Tag: statistics

J Neurosurg Pediatr. 2023 Mar 10:1-5. doi: 10.3171/2023.1.PEDS22324. Online ahead of print.

ABSTRACT

OBJECTIVE: Epidural hematoma (EDH) has rarely been studied specifically in infants. The objective of this study was to investigate the outcomes of patients aged < 18 months (infants) with EDH.

METHODS: The authors conducted a single-center retrospective study of 48 infants aged less than 18 months who underwent an operation for a supratentorial EDH in the last decade. Clinical, radiological, and biological variables were used in a statistical analysis to identify factors predictive of radiological and clinical outcome.

RESULTS: Forty-seven patients were included in the final analysis. Seventeen children (36%) had cerebral ischemia on postoperative imaging, either due to stroke (cerebral herniation) or by local compression. Factors associated with ischemia after multivariate logistic regression were the presence of an initial neurological deficit (76% vs 27%, p = 0.03), low platelet count (mean 192 vs 267 per mm3, p = 0.01), low fibrinogen level (mean 1.4 vs 2.2 g/L, p = 0.04) and long intubation time (mean 65.7 vs 10.1 hours, p = 0.03). Cerebral ischemia on MRI was predictive of a poor clinical outcome.

CONCLUSIONS: Infants with EDH have a low mortality rate but a high risk of cerebral ischemia, along with long-term neurological sequelae.

PMID:36905671 | DOI:10.3171/2023.1.PEDS22324

J Neurosurg Pediatr. 2023 Mar 10:1-10. doi: 10.3171/2023.1.PEDS22349. Online ahead of print.

ABSTRACT

OBJECTIVE: Unicoronal craniosynostosis (UCS) is characterized by complex orbital deformity and is typically treated by asymmetrical fronto-orbital remodeling (FOR) during the 1st year of life. The aim of this study was to elucidate to what extent orbital morphology is corrected by surgical treatment.

METHODS: The extent to which orbital morphology was corrected by surgical treatment was tested by analysis of differences in volume and shape between synostotic, nonsynostotic, and control orbits at two time points. In total, 147 orbits were analyzed from patient CT images obtained preoperatively (mean age 9.3 months), at follow-up (mean age 3.0 years), and in matched controls. Semiautomatic segmentation software was used to determine orbital volume. For analysis of orbital shape and asymmetry, geometrical models, signed distance maps, principal modes of variation, and three objective parameters (mean absolute distance, Hausdorff distance, and dice similarity coefficient) were generated by statistical shape modeling.

RESULTS: Orbital volumes on both the synostotic and nonsynostotic sides were significantly smaller at follow-up than volumes in controls and significantly smaller both preoperatively and at follow-up than orbital volumes on the nonsynostotic side. Significant differences in shape were identified globally and locally, both preoperatively and at 3 years of age. Compared with controls, deviations were mostly found on the synostotic side at both time points. Asymmetry between synostotic and nonsynostotic sides was significantly decreased at follow-up, but not compared with the inherent asymmetry of controls. On a group level, the preoperative synostotic orbit was mainly expanded in the anterosuperior and anteroinferior regions and smallest on the temporal side. At follow-up, the mean synostotic orbit was still larger superiorly but also expanded in the anteroinferior temporal region. Overall, the morphology of nonsynostotic orbits was more similar to that of controls than to synostotic orbits. However, the individual variation in orbital shape was greatest for nonsynostotic orbits at follow-up.

CONCLUSIONS: In this study, the authors presented what is, to their knowledge, the first objective automatic 3D bony evaluation of orbital shape in UCS, defining in greater detail than has been done previously how synostotic orbits differ from nonsynostotic and control orbits, and how orbital shape changes from 9.3 months of age preoperatively to 3 years of age at the postoperative follow-up. Despite surgical treatment, both local and global deviations in shape persist. These findings may have implications for future directions in the development of surgical treatment. Future studies connecting orbital morphology to ophthalmic disorders, aesthetics, and genetics could provide further insight to enable better outcomes in UCS.

PMID:36905670 | DOI:10.3171/2023.1.PEDS22349

J Neurosurg Pediatr. 2023 Mar 10:1-8. doi: 10.3171/2023.1.PEDS22461. Online ahead of print.

ABSTRACT

OBJECTIVE: Posthemorrhagic hydrocephalus (PHH) remains a major morbidity of premature birth resulting from intraventricular hemorrhage (IVH). National consensus guidelines for the timing of surgical interventions are lacking, which leads to considerable variations in management among neonatal intensive care units (NICUs). Early intervention (EI) has been shown to improve outcomes, but the authors hypothesized that the timing from IVH to intervention affects the comorbidities and complications associated with PHH management. The authors used a large national inpatient care data set to characterize comorbidities and complications associated with PHH management in premature infants.

METHODS: The authors used hospital discharge data from the 2006-2019 Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Database (KID) to conduct a retrospective cohort study of premature pediatric patients (weight < 1500 g) with PHH. The predictor variable was the timing of the PHH intervention (EI ≤ 28 days vs late intervention [LI] > 28 days). Hospital stay data included hospital region, gestational age, birth weight (BW), length of stay (LOS), PHH treatment procedures, comorbidities, surgical complications, and death. Statistical analysis included chi-square and Wilcoxon rank-sum tests, Cox proportional hazards regression, logistic regression, and a generalized linear model with Poisson and gamma distributions. Analysis was adjusted for demographic characteristics, comorbidities, and death.

RESULTS: Of the 1853 patients diagnosed with PHH, 488 (26%) had documented timing of surgical interventions during their hospital stay. More patients had LI than EI (75%). The patients in the LI group of patients had younger gestational age and lower BW. There were significant regional differences in the timing of treatment: hospitals in the West performed EI, whereas hospitals in the South performed LI, even after adjustment for gestational age and BW. The LI group was associated with longer median LOS and more total hospital charges compared with the EI group. More temporary CSF diversion procedures occurred in the EI group, whereas more permanent CSF-diverting shunts were placed in the LI group. Shunt/device replacement and complications did not differ between the two groups. The LI group had 2.5-fold higher odds of sepsis (p < 0.001) and almost 2-fold higher odds of retinopathy of prematurity (p < 0.05) than the EI group.

CONCLUSIONS: The timing of PHH interventions differs by region in the United States, whereas the association of potential benefits with treatment timing suggests the importance of national consensus guidelines. Development of these guidelines can be informed by data regarding treatment timing and patient outcomes available in large national data sets, which provide insights into comorbidities and complications of PHH interventions.

PMID:36905669 | DOI:10.3171/2023.1.PEDS22461

J Neurosurg Pediatr. 2023 Mar 10:1-10. doi: 10.3171/2023.1.PEDS22222. Online ahead of print.

ABSTRACT

OBJECTIVE: The goal of this study was to review the efficacy and safety of different surgical techniques used for treatment of Chiari malformation type I (CM-I) in children.

METHODS: The authors retrospectively reviewed 437 consecutive children surgically treated for CM-I. Procedures were classified into four groups: bone decompression (posterior fossa decompression [PFD]) and duraplasty (PFD with duraplasty [PFDD]), PFDD with arachnoid dissection (PFDD+AD), PFDD with tonsil coagulation of at least one cerebellar tonsil (PFDD+TC), and PFDD with subpial tonsil resection of at least one tonsil (PFDD+TR). Efficacy was measured as a greater than 50% reduction in the syrinx by length or anteroposterior width, patient-reported improvement in symptoms, and rate of reoperation. Safety was measured as the rate of postoperative complications.

RESULTS: The mean patient age was 8.4 years (range 3 months to 18 years). In total, 221 (50.6%) patients had syringomyelia. The mean follow-up was 31.1 months (range 3-199 months), and there was no statistically significant difference between groups (p = 0.474). Preoperatively, univariate analysis showed that non-Chiari headache, hydrocephalus, tonsil length, and distance from the opisthion to brainstem were associated with the surgical technique used. Multivariate analysis demonstrated that hydrocephalus was independently associated with PFD+AD (p = 0.028), tonsil length was independently associated with PFD+TC (p = 0.001) and PFD+TR (p = 0.044), and non-Chiari headache was inversely associated with PFD+TR (p = 0.001). In the treatment groups postoperatively, symptoms improved in 57/69 (82.6%) PFDD patients, 20/21 (95.2%) PFDD+AD patients, 79/90 (87.8%) PFDD+TC patients, and 231/257 (89.9%) PFDD+TR patients, and differences between groups were not statistically significant. Similarly, there was no statistically significant difference in postoperative Chicago Chiari Outcome Scale scores between groups (p = 0.174). Syringomyelia improved in 79.8% of PFDD+TC/TR patients versus only 58.7% of PFDD+AD patients (p = 0.003). PFDD+TC/TR remained independently associated with improved syrinx outcomes (p = 0.005) after controlling for which surgeon performed the operation. For those patients whose syrinx did not resolve, no statistically significant differences between surgery groups were observed in the length of follow-up or time to reoperation. Overall, there was no statistically significant difference between groups in postoperative complication rates, including aseptic meningitis and CSF- and wound-related issues, or reoperation rates.

CONCLUSIONS: In this single-center retrospective series, cerebellar tonsil reduction, by either coagulation or subpial resection, resulted in superior reduction of syringomyelia in pediatric CM-I patients, without increased complications.

PMID:36905667 | DOI:10.3171/2023.1.PEDS22222

J Neurosurg. 2023 Mar 10:1-5. doi: 10.3171/2023.1.JNS222171. Online ahead of print.

ABSTRACT

OBJECTIVE: Transfemoral access (TFA) has been the traditional route of arterial access for neurointerventional procedures. Femoral access site complications may occur in 2%-6% of patients. Management of these complications often requires additional diagnostic tests or interventions, each of which may increase the cost of care. The economic impact of a femoral access site complication has not yet been described. The objective of this study was to evaluate the economic consequences of femoral access site complications.

METHODS: The authors conducted a retrospective review of patients undergoing neuroendovascular procedures at their institute and identified those who experienced femoral access site complications. The subset of patients experiencing these complications during elective procedures was matched in a 1:2 fashion to a control group undergoing similar procedures and not experiencing an access site complication.

RESULTS: Femoral access site complications were identified in 77 patients (4.3%) over a 3-year period. Thirty-four of these complications were considered major, requiring blood transfusion or additional invasive treatment. There was a statistically significant difference in total cost ($39,234.84 vs $23,535.32, p = 0.001), total reimbursement ($35,500.24 vs $24,861.71, p = 0.020) and reimbursement minus cost (-$3734.60 vs $1326.39, p = 0.011) between the complication and control cohorts in elective procedures, respectively.

CONCLUSIONS: Although occurring relatively infrequently, femoral artery access site complications increase the cost of care for patients undergoing neurointerventional procedures; how this influences the cost effectiveness of neurointerventional procedures warrants further investigation.

PMID:36905662 | DOI:10.3171/2023.1.JNS222171

Acta Oncol. 2023 Mar 11:1-7. doi: 10.1080/0284186X.2023.2186187. Online ahead of print.

ABSTRACT

BACKGROUND: Oligoprogression (OPD) is defined as a condition where limited progression (1-3 metastases) is observed in patients undergoing systemic cancer treatment. In this study we investigated the impact of stereotactic body radiotherapy (SBRT) in patients with OPD from metastatic lung cancer.

MATERIAL AND METHODS: Data from a cohort of consecutive patients with SBRT treated between June 2015 and August 2021 were collected. All extracranial metastatic sites of OPD from lung cancer were included. Dose regimens consisted of 24 in 2 fractions, 30-51 Gy in 3 fractions, 30-55 Gy in 5 fractions, 52.5 Gy in 7 fractions and 44-56 Gy in 8 fractions. Kaplan-Meier method was used to calculate Overall Survival (OS), Local Control (LC), and Disease-Free Survival (DFS) from the start date of SBRT to the event.

RESULTS: Sixty-three patients, 34 female and 29 males were included. Median age was 75 years (range 25-83). All patients received concurrent systemic treatment before the start of the SBRT: 19 chemotherapy (CT), 26 CT plus immunotherapy (IT) or Tyrosin kinase inhibitors (TKI) and 18 IT/TKI. SBRT was delivered to the lung (n = 29), mediastinal node (n = 9), bone (n = 7), adrenal gland (n = 19), other visceral metastases (1) and other node metastases (n = 4). After a median follow-up of 17 months, median OS was 23 months. LC was 93% at 1 year and 87% at 2 years. DFS was 7 months. According to our results, there was no statistically significant correlation between prognostic factors and OS after SBRT in OPD patients.

CONCLUSIONS: Median DFS was 7 months, translating into the continuation of effective systemic treatment as other metastases grow slowly. In patients with oligoprogression disease, SBRT is a valid and efficient treatment that may enable postponing the switch of systemic line.

PMID:36905644 | DOI:10.1080/0284186X.2023.2186187

Scand J Occup Ther. 2023 Mar 11:1-9. doi: 10.1080/11038128.2023.2184420. Online ahead of print.

ABSTRACT

BACKGROUND: Older drivers with mild cognitive impairment (MCI) often show declining driving performance. Evidence is lacking regarding whether their driving skills can be improved after practice.

AIMS/OBJECTIVES: To compare the practice effects of older drivers with MCI and drivers with normal cognition in an unfamiliar, standardized driving course with three practices.

MATERIALS AND METHODS: Single-blind two-group observational design. Twelve drivers with confirmed MCI as the experimental group and ten with normal cognition (NC) as the control, all ≥ 55 years old. The primary outcome was to assess the practice effects, measured with an in-car global-positioning-system mobile application to compare the speed and directional control of a complex manoeuvre after practices. Secondary outcomes were to assess the pass/fail rate and mistakes observed for the 3^rd/final on-road driving practice. No instructions were given during practice. Descriptive statistics and the Mann-Whitney U test were used for data analysis.

RESULTS: No significant inter-group difference in the pass/fail rate and number of mistakes. Some MCI drivers performed better in the speed and directional control of the S-Bend manoeuvre after practices.

CONCLUSIONS: The driving performance of drivers with MCI may improve with practice.

SIGNIFICANCE: Older drivers with MCI may potentially benefit from driver retraining.

CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (Identifier: NCT04648735).

PMID:36905632 | DOI:10.1080/11038128.2023.2184420

J Am Podiatr Med Assoc. 2023 Jan-Feb;113(1):21-229. doi: 10.7547/21-229.

ABSTRACT

BACKGROUND: Studies on the sensory perception of mass mostly focus on the hands rather than the feet. The aim of our study is to measure how accurately runners can perceive additional shoe mass in comparison to a control shoe (CS) while running, and moreover, whether there is a learning effect in the perception of mass. Indoor running shoes were categorized as a CS (283 g) and shoes with four additional masses: shoe 2 (+50 g), shoe 3 (+150 g), shoe 4 (+250 g), and shoe 5 (+315 g).

METHODS: There were 22 participants in the experiment, which was divided into two sessions. In session 1, participants ran on a treadmill for 2 min with the CS and then put on one set of weighted shoes and ran for another 2 min at a preferred velocity. A binary question was used after the pair test. This process was repeated for all the shoes to compare them with the CS.

RESULTS: Based on our statistical analysis (mixed effect logistic regression), the independent variable (ie, mass) did have a significant effect on perceived mass (F4,193 = 10.66, P < .0001), whereas repeating the task did not show a significant learning effect (F1,193 = 1.06, P = .30).

CONCLUSIONS: An increase of 150 g is the just-noticeable difference among other weighted shoes and the Weber fraction is equal to 0.53 (150:283 g). Learning effect did not improve by repeating the task in two sessions in the same day. This study facilitates our understanding about sense of force and enhances multibody simulation in running.

PMID:36905625 | DOI:10.7547/21-229

J Am Podiatr Med Assoc. 2023 Jan-Feb;113(1):21-008. doi: 10.7547/21-008.

ABSTRACT

BACKGROUND: Clinical studies have shown that posterior malleolar fractures treated with a posterior buttress plate have improved outcomes compared to anterior-to-posterior screw fixation. The aim of this study was to evaluate the impact of posterior malleolus fixation on clinical and functional results.

METHODS: The patients with posterior malleolar fractures who were treated between January of 2014 and April of 2018 at our hospital were investigated retrospectively. Fifty-five patients included in the study were divided into three groups according to the fixation preferences of fractures (group I, posterior buttress plate; group II, anterior-to-posterior screw; and group III, nonfixated). The groups consisted of 20, nine, and 26 patients, respectively. These patients were analyzed according to demographic data, fixation preferences of fractures, mechanism of injury, hospitalization length of stay, surgical time, syndesmosis screw use, follow-up time, complications, Haraguchi fracture classification, van Dijk classification, American Orthopaedic Foot and Ankle Society score, and plantar pressure analysis.

RESULTS: There were no statistically significant differences between the groups in terms of gender, operation side, injury mechanism, length of stay, anesthesia types, and syndesmotic screw usage. However, when the age, follow-up time, operation time, complications, Haraguchi classification, van Dijk classification, and American Orthopaedic Foot and Ankle Society scores were evaluated, statistically significant differences were observed between the groups. Plantar pressure analysis data showed that group I yielded balanced pressure distribution between both feet compared to the other study groups.

CONCLUSIONS: The posterior buttress plating of posterior malleolar fractures yielded better clinical and functional outcomes compared to the anterior-to-posterior screw fixation and nonfixated groups.

PMID:36905619 | DOI:10.7547/21-008

Int J Epidemiol. 2023 Mar 11:dyad023. doi: 10.1093/ije/dyad023. Online ahead of print.

ABSTRACT

Common tasks encountered in epidemiology, including disease incidence estimation and causal inference, rely on predictive modelling. Constructing a predictive model can be thought of as learning a prediction function (a function that takes as input covariate data and outputs a predicted value). Many strategies for learning prediction functions from data (learners) are available, from parametric regressions to machine learning algorithms. It can be challenging to choose a learner, as it is impossible to know in advance which one is the most suitable for a particular dataset and prediction task. The super learner (SL) is an algorithm that alleviates concerns over selecting the one ‘right’ learner by providing the freedom to consider many, such as those recommended by collaborators, used in related research or specified by subject-matter experts. Also known as stacking, SL is an entirely prespecified and flexible approach for predictive modelling. To ensure the SL is well specified for learning the desired prediction function, the analyst does need to make a few important choices. In this educational article, we provide step-by-step guidelines for making these decisions, walking the reader through each of them and providing intuition along the way. In doing so, we aim to empower the analyst to tailor the SL specification to their prediction task, thereby ensuring their SL performs as well as possible. A flowchart provides a concise, easy-to-follow summary of key suggestions and heuristics, based on our accumulated experience and guided by SL optimality theory.

PMID:36905602 | DOI:10.1093/ije/dyad023