Category: Nevin Manimala

Qual Life Res. 2021 Aug 21. doi: 10.1007/s11136-021-02968-1. Online ahead of print.

ABSTRACT

PURPOSE: Missing scores complicate analysis of the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) because patients with and without missing scores may systematically differ. We focus on optimal analysis methods for incomplete PRO-CTCAE items, with application to two randomized, double-blind, placebo-controlled, phase III trials.

METHODS: In Alliance A091105 and COMET-2, patients completed PRO-CTCAE items before randomization and several times post-randomization (N = 64 and 107, respectively). For each trial, we conducted between-arm comparisons on the PRO-CTCAE via complete-case two-sample t-tests, mixed modeling with contrast, and multiple imputation followed by two-sample t-tests. Because interest lies in whether CTCAE grades can inform missing PRO-CTCAE scores, we performed multiple imputation with and without CTCAE grades as auxiliary variables to assess the added benefit of including them in the imputation model relative to only including PRO-CTCAE scores across all cycles.

RESULTS: PRO-CTCAE completion rates ranged from 100.0 to 71.4% and 100.0 to 77.1% across time in A091105 and COMET-2, respectively. In both trials, mixed modeling and multiple imputation provided the most similar estimates of the average treatment effects. Including CTCAE grades in the imputation model did not consistently narrow confidence intervals of the average treatment effects because correlations for the same PRO-CTCAE item between different cycles were generally stronger than correlations between each PRO-CTCAE item and its corresponding CTCAE grade at the same cycle.

CONCLUSION: For between-arm comparisons, mixed modeling and multiple imputation are informative techniques for handling missing PRO-CTCAE scores. CTCAE grades do not provide added benefit for informing missing PRO-CTCAE scores. ClinicalTrials.gov Identifiers: NCT02066181 (Alliance A091105); NCT01522443 (COMET-2).

PMID:34420143 | DOI:10.1007/s11136-021-02968-1

Int Ophthalmol. 2021 Aug 22. doi: 10.1007/s10792-021-02009-3. Online ahead of print.

ABSTRACT

PURPOSE: To investigate the risk factors and the clinical characteristics of the hypertensive phase (HP) after Ahmed glaucoma valve (AGV) implantation.

METHODS: This retrospective study included 60 eyes of 57 patients who underwent AGV implantation and with at least 1-year follow-up. HP was defined as intraocular pressure (IOP) > 21 mmHg in the first 3 months after the surgery. Independent samples t-test and Chi-square test were used to compare differences in patients with the HP and the non-HP groups. Univariable and multivariable logistic regression analyses were used to determine the risk factors for the development of the HP. Statistical significance was assumed at p < 0.05 level.

RESULTS: HP was observed in 31 eyes (51.7%) with an average peak IOP of 27.6 ± 4.5 mmHg (range 22-40 mmHg). The resolution of HP was noted in 27 eyes (87.1%) at the 3rd month postoperative visit. The number of glaucoma medications at the last postoperative visit and IOP values from 1 month to 1 year were significantly higher in the HP group (all p < 0.05). Patients with traumatic glaucoma showed the highest rate (83.3%) of HP development. In the multivariable analysis, a preoperative IOP > 30 mmHg (p = 0.03, OR:5.82; reference: ≤ 25 mmHg) and younger age (41-64 years, p = 0.02, OR:8.49; ≤ 40 years, p = 0.001, OR:19.62; reference: ≥ 65 years) were independently associated with the occurrence of HP.

CONCLUSION: Hypertensive phase was observed in half of the patients undergoing AGV implantation. A higher mean preoperative IOP and younger age were risk factors for HP development. Although the majority resolved at the 3-month visit, eyes with HP had higher mean IOPs and required more IOP lowering medications.

PMID:34420122 | DOI:10.1007/s10792-021-02009-3

Hernia. 2021 Aug 22. doi: 10.1007/s10029-021-02488-4. Online ahead of print.

ABSTRACT

INTRODUCTION: Surgeons rely on randomized controlled trials (RCT) to compare the effectiveness of treatments. RCTs require careful planning and substantial effort to complete. Because of the careful study design, statistics performed are often easy to reproduce such as Chi-squared or t-test. Issues such as statistical discordance, or reporting statistical results that cannot be reproduced, should be uncommon.

METHODS: RCTs pertaining to hernias were identified in PubMed using the search terms “hernia” and “randomized controlled trial.” Studies were selected using a random number generator. Studies were included if the primary outcome could be reproduced using the data and statistical test reported in the manuscript. Discordance between the obtained p-value from our analysis and the published p-value was assessed. Primary outcome was the number of studies that reported p-values that crossed the level of statistical significance (p-value = 0.05) but on reproduction analysis did not.

RESULTS: Of the 100 included RCTs, five reported p-values that crossed the “p = 0.05” threshold that our team was unable to reproduce using the statistical test reported in the manuscript. An additional three studies reported p-values that crossed the “p = 0.05” threshold that our team was unable to reproduce using the appropriate statistical test (i.e., Fisher’s exact test when all expected cell counts < 5). All eight studies published p-values < 0.05, whereas, our re-analysis demonstrated p ≥ 0.05.

CONCLUSION: Eight percent of the RCTs analyzed in this study reported p-values < 0.05 that on reproduction analysis was ≥ 0.05. The next steps should be to determine reasons for discordance and how to prevent this from happening.

PMID:34420111 | DOI:10.1007/s10029-021-02488-4

Eur J Health Econ. 2021 Aug 21. doi: 10.1007/s10198-021-01361-6. Online ahead of print.

ABSTRACT

This paper compares the value per statistical life (VSL) in the context of suicide prevention to that of prevention of traffic fatalities. We conducted a contingent valuation survey with questions on willingness to pay (WTP) in both contexts by administering a web questionnaire to 1038 individuals aged 18 to 80. We conjectured that WTP for a given impact on the number of fatalities would be lower for suicide prevention because suicide, at least to some degree, is the result of individuals’ own decisions. However, this hypothesis was not supported by the within- or between-sample estimates of WTP or by responses to direct questions. Hence, no support is provided for the use of a lower valuation of the impact of suicide prevention than for risk-reducing programs in other fields, such as traffic safety. This implies that the same VSL should be used for evaluating suicide prevention interventions and for risk-reducing programs in other policy areas and funds for the prevention of fatalities should be directed to the area with the lowest cost per life saved.

PMID:34420119 | DOI:10.1007/s10198-021-01361-6

Insights Imaging. 2021 Aug 21;12(1):120. doi: 10.1186/s13244-021-01063-w.

ABSTRACT

PURPOSE: To compare the imaging quality, T stage and extramural venous invasion (EMVI) evaluation between the conventional and synthetic T2-weighted imaging (T2WI), and to investigate the role of quantitative values obtained from synthetic magnetic resonance imaging (MRI) for assessing nodal staging in rectal cancer (RC).

METHODS: Ninety-four patients with pathologically proven RC who underwent rectal MRI examinations including synthetic MRI were retrospectively recruited. The image quality of conventional and synthetic T2WI was compared regarding signal-to-noise ratio (SNR), contrast-to-noise (CNR), sharpness of the lesion edge, lesion conspicuity, absence of motion artifacts, and overall image quality. The accuracy of T stage and EMVI evaluation on conventional and synthetic T2WI were compared using the Mc-Nemar test. The quantitative T1, T2, and PD values were used to predict the nodal staging of MRI-evaluated node-negative RC.

RESULTS: There were no statistically significant differences between conventional and synthetic T2WI in SNR, CNR, overall image quality, lesion conspicuity, and absence of motion artifacts (p = 0.058-0.978). There were no significant differences in the diagnostic accuracy of T stage and EMVI between conventional and synthetic T2WI from two observers (p = 0.375 and 0.625 for T stage; p = 0.625 and 0.219 for EMVI). The T2 value showed good diagnostic performance for predicting the nodal staging of RC with the area under the receiver operating characteristic, sensitivity, specificity, and accuracy of 0.854, 90.0%, 71.4%, and 80.3%, respectively.

CONCLUSIONS: Synthetic MRI may facilitate preoperative staging and EMVI evaluation of RC by providing synthetic T2WI and quantitative maps in one acquisition.

PMID:34420097 | DOI:10.1186/s13244-021-01063-w

J Math Biol. 2021 Aug 21;83(3):28. doi: 10.1007/s00285-021-01654-7.

ABSTRACT

Rooted triples, rooted binary phylogenetic trees on three leaves, are sufficient to encode rooted binary phylogenetic trees. That is, if [Formula: see text] and [Formula: see text] are rooted binary phylogenetic X-trees that infer the same set of rooted triples, then [Formula: see text] and [Formula: see text] are isomorphic. However, in general, this sufficiency does not extend to rooted binary phylogenetic networks. In this paper, we show that trinets, phylogenetic network analogues of rooted triples, are sufficient to encode rooted binary orchard networks. Rooted binary orchard networks naturally generalise rooted binary tree-child networks. Moreover, we present a polynomial-time algorithm for building a rooted binary orchard network from its set of trinets. As a consequence, this algorithm affirmatively answers a previously-posed question of whether there is a polynomial-time algorithm for building a rooted binary tree-child network from the set of trinets it infers.

PMID:34420100 | DOI:10.1007/s00285-021-01654-7

Heart Vessels. 2021 Aug 22. doi: 10.1007/s00380-021-01924-w. Online ahead of print.

ABSTRACT

Pulmonary embolism (PE) patients with right ventricular (RV) involvement are a heterogenous group who mandate further risk stratification. Our objective was to evaluate the efficacy of the PE severity index (PESI) for predicting adverse clinical outcomes among PE patients with RV involvement. Consecutive normotensive PE patients with RV involvement were allocated according to admission PESI score (PESI ≤ III vs. PESI ≥ IV). The primary outcome included hemodynamic instability and in-hospital mortality. Secondary outcomes included each component of the primary outcome as well as mechanical ventilation, thrombolytic therapy, acute kidney injury, and major bleeding. Multivariable logistic regression model was performed to assess the independent association between the PESI score and primary outcome. C-Statistic was used to compare the PESI with the BOVA score. A total of 253 patients were evaluated: 95 (38%) with a PESI ≥ IV. Of them, 82 (32%) patients were classified as intermediate-low risk and 171 (68%) as intermediate-high risk. Fifty (20%) patients had at least 1 adverse event. Multivariate analysis demonstrated the PESI to be an independent predictor for the primary outcome (HR 4.81, CI 95%, 1.15-20.09, p = 0.031), which was increased with a concomitant increase of the PESI score (PESI I 4.2%, PESI II 3.4%, PESI III 12%, PESI IV 16.3%, PESI V 23.1%, p for trend < 0.001). C-Statistic analysis for the PESI score yielded an AUC-0.746 (0.637-0.854), p = 0.001, compared to the BOVA score: AUC-0.679 (0.584-0.775), p = 0.011. PESI score was found to predict adverse outcomes among normotensive PE patients with RV involvement.

PMID:34420078 | DOI:10.1007/s00380-021-01924-w

J Contam Hydrol. 2021 Aug 9;243:103864. doi: 10.1016/j.jconhyd.2021.103864. Online ahead of print.

ABSTRACT

We propose a simulation-optimization (SO) model based on a novel two-step strategy for the optimal design of groundwater remediation systems. The SO models are developed by coupling simulation models directly or through the extreme learning machine (ELM) with evolutionary hunting strategy based metaheuristics (EHSMs). In the first step, EHSMs with a combinatorial optimization technique are used to obtain optimal pumping locations by minimizing the percentage of contaminant mass that remained in the aquifer while keeping the pumping strategy as constant. In the second step, the optimal pumping locations are directly used as input, and a composite function is employed to minimize the sum of the water extraction rates and the percentage of extracted contaminant mass by constraining hydraulic heads and contaminant concentrations. The performance of the two-step strategy is found to be slightly better and computationally more efficient than the alternate approach. Moreover, various statistical measures suggest the superiority of EHSMs over other metaheuristics for groundwater remediation.

PMID:34418818 | DOI:10.1016/j.jconhyd.2021.103864

J Contam Hydrol. 2021 Aug 14;243:103870. doi: 10.1016/j.jconhyd.2021.103870. Online ahead of print.

ABSTRACT

Subsurface remediation using nanoscale zero valent iron (nZVI) is a promising in-situ technology that can transform certain groundwater contaminants into non-toxic compounds. However, field scale implementation of nZVI technology has faced major challenges due to poor subsurface mobility, limited longevity and well clogging, all leading to a shorter nZVI travel distance. This distance nZVI travels in the subsurface is an important parameter since it influences the amount of contaminants that can be reached and thereby remediated. There are several factors which may affect nZVI travel distance such as groundwater velocity, injection concentration and rate, lag period (duration when nZVI injection is stopped), solution viscosity, and subsurface heterogeneity. Although various studies have been performed to reveal the effect of different factors on nZVI transport in homogeneous domains, few studies have focused on heterogeneous media, which is more representative of field conditions. In this study, a statistical analysis was performed using a two-dimensional numerical model which simulated carboxymethyl cellulose (CMC) stabilized nZVI transport in randomly distributed soil permeability fields of two aquifers to examine the factors that have the greatest impact on nZVI travel distance. Among all possible factors, field scale solution viscosity and injection rate had a statistically significant effect on nZVI travel distance in both the horizontal and vertical directions, as well as, on the attached mass. Additionally, the lag period between injections had a statistically significant effect on the attached mass, but not the travel distance. These results suggest that having a long injection period followed by a short lag phase during field deployment may result in less nZVI attachment. Lastly, aquifer heterogeneity impacted the nZVI spread while the impact of intrinsic groundwater velocity and injection concentration was found not to be statistically significant. Results from this numerical study can aid in field-scale CMC-nZVI injection by identifying key factors for remediation optimization.

PMID:34418819 | DOI:10.1016/j.jconhyd.2021.103870

Geriatr Nurs. 2021 Aug 18;42(5):1084-1092. doi: 10.1016/j.gerinurse.2021.06.016. Online ahead of print.

ABSTRACT

A theory-guided non-experimental, descriptive, correlational design was used to evaluate how entry and passage variables were related to nursing home adjustment for individuals with dementia. Older adults with dementia may be unable to speak for themselves, therefore proxy responses of Certified Nursing Assistants (CNAs) provided the data for completion of the Nursing Home Adjustment Scale.¹ Guided by the Meleis’ Theory of Transitions, entry level factors (i.e. age, previous residence, gender, and choice), and passage variables (i.e. length of stay, extent of dementia, functional abilities, and depression) were entered into a regression equation as predictors of nursing home adjustment. Information about extent of dementia, functional abilities and depression was derived from the Minimum Data Set (MDS) maintained for all residents per Medicare and Medicaid guidelines. Descriptive and inferential statistics were calculated using IBM Statistical Package for the Social Sciences (SPSS) 26.0 software. Results indicated an inverse relationship between nursing home adjustment and depression as measured by the PHQ-9. There was no support for relationships among other variables. CNA proxy responses were found to be reliable in that they were significantly correlated with nursing responses on the same measure. This study supports the use of CNA proxy responses as a method to evaluate the experience of individuals with dementia.

PMID:34418841 | DOI:10.1016/j.gerinurse.2021.06.016