Nevin Manimala

PLoS One. 2021 Oct 15;16(10):e0258330. doi: 10.1371/journal.pone.0258330. eCollection 2021.

ABSTRACT

BACKGROUND: Null Hypothesis Significance Testing (NHST) is the most familiar statistical procedure for making inferences about population effects. Important problems associated with this method have been addressed and various alternatives that overcome these problems have been developed. Despite its many well-documented drawbacks, NHST remains the prevailing method for drawing conclusions from data. Reasons for this have been insufficiently investigated. Therefore, the aim of our study was to explore the perceived barriers and facilitators related to the use of NHST and alternative statistical procedures among relevant stakeholders in the scientific system.

METHODS: Individual semi-structured interviews and focus groups were conducted with junior and senior researchers, lecturers in statistics, editors of scientific journals and program leaders of funding agencies. During the focus groups, important themes that emerged from the interviews were discussed. Data analysis was performed using the constant comparison method, allowing emerging (sub)themes to be fully explored. A theory substantiating the prevailing use of NHST was developed based on the main themes and subthemes we identified.

RESULTS: Twenty-nine interviews and six focus groups were conducted. Several interrelated facilitators and barriers associated with the use of NHST and alternative statistical procedures were identified. These factors were subsumed under three main themes: the scientific climate, scientific duty, and reactivity. As a result of the factors, most participants feel dependent in their actions upon others, have become reactive, and await action and initiatives from others. This may explain why NHST is still the standard and ubiquitously used by almost everyone involved.

CONCLUSION: Our findings demonstrate how perceived barriers to shift away from NHST set a high threshold for actual behavioral change and create a circle of interdependency between stakeholders. By taking small steps it should be possible to decrease the scientific community’s strong dependence on NHST and p-values.

PMID:34653185 | DOI:10.1371/journal.pone.0258330

PLoS One. 2021 Oct 15;16(10):e0258560. doi: 10.1371/journal.pone.0258560. eCollection 2021.

ABSTRACT

BACKGROUND: Priapism impairs quality of life and has a predilection for males with sickle cell disease (SCD). The Priapism Impact Profile (PIP) is a novel 12-item instrument designed to measure general health-related impact of priapism. The aim of the study was to evaluate the validity and reliability of the PIP in a Jamaican cohort of SCD patients experiencing priapism.

METHODS: One hundred SCD patients with a history of priapism were recruited from a sickle cell clinic in Kingston, Jamaica and administered the PIP questionnaire. Patients rated each item of the PIP for clarity and importance. Statistical testing was employed to evaluate the psychometric performance of the PIP. Content validation was assessed based on patient descriptive rating of the items based on clarity, and importance and criterion-oriented validity were assessed by evaluating the PIP’s ability to distinguish between patient subgroups. Test-retest repeatability was assessed in 20 of the 100 patients.

RESULTS: Patients were stratified into active (54) and remission (46) priapism groups based on their experience of priapism within the past year. Patients in the active priapism group were younger (p = 0.011), had a shorter duration of disease (p = 0.023), and had more frequent priapism episodes (p = 0.036) than the remission group. PIP questionnaire scores differed significantly with respect to priapism activity (p < 0.001) and prevalence of erectile dysfunction (p < 0.05) but not by priapism severity (p = 0.62). The PIP questionnaire had good content validity, with questions rated as having medium or high clarity and importance by an average of 82.8% and 69.2% of patients, respectively.

CONCLUSION: The PIP questionnaire was successfully validated in a Jamaican cohort of SCD patients and adequately discriminated patients with active priapism from those in remission. The instrument may be utilized in routine clinical management of patients with SCD-associated priapism. Further clinical investigations are warranted in other populations.

PMID:34653184 | DOI:10.1371/journal.pone.0258560

Opt Lett. 2021 Oct 15;46(20):5260-5263. doi: 10.1364/OL.428761.

ABSTRACT

Unitary learning is a backpropagation (BP) method that serves to update unitary weights in fully connected deep complex-valued neural networks, meeting a prior unitary in an active modulation diffractive deep neural network. However, the square matrix characteristic of unitary weights in each layer results in its learning belonging to a small-sample training, which produces an almost useless network that has a fairly poor generalization capability. To alleviate such a serious over-fitting problem, in this Letter, optical random phase dropout is formulated and designed. The equivalence between unitary forward and diffractive networks deduces a synthetic mask that is seamlessly compounded with a computational modulation and a random sampling comb called dropout. The dropout is filled with random phases in its zero positions that satisfy the Bernoulli distribution, which could slightly deflect parts of transmitted optical rays in each output end to generate statistical inference networks. The enhancement of generalization benefits from the fact that massively parallel full connection with different optical links is involved in the training. The random phase comb introduced into unitary BP is in the form of conjugation, which indicates the significance of optical BP.

PMID:34653167 | DOI:10.1364/OL.428761

Surg Laparosc Endosc Percutan Tech. 2021 Oct 14. doi: 10.1097/SLE.0000000000001015. Online ahead of print.

ABSTRACT

BACKGROUND: The use of nonradiation endoscopic retrograde cholangiopancreatography (NR-ERCP) for choledocholithiasis is still limited. Hereby, we introduced our experience of digital cholangioscopy (DCS)-assisted NR-ERCP for retrieval of common bile duct stones.

METHODS: Altogether, data of 132 patients who underwent DCS-assisted NR-ERCP for choledocholithiasis were collected. Procedure details, complications, and short-term follow-up were reviewed and analyzed and were compared with those of conventional endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS: Routine stone extraction and laser lithotripsy were planned in 116 and 16 patients, respectively. Biliary access was successfully achieved by standard biliary cannulation and by advanced techniques in 99 and 33 patients, respectively. Complete stone removal was achieved in a single session in all patients. Routine stone extraction was performed in 117 patients, and laser lithotripsy was applied in 15 patients, among whom 14 patients with planned lithotripsy and 1 unexpected impacted stone found during the procedure. Unexpected right localized intrahepatic stones and purulent cholecystitis were found in 1 and 3 patients, respectively. Three mild and 1 moderate pancreatitis, 5 cases of hyperamylasemia, and 2 cases of leukocytosis occurred as complications. Short-term follow-up revealed no stone residual. Procedure details, technical success, and complications were not statistically different than conventional ERCP.

CONCLUSIONS: DCS-assisted NR-ERCP is technically feasible, efficient, and safe for retrieval of common bile duct stones. This novel method is superior to conventional ERCP on detecting unexpected concomitant biliary diseases.

PMID:34653113 | DOI:10.1097/SLE.0000000000001015

J Orthop Trauma. 2021 Oct 12. doi: 10.1097/BOT.0000000000002290. Online ahead of print.

ABSTRACT

OBJECTIVE: Vital signs and laboratory values are used to guide decisions to use damage control techniques in lieu of early definitive fracture fixation. Prior models attempted to predict mortality risk but have limited utility. There is a need for a dynamic model that captures evolving physiologic changes during a trauma patient’s hospital course.

METHODS: The Parkland Trauma Index of Mortality (PTIM) is a machine-learning algorithm that uses electronic medical record (EMR) data to predict mortality within 48 hours during the first 3 days of hospitalization. It updates every hour, re-calculating as physiology changes. The model was developed using 1,935 trauma patient encounters from 2009-2014 and validated on 516 patient encounters from 2015-2016. Model performance was evaluated statistically. Data was collected retrospectively on its performance after one year of clinical use.

RESULTS: In the validation data set, PTIM accurately predicted 52 of 63 12-hour time intervals within 48 hours of mortality, for sensitivity of 82.5% (95% CI 73.1% – 91.9%). Specificity was 93.6% (95% CI 92.5% – 94.8%), and PPV was 32.5% (95% CI 25.2% – 39.7%). PTIM predicted survival for 1,608 time intervals and was incorrect only 11 times, yielding a NPV of 99.3% (95% CI 98.9% – 99.7%). AUC of the ROC curve was 0.94.During the first year of clinical use, when used in 776 patients, the last PTIM score accurately predicted 20 of the 23 12-hour time intervals within 48 hours of mortality, for a sensitivity of 86.9% (95% CI 73% – 100%). Specificity was 94.7% (95% CI 93% – 96%), and the PPV was 33.3% (95% CI 21.4% – 45%). The model predicted survival for 716 time intervals and was incorrect 3 times, yielding a NPV of 99.6% (95% CI 99.1% – 100%). AUC of the ROC curve was 0.97.

CONCLUSION: By adapting with the patient’s physiologic response to trauma and relying on EMR data alone, the PTIM overcomes many of the limitations of prior models. It may help inform decision-making for trauma patients early in their hospitalization.

LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

PMID:34653106 | DOI:10.1097/BOT.0000000000002290

J Cataract Refract Surg. 2021 Sep 20. doi: 10.1097/j.jcrs.0000000000000821. Online ahead of print.

ABSTRACT

PurposeTo compare axial length (AL) measurements in long eyes by two swept-source optical coherence tomography (SS-OCT) biometers, one based on the group refractive index (IOLMaster 700, Zeiss) and the other based on sum of segments (Argos, Movu), and compare these measurements to previously published methods to optimize AL.SettingI.R.C.C.S. – G.B. Bietti Foundation, Rome, ItalyDesignProspective case seriesMethodsAL was measured with both optical biometers in myopic patients (AL > 24.00 mm) and compared to the values obtained with Wang-Koch adjustment, polynomial equations for the Holladay 1 and 2 formulas and Cooke modified AL (CMAL).ResultsIn 102 eyes of 55 subjects, a statistically significant difference (p<0.0001) was found among the 6 AL values. Post-test revealed that Argos measurements (26.90 ±1.61 mm) were significantly lower compared to those provided by all methods (p <0.001) but CMAL, whereas IOLMaster 700 measurements (27.01 ±1.65) were higher (p <0.001). No difference was found between the two Holladay equations. CMAL values did not reveal any difference compared to those of the Argos, but a proportional bias showed that in longer eyes CMAL provided smaller values (p <0.0001, r = -0.7221). AL overestimation by the IOLMaster 700 AL compared to the Argos was higher the longer the eye was (p <0.0001, r = 0.6959, r2 = 0.4842).ConclusionThe SS-OCT optical biometer based on the group refractive index overestimates AL compared to the device using segmented AL. CMAL provides the measurements closest to those of the device using segmented AL.

PMID:34653096 | DOI:10.1097/j.jcrs.0000000000000821

Chin Med J (Engl). 2021 Oct 13. doi: 10.1097/CM9.0000000000001799. Online ahead of print.

ABSTRACT

BACKGROUND: Finding an optimal treatment strategy for adolescent idiopathic scoliosis (AIS) patients remains challenging because of its intrinsic complexity. For mild to moderate scoliosis patients with lower skeletal growth potential (Risser 3-5), most clinicians agree with observation treatment; however, the curve progression that occurs during puberty, the adolescent period, and even in adulthood, remains a challenging issue for clinicians. The aim of the study is to investigate the efficacy of Schroth exercise in AIS patients with lower skeletal growth potential (Risser 3-5) and moderate scoliosis (Cobb angle 20°-40°).

METHODS: From 2015 to 2017, data of 64 patients diagnosed with AIS in Peking University Third Hospital were reviewed. Forty-three patients underwent Schroth exercise were classified as Schroth group, and 21 patients underwent observation were classified as observation group. Outcomes were measured by health-related quality of life (HRQOL) and radiographic parameters. HRQOL was assessed using the visual analog scale (VAS) scores for back, Scoliosis Research Society-22 (SRS-22) patient questionnaire. Radiographic spinopelvic parameters were obtained from anteroposterior and lateral X-rays. The pre-treatment and post-treatment HRQOL and radiographic parameters were tested to validate Schroth exercise efficacy. The inter-rater reliability of the radiographic parameters was tested using the interclass correlation coefficient (ICC). The paired t test was used to examine HRQOL and radiographic parameters. Clinical relevance between C2-C7 sagittal vertical axis (SVA) and thoracic kyphosis was analyzed using Spearman correlation.

RESULTS: In Schroth group, VAS back score, SRS-22 pain, and SRS-22 self-image domain were significantly improved from pre-treatment 3.0 ± 0.8, 3.6 ± 0.5, and 3.5 ± 0.7 to post-treatment 1.6 ± 0.6 (t = 5.578, P = 0.013), 4.0 ± 0.3 (t = -3.918, P = 0.001), and 3.7 ± 0.4 (t = -6.468, P < 0.001), respectively. No significant improvements of SRS-22 function domain (t = -2.825, P = 0.088) and mental health domain (t = -3.174, P = 0.061) were observed. The mean Cobb angle decreased from 28.9 ± 5.5° to 26.3 ± 5.2° at the final follow-up, despite no statistical significance was observed (t = 1.853, P = 0.102). The mean C2-C7 SVA value decreased from 21.7 ± 8.4 mm to 17.0 ± 8.0 mm (t = -1.224 P = 0.049) and mean T1 tilt decreased from 4.9 ± 4.2 ° to 3.5 ± 3.1° (t = 2.913, P = 0.011). No significant improvement of radiographic parameters and HRQOL were observed in observation group.

CONCLUSIONS: For AIS patients with a Risser 3-5 and a Cobb angle 20°-40°, Schroth exercises improved HRQOL and halted curve progression during the follow-up period. Both cervical spine alignment and shoulder balance were also significantly improved after Schroth exercises. We recommend Schroth exercises for patients with AIS.

PMID:34653079 | DOI:10.1097/CM9.0000000000001799

Chin Med J (Engl). 2021 Oct 13. doi: 10.1097/CM9.0000000000001787. Online ahead of print.

ABSTRACT

BACKGROUND: Ankylosing spondylitis (AS) is a common chronic progressive rheumatic disease. The aim of this study was to explore factors influencing abnormal bone mineral density (BMD) in young and middle-aged patients with AS.

METHODS: From July 2014 to August 2018, hospitalized patients with AS and health examinees in the health examination center of our clinics, ranging in age from 20 to 50 years, were monitored. The BMD of the lumbar spine and femoral neck of AS patients and those of a healthy control group were measured using dual-energy X-ray absorption. The BMDs of AS patients were compared with respect to age, course of disease, iritis, smoking habits, sex, height, weight, body mass index (BMI), medication use, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), platelet volume, platelet count, uric acid (UA), alkaline phosphatase (AKP), and calcium ion levels. Single-nucleotide polymorphisms (SNPs) related to BMD were screened using genome-wide association analysis.

RESULTS: There was no statistical difference in the proportion of abnormal bone masses between the different body parts. The BMD of all bones in AS patients was lower than that in healthy controls (P < 0.05). Additionally, BMD was correlated with serum calcium and CRP in AS patients (P < 0.05), but not with age, platelet volume, platelet count, ESR, UA, AKP, height, weight, and BMI. The incidence of abnormal bone mass in AS patients was correlated with sex (P < 0.05), but not with medication use, iritis, or smoking. BMD of the lumbar spine in AS patients did not correlate linearly with the course of the disease, but BMD of the femoral neck correlated linearly with the course of the disease (P < 0.05). BMD was correlated with multiple SNPs in patients with AS. Lumbar BMD was correlated with rs7025373 and rs7848078. Femoral head BMD was correlated with 3:102157365, 3:102157417, rs1252202, rs1681355, rs3891857, rs7842614, and rs9870734, suggesting that genetic factors play a role in BMD in patients with AS.

CONCLUSIONS: The proportion of abnormal bone mass in AS patients was higher than that in healthy individuals of the same age. The factors related to BMD in patients with AS are gender, CRP, and blood calcium. The BMD of the femoral neck of AS patients decreases with the course of the disease, but BMD of the lumbar spine is not related to the course of the disease. BMD in AS patients is associated with multiple SNPs.

PMID:34653076 | DOI:10.1097/CM9.0000000000001787

Eur J Cancer Prev. 2021 Oct 11. doi: 10.1097/CEJ.0000000000000722. Online ahead of print.

ABSTRACT

BACKGROUND: Gastric cancer is worldwide the fourth more common cancer type by incidence, and the third by mortality. We analyzed three missense variants of TAS2R38 gene: rs713598 (A49P), rs1726866 (V262A), and rs10246939 (I296V). These variants and their combination in haplotypes (proline, alanine and valine/tasters or alanine, valine and isoleucine/nontasters) and diplotypes are responsible for individual differences in bitter perception. The single-nucleotide polymorphisms and the related phenotypes are known to be associated with susceptibility to Gram-negative bacterial infections, such as Helicobacter pylori, and with risk of various cancer types. An association between intermediate tasters (as defined by TAS2R38 diplotypes) and increased risk of gastric cancer was reported in a Korean population.

METHODS: We analyzed 2616 individuals of Latin American origin, representing the whole spectrum of lesions from gastritis to gastric cancer.

RESULTS: Comparing cancer cases vs. noncancers we observed a decrease in risk associated with heterozygous carriers of rs10246939 (P = 0.006) and rs1726866 (P = 0.003) when compared with homozygotes of the more common allele. Also, the analysis of diplotypes/phenotypes reflected the same association, with super-tasters showing a borderline increased risk of developing gastric cancer compared to medium-tasters [odds ratio (OR) = 1.63; 95% confidence interval (CI), 1.04-2.56; P = 0.033]. Also, nontasters showed an increased risk when compared to medium-tasters although not reaching statistical significance (OR = 1.58; 95% CI, 0.80-2.87; P = 0.203). We also tested the interactions between the TAS2R38 genotypes and H. pylori cagA status in a subset of samples and found no interaction.

CONCLUSION: In conclusion, our results suggest only a modest contribution of TAS2R38 gene genetic variability in gastric cancer etiology.

PMID:34653070 | DOI:10.1097/CEJ.0000000000000722

J Clin Gastroenterol. 2021 Oct 14. doi: 10.1097/MCG.0000000000001618. Online ahead of print.

ABSTRACT

GOAL: Our study aimed to explore the incidence of bleeding from ulcers due to premature band slippage and to identify possible associated factors.

BACKGROUND: Band ligation (BL) plays a vital role in treating esophageal varices; however, the procedure carries a considerable risk of band slippage, variceal site ulcer formation, and posttreatment bleeding.

MATERIALS AND METHODS: We retrospectively reviewed the records of patients with esophageal varices who underwent endoscopic hemostasis by BL at our institution between 2015 and 2020. We statistically compared the patients with post-BL ulcer bleeding and those without (controls). The outcome variable was the development of BL-induced ulcer bleeding. The patients’ demographics, clinical, and laboratory parameters, and BL procedure parameters were independent variables. Univariate followed by a multivariate logistic regression were performed to identify possible associated factors from the odds ratio (OR).

RESULTS: Of the 4579 eligible patients, 388 (8.5%) presented with post-BL ulcer bleeding. The presence of high-risk stigmata indicated a 1.271 times higher risk of bleeding [95% confidence interval (CI):1.018-1.587], and a greater number of varices was associated with an increased risk of post-BL ulcer bleeding [OR=1.184 (95% CI: 1.073-1.307)]. Conversely, the use of fewer bands per variceal site was associated with fewer bleeding incidents [OR=1.308 (95% CI: 1.090-1.569)]. Univariate analysis identified proton pump inhibitor as protective [OR=0.770 (95% CI: 0.603-0.983)]; however, the difference was not significant after multivariate analysis [OR=1.283 (95% CI: 1.003-1.640)].

CONCLUSIONS: The overall incidence of post-BL ulcer bleeding was 8.5%. The presence of high-risk stigmata, higher number of varices, and bands per variceal site were associated with an increased risk of post-BL bleeding. The effect of adjuvant proton pump inhibitors was not statistically significant.

PMID:34653067 | DOI:10.1097/MCG.0000000000001618