Category: Statistics

Semin Dial. 2022 Jan 27. doi: 10.1111/sdi.13056. Online ahead of print.

ABSTRACT

BACKGROUND: The arteriovenous fistulas (AVF) continue to be the most prevalent type of vascular access for hemodialysis (HD). However, the appropriate locations of AVF are controversial. We conducted the meta-analysis to investigate the differences in patency between upper-arm and forearm AVF.

METHODS: PubMed, EMBASE, CENTRAL, and ISI Web of Science were searched to identify studies with differences in AVF patency at different locations. Reviewers searched the database, screened studies according to inclusion criteria, and conducted Meta-analysis.

RESULTS: A total of 12 studies involving 3437 patients were selected. Pooled data showed that primary patency (PP) of AVF were higher in upper-arm than forearm at 1 and 2 years (odds ratio [OR] = 1.54, p = 0.0005; OR = 2.45, p = 0.001), but the differences in cumulative patency (CP) were not statistically significant at 1 and 2 years (OR = 2.10, p = 0.08; OR = 2.16, p = 0.1). The differences in PP and CP between upper-arm and forearm AVF in patients older than 65 years were not statistically significant at 1 (OR = 1.61, p = 0.05; OR = 2.05, p = 0.17) and 2 years (OR = 3.40, p = 0.13; OR = 1.38, p = 0.16). In Asian patients, the differences in PP and CP between upper-arm and forearm AVF were not statistically significant at 1 (OR = 1.17, p = 0.41; OR = 1.02, p = 0.94) and 2 years (OR = 2.95, p = 0.08; OR = 1.23, p = 0.41).

CONCLUSIONS: In this study, the CP of upper-arm and forearm AVF was similar in overall population. There was no difference in PP and CP of AVF between upper-arm and forearm in Asian population or the elderly. The forearm AVF could be consider to be the first choice. for Asian patients or the elderly.

PMID:35088450 | DOI:10.1111/sdi.13056

Scand J Med Sci Sports. 2022 Jan 28. doi: 10.1111/sms.14130. Online ahead of print.

ABSTRACT

PURPOSE: Improving cardiopulmonary reserve, or peak oxygen consumption( $\dot{V}$ O_2peak ), may reduce postoperative complications, however this may be difficult to achieve between diagnosis and surgery. Our primary aim was to assess the efficacy of an approximate 14-session, preoperative High Intensity Interval Training(HIIT) program to increase $\dot{V}$ O_2peak by a clinically-relevant 2 mL·kg^-1 ·min^-1 . Our secondary aim was to document clinical outcomes.

METHODOLOGY: In this prospective study, participants aged 45-85 undergoing major abdominal surgery were randomised to standard care or 14 sessions of HIIT over 4 weeks. HIIT sessions involved approximately thirty minutes of stationary cycling. Interval training alternated one minute of high (with the goal of reaching 90% max heart rate at least once during the session) and low/moderate intensity cycling. Cardiopulmonary exercise testing(CPET) measured the change in $\dot{V}$ O_2peak from baseline to surgery. Clinical outcomes included postoperative complications, length of stay(LOS) and Short Form-36 quality of life questionnaire(SF-36).

RESULTS: Of 63 participants, 46 completed both CPETs and 50 completed clinical follow-up. There was a significant improvement in the HIIT group’s mean $\pm$ SD $\dot{V}$ O_2peak (HIIT 2.87 $\pm$ 1.94 mL·kg¹ ·min^-1 vs standard care 0.15 $\pm$ 1.93, with an overall difference of 2.73 mL·kg¹ ·min^-1 95%CI [1.53, 3.93] p<0.001). There were no statistically significant differences between groups for clinical outcomes, although the observed differences consistently favoured the exercise group. This was most notable for total number of complications (0.64 v 1.16 per patient, p=0.07), SF-36 physical component score (p=0.06), and LOS (mean 5.5 v 7.4 days, p=0.07).

CONCLUSIONS: There was a significant improvement in $\dot{V}$ O_2peak with a four-week preoperative HIIT program. Further appropriately-powered work is required to explore the impact of preoperative HIIT on postoperative clinical outcomes.

PMID:35088469 | DOI:10.1111/sms.14130

J Orthop Res. 2022 Jan 27. doi: 10.1002/jor.25287. Online ahead of print.

ABSTRACT

This study investigated the effect of romosozumab on bone union in a rat posterolateral lumbar fixation model. Posterolateral lumbar fixation was performed on 8-week-old male Sprague Dawley rats (n=20). For bone grafting, autogenous bone (40 mg) was harvested from the spinous processes of the 10th thoracic vertebra until the 2nd lumbar vertebra and implanted between the intervertebral joints and transverse processes of the 4th and 5th lumbar vertebrae on both sides. Rats were matched by body weight and equally divided into two groups: R group (Evenity®, 25 mg/kg) and control (C) group (saline). Subcutaneous injections were administered twice a week until 8 weeks after surgery. Computed tomography was performed at surgery and week 8 after surgery. The area and percentage of bone trabeculae in the total area of bone fusion were calculated. Statistical analysis was performed using an unpaired t-test (P<0.05). We found that the R group rats had significantly higher mean bone union rate and volume than did the C group rats at all time courses starting week 4 after surgery. The R group had significantly higher increase rates than did the C group at weeks 4 and 6 after surgery. The percentage of bone trabeculae area in the R group was approximately 1.7 times larger than that in the C group. Thus, we demonstrated that romosozumab administration has stimulatory effects on bony outgrowth at bone graft sites. We attribute this to the modeling effect of romosozumab. This article is protected by copyright. All rights reserved.

PMID:35088447 | DOI:10.1002/jor.25287

Clin Anat. 2022 Jan 28. doi: 10.1002/ca.23837. Online ahead of print.

ABSTRACT

BACKGROUND: There have been no studies with large sample sizes on growth of the pedicle of C2 in children. In the present study we measured the pedicle of C2 through computed tomography (CT) imaging in children aged less than 14 years and evaluated the suitability of the 3.5-mm screw for the pedicle in such children.

METHODS: The study was conducted on CT morphometric images of 420 children in our hospital between June 2018 and June 2020. The width (D1), length (D2), height (D3), inclination angle (α), and tail angle (β) of the C2 pedicle were measured. One-way analysis of variance and Student’s t test were used for statistical analyses. The least-square method was used to analyze the curve fitting the trend of anatomical change in the pedicle. The largest degree of goodness of fit determined the best-fitting curve.

RESULTS: The size of the pedicle of C2 increased with age. The median ranges of D1, D2, D3, α, and β were 3.312-5.431 mm, 11.732-23.645 mm, 3.597-8.038 mm, 32.583°-36.640°, and 24.867°-31.567°, respectively. The curves fitting the trends of D1 and D3 were power functions, whereas D2 was fitted by a logarithmic curve. However, no curve fitted α or β.

CONCLUSION: A 3.5-mm screw can be placed in the pedicle of C2 in children aged more than one year. The growth and development trend of this pedicle can provide an anatomical reference for deciding on posterior cervical surgery and for selecting and designing pedicle screws for children.

PMID:35088448 | DOI:10.1002/ca.23837

Risk Anal. 2021 Dec;41(12):2392-2414. doi: 10.1111/risa.13758. Epub 2021 Jun 2.

ABSTRACT

In risk analysis, sensitivity measures quantify the extent to which the probability distribution of a model output is affected by changes (stresses) in individual random input factors. For input factors that are statistically dependent, we argue that a stress on one input should also precipitate stresses in other input factors. We introduce a novel sensitivity measure, termed cascade sensitivity, defined as a derivative of a risk measure applied on the output, in the direction of an input factor. The derivative is taken after suitably transforming the random vector of inputs, thus explicitly capturing the direct impact of the stressed input factor, as well as indirect effects via other inputs. Furthermore, alternative representations of the cascade sensitivity measure are derived, allowing us to address practical issues, such as incomplete specification of the model and high computational costs. The applicability of the methodology is illustrated through the analysis of a commercially used insurance risk model.

PMID:35088442 | DOI:10.1111/risa.13758

Stat Med. 2022 Jan 27. doi: 10.1002/sim.9330. Online ahead of print.

ABSTRACT

The control of ambient air quality in the United States has been a major public health success since the passing of the Clean Air Act, with particulate matter (PM) reductions resulting in an estimated 160 000 premature deaths prevented in 2010 alone. Currently, public policy is oriented around lowering the levels of individual pollutants and this focus has driven the nature of much epidemiological research. Recently, attention has been given to viewing air pollution as a complex mixture and to developing a multi-pollutant approach to controlling ambient concentrations. We present a statistical approach for estimating the health impacts of complex environmental mixtures using a mixture-altering contrast, which is any comparison, intervention, policy, or natural experiment that changes a mixture’s composition. We combine the notion of mixture-altering contrasts with sliced inverse regression, propensity score matching, and principal stratification to assess the health effects of different air pollution chemical mixtures. We demonstrate the application of this approach in an analysis of the health effects of wildfire PM air pollution in the Western US.

PMID:35088427 | DOI:10.1002/sim.9330

Int J Eat Disord. 2022 Jan 27. doi: 10.1002/eat.23686. Online ahead of print.

ABSTRACT

OBJECTIVE: Fear of weight gain (FOWG) is increasingly implicated in the maintenance of binge-spectrum eating disorders (EDs; e.g., bulimia nervosa [BN], binge-eating disorder [BED]) through the pathway of increased dietary restriction. However, particularly in binge-spectrum EDs, research is nascent and based on retrospective self-report. To improve treatment outcomes, it is critical to better understand the momentary relations between FOWG and dietary restriction.

METHOD: Sixty-seven adults with binge spectrum EDs completed a 7-14-day ecological momentary assessment protocol that included items regarding FOWG, ED behaviors, and types of dietary restriction (e.g., attempted restraint vs. actual restriction) several times per day. Multilevel models were used to evaluate reciprocal associations between FOWG and dietary restriction, and to evaluate the indirect of effects of dietary restriction on the relation between FOWG and binge eating.

RESULTS: While main effects were not statistically significant, ED presentation significantly moderated the association between increases in FOWG at time1 and both attempted and actual avoidance of enjoyable foods at time2 such that those with BN-spectrum EDs were more likely to avoid enjoyable foods following increased FOWG compared to those with BED-spectrum EDs. Engagement in restriction at time1 was not associated with decreased FOWG at time2.

DISCUSSION: Prospective associations between FOWG and restriction suggest that individuals with BN may be more likely to restrict their eating following increased FOWG. These findings suggest FOWG may be an important target for future treatments.

PMID:35088433 | DOI:10.1002/eat.23686

Thromb Haemost. 2022 Jan 27. doi: 10.1055/a-1753-2748. Online ahead of print.

ABSTRACT

In certain clinical situations, it is necessary to determine whether clinically relevant plasma levels of direct oral anticoagulants (DOACs) are present. We examined whether qualitative testing of DOACs in urine samples can exclude DOAC plasma concentrations of >30 ng/mL. This prospective single centre cohort study included consecutive patients treated with an oral direct factor Xa inhibitor (DXI) (apixaban, n=31, rivaroxaban, n=53) and direct thrombin inhibitor (DTI) (dabigatran, n=44). We aimed to define the negative predictive value (NPV) and other statistical parameters of detecting DXIs and DTIs by DOAC Dipstick at plasma concentrations of >30 ng/mL. We also determined the best-fit threshold plasma levels using chromogenic substrate assays by logistic regression analysis. Between July 2020 and July 2021, 128 eligible patients (mean age 66 years, 55 females) were included into the study. The NPVs and sensitivities for DXI and DTI of DOAC Dipstick were 100% at >30 ng/ml plasma, for specificities 6% and 21% and for positive predictive values 62% and 72%, respectively. All diagnostic statistical tests improved to values between 86% and 100% at best fitting plasma thresholds of >14 ng/mL for DXI and >19 ng/mL for DTI. Visual analysis using the DOAC Dipstick was 100% in agreement with that of the optoeletronic DOASENSE Reader for all three DOACs. DOAC Dipstick testing can reliably exclude the presence of DOACs in urine samples at best fitting thresholds of >14 and >19 ng/mL in plasma. The performance of the DOAC Dipstick at detecting lower DOAC concentrations in plasma requires confirmation.

PMID:35088395 | DOI:10.1055/a-1753-2748

Acta Obstet Gynecol Scand. 2022 Jan 27. doi: 10.1111/aogs.14318. Online ahead of print.

ABSTRACT

INTRODUCTION: Conflicting reports of increases and decreases in rates of preterm birth (PTB) and stillbirth in the general population during the coronavirus disease 2019 (COVID-19) pandemic have surfaced. The objective of our study was to conduct a living systematic review and meta-analyses of studies reporting pregnancy and neonatal outcomes by comparing the pandemic and pre-pandemic periods.

MATERIAL AND METHODS: We searched the PubMed and Embase databases and reference lists of articles published up until November 20, 2021, and included English language studies that compared outcomes between the COVID-19 pandemic time period with pre-pandemic time periods. Risk of bias was assessed using the Newcastle-Ottawa scale. We conducted random-effects meta-analysis using the inverse variance method.

RESULTS: Fifty-two studies with low-to-moderate risk of bias, reporting on 2 372 521 pregnancies during the pandemic period and 28 518 300 pregnancies during the pre-pandemic period, were included. There was significant reduction in unadjusted estimates of PTB (43 studies, unadjusted odds ratio [uaOR] 0.95, 95% CI 0.93-0.98), but not in adjusted estimates (five studies, adjusted OR [aOR] 0.94, 95% CI 0.74-1.19). This reduction was noted in studies from single centers/health areas (29 studies, uaOR 0.90, 95% CI 0.85-0.94) but not in regional/national studies (14 studies, uaOR 0.99, 95% CI 0.99-1.01). There was reduction in spontaneous PTB (nine studies, uaOR 0.91, 95% CI 0.88-0.94) but not in induced PTB (eight studies, uaOR 0.90, 95% CI 0.79-1.01). There was no difference in the odds of stillbirth between the pandemic and pre-pandemic time periods (32 studies, uaOR 1.07, 95% CI 0.97-1.18 and three studies, aOR 1.18, 95% CI 0.86-1.63). There was an increase in mean birthweight during the pandemic period compared with the pre-pandemic period (nine studies, mean difference 21 g, 95% CI 13-30 g). The odds of maternal mortality were increased (five studies, uaOR 1.15, 95% CI 1.05-1.26); however, only unadjusted estimates were available, and the result was mostly influenced by one study from Mexico. There was significant publication bias for the outcome of PTB.

CONCLUSIONS: The COVID-19 pandemic may be associated with a reduction in PTB; however, referral bias cannot be excluded. There was no statistically significant difference in stillbirths between pandemic and pre-pandemic periods.

PMID:35088409 | DOI:10.1111/aogs.14318

J Racial Ethn Health Disparities. 2022 Jan 27. doi: 10.1007/s40615-022-01241-6. Online ahead of print.

ABSTRACT

PURPOSE: Underrepresented minority student recruitment initiatives from medical school admissions and diversity offices can bring equity for those learners underrepresented in medicine. Measuring growth of the applicant pool helps determine the impact of such initiatives in helping diversify the healthcare workforce.

AIM: The authors evaluated underrepresented minority applicant pool growth at the Brody School of Medicine to determine whether predominantly White institutions or historically Black colleges and universities have accounted for the most growth in minority applicants in recent years.

METHODS: Outreach outcomes across the state were obtained by comparing applicant and matriculant demographics. Data on all applicants and matriculants were retrieved from the school’s institutional records and classified according to student self-identification as underrepresented minority. Using Chi-square tests, authors aimed to determine whether the proportion of minority students increased among applicants and matriculants since 2016, the year of restructuring outreach. In further analysis, the number of graduates from historically Black colleges and universities as compared to minority graduates from predominantly White schools was evaluated.

RESULTS: The authors identified 7,848 applicants and 654 matriculants over the evaluation period. The proportion of learners identifying as underrepresented minority increased from 17% before 2016 (622/3,672) to 20% after 2016 (835/4,176; p = 0.001). The proportion of applicants who did not graduate from a historically Black college or university increased slightly after 2016 (89% of underrepresented minority applicants before 2016 vs. 92% of underrepresented minority applicants after 2016), but this increase was not statistically significant (p = 0.097).

CONCLUSION: Applicant growth has been more significant for underrepresented minority applicants from predominantly White institutions. Graduates of targeted historically Black colleges and universities who applied to Brody School of Medicine were better prepared, resulting in increased chances of admission.

PMID:35088390 | DOI:10.1007/s40615-022-01241-6