Nevin Manimala

Scand Stat Theory Appl. 2024 Jun;51(2):672-696. doi: 10.1111/sjos.12695. Epub 2023 Nov 8.

ABSTRACT

This article proposes a distance-based framework incentivized by the paradigm shift towards feature aggregation for high-dimensional data, which does not rely on the sparse-feature assumption or the permutation-based inference. Focusing on distance-based outcomes that preserve information without truncating any features, a class of semiparametric regression has been developed, which encapsulates multiple sources of high-dimensional variables using pairwise outcomes of between-subject attributes. Further, we propose a strategy to address the interlocking correlations among pairs via the U-statistics-based estimating equations (UGEE), which correspond to their unique efficient influence function (EIF). Hence, the resulting semiparametric estimators are robust to distributional misspecification while enjoying root-n consistency and asymptotic optimality to facilitate inference. In essence, the proposed approach not only circumvents information loss due to feature selection but also improves the model’s interpretability and computational feasibility. Simulation studies and applications to the human microbiome and wearables data are provided, where the feature dimensions are tens of thousands.

PMID:39101047 | PMC:PMC11296665 | DOI:10.1111/sjos.12695

JVS Vasc Sci. 2024 Jun 11;5:100211. doi: 10.1016/j.jvssci.2024.100211. eCollection 2024.

ABSTRACT

BACKGROUND: High lipoprotein (a) [Lp(a)] is associated with adverse limb events in patients undergoing lower extremity revascularization. Lp(a) levels are genetically pre-determined, with LPA gene encoding for two apolipoprotein (a) [apo(a)] isoforms. Isoform size variations are driven by the number of kringle IV type 2 (KIV-2) repeats. Lp(a) levels are inversely correlated with isoform size. In this study, we examined the role of Lp(a) levels, apo(a) size, and inflammatory markers with lower extremity revascularization outcomes.

METHODS: Twenty-five subjects with chronic peripheral arterial disease (PAD) underwent open or endovascular lower extremity revascularization (mean age, 66.7 ± 9.7 years; Female = 12; Male = 13; Black = 8; Hispanic = 5; and White = 12). Pre- and postoperative medical history, self-reported symptoms, ankle-brachial indices (ABIs), and lower extremity duplex ultrasounds were obtained. Plasma Lp(a), apoB100, lipid panel, and pro-inflammatory markers (IL-6, IL-18, hs-CRP, TNFα) were assayed preoperatively. Isoform size was estimated using gel electrophoresis and weighted isoform size (wIS) calculated based on % isoform expression. Firth logistic regression was used to examine the relationship between Lp(a) levels and wIS with procedural outcomes: symptoms (better/worse), early primary patency at 2 to 4 weeks, ABIs, and reintervention within 3 to 6 months. We controlled for age, sex, history of diabetes, smoking, statin, antiplatelet, and anticoagulation use.

RESULTS: Median plasma Lp(a) level was 108 (interrquartile range, 44-301) nmol/L. The mean apoB100 level was 168.0 ± 65.8 mg/dL. These values were not statistically different among races. We found no association between Lp(a) levels and wIS with measured plasma pro-inflammatory markers. However, smaller apo(a) wIS was associated with occlusion of the treated lesion(s) in the postoperative period (odds ratio, 1.97; 95% confidence interval, 1.01-3.86; P < .05). The relationship of smaller apo(a) wIS with reintervention was not as strong (odds ratio, 1.57; 95% confidence interval, 0.96-2.56; P = .07). We observed no association between wIS with patient reported symptoms or change in ABIs.

CONCLUSIONS: In this small study, subjects with smaller apo(a) isoform size undergoing peripheral arterial revascularization were more likely to experience occlusion in the postoperative period and/or require reintervention. Larger cohort studies identifying the mechanism and validating these preliminary data are needed to improve understanding of long-term peripheral vascular outcomes.

PMID:39101011 | PMC:PMC11296070 | DOI:10.1016/j.jvssci.2024.100211

J Child Orthop. 2024 May 3;18(4):404-413. doi: 10.1177/18632521241234768. eCollection 2024 Aug.

ABSTRACT

BACKGROUND: Joint range of motion based on the neutral null method, muscle strength based on manual muscle testing, and selective voluntary motor control based on selective control assessment of the lower extremity are standard parameters of a pediatric three-dimensional clinical gait analysis. Lower-limb reference data of children are necessary to identify and quantify abnormalities, but these are limited and when present restricted to specific joints or muscles.

METHODS: This is the first study that encompasses the aforementioned parameters from a single group of 34 typically developing children aged 5-17 years. Left and right values were averaged for each participant, and then the mean and standard deviation calculated for the entire sample. The data set was tested for statistical significance (p < 0.05).

RESULTS: Joint angle reference values are mostly consistent with previously published standards, although there is a large variability in the existing literature. All muscle strength distributions, except for M. quadriceps femoris, differ significantly from the maximum value of 5. The mean number of repetitions of heel-rise test is 12 ± 5. Selective voluntary motor control shows that all distributions, except for M. quadriceps femoris, differ significantly from the maximum value of 2.

CONCLUSION: Since typically developing children do not match expectations and reference values from the available literature and clinical use, this study emphasizes the importance of normative data. Excessively high expectations lead to typically developing children being falsely underestimated and affected children being rated too low. This is of great relevance for therapists and clinicians.

LEVEL OF EVIDENCE: 3.

PMID:39100986 | PMC:PMC11295375 | DOI:10.1177/18632521241234768

J Child Orthop. 2024 Apr 29;18(4):441-449. doi: 10.1177/18632521241244624. eCollection 2024 Aug.

ABSTRACT

PURPOSE: Tibialis anterior tendon shortening combined with tendon Achilles lengthening showed satisfactory short- and long-term outcomes for pes equinus treatment. This retrospective study aimed to evaluate the effectiveness of a single tibialis anterior tendon shortening-tendon Achilles lengthening procedure for treating pes equinus, in a homogeneous unilateral cerebral palsy patient group.

METHODS: Gait analysis was conducted on 22 unilateral cerebral palsy patients (mean age at surgery = 13.3 years, standard deviation = 3 years) before and within 2.5 years (standard deviation = 0.61 years) after the tibialis anterior tendon shortening-tendon Achilles lengthening procedure. Primary outcome measures included foot drop occurrence in swing, foot dorsiflexion and the first ankle rocker presence compared to healthy reference data. Movement analysis profile and gait profile score were also calculated for the entire gait cycle. The clinical exam and the A2 peak ankle power were analyzed. Statistical analysis used the paired Wilcoxon’s sign rank test (p < 0.05).

RESULTS: Post-operatively, significant improvements were observed in ankle dorsiflexion during swing (p = 0.0006) and reduced foot drop in swing (p = 0.0107). The occurrence of a first ankle rocker did not significantly change (p = 0.1489). Significant improvements in gait profile score and movement analysis profile for all joints and planes indicate overall gait quality improvement. The foot progression changed significantly (p = 0.0285), with a greater external orientation. Nineteen out of 22 patients were able to quit wearing their ankle foot orthoses.

CONCLUSION: Tibialis anterior tendon shortening and tendon Achilles lengthening combination yielded positive outcomes, showing increased foot dorsiflexion, first ankle rocker presence, and overall improved gait quality. These findings support the effectiveness of this surgical approach for treating pes equinus in children with unilateral spastic cerebral palsy.

PMID:39100984 | PMC:PMC11295372 | DOI:10.1177/18632521241244624

J Child Orthop. 2024 Feb 14;18(4):393-398. doi: 10.1177/18632521241229978. eCollection 2024 Aug.

ABSTRACT

PURPOSE: Developmental hip dysplasia is a prevalent pediatric musculoskeletal condition that lacks international standardized screening. We sought to characterize developmental hip dysplasia screening practices in countries with the top global health indices. We also explored diverse definitions in reported epidemiologic rates of this condition.

METHODS: We performed a scoping review of developmental hip dysplasia screening protocols utilizing countries ranked in the top 25 of the Bloomberg Global Health Index using a protocolized search strategy, progressing from academic to layperson sources. A reference was eligible for inclusion if it mentioned the countries’ screening program and developmental hip dysplasia was the pathology of concern. Incidence rates, when present, were also recorded. The United States Census Bureau’s International Database tool provided countries’ populations. We compiled the data and performed descriptive statistics and appropriate validation methods.

RESULTS: Twenty countries (80%) had searchable screening programs. Clinical screening with selective universal screening was the most commonly observed (n = 16). Four countries had universal ultrasound screening: Switzerland, Austria, Germany, and Slovenia. Five countries did not have searchable programs. No countries employed radiographic screening. Incidence rates were expressly stated in the literature for nine countries; however, the cohort of interest varied from developmental hip dysplasia versus severity of developmental hip dysplasia versus miscellaneous (e.g. requiring hospitalization).

CONCLUSION: The findings of this investigation highlight international inconsistencies regarding developmental hip dysplasia screening and epidemiologic data. Screening variations exist despite consensus statements calling for uniformity. We agree with prior literature advocating for increasing consistency in developmental hip dysplasia management or, at a minimum, increasing transparency regarding how we manage these young patients.

PMID:39100982 | PMC:PMC11295378 | DOI:10.1177/18632521241229978

J Child Orthop. 2024 Mar 27;18(4):386-392. doi: 10.1177/18632521241240367. eCollection 2024 Aug.

ABSTRACT

PURPOSE: Our purpose was to analyze the impact of Pavlik Harness treatment on children motor skills development, comparing to a control group.

METHODS: A total of 121 children were included: 55 cases (children with Developmental Dysplasia of the Hip) and 66 healthy controls. Cases were recruited from 2017 to 2021 and followed up to 2022. Controls (healthy children without orthopedic pathology) were recruited from 2020 to 2022. The primary endpoint was the time of achievement of three gross motor milestones (sitting without support, hands-and-knees crawling, and walking independently).

RESULTS: The groups had no differences regarding sex distribution, gestational age, birth weight, and rate of twin pregnancy. The prevalence of positive family history of Development Dysplasia of the Hip (20.0% vs 3.0%, p < 0.003), breech presentation (38.2% vs 1.5%, p < 0.001), and C-section delivery (60.0% vs 19.7%, p < 0.001) was significantly higher in Development Dysplasia of the Hip group. Children with Development Dysplasia of the Hip achieved the three gross milestones evaluated 1 month later than healthy controls, although this was not statistically significant (p = 0.133 for sitting, p = 0.670 for crawling, and p = 0.499 for walking).

CONCLUSION: Children with Development Dysplasia of the Hip, treated by Pavlik harness, do not have significant delays in motor skills acquisition.

PMID:39100978 | PMC:PMC11295376 | DOI:10.1177/18632521241240367

J Child Orthop. 2024 Jul 27;18(4):360-371. doi: 10.1177/18632521241264183. eCollection 2024 Aug.

ABSTRACT

PURPOSE: Three-dimensional printing has evolved into a cost-effective and accessible tool. In orthopedic surgery, creating patient-specific anatomical models and instrumentation improves visualization and surgical accuracy. In pediatric orthopedics, three-dimensional printing reduces operating time, radiation exposure, and blood loss by enhancing surgical efficacy. This review compares outcomes of three-dimensional printing-assisted surgeries with conventional surgeries for upper and lower extremity pediatric surgeries.

METHODS: A complete search of medical literature up to August 2023, using Ovid Medline, EMBASE, Scopus, Web of Science, and Cochrane Library was conducted in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Broad search terms included “pediatrics,” “orthopedic,” and “3D-printing.” Eligible studies were assessed for intraoperative time, blood loss, and fluoroscopy exposure.

RESULTS: Out of 3299 initially identified articles, 14 articles met inclusion criteria. These studies included 409 pediatric patients, with ages averaging 9.51 years. The majority were retrospective studies (nine), with four prospective and one experimental study. Studies primarily utilized three-dimensional printing for navigation templates and implants. Results showed significant reductions in operative time, blood loss, and radiation exposure with three-dimensional printing. Complication occurrences were generally lower in three-dimensional printing surgeries, but there was no statistical significance.

CONCLUSIONS: Three-dimensional printing is an emerging technology in the field of orthopedics, and it is primarily used for preoperative planning. For pediatric upper and lower extremity surgeries, three-dimensional printing leads to decreased operating room time, decreased intraoperative blood loss, and reduced radiation exposure. Other uses for three-dimensional printing include education, patient communication, the creation of patient-specific instrumentation and implants.

LEVEL OF EVIDENCE: Level III.

PMID:39100975 | PMC:PMC11295370 | DOI:10.1177/18632521241264183

Diabetes Metab Syndr Obes. 2024 Jul 29;17:2845-2853. doi: 10.2147/DMSO.S459478. eCollection 2024.

ABSTRACT

PURPOSE: The purpose of this study is to describe diabetes distress and related factors among Chinese Americans with type 2 diabetes in New York City (NYC).

METHODS: We conducted a secondary data analysis of the baseline data from three research studies conducted among community-dwelling Chinese American adults with type 2 diabetes. Diabetes Distress Scale (DDS) was used to measure sources of diabetes distress including emotional-, regimen-, interpersonal-, and physician-related distress. A score of 2 or greater indicates moderate diabetes distress or higher. Patient Health Questionnaire-2 (PHQ-2) was used to measure depressive symptoms. Participants’ sociodemographic information was also collected. Descriptive statistics were used to describe diabetes distress, and logistic least absolute shrinkage and selection operator (LASSO) regression was used to examine factors associated with diabetes distress level.

RESULTS: Data from 178 participants (mean age 63.55±13.56 years) were analyzed. Most participants were married (76.40%), had a high school degree or less (65.73%), had a household annual income < $25,000 (70.25%), and reported limited English proficiency (93.22%). About 25.84% reported moderate or higher overall distress. The most common sources of distress were emotional burden (29.78%), followed by regimen- (28.65%), interpersonal- (18.54%), and physician-related distress (14.04%). Participants who were younger, female, limited English proficient, and had elevated depressive symptoms were more likely to have higher diabetes distress.

CONCLUSION: Diabetes distress is prevalent among Chinese immigrants with type 2 diabetes, especially emotional- and regimen-related distress. Given the known link between diabetes distress and poor glycemic control, it is critical to screen for diabetes distress at primary care clinics and incorporate psychological counseling in diabetes care in this underserved population.

PMID:39100965 | PMC:PMC11296360 | DOI:10.2147/DMSO.S459478

Glob Epidemiol. 2024 Jul 8;8:100154. doi: 10.1016/j.gloepi.2024.100154. eCollection 2024 Dec.

ABSTRACT

BACKGROUND: Bias away from the null in odds ratios (OR), aggravated by low power, is a well-known phenomenon in statistics (sparse data bias). Such bias increases in presence of selection of “significant” results on the basis of null hypothesis testing (effect size magnification, ESM).

OBJECTIVES: We seek to illustrate these issues and adjust for suspected sparse data bias in the context of a reported more than doubling of the odds of new onset type 2 diabetes in presence of occupational trichlorfon insecticide exposure reported in the Agricultural Health Study.

METHODS: We performed ESM analysis on the crude ORs extracted from the contingency table in the published report, which is done by simulating selected OR given a posited true OR. Next, we applied easily accessible methods that adjust for sparse data bias to the extracted contingency tables, including data augmentation, bootstrap, Firth’s regression, and Bayesian methods with weakly informative priors.

RESULTS: During the ESM analysis, we observed that there was a reasonable chance that a “statistically significant” OR of around 2.5-2.6 would be observed for true OR of 1.2. Adjustment for sparse data bias revealed that Bayesian methods outperformed alternative approaches in terms of yielding more precise inference, while not making unjustified distributional assumptions about estimates of OR. The OR in the original paper of about 2.5-2.6 was reduced on average to OR of 1.9 to 2.2, with 95% (Bayesian) credible intervals that included the null.

DISCUSSION: It is reasonable to adjust ORs for sparse data bias when the reported association has societal importance, because policy must be informed by the least biased estimates of the effect. We think that such adjustment would lead to a more appropriate evaluation of the extent of evidence on the contribution of occupational exposure to trichlorfon pesticide to risk of new onset diabetes.

PMID:39100964 | PMC:PMC11295935 | DOI:10.1016/j.gloepi.2024.100154