Tag: statistics

Epidemiology. 2021 Jun 24. doi: 10.1097/EDE.0000000000001381. Online ahead of print.

ABSTRACT

Quantitative bias analyses allow researchers to adjust for uncontrolled confounding, given specification of certain bias parameters. When researchers are concerned about unknown confounders, plausible values for these bias parameters will be difficult to specify. Ding and VanderWeele developed bounding factor and E-value approaches that require the user to specify only some of the bias parameters. We describe the mathematical meaning of bounding factors and E-values as well as the plausibility of these methods in an applied context. We encourage researchers to pay particular attention to the assumption made, when using E-values, that the prevalence of the uncontrolled confounder among the exposed is 100% (or, equivalently, the prevalence of the exposure among those without the confounder is 0%). We contrast methods that attempt to bound biases or effects and alternative approaches such as quantitative bias analysis. We provide an example where failure to make this distinction led to erroneous statements. If the primary concern in an analysis is with known but unmeasured potential confounders, then E-values are not needed and may be misleading. In cases where the concern is with unknown confounders, the E-value assumption of an extreme possible prevalence of the confounder limits its practical utility.

PMID:34224472 | DOI:10.1097/EDE.0000000000001381

Appl Immunohistochem Mol Morphol. 2021 Jul 2. doi: 10.1097/PAI.0000000000000949. Online ahead of print.

ABSTRACT

We performed a pilot study in anticipation of using long-aged precut formalin-fixed paraffin-embedded tissue sections stored in real-world conditions for translational biomarker studies of topoisomerase 2A (TOP2A), Ki67, and human epidermal growth factor receptor 2 (HER2) in endometrial cancer. Formalin-fixed paraffin-embedded tissue blocks or unstained slides or both from GOG-0177 were collected centrally (1999-2000) and stored at room temperature. During 2004 to 2011 specimens were stored at 4°C. Matched pairs of stored slides and freshly cut slides from stored blocks were analyzed for TOP2A (KiS1), Ki67 (MIB1), and HER2 (HercepTest) proteins. To assess DNA stability (HER2 PathVision), fluorescence in situ hybridization (FISH) was repeated on stored slides from 21 cases previously shown to be HER2 amplified. Immunohistochemistry (IHC) staining intensity and extent, mean FISH copies/cell, and copy number ratios were compared using the κ statistic for concordance or signed rank test for differences in old cut versus new cut slides. IHC results reflected some protein degradation in stored slides. The proportion of cells with TOP2A staining was lower on average by 12% in older sections (P=0.03). The proportion of Ki67-positive cells was lower in stored slides by an average of 10% (P<0.01). Too few cases in the IHC cohort were FISH positive for any conclusions. HER2 amplification by FISH was unaffected by slide storage. We conclude that use of aged stored slides for proliferation markers TOP2A and Ki67 is feasible but may modestly underestimate true values in endometrial cancer. Pilot studies for particular storage conditions/durations/antigens to be used in translational studies are warranted.

PMID:34224438 | DOI:10.1097/PAI.0000000000000949

Eye Contact Lens. 2021 Jul 1. doi: 10.1097/ICL.0000000000000816. Online ahead of print.

ABSTRACT

OBJECTIVES: To assess the potential effects of switching to online lecture format on dry eye symptoms and dry eye disease (DED) risk factors.

METHODS: An anonymous cross-sectional online survey was conducted in 812 university students (mean age, 21.5±4.0 years). Participants were classified according to the number of hours the participants took online lectures into online students or in-person students. Respondents completed a total of three DED questionnaires (Ocular Surface Disease Index [OSDI]; 5-item Dry Eye Questionnaire; 8-item Contact Lens Dry Eye Questionnaire) and were surveyed on dry eye risk factors contemplated by the Tear Film and Ocular Surface Society Dry Eye Workshop II in addition to other factors potentially linked to dry eye.

RESULTS: Five hundred twenty-three subjects (64.4%) were classified into the online group and 289 (35.6%) into the in-person group. No statistically significant age (P=0.266) or sex (P=0.423) differences were found between groups. Students taking online lectures used the computer more, spent less time outdoors, practised more exercise, wore a face mask for less time, experienced fewer allergies and fewer psoriasis episodes, and obtained a higher OSDI score (P<0.029 for all). Multivariate logistic regression analysis revealed that the hours of online lectures taken per week was independently associated with having a positive OSDI score (P=0.022).

CONCLUSIONS: Taking online lectures is independently associated with having dry eye symptoms. Despite a lower prevalence of DED risk factors, a higher computer use is probably behind the greater ocular dryness reported by online students.

PMID:34224445 | DOI:10.1097/ICL.0000000000000816

J Craniofac Surg. 2021 Jun 30. doi: 10.1097/SCS.0000000000007760. Online ahead of print.

ABSTRACT

This study aimed to compare the upper-airway morphology between strictly matched Syrian (n = 43) and Hungarian (n = 43) adolescents with Class II/1 malocclusion and identify potential associations between upper airway depths and skeletofacial characteristics. Lateral cephalograms were analyzed, and independent-samples tests and correlation coefficients were used for the statistical analyses. The upper-pharyngeal airway was significantly narrower and the soft palate angle was significantly greater in the Syrian adolescents. Alternatively, the hyoid bone was more posteriorly positioned in the Hungarian adolescents when compared to their counterparts. Depths of the upper and middle pharynx were moderately correlated with sagittal and vertical skeletal dimensions only among Syrian subjects. The depth of the lower pharynx was moderately correlated with hyoid bone position, cervical length, and lip-chin-throat angle only among Hungarian subjects. These findings might have potential implications for optimizing the effects of orthognathic/orthodontic treatments on airway structures in these 2 groups.

PMID:34224460 | DOI:10.1097/SCS.0000000000007760

J Occup Environ Med. 2021 Jul 1. doi: 10.1097/JOM.0000000000002310. Online ahead of print.

ABSTRACT

OBJECTIVE: The aim of this study is to evaluate whether the exposure to a low dose of Nickel could determinate a variation in levels of progesterone in outdoor workers.

MATERIALS AND METHODS: 261 subjects were divided by gender, task, age, seniority and cigarette smoking habit. For each workers was evaluated the dose of blood progesterone and urinary nickel.The statistical analysis was performed.

RESULTS: The Pearson correlation showed a statistically significant correlation between urinary nickel levels and progesterone. The Multiple linear regression showed a significant correlation between progesterone and urinary nickel in the total sample and in the subgroups of smokers and workers with tasks of traffic direction.

CONCLUSIONS: The results of our study suggest that occupational exposure to low doses of nickel present in urban pollution may influence to progesterone levels in outdoor workers.

PMID:34224421 | DOI:10.1097/JOM.0000000000002310

Clin Spine Surg. 2021 Jul 1. doi: 10.1097/BSD.0000000000001228. Online ahead of print.

ABSTRACT

STUDY DESIGN: This was a retrospective cohort review.

OBJECTIVE: The objective of this study was to determine the rate of fusion associated with an expandable cage and iliac crest bone graft in minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) surgery.

SUMMARY OF BACKGROUND DATA: MI-TLIF is a commonly performed procedure, but challenges inherent in MI-TLIF technique can make achieving an interbody fusion difficult.

METHODS: A retrospective review was performed on consecutive patients treated with an MI-TLIF for degenerative lumbar pathology. Patients that completed patient-reported outcome measures and 1-year computed tomography (CT)-scans for fusion analysis were included. Fusion morphology was analyzed by evaluating CT scans for location of bridging trabecular bone in relation to the cage. Patients with bridging bone were considered fused. Preoperative and postoperative health-related quality of life scores were compared. A Kolmogrov-Smirnoff test was used to determine normality of health-related outcome scores. A Friedman 2-way analysis of variance by ranks with pairwise comparisons to determine statistical significance of differences between the date of a follow-up examination and preoperative examination was done.

RESULTS: Of 75 patients evaluated 23 patients were excluded due to loss to follow-up, adjacent segment degeneration, inability to obtain a CT scan, or reoperation for nonfusion related symptoms. Of 61 disk spaces that were included, 55 had bridging bone through the intervertebral cage, resulting in an overall fusion rate of 90.2%. There was a higher rate of fusion at L5-S1 as compared to L4-L5. There was mean improvement in patient-reported outcome measures for Oswestry Disability Index, Short Form-12 Physical Component Score, Visual Analog Scale Back/Leg pain, and Patient-Reported Outcome Measurement Information System Physical Function. There were no complications associated with iliac crest bone graft harvesting.

CONCLUSION: Combining an expandable cage with iliac crest autograft bone harvested through a minimally invasive technique can allow for improved fusion rates without graft-site complications in MI-TLIF surgery.

PMID:34224423 | DOI:10.1097/BSD.0000000000001228

Vopr Kurortol Fizioter Lech Fiz Kult. 2021;98(3):60-66. doi: 10.17116/kurort20219803160.

ABSTRACT

A scientific review is devoted to the study of the coastal climate in the resort treatment role of patients with chronic diseases and its impact on the health and life quality of the population of the seacoasts. The sources were the Cochrane Library, PubMed MEDLINE, MedlinePlus, PedRO, Google Scholar, British Medical Journal, Elsevier, The Global Wellness Institute, eLIBRARY.ru. The review includes 40 publications including 22 domestic and 18 foreign ones on clinical and surrogate outcomes of climate-therapy at seaside resorts in the structure of spa treatment in patients with chronic diseases. The health problems among the population of the seacoasts are considered. The features of conducting evidence-based studies in assessing the effects of climate procedures are noted. The analysis of the therapeutic and health-improving effect results of the seaside climate and the associated forms of thalassotherapy – terrenkur, swimming, aqua gymnastics, sea bathing, heliotherapy, landscape therapy, and the use of maricultureis carried out. The article presents statistically reliable data on the favorable outcomes of treatment of chronic forms of musculoskeletal, skin, pulmonary and cardiac pathology under the influence of thalassotherapy methods. It was found that the effectiveness of climate-therapy in oncological practice, the treatment of pollinosis, the use of algae and other maricultures has been insufficiently proven: the possibility of percutaneous permeability to seawater and its components. The risk of developing negative meteorological reactions during climate-therapy was noted.

PMID:34223756 | DOI:10.17116/kurort20219803160

Rev Esp Quimioter. 2021 Jul 5:barbero05jul2021. doi: 10.37201/req/033.2021. Online ahead of print.

ABSTRACT

OBJECTIVE: Several factors have been associated with the prognosis of prosthetic joint infection (PJI) treated with surgical debridement, antibiotic therapy, and implant retention (DAIR). There is no evidence about the right empirical antibiotic treatment when the causal microorganism is not still identified.

METHODS: We conducted a retrospective observational study in patients with PJI treated with DAIR between 2009 and 2018 in our center. We analyze the risk factors related with their prognosis and the influence of active empirical antibiotic therapy against causative microorganisms in final outcomes.

RESULTS: A total of 80 PJI cases treated with DAIR, from 79 patients (58.7% women, mean age 76.3 years), were included in the study period. Among the cases in which empirical antibiotic therapy were active against the causative microorganisms, the success rate was 46/65 (69.2%) vs 1/15 when not (6.7%, OR 31.5, p = 0.001). Factors related to the success or failure of the DAIR were analyzed with multivariate analysis. We found that active empirical antibiotic treatment remained statistically significant as a good prognostic factor (OR 0.04, p <0.01).

CONCLUSIONS: Empirical antibiotic treatment could be an important factor in the prognosis of PJI treated with DAIR. To identify cases at risk of infection by multidrug resistant microorganisms could be useful to guide empirical antibiotic therapy.

PMID:34223760 | DOI:10.37201/req/033.2021

Arch Razi Inst. 2021 Jul;76(2):283-291. doi: 10.22092/ari.2019.124040.1268. Epub 2021 Jul 1.

ABSTRACT

It is necessary to understand the frequency of virulence factor-encoding genes in the assessment of the carriage proportion. Moreover, it is required in the characterization of major unique antigens that are useful in the development of effective immunological-based preventive measures. The current study aimed to evaluate the frequency of three encoding-virulence genes associated with Enterotoxigenic (ET) and Shigatoxigenic Escherichia coli (E. coli/EC) pathotypes (k99, stx1, and stx2) in North of Sistan and Baluchistan Province, Iran. The frequency of k99, stx1, and stx2 was determined via polymerase chain reaction among E. coli isolates collected from the feces of the clinically healthy suckling (n=50) and diarrheic calves (n=50). The k99 gene was absent in all isolates, and the frequencies of the E. coli containing stx1 and stx2 or both stx1 and stx2 were estimated at 8%, 14%, and 4%, respectively, in the clinically healthy suckling calves (P&amp;gt;0.05), compared to 24%, 16%, and 6% in diarrheic animals (p &amp;lt;0.05). Among the three studied genes, there was a statistically significant difference between clinically healthy suckling and diarrheic calves in terms of the frequency of E. coli isolatescontaining stx1. On the other hand, the results of this study indicated that k99 was not a major fimbrial antigen-encoding gene in the ETECpopulation in the region. It is assumed that in any health measure intended to control the pathogen, other genes involved with encoding fimbriae should also be considered. The noticeable high frequency of E. coli isolates bearing stx1 and/or stx2 virulence elementsboth in clinically healthy and diarrheic suckling calves in this study isa concern for public health. Accordingly, it is recommended that further epidemiological studies be conducted on the role of the stx1 gene in the diarrhea of suckling calves in Sistan and Baluchistan Province, Iran.

PMID:34223727 | DOI:10.22092/ari.2019.124040.1268

Can J Surg. 2021 Jul 5;64(4):E364-E370. doi: 10.1503/cjs.005420.

ABSTRACT

BACKGROUND: In 2017, a provincial guideline was created to fast track and standardize care for pediatric appendicitis in Alberta. We conducted a study to determine the impact of implementation of the guideline at our institution on length of stay (LOS), antibiotic stewardship efforts and costs.

METHODS: We performed a retrospective review of the charts of all patients younger than 18 years of age who underwent appendectomy at our institution in 2 periods: before guideline implementation (Dec. 1, 2016, to May 31, 2017) and after implementation (Dec. 1, 2017, to May 31, 2018). We compared LOS, duration of antibiotic therapy, 30-day postdischarge complication rates and variable cost between the 2 cohorts.

RESULTS: Of the 276 total appendectomy procedures performed, 185 were for simple appendicitis (81 before guideline implementation and 104 after implementation), and 91 were for complicated appendicitis (44 and 47, respectively). The median LOS was shorter in the postimplementation cohort for both simple and complicated appendicitis (15.5 h [interquartile range (IQR) 12-19 h] v. 17.0 h [IQR 13-22 h], p = 0.03; and 3.0 d [IQR 2-4 d] v. 3.0 d [IQR 3-5 d], p = 0.05, respectively). Patients with complicated appendicitis had fewer antibiotic days after guideline implementation; the difference was statistically significant for patients without diffuse peritoneal contamination or abscess formation (p = 0.02). There were no differences between the cohorts with respect to 30-day rates of complications, including emergency department visits, readmission and surgical site infections. After guideline implementation, the average variable cost per patient was reduced by $230, equating to a total average annual cost savings of $75 842 for our institution.

CONCLUSION: The implementation of a provincial guideline aimed at standardizing care in pediatric appendicitis at our institution was associated with shortened LOS, improved antibiotic stewardship efforts and reduced cost of care. Other institutions may replicate our model of a standardized pathway in the management of pediatric appendicitis in an effort to improve the quality of patient care and reduce health care costs.

PMID:34223740 | DOI:10.1503/cjs.005420