALS, but not in PwPD, beyond changes seen with healthy aging. Both patient cohorts displayed preserved lingual pressure during saliva swallows. Future studies exploring longitudinal changes in tongue pressure generation on isometric and saliva swallowing tasks will be needed to confirm whether tongue pressure measures serve as noninvasive clinical biomarkers of swallowing impairment.

PMID:35858265 | DOI:10.1044/2022_AJSLP-21-00385

J Speech Lang Hear Res. 2022 Jul 18;65(7):2594-2607. doi: 10.1044/2022_JSLHR-22-00141. Epub 2022 Jul 5.

ABSTRACT

PURPOSE: The purpose of this meta-analysis was to assess the frequency of sex, race, and ethnicity reporting and proportional representation in funded, noncancerous voice clinical trials to determine the state of compliance with National Institutes of Health (NIH) guidelines for inclusivity in clinical research.

METHOD: Clinical trials registered with the NIH/U.S. National Library of Medicine between January 1988 and September 2021 were analyzed. Primary reports of the trials were obtained from clinicaltrials.gov and PubMed. Outcomes included the proportion of trials reporting sex, race, and ethnicity and the proportion of participants by sex, race, and ethnicity in the trials. Descriptive statistics and chi-square tests were used to analyze the data with 95% confidence intervals (CIs) reported.

RESULTS: The search yielded 46 research studies. After inclusion and exclusion criteria were applied and attempts to locate studies were conducted, 11 total articles were ultimately evaluated. Descriptively, there were more female subjects, yet overall, no significant difference in sex distribution (χ² = 0.07, p = .75, 95% CI [-0.25, -0.19]). Race and ethnicity were only reported in two clinical trials. Black participants were underrepresented in one clinical trial (χ² = 4.93, p = .02, 95% CI [-0.11, -0.02]), whereas Hispanic participants were underrepresented in a second trial (χ² = 11.27, p < .00, 95% CI [-0.20, – 0.13]).

CONCLUSIONS: This preliminary analysis highlights the disparities in race and ethnicity recruitment and reporting in noncancerous voice clinical trials. There is a need for strategic recruitment strategies and improved reporting practices to adhere to the NIH inclusivity directives.

PMID:35858261 | DOI:10.1044/2022_JSLHR-22-00141

J Speech Lang Hear Res. 2022 Jul 18;65(7):2586-2593. doi: 10.1044/2022_JSLHR-21-00632. Epub 2022 Jul 5.

ABSTRACT

PURPOSE: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects bulbar functions including speech and voice. Voice onset time (VOT) was examined in speakers with ALS in early and late stages to explore the coordination of the articulatory and phonatory systems during speech production.

METHOD: VOT was measured in nonword /bap/ produced by speakers with early-stage ALS (n = 11), late-stage ALS (n = 6), and healthy controls (n = 13), and compared with speech performance decline (a marker of disease progression) in ALS.

RESULTS: Overall comparison of the VOT values among the three groups showed a significant difference, F(2,27) = 11.71, p < .01. Speakers in late-stage ALS displayed longer voicing lead (negative VOT) than both healthy speakers and speakers in early-stage ALS. VOT was also significantly negatively correlated with speech performance (i.e., Intelligible Speaking Rate), r(15) = .74, p < .01.

CONCLUSIONS: Speakers with more severe ALS showed greater occurrence of voicing lead and longer voicing lead. Findings show voicing precedes articulatory onset with disease progression in the production of bilabial stops, which suggests that the relative timing of coordination between the supralaryngeal structures and the phonatory system is affected in the late stage of ALS.

PMID:35858258 | DOI:10.1044/2022_JSLHR-21-00632

Am J Physiol Endocrinol Metab. 2022 Jul 20. doi: 10.1152/ajpendo.00052.2022. Online ahead of print.

ABSTRACT

The objective of this study was to investigate the effect of dietary fatty acid (FA) composition on bile acid (BA) metabolism in a pig model of NAFLD, by using a multiomics approach combined with histology and serum biochemistry. Thirty 20-d-old Iberian pigs pair-housed in pens were randomly assigned to receive 1 of 3 hypercaloric diets for 10 weeks: 1) lard-enriched (LAR; n=5 pens), 2) olive oil-enriched (OLI, n=5), and 3) coconut oil-enriched (COC; n=5). Animals were euthanized on week 10 after blood sampling, and liver, colon and distal ileum (DI) were collected for histology, metabolomics, and transcriptomics. Data were analyzed by multivariate and univariate statistics. Compared with OLI and LAR, COC increased primary and secondary BAs in liver, plasma and colon. In addition, both COC and OLI reduced circulating fibroblast growth factor 19, increased hepatic necrosis, composite lesion score, and liver enzymes in serum, and upregulated genes involved in hepatocyte proliferation and DNA repair. The severity of liver disease in COC and OLI pigs was associated with increased levels of phosphatidylcholines, medium-chain triacylglycerides, trimethylamine-N-oxide, and long-chain acylcarnitines in the liver, and the expression of pro-fibrotic markers in DI, but not with changes in the composition or size of BA pool. In conclusion, our results indicate a role of dietary FAs in the regulation of BA metabolism and progression of NAFLD. Interventions that aim to modify the composition of dietary FAs, rather than to regulate BA metabolism or signaling, may be more effective in the treatment of NAFLD.

PMID:35858244 | DOI:10.1152/ajpendo.00052.2022

J Speech Lang Hear Res. 2022 Jul 18;65(7):2677-2690. doi: 10.1044/2022_JSLHR-21-00522. Epub 2022 Jul 6.

ABSTRACT

PURPOSE: Individual-randomized trials are the gold standard for testing the efficacy and effectiveness of drugs, devices, and behavioral interventions. Health care delivery, educational, and programmatic interventions are often complex, involving multiple levels of change and measurement precluding individual randomization for testing. Cluster-randomized trials and cluster-randomized stepped-wedge trials are alternatives where the intervention is allocated at the group level, such as a clinic or a school, and the outcomes are measured at the person level. These designs are introduced along with the statistical implications of similarities among individuals within the same cluster. We also illustrate the parameters that have the most impact on the likelihood of detecting intervention effects, which must be considered when planning these trials.

CONCLUSION: Cluster-randomized and stepped-wedge designs should be considered by researchers as experimental alternatives to individual-randomized trials when testing speech, language, and hearing care interventions in real-world settings.

PMID:35858257 | DOI:10.1044/2022_JSLHR-21-00522

J Refract Surg. 2022 Jul;38(7):465-473. doi: 10.3928/1081597X-20220516-01. Epub 2022 Jul 1.

ABSTRACT

PURPOSE: To explore ocular refraction shift after Neodymium: yttrium aluminum garnet (Nd:YAG) posterior capsulotomy in pseudophakic eyes.

METHODS: A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases until November 10, 2021. Studies on the evaluation of changes in spherical equivalent (SE), cylindrical error (CE), or anterior chamber depth (ACD) after Nd:YAG laser capsulotomy were included in the meta-analysis. The review was registered in the international platform of registered systematic review and meta-analysis protocols (INPLASY202120059).

RESULTS: A total of 805 eyes from 18 studies were included in the final analysis. The pooled mean differences in SE from baseline to postoperative follow-up points were not significant (1 hour: 0.04 diopters [D], 95% CI: -0.13 to 0.21, P = .644; 1 week: 0.04 D, 95% CI: -0.12 to 0.20, P = .640; 1 month: 0.05 D, 95% CI: -0.06 to 0.16, P = .349). There was no significant difference between baseline CE and any subsequent visit (1 week: 0.14 D, 95% CI: -0.06 to 0.33, P = .172; 1 month: 0.17 D, 95% CI: -0.04 to 0.38, P = .108). No statistical difference in ACD from baseline was observed either (1 hour: 0.01 mm, 95% CI: -0.07 to 0.09, P = .846; 1 week: -0.12 mm, 95% CI: -0.24 to 0.01, P = .079; 1 month: -0.06, 95% CI: -0.14 to 0.01, P = .110).

CONCLUSIONS: Neither ocular refraction nor ACD changed within 1 month after laser capsulotomy, suggesting laser capsulotomy did not affect ocular refraction in short-term observation. [J Refract Surg. 2022;38(7):465-473.].

PMID:35858199 | DOI:10.3928/1081597X-20220516-01

J Refract Surg. 2022 Jul;38(7):422-427. doi: 10.3928/1081597X-20220602-02. Epub 2022 Jul 1.

ABSTRACT

PURPOSE: To determine the reliability of the percentage of tissue altered (PTA) calculation as part of the planning strategy for myopic laser in situ keratomileusis (LASIK) by comparing the estimated PTA provided by preoperative calculation to the postoperative PTA actually achieved in microkeratome-assisted myopic LASIK.

METHODS: This retrospective study included 3,624 eyes of 3,624 patients who underwent mechanical microkeratome-assisted LASIK surgery for myopic correction. The calculated preoperative PTA values based on the planned flap thickness and ablation depth were compared with the actual achieved postoperative PTA using the difference of corneal central thickness postoperatively for assessing the achieved ablation depth and the intraoperative ultrasound-assisted flap thickness measurement. Regression analysis was performed to reveal preoperative parameters that might influence PTA calculation accuracy.

RESULTS: The mean difference between the estimated and achieved PTA was 0.451 ± 3.45% (P < .001) (95% CI: 0.3708 to 0.5322) with a preoperative and postoperative mean PTA of 31.07 ± 4.07% and 31.52 ± 5.78%, respectively. The differences between the achieved and planned maximum ablation depth and flap thickness were 4.32 ± 13.70 µm (P < .001) and -1.61 ± 13.66 µm (P < .001), respectively.

CONCLUSIONS: Although a statistically significant difference was found between the preoperative calculated PTA and actually achieved PTA, the difference in PTA value (less than 1%) was clinically non-significant and indicated a highly reliable metric for preoperative refractive surgery planning. [J Refract Surg. 2022;38(7):422-427.].

PMID:35858196 | DOI:10.3928/1081597X-20220602-02

J Refract Surg. 2022 Jul;38(7):443-449. doi: 10.3928/1081597X-20220602-01. Epub 2022 Jul 1.

ABSTRACT

PURPOSE: To assess the accuracy of the following intraocular lens (IOL) power formulas: Barrett True-K No History (BTKNH), Emmetropia Verifying Optical 2.0 Post Myopic LASIK/PRK (EVO 2.0), Haigis-L, American Society of Cataract and Refractive Surgery (ASCRS) average, and Shammas, designed for patients who have undergone previous myopic refractive surgery, independent of preexisting clinical history and corneal tomographic measurements.

METHODS: Data from 302 eyes of 302 patients who previously underwent myopic refractive surgery and had cataract surgery done by a single surgeon with only one IOL type inserted were included. The predicted refraction was calculated for each of the formulas and compared with the actual refractive outcome to give the prediction error. Subgroup analysis based on the axial length and mean keratometry was performed.

RESULTS: On the basis of mean absolute prediction error (MAE), the formulas were ranked as follows: Haigis-L (0.61 diopters [D]), ASCRS average (0.63 D), BTKNH (0.67 D), EVO 2.0 (0.68 D), and Shammas (0.69 D). The Haigis-L had a statistically significant lower MAE compared with all formulas (P < .05) except the ASCRS average. Hyperopic mean prediction errors were seen in all formulas for axial lengths of greater than 30 mm or mean keratometry values of 35.00 diopters or less.

CONCLUSIONS: The Haigis-L and the ASCRS average formulas provided the most accurate results in the overall population evaluated in this study. Moreover, according to data observed, it is important to be careful handling very long eyes and very flat corneas because hyperopic refractions could be more common. [J Refract Surg. 2022;38(7):443-449.].

PMID:35858195 | DOI:10.3928/1081597X-20220602-01

J Refract Surg. 2022 Jul;38(7):404-413. doi: 10.3928/1081597X-20220516-03. Epub 2022 Jul 1.

ABSTRACT

PURPOSE: To report subjective and objective quality of vision (QoV) results for high myopic small incision lenticule extraction (SMILE) between -9.00 and -13.00 diopters (D).

METHODS: This was a prospective study recruiting 114 patients undergoing SMILE with attempted spherical equivalent refraction (SEQ) correction from -9.00 to -13.00 D, and cylinder up to 5.00 D. Patients were informed before surgery of the increased risk of QoV symptoms. Patients completed the Rasch validated QoV questionnaire. Objective QoV was assessed by corneal and whole eye aberrations, HD Analyzer Objective Scatter Index (OSI) (Keeler), and contrast sensitivity. Patient satisfaction was assessed on a scale from 0 (very dissatisfied) to 10 (very satisfied). Individual item and total Rasch-scaled scores for the three subscales (frequency, severity, and bothersomeness) of the QoV questionnaire were calculated before and 12 months after surgery.

RESULTS: The mean patient satisfaction score was 9.27 ± 1.18 (range: 2 to 10), 8 or higher in 93%, and 7 or higher in 98% of patients. One patient with a satisfaction score of 2 had a simple refractive error re-treatment and then reported a satisfaction score of 10. The total mean ± standard deviation Rasch-scaled QoV score for the frequency, severity, and bothersomeness subscales before surgery was 24 ± 19, 20 ± 16, and 19 ± 18, respectively. Scores increased after surgery to 41 ± 18, 32 ± 16, and 30 ± 21, respectively (P < .001). Corneal aberrations (6 mm, OSI) increased on average by 0.39 µm for spherical aberration, 0.41 µm for coma, and 0.56 µm for higher order aberrations root mean square. OSI increased on average by 0.58. There was a small but statistically significant improvement in contrast sensitivity at 3, 6, 12, and 18 cycles per degree. There were no statistically significant correlations found between subjective scores for starbursts and objective measurements.

CONCLUSIONS: Satisfaction was high following SMILE for high myopia. As expected, there was an increase in QoV symptoms, mainly glare and starbursts. The acceptance of QoV symptoms for high myopic SMILE was high, indicating that residual refractive error and visual acuity are the major drivers for patient satisfaction with appropriate preoperative informed consent. [J Refract Surg. 2022;38(7):404-413.].

PMID:35858192 | DOI:10.3928/1081597X-20220516-03