Tag: statistics

J Sports Med Phys Fitness. 2021 Jul;61(7):1027-1032. doi: 10.23736/S0022-4707.20.11518-4.

ABSTRACT

BACKGROUND: Stressful conditions during competitive golf putting may result in impaired performance, producing physiological changes. Nevertheless, simultaneous measurements of postural sway (PS), heart rate variability (HRV) and electrodermal activity (EDA) during a competitive golf putting have not yet been examined. This study aims at describing if changes in PS, HRV and EDA during golf putting, might affect the golfer’s performance.

METHODS: Based on EGA-handicap, 40 amateur golfers were divided in 2 groups. They competed in an indoor round of golf putting. PS, EDA, HRV and putting performance (SCORE) were recorded at basal and during competition.

RESULTS: During the putting round, a significant increase in low-frequency power (LF) and decrease in high-frequency power (HF) was found in Group A, leading to an increased LF/HF ratio. The heart rate increased significantly more in Group A than in Group B, but the stress index (SI) remained lower in this group. EDA significantly increased in both groups, with no statistical difference between groups. No statistical difference in SCORE was observed.

CONCLUSIONS: Despite the significant differences observed between the two groups, both at baseline and in response to competition, no variation of the studied variables was associated with a better putting performance.

PMID:34296843 | DOI:10.23736/S0022-4707.20.11518-4

J Magn Reson Imaging. 2021 Jul 23. doi: 10.1002/jmri.27841. Online ahead of print.

ABSTRACT

BACKGROUND: Currently, it is necessary to investigate how to combine biparametric magnetic resonance imaging (bpMRI) with various clinical parameters for the detection of clinically significant prostate cancer (csPCa).

PURPOSE: To develop a multivariate prebiopsy nomogram using clinical and bpMRI parameters for estimating the probability of csPCa.

STUDY TYPE: Retrospective, single-center study.

SUBJECTS: Two hundred and twenty-six patients who underwent targeted biopsy (TBx) for the MRI-suspected index lesion because of clinical suspicions of PCa.

FIELD STRENGTH/SEQUENCE: A 3 T MRI including turbo spin-echo T₂ -weighted and diffusion-weighted single-shot echo-planar imaging sequences.

ASSESSMENT: Prebiopsy clinical and bpMRI parameters were patient age, biopsy history (biopsy-naïve or repeated biopsy status), prostate-specific antigen density (PSAD), Prostate Imaging-Reporting and Data System version 2.1 (PI-RADSv2.1), and apparent diffusion coefficient ratio (ADCR). ADCR was defined as mean ADC of the index lesion divided by mean ADC of the contralateral prostatic region. A multivariate prebiopsy nomogram for csPCa (i.e. Gleason sum ≥7) was developed. Area under the curve (AUC) of each parameter and prebiopsy nomogram was assessed. Five-fold cross-validation was performed for robust estimation of performance of the prebiopsy nomogram.

STATISTICAL TESTS: Logistic regression, receiver-operating curve, and 5-fold cross-validation. P-value < 0.05 was considered statistically significant.

RESULTS: Proportion of csPCa was 31.9% (72/226). The AUCs of age, biopsy-naïve status, PSAD, PI-RADSv2.1, ADCR, and prebiopsy nomogram were 0.657 (95% confidence interval [CI], 0.580-0.733), 0.593 (95% CI, 0.525-0.660), 0.762 (95% CI, 0.697-0.826), 0.824 (95% CI, 0.770-0.878), 0.829 (95% CI, 0.769-0.888), and 0.906 (95% CI, 0.863-0.948), respectively: AUC of nomogram was significantly different than that of individual parameter. In the 5-fold cross-validation, the mean AUC of the prebiopsy nomogram for csPCa was 0.888 (95% CI, 0.786-0.983).

DATA CONCLUSIONS: This multivariate prebiopsy nomogram using clinical and bpMRI parameters may help estimate the probability of csPCa in patients undergoing TBx. ADCR seems to enhance the role of bpMRI in detecting csPCa.

LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

PMID:34296803 | DOI:10.1002/jmri.27841

J Magn Reson Imaging. 2021 Jul 23. doi: 10.1002/jmri.27847. Online ahead of print.

ABSTRACT

BACKGROUND: Intravoxel incoherent motion (IVIM) tensor imaging is a promising technique for diagnosis and monitoring of cardiovascular diseases. Knowledge about measurement repeatability, however, remains limited.

PURPOSE: To evaluate short-term repeatability of IVIM tensor imaging in normal in vivo human hearts.

STUDY TYPE: Prospective.

POPULATION: Ten healthy subjects without history of heart diseases.

FIELD STRENGTH/SEQUENCE: Balanced steady-state free-precession cine sequence and single-shot spin-echo echo planar IVIM tensor imaging sequence (9 b-values, 0-400 seconds/mm² and six diffusion-encoding directions) at 3.0 T.

ASSESSMENT: Subjects were scanned twice with an interval of 15 minutes, leaving the scanner between studies. The signal-to-noise ratio (SNR) was evaluated in anterior, lateral, septal, and inferior segments of the left ventricle wall. Fractional anisotropy (FA), mean diffusivity (MD), mean fraction (MF), and helix angle (HA) in the four segments were independently measured by five radiologists.

STATISTICAL TESTS: IVIM tensor indexes were compared between observers using a one-way analysis of variance or between scans using a paired t-test (normal data) or a Wilcoxon rank-sum test (non-normal data). Interobserver agreement and test-retest repeatability were assessed using the intraclass correlation coefficient (ICC), within-subject coefficient of variation (WCV), and Bland-Altman limits of agreements.

RESULTS: SNR of inferior segment was significantly lower than the other three segments, and inferior segment was therefore excluded from repeatability analysis. Interobserver repeatability was excellent for all IVIM tensor indexes (ICC: 0.886-0.972; WCV: 0.62%-4.22%). Test-retest repeatability was excellent for MD of the self-diffusion tensor (D) and MF of the perfusion fraction tensor (f_p ) (ICC: 0.803-0.888; WCV: 1.42%-9.51%) and moderate for FA and MD of the pseudo-diffusion tensor (D^* ) (ICC: 0.487-0.532; WCV: 6.98%-10.89%). FA of D and f_p and HA of D presented good test-retest repeatability (ICC: 0.732-0.788; WCV: 3.28%-8.71%).

DATA CONCLUSION: The D and f_p indexes exhibited satisfactory repeatability, but further efforts were needed to improve repeatability of D^* indexes.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

PMID:34296813 | DOI:10.1002/jmri.27847

Can J Surg. 2021 Jul 23;64(4):E407-E413. doi: 10.1503/cjs.008620.

ABSTRACT

BACKGROUND: There has been a continuing trend toward decreasing the length of hospital stay for patients undergoing total hip arthroplasty (THA). We aimed to investigate the impact of timing of discharge on gait and patient-reported outcomes early after THA.

METHODS: In this prospective observational cohort study conducted from May 2014 to November 2015, we measured gait velocity, stride length, single-limb support and single-limb support symmetry in adults aged 18-75 years before direct anterior THA, at discharge from the hospital, and 2, 6 and 12 weeks postoperatively. All procedures were performed by a single surgeon. Patients were discharged on the same day as surgery (outpatient group) or stayed at least 1 night in hospital (inpatient group). Participants also completed the Timed Up and Go test (all postoperative time points) and a series of questionnaires (Western Ontario and McMaster Universities Osteoarthritis Index [6 and 12 wk], 12-Item Short Form Health Survey [2, 6 and 12 wk], Harris Hip Score [12 wk] and a pain visual analogue scale [all postoperative time points]).

RESULTS: Thirty-six participants were enrolled in the study, of whom 16 were outpatients and 20 were inpatients. The mean pain rating at the time of discharge was lower in the outpatient group than in the inpatient group (adjusted mean difference -1.5, 95% confidence interval -3.0 to 0.0). We found no other significant differences between the groups for any gait, patient-reported or surgical outcome.

CONCLUSION: There were no statistically significant differences in gait or patient-reported outcomes after direct anterior THA between patients who stayed overnight and those who were discharged as outpatients. Patients discharged as outpatients were younger than those who stayed overnight. Our results suggest that discharging patients as an outpatient after direct anterior THA may have a similar impact on patient function and outcomes as a standard overnight stay in hospital.

PMID:34296768 | DOI:10.1503/cjs.008620

NMR Biomed. 2021 Jul 23:e4582. doi: 10.1002/nbm.4582. Online ahead of print.

ABSTRACT

Ischemic events related to carotid disease are far more strongly associated with plaque instability than stenosis. 3D high-resolution diffusion-weighted (DW) imaging can provide quantitative diffusion measurements on carotid atherosclerosis and may improve detection of vulnerable intraplaque hemorrhage (IPH). The 3D DW-stack of stars (SOS) sequence was implemented with 3D SOS acquisition combined with DW preparation. After simulation of signals created from 3D DW-SOS, phantom studies were performed. Three healthy subjects and 20 patients with carotid disease were recruited. Apparent diffusion coefficient (ADC) values were statistically analyzed on three subgroups by using a two-group comparison Wilcoxon-Mann-Whitney U test with p values less than 0.05: symptomatic versus asymptomatic; IPH-positive versus IPH-negative; and IPH-positive symptomatic versus asymptomatic plaques to determine the relationship with plaque vulnerability. ADC values calculated by 3D DW-SOS provided values similar to those calculated from other techniques. Mean ADC of symptomatic plaque was significantly lower than asymptomatic plaque (0.68 ± 0.18 vs. 0.98 ± 0.16 x 10^-3 mm² /s, p < 0.001). ADC was also significantly lower in IPH-positive versus IPH-negative plaque (0.68 ± 0.13 vs. 1.04 ± 0.11 x 10^-3 mm² /s, p < 0.001). Additionally, ADC was significantly lower in symptomatic versus asymptomatic IPH-positive plaque (0.57 ± 0.09 vs. 0.75 ± 0.11 x 10^-3 mm² /s, p < 0.001). Our results provide strong evidence that ADC measurements from 3D DW-SOS correlate with the symptomatic status of extracranial internal carotid artery plaque. Further, ADC improved discrimination of symptomatic plaque in IPH. These data suggest that diffusion characteristics may improve detection of destabilized plaque leading to elevated stroke risk.

PMID:34296793 | DOI:10.1002/nbm.4582

J Magn Reson Imaging. 2021 Jul 23. doi: 10.1002/jmri.27846. Online ahead of print.

ABSTRACT

BACKGROUND: Cholangiocarcinoma is a type of hepatobiliary tumor. For perihilar cholangiocarcinoma (pCCA), patients who experience early recurrence (ER) have a poor prognosis. Preoperative accurate prediction of postoperative ER can avoid unnecessary operation; however, prediction is challenging.

PURPOSE: To develop a novel signature based on clinical and/or MRI radiomics features of pCCA to preoperatively predict ER.

STUDY TYPE: Retrospective.

POPULATION: One hundred eighty-four patients (median age, 61.0 years; interquartile range: 53.0-66.8 years) including 115 men and 69 women.

FIELD STRENGTH/SEQUENCE: A 1.5 T; volumetric interpolated breath-hold examination (VIBE) sequence.

ASSESSMENT: The models were developed from the training set (128 patients) and validated in a separate testing set (56 patients). The contrast-enhanced arterial and portal vein phase MR images of hepatobiliary system were used for extracting radiomics features. The correlation analysis, least absolute shrinkage and selection operator (LASSO) logistic regression (LR), backward stepwise LR were mainly used for radiomics feature selection and modeling (Model^radiomic ). The univariate and multivariate backward stepwise LR were used for preoperative clinical predictors selection and modeling (Model^clinic ). The radiomics and preoperative clinical predictors were combined by multivariate LR method to construct clinic-radiomics nomogram (Model^combine ).

STATISTICAL TESTS: Chi-squared (χ² ) test or Fisher’s exact test, Mann-Whitney U-test or t-test, Delong test. Two tailed P < 0.05 was considered statistically significant.

RESULTS: Based on the comparison of area under the curves (AUC) using Delong test, Model^clinic and Model^combine had significantly better performance than Model^radiomic and tumor-node-metastasis (TNM) system in training set. In the testing set, both Model^clinic and Model^combine had significantly better performance than TNM system, whereas only Model^combine was significantly superior to Model^radiomic . However, the AUC values were not significantly different between Model^clinic and Model^combine (P = 0.156 for training set and P = 0.439 for testing set).

DATA CONCLUSION: A noninvasive model combining the MRI-based radiomics signature and clinical variables is potential to preoperatively predict ER for pCCA.

LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 4.

PMID:34296802 | DOI:10.1002/jmri.27846

Lakartidningen. 2021 Jul 23;118:21120.

ABSTRACT

Infection fatality ratio (IFR) in covid-19 is highly debated in international and Swedish press. In Sweden, three different estimates have been used to estimate mortality, based on statistics either from the Swedish National Board of Health and Welfare, and the Public Health Agency of Sweden, whereas excess mortality calculated by EuroMOMO. Mortality is based on death certificates, which can be accurate or erroneous, but previous analyses have suggested that over- and underdiagnosis usually even out. EuroMOMO on the other hand reports all-cause mortality compared to an estimated baseline. In view of high correlation between the different measures, we suggest that mortality is relatively correctly reported in Sweden. We discuss IFR internationally and in Sweden, and suggest that IFR in the Western world is approximately 0.5-1%. However, these numbers will change over time depending on immunity induced by vaccination efforts, but also the potential spread of new virus variants.

PMID:34296754

Dev Med Child Neurol. 2021 Jul 23. doi: 10.1111/dmcn.14993. Online ahead of print.

ABSTRACT

AIM: To investigate neurodevelopmental outcome of children with open prenatal spina bifida aperta (SBA) repair.

METHOD: Prenatal SBA repair was performed in 130 fetuses at the Zurich Center between 2010 and 2019. Seventy-seven children underwent 1 year assessment with the Griffiths Mental Developmental Scales (Griffiths) and 65 with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) at 2 years. Anatomical and functional level and ambulation status were assessed. Descriptive statistics and multiple linear regression analyses for risk factors were performed.

RESULTS: The Bayley-III cognition composite score in children with prenatal SBA repair was within normal limits but lower compared to population norms (mean=95.15, SD=14.683 vs norm=100, SD=15, p=0.01). Fine motor development (mean=9.58, SD=2.744, p=0.227) was typical while gross motor development was lower than the norm (mean=3.02, SD=2.758 vs norm=10, SD=3, p<0.001). Griffiths developmental quotient subscales correlated significantly with corresponding Bayley-III scores (all p<0.001, r=0.519-0.594). At 2 years, 50.8% could walk.

INTERPRETATION: Children with non-trial open prenatal SBA repair show favourable cognitive outcome in the low-average range at 1 and 2 years of age. While gross motor function remained delayed, fine motor function was age appropriate. The correlation between Griffiths and Bayley-III allows a prediction about neurodevelopmental outcome at the age of 1 year.

PMID:34296763 | DOI:10.1111/dmcn.14993

Can J Surg. 2021 Jul 23;64(4):E403-E406. doi: 10.1503/cjs.000620.

ABSTRACT

BACKGROUND: The federal Cannabis Act came into force on Oct. 17, 2018, in Canada, making Canada only the second country in the world to legalize the cultivation, acquisition, possession and consumption of cannabis and its by-products. This provided a unique opportunity to evaluate the impact of this legislation on drug-related trauma.

METHODS: We performed a prospective observational study on the use of cannabis and other illicit drugs in the trauma population at a lead Canadian trauma centre in London, Ontario, in the 3 months before (July 1 to Sept. 30, 2018) and 3 months after (Nov. 1, 2018, to Jan. 31, 2019) the legalization of cannabis in Canada. We defined cannabis use as a positive cannabinoid screen result at the time of assessment by the trauma team. We also screened for opioids, amphetamines and cocaine.

RESULTS: A total of 210 patients were assessed by our trauma service between July 1 and Sept. 30, 2018, and 141 patients were assessed between Nov. 1, 2018, and Jan. 31, 2019. Motor vehicle collisions were the most common cause of trauma both before (101 [48.1%]) and after (67 [47.5%]) legalization. The mean Injury Severity Score was 17.6 (standard deviation [SD] 13.0) and 19.7 (SD 14.8), respectively. Drug screens were done in 88 patients (41.9%) assessed before legalization and 99 patients (70.2%) assessed after legalization. There was no difference in the rate of positive cannabinoid screen results before and after legalization (22 [25%] v. 22 [22%]). There was a trend toward higher rates of positive cannabinoid screen results (2/10 [20%] v. 5/8 [62%]) and positive toxicology screen results (5/10 [50%] v. 6/8 [75%]) after legalization among patients with penetrating trauma, but our sample was too small to achieve statistical significance.

CONCLUSION: We found no difference in the rates of positive cannabinoid screen results among patients assessed at our trauma centre in the 3 months before and the 3 months after legalization of cannabis; however, there was a trend toward an increase in the rates of positive results of toxicology screens and cannabinoid screens among those with penetrating trauma. These preliminary single-centre data showing no increased rates of cannabis use in patients with trauma after legalization are reassuring.

PMID:34296708 | DOI:10.1503/cjs.000620

Cereb Cortex. 2021 Jul 23:bhab270. doi: 10.1093/cercor/bhab270. Online ahead of print.

NO ABSTRACT

PMID:34296751 | DOI:10.1093/cercor/bhab270