Category: Statistics

Ann Afr Med. 2021 Oct-Dec;20(4):276-281. doi: 10.4103/aam.aam_61_20.

ABSTRACT

AIM: The aim of the study was to evaluate the 1-year outcome of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy in an eye unit in sub-Saharan Africa.

METHODOLOGY: This retrospective study included 182 eyes of 172 patients managed in the vitreoretinal unit between 2016 and 2019 who were treated with intravitreal anti-VEGF bevacizumab (1.25 mg/0.05 ml) with at least 1 year of follow-up. The outcome measures were change in best-corrected visual acuity (BCVA) over 1 year of follow-up, the number of injections taken, and complications.

RESULTS: The mean age was 61.1 ± 16.3 years (male-to-female ratio of 1:1.1) and about 62.1% above >60 years. A total of 330 injections were given during the period audited. The mean number of injections was 1.8 ± 0.93. Ninety-four (51.7%) eyes had only one injection, while 33 (18.1%), 50 (27.5%), and 5 (2.7%) had 2, 3, and 4 injections, respectively. About 78.5% had moderate-to-severe visual impairment at baseline and 44.5%, 16.4%, 12.6%, and 7.1% at 1, 3, 6, and 12 months post injections, respectively. The mean BCVA improved for all eyes from 1.67 ± 0.91 logarithm of minimum angle of resolution (logMAR) at baseline to 1.50 ± 1.27 logMAR at 1 year. The logMAR letters gained was 23 at 1 month and 8.25 at 1 year; the eyes that had three injections gained 10 letters, while those that had one injection gained three letters. Eyes with age-related macular degeneration and idiopathic polypoidal choroidopathy gained 7.5 and 9 letters, respectively, at 1 year after at least three injections. There was a statistically significant association between an increasing number of injections and improved visual outcome (P = 0.043). One patient each developed endophthalmitis (0.6%) and inferior retinal detachment (0.6%) post injection.

CONCLUSION: Visual acuity gain was recorded in patients who had intravitreal anti-VEGF injections in 1 year. It is recommended that patients should have more than one injection.

PMID:34893565 | DOI:10.4103/aam.aam_61_20

Neurology. 2021 Dec 10:10.1212/WNL.0000000000013119. doi: 10.1212/WNL.0000000000013119. Online ahead of print.

ABSTRACT

OBJECTIVE: To 1) compare adherence to antiseizure medications (ASMs) versus non-ASMs among individuals with epilepsy, 2) assess the degree to which variation in adherence is due to differences between individuals versus between medication classes among individuals with epilepsy, and 3) compare adherence in individuals with versus without epilepsy.

METHODS: This was a retrospective cohort study using Medicare. We included beneficiaries with epilepsy (≥1 ASM, plus International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes), and a 20% random sample without epilepsy. Adherence for each medication class was measured by the proportion of days covered (PDC) in 2013-2015. We used Spearman correlation coefficients, Cohen’s kappa statistics, and multilevel logistic regressions.

RESULTS: There were 83,819 beneficiaries with epilepsy. Spearman correlation coefficients between ASM PDCs and each of the 5 non-ASM PDCs ranged 0.44-0.50, Cohen’s kappa ranged 0.33-0.38, and within-person differences between each ASM’s PDC minus each non-ASM’s PDC were all statistically significant (p<0.01) though median differences were all very close to 0. Fifty-four percent of variation in adherence across medications was due to differences between individuals. Adjusted predicted probabilities of adherence were: ASMs 74% (95% confidence interval [CI] 73%-74%), proton pump inhibitors 74% (95% CI 74%-74%), antihypertensives 77% (95% CI 77%-78%), selective serotonin reuptake inhibitors 77% (95% CI 77%-78%), statins 78% (95% CI 78%-79%), and levothyroxine 82% (95% CI 81%-82%). Adjusted predicted probabilities of adherence to non-ASMs were 80% (95% CI 80%-81%) for beneficiaries with epilepsy versus 77% (77%-77%) for beneficiaries without epilepsy.

CONCLUSION: Among individuals with epilepsy, ASM and non-ASM adherence were moderately correlated, half of variation in adherence was due to between-person rather than between-medication differences, adjusted adherence was slightly lower for ASMs than several non-ASMs, and epilepsy was associated with a quite small increase in adherence to non-ASMs. Nonadherence to ASMs may provide an important cue to the clinician to inquire about adherence to other potentially life-prolonging medications as well. Although efforts should focus on improving ASM adherence, patient-level rather than purely medication-specific behaviors are also critical to consider when developing interventions to optimize adherence.

PMID:34893556 | DOI:10.1212/WNL.0000000000013119

Ann Afr Med. 2021 Oct-Dec;20(4):270-275. doi: 10.4103/aam.aam_59_20.

ABSTRACT

BACKGROUND: Alleviation of labour pain is known to improve maternal and fetal outcome. Combined Spinal-Epidural (CSE) analgesia is an excellent method.

AIM AND OBJECTIVES: In view of reports of its concerns on labour, this study was conducted to evaluate the progress of labour, obstetric outcome in cases with and without CSE analgesia, the maternal pain relief and fetomaternal adverse effects.

MATERIALS AND METHODS: In this comparative study, 60 parturients were allocated into case and control groups of 30 each. CSE analgesia was administered utilizing 0.5 ml of 0.125% Levobupivacaine / 0.2% Ropivacaine with 2 mcg/ml fentanyl. Progress of labour was recorded in partogram including duration of labour, mode of delivery, pain relief – Visual Analogue Scale (VAS) score, development of motor block, maternal satisfaction and Apgar score. Data was analyzed by Descriptive and Inferential statistics.

RESULTS: Mean duration of first and second stage of labour among cases was 530±44.1 minutes, 61.5±12.7 minutes respectively and that of control was 526.6±64.9 minutes, 60±10.8 minutes respectively with no prolongation of labour P > 0.05. CSE analgesia did not alter the mode of delivery P=0.145 with rapid onset of pain relief. Apgar score was normal in both groups. Total 29 (97%) parturients experienced effective labour analgesia following CSE analgesia with VAS score 0. Maternal adverse effects included pruritus, transient initial motor blockade and post spinal headache.

CONCLUSION: CSE analgesia did not affect the duration of labour, mode of delivery with minimal fetomaternal adverse effects and provides rapid onset of pain relief . CSE analgesia can be considered for safe and effective labour analgesia.

PMID:34893564 | DOI:10.4103/aam.aam_59_20

Proc Natl Acad Sci U S A. 2021 Dec 14;118(50):e2118893118. doi: 10.1073/pnas.2118893118.

NO ABSTRACT

PMID:34893544 | DOI:10.1073/pnas.2118893118

J Neurosci. 2021 Dec 10:JN-RM-1487-21. doi: 10.1523/JNEUROSCI.1487-21.2021. Online ahead of print.

ABSTRACT

The striatum’s complex microcircuit is made by connections within and between its D1- and D2-receptor expressing projection neurons and at least five species of interneuron. Precise knowledge of this circuit is likely essential to understanding striatum’s functional roles and its dysfunction in a wide range of movement and cognitive disorders. We introduce here a Bayesian approach to mapping neuron connectivity using intracellular recording data, which lets us simultaneously evaluate the probability of connection between neuron types, the strength of evidence for it, and its dependence on distance. Using it to synthesise a complete map of the mouse striatum, we find strong evidence for two asymmetries: a selective asymmetry of projection neuron connections, with D2 neurons connecting twice as densely to other projection neurons than do D1 neurons, but neither subtype preferentially connecting to another; and a length-scale asymmetry, with interneuron connection probabilities remaining non-negligible at more than twice the distance of projection neuron connections. We further show our Bayesian approach can evaluate evidence for wiring changes, using data from the developing striatum and a mouse model of Huntington’s disease. By quantifying the uncertainty in our knowledge of the microcircuit, our approach reveals a wide range of potential striatal wiring diagrams consistent with current data.SIGNIFICANCE STATEMENTTo properly understand a neuronal circuit’s function, it is important to have an accurate picture of the rate of connection between individual neurons and how this rate changes with the distance separating pairs of neurons. We present a Bayesian method for extracting this information from experimental data and apply it to the mouse striatum, a subcortical structure involved in learning and decision-making, which is made up of a variety of different projection neurons and interneurons. Our resulting statistical map reveals not just the most robust estimates of the probability of connection between neuron types, but also the strength of evidence for them, and their dependence on distance.

PMID:34893550 | DOI:10.1523/JNEUROSCI.1487-21.2021

BMJ Open Respir Res. 2021 Dec;8(1):e001042. doi: 10.1136/bmjresp-2021-001042.

ABSTRACT

BACKGROUND: Respiratory disorders, including apnoea, are common in preterm infants due to their immature respiratory control compared with term-born infants. However, our inability to accurately measure respiratory rate in hospitalised infants results in unreported episodes of apnoea and an incomplete picture of respiratory activity.

METHODS: We develop, validate and use a novel algorithm to identify interbreath intervals (IBIs) and apnoeas in preterm infants. In 42 preterm infants (1600 hours of recordings), we assess IBIs from the chest electrical impedance pneumograph using an adaptive amplitude threshold for the detection of breaths. The algorithm is refined by comparing its accuracy with clinically observed breaths and pauses in breathing. We develop an automated classifier to differentiate periods of true apnoea from artefactually low amplitude signal. We assess the performance of this algorithm in the detection of morphine-induced respiratory depression. Finally, we use the algorithm to investigate whether retinopathy of prematurity (ROP) screening alters the IBI distribution.

RESULTS: Individual breaths were detected with a false-positive rate of 13% and a false-negative rate of 12%. The classifier identified true apnoeas with an accuracy of 93%. As expected, morphine caused a significant shift in the IBI distribution towards longer IBIs. Following ROP screening, there was a significant increase in pauses in breathing that lasted more than 10 s (t-statistic=1.82, p=0.023). This was not reflected by changes in the monitor-derived respiratory rate and no episodes of apnoea were recorded in the medical records.

CONCLUSIONS: We show that our algorithm offers an improved method for the identification of IBIs and apnoeas in preterm infants. Following ROP screening, increased respiratory instability can occur even in the absence of clinically significant apnoeas. Accurate assessment of infant respiratory activity is essential to inform clinical practice.

PMID:34893521 | DOI:10.1136/bmjresp-2021-001042

Clin J Am Soc Nephrol. 2021 Dec 10:CJN.08180621. doi: 10.2215/CJN.08180621. Online ahead of print.

NO ABSTRACT

PMID:34893504 | DOI:10.2215/CJN.08180621

J Investig Med. 2021 Dec 10:jim-2021-001961. doi: 10.1136/jim-2021-001961. Online ahead of print.

ABSTRACT

This meta-analysis and systematic review investigated the efficacy of bisphosphonates on the incidence of hip fracture (IHF) in patients of different ages with osteoporosis or osteopenia. We searched Web of Science, Embase, the Cochrane Database, and PubMed from inception to January 10, 2021, for trials reporting the effects of bisphosphonates on the IHF. We included only randomized, double-blind, placebo-controlled clinical trials. We pooled data using a random-effects meta-analysis with risk ratios (RRs) and reported 95% CIs. We also used the Cochran Q and I² statistics to assess the heterogeneity in the results of individual studies. The primary endpoints were the total numbers of people in the bisphosphonates and placebo groups and the numbers of IHFs during the follow-up periods. Bisphosphonates reduced the IHF with an overall effect (RR: 0.66; 95% CI: 0.56 to 0.77; zoledronic acid: RR: 0.60; 95% CI: 0.46 to 0.78; risedronate: RR: 0.74; 95% CI: 0.59 to 0.94, and alendronate: RR: 0.61; 95% CI: 0.40 to 0.95). The result of the heterogeneity assessment was I²=0, p=0.97. In all age groups (all ages, ≥55 years old, ≥65 years old), bisphosphonates reduced the IHF. In the ≥55 years old and ≥65 years old age groups, the RR and 95% CI were 0.63 and 0.43 to 0.93, and 0.60 and 0.44 to 0.81, respectively. Bisphosphonate reduced the IHF in the general population and all age groups (≥55 years old and ≥65 years old). Zoledronic acid, risedronate and alendronate reduced the IHF in osteoporosis or osteopenia populations. The association between bisphosphonate and the IHF does not appear to be influenced by age.

PMID:34893517 | DOI:10.1136/jim-2021-001961

BMJ Open. 2021 Dec 10;11(12):e053983. doi: 10.1136/bmjopen-2021-053983.

ABSTRACT

OBJECTIVE: To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain.

SETTINGS: The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied.

PARTICIPANTS: This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020.

INTERVENTIONS: An exploratory factorial analysis was performed to select the most relevant variables of the sample.

PRIMARY AND SECONDARY OUTCOME MEASURES: Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection.

RESULTS: Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10⁵ people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade ≥3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10⁵ people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated.

CONCLUSIONS: Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10⁵ people/week) was a statistically independent predictor of mortality.

TRIAL REGISTRATION NUMBER: CEIM 20/217.

PMID:34893486 | DOI:10.1136/bmjopen-2021-053983

BMJ Open. 2021 Dec 10;11(12):e052277. doi: 10.1136/bmjopen-2021-052277.

ABSTRACT

INTRODUCTION: The introduction of multiparametric MRI (mpMRI) has improved almost every aspect of the prostate cancer diagnostic pathway. However, the novel imaging technique, prostate-specific membrane antigen positron emission tomography (PSMA PET) may have demonstrable accuracy in detecting and staging prostate cancer. Here, we describe a protocol for a systematic review and meta-analysis comparing mpMRI to PSMA PET for the diagnosis of suspected prostate cancer.

METHODS AND ANALYSIS: A systematic search of MEDLINE, EMBASE, PubMed and Cochrane databases will be conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed for screening, data extraction, statistical analysis and reporting. Included papers will be full-text articles providing original data, written in English articles and comparing the use of PSMA PET with mpMRI in the diagnosis of prostate cancer. All studies published between July 1977 and March 2021 will be eligible for inclusion. Study bias and quality will be assessed using Quadas-2 score. To ensure the quality of the reporting of studies, this protocol is written following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 checklist.

ETHICS AND DISSEMINATION: Ethical approval will not be required for this systematic review. Findings will be disseminated through peer-reviewed publications and presentations at both national and international conferences.

PROSPERO REGISTRATION NUMBER: CRD42021239296.

PMID:34893484 | DOI:10.1136/bmjopen-2021-052277