Tag: statistics

Transl Vis Sci Technol. 2022 Jun 1;11(6):12. doi: 10.1167/tvst.11.6.12.

ABSTRACT

PURPOSE: To report the long-term observations of the electrode-tissue interface and perceptual stability in humans after chronic stimulation with a 44-channel suprachoroidal retinal implant.

METHODS: Four subjects (S1-4) with end-stage retinitis pigmentosa received the implant unilaterally (NCT03406416). Electrode impedances, electrode-retina distance (measured using optical coherence tomography imaging), and perceptual thresholds were monitored up to 181 weeks after implantation as the subjects used the prosthesis in the laboratory and in daily life. Stimulation charge density was limited to 32 µC/cm2 per phase.

RESULTS: Electrode impedances were stable longitudinally. The electrode-retina distances increased after surgery and then stabilized, and were well-described by an asymptotic exponential model. The stabilization of electrode-retina distances was variable between subjects, stabilizing after 45 weeks for S1, 63 weeks for S2, and 24 weeks for S3 (linear regression; Pgradient > 0.05). For S4, a statistically significant increase in electrode-retina distance persisted (P < 0.05), but by the study end point the rate of increase was clinically insignificant (exponential model: 0.33 µm/wk). Perceptual electrical thresholds were stable in one subject, decreased over time in two subjects (linear model; P < 0.05), and increased slightly in one subject but remained within the predefined charge limits (P = 0.02).

CONCLUSIONS: Chronic stimulation with the suprachoroidal retinal prosthesis over 3 years resulted in stable impedances, small individual changes in perceptual electrical thresholds, and no clinically significant increase in electrode-retina distances after a period of settling after surgery.

TRANSLATIONAL RELEVANCE: Chronic stimulation with the 44-channel suprachoroidal retinal implant with a charge density of up to 32 µC/cm2 per phase is suitable for long-term use in humans.

PMID:35696133 | DOI:10.1167/tvst.11.6.12

Trans R Soc Trop Med Hyg. 2022 Jun 13:trac053. doi: 10.1093/trstmh/trac053. Online ahead of print.

ABSTRACT

Previous epidemiologic evidence suggests a protective effect of Toxoplasma gondii infection against multiple sclerosis (MS) development; however, inconsistent findings have been reported in this regard. Therefore, we performed an updated meta-analysis of observational studies to investigate the association of To. gondii infection with MS development. We searched all articles published in PubMed, Scopus, Embase and Web of Science databases as of 20 December 2021. A random effects meta-analysis model was used to generate the pooled OR at 95% CIs. The heterogeneity between studies was assessed using I2 and Cochran’s Q statistics. Moreover, the likelihood of publication bias was determined by Egger’s regression test. A total of 11 studies were eligible for meta-analysis, including 1172 MS cases and 1802 controls. Our findings indicated that 29.8% (95% CI 22.8 to 37.2%) of MS patients were seropositive for To. gondii infection, compared with 34.2% (95% CI 21.9 to 47.6%) of control subjects. The estimated pooled OR was 0.79 (95% CI 0.49 to 1.26), suggesting a non-significant negative association between To. gondii infection and MS development (p>0.05). The current study does not support the significant protective role of To. gondii infection on MS development. Our findings imply that further well-designed epidemiological and mechanistic studies are warranted to ascertain the possible association between To. gondii infection and MS and to exclude the potential confounders.

PMID:35696089 | DOI:10.1093/trstmh/trac053

Pharmacoeconomics. 2022 Jun 13. doi: 10.1007/s40273-022-01155-5. Online ahead of print.

ABSTRACT

This technical note discusses how dummy and effects coding of categorical respondent characteristics in a class membership probability function should be interpreted by researchers employing a latent class analysis to explore preference heterogeneity in a discrete-choice experiment. Previous work highlighted issues arising from such coding when interpreting an alternative specific constant that represents an opt-out alternative or current situation in a discrete-choice experiment and did not fully address how this coding impacts the interpretation of parameters resulting from the membership probability function in a latent class analysis. Although latent class membership probability could be predicted separately for each respondent or subgroup of respondents, conclusions are often drawn directly from the model estimation using the full sample, which requires correctly interpreting the estimated parameters. In these cases, the misinterpretation that may arise if the problem is ignored could impact the policy conclusions and recommendations drawn based on the discrete-choice experiment results. This note provides an example comparing dummy and effects coding used to model respondent characteristics in the membership probability function in a discrete-choice experiment aimed to explore preferences for the treatment of chronic pain in the USA.

PMID:35696072 | DOI:10.1007/s40273-022-01155-5

Infection. 2022 Jun 13. doi: 10.1007/s15010-022-01859-y. Online ahead of print.

ABSTRACT

OBJECTIVES: To assess the severity of symptoms, duration of infection and viral loads of health-care workers (HCWs) who tested positive for Coronavirus disease 2019 (COVID-19) during Omicron’s prevalence, in regard to vaccination and previous infection.

METHODS: During 2 weeks of highest rate of COVID-19 cases in Bosnia and Herzegovina, the positive nasopharyngeal swabs were analysed in 141 HCWs by reverse transcription quantitative PCR, targeting four different genes: RdRp, E, N and nsp14. Uniformed questionnaire was used to collect relevant sociodemographic and epidemiological data from HCWs divided into four groups: unvaccinated/not previously infected (group 1); unvaccinated/previously infected (group 2); vaccinated/not previously infected (group 3); and vaccinated/previously infected (group 4).

RESULTS: We observed that occurrence of fever and smell or taste loss were more frequent in group 1 (86.4% and 25%) and group 3 (76.9% and 19.2%), in comparison to group 2 (64.4% and 6.7%) and group 4 (69.2% and 3.8%), (p = 0.023 and p = 0.003). Although statistically not significant, group 2 (61.9%), group 3 (65.4%), and group 4 (70.8%) experienced negativization within 7 days of positive RT-qPCR test, whereas 51.2% of HCWs from group 1 tested negative later on. There is no significant difference between all four groups regarding Ct values of analysed genes.

CONCLUSION: During Omicron’s prevalence, the vaccination had less substantial effect on symptomatic disease among HCWs, while fever and loss of smell or taste were considerably less likely to occur upon reinfection. Since viral loads and negativization periods do not seem to significantly vary, irrespective of pre-existing immunity, systemic vaccination and mask-wearing should still be considered among HCWs.

PMID:35696057 | DOI:10.1007/s15010-022-01859-y

Neurol Sci. 2022 Jun 13. doi: 10.1007/s10072-022-06201-w. Online ahead of print.

ABSTRACT

Relief from migraine attacks may be obtained through non-pharmacological therapy during pregnancy when most drugs are contraindicated. There is accumulating evidence for the efficacy and safety of acupuncture for migraine in the general population but very little to no data on acupuncture during pregnancy. With this retrospective study, we wanted to determine whether an association exists between acupuncture treatment and preterm delivery and side effects of therapy. The initial study group was 68 women with migraine (29.78% with aura and 70.21% without aura), 47 of which responded to a questionnaire on acupuncture safety within 6 weeks of delivery. A so-called Formula Acupuncture was used for all these patients in order to permit comparison. Influence of acupuncture on gestational age at birth was carried out according to number of treatment sessions (more than and fewer than 10) and stratifying the study sample by age group (over and under 30 years) and risk pregnancy. Analysis showed no statistically significant difference in gestational duration between the two groups or an association between the number of acupuncture sessions and preterm delivery. Symptoms during treatment were generally transient or mild. The most common symptoms were relaxation, pain at the insertion sites, mild bleeding, and paresthesia. Our preliminary data indicate that acupuncture may be safe during pregnancy in women with migraine.

PMID:35695988 | DOI:10.1007/s10072-022-06201-w

Obes Surg. 2022 Jun 13. doi: 10.1007/s11695-022-06152-3. Online ahead of print.

ABSTRACT

BACKGROUND: Postoperative bleeding from the staple line after sleeve gastrectomy occurs in 2-8% of patients and it is associated with increased length and cost of hospitalization and may demand reoperation to gain hemostasis. Reinforced staplers are used by bariatric surgeons to reduce the incidence of postoperative leak but can have a role in avoiding bleeding. The aim of this study is to analyze the effects of reinforcement on the whole gastric staple line during sleeve gastrectomy on postoperative bleeding.

METHODS: Four hundred forty-eight consecutive patients undergoing sleeve gastrectomy from November 2012 to April 2019 were divided into two groups. In the Top-only group only the top staple shot was realized with reinforced material (GORE® SEAMGUARD®) while in the Bottom-to-Top group, patients received full staple line reinforcement. Statistical analysis focused on postoperative leak and bleeding, and length of stay; a propensity score matching analysis was performed to reduce between-group characteristics imbalance.

RESULTS: One hundred forty-five (Top-only) and 303 (Bottom-to-Top) patients were included. Four (2.8%) patients in the Top-only group and none in the Bottom-to-Top group experienced severe bleeding (p = 0.004); the difference was still significant after propensity score matching. Length of stay was significantly shorter for the Bottom-to-Top group before and after propensity score matching (4 vs. 5 days, p < 0.001).

CONCLUSIONS: Staple line buttressing reduces the incidence of severe postoperative bleeding when performed on the whole staple line, and it is associated with a shorter hospitalization.

PMID:35696051 | DOI:10.1007/s11695-022-06152-3

Neurol Sci. 2022 Jun 13. doi: 10.1007/s10072-022-06192-8. Online ahead of print.

ABSTRACT

BACKGROUND: Neurodegenerative genes are critical in neuronal loss in Parkinson’s disease (PD). We performed a systematic meta-analysis including all the studies published on PD risk related to genes encoding enzymes vital for dopamine metabolism and neuron survival.

METHODS: We included neurodegeneration-related genes which were divided into four groups according to their functions: main enzymes in dopamine metabolism, receptors and transporters for dopamine or other metabolites, neuroprotective factors for dopaminergic neurons, and genes associated with dopaminergic neurons survival reported in other neurological diseases. We collected original articles from PubMed, Embase, and Web of Science databases. Revman 5.3 software was used to analyze data. The allele model (AM) was used to test the effect size of the effect allele between the case group and the control group and secondary analysis using the dominant model (DM) and recessive model (RM) to analyze the contributions from heterozygote and homozygote to the allele risk. Odds ratio (OR) and 95% confidence interval (CI) were used to present the pooled results.

RESULTS: We included 31 variants in 20 genes for the final pooled analysis. Consequently, SLC6A4/5-HTT HTTLPR, BDNF rs56164415, FGF20 rs1721100, PARK16 rs823128, rs823156, rs947211, APOE e2, A2M rs669, RIT2 rs12456492, MAPT intron 9 H1H2, and STH rs62063857 variants were statistically associated with PD risk while researched variants in COMT, DBH, MAO, DAT/SLC6A3, DRD2, GRIN2B, GSK3β, ATP13A2, LINGO1, PICALM, and GRN were not related to PD risk.

CONCLUSION: Several variants from neurodegeneration-related genes are associated with PD risk, which may help deepen the understanding of PD pathogenesis and improve clinical treatment strategies.

PMID:35695987 | DOI:10.1007/s10072-022-06192-8

Clin Exp Med. 2022 Jun 13. doi: 10.1007/s10238-022-00840-1. Online ahead of print.

ABSTRACT

To investigate the relationship between human immunodeficiency virus (HIV) infection and the risk of mortality among coronavirus disease 2019 (COVID-19) patients based on adjusted effect estimate by a quantitative meta-analysis. A random-effects model was used to estimate the pooled effect size (ES) with corresponding 95% confidence interval (CI). I² statistic, sensitivity analysis, Begg’s test, meta-regression and subgroup analyses were also conducted. This meta-analysis presented that HIV infection was associated with a significantly higher risk of COVID-19 mortality based on 40 studies reporting risk factors-adjusted effects with 131,907,981 cases (pooled ES 1.43, 95% CI 1.25-1.63). Subgroup analyses by male proportion and setting yielded consistent results on the significant association between HIV infection and the increased risk of COVID-19 mortality. Allowing for the existence of heterogeneity, further meta-regression and subgroup analyses were conducted to seek the possible source of heterogeneity. None of factors might be possible reasons for heterogeneity in the further analyses. Sensitivity analysis indicated the robustness of this meta-analysis. The Begg’s test manifested that there was no publication bias (P = 0.2734). Our findings demonstrated that HIV infection was independently associated with a significantly increased risk of mortality in COVID-19 patients. Further well-designed studies based on prospective study estimates are warranted to confirm our findings.

PMID:35695974 | DOI:10.1007/s10238-022-00840-1

Dig Dis Sci. 2022 Jun 13. doi: 10.1007/s10620-022-07518-4. Online ahead of print.

ABSTRACT

BACKGROUND: The utility of combination rectal NSAID and topical epinephrine (EI) or rectal NSAID and normal saline (SI) sprayed on duodenal papilla in the prevention of post-ERCP pancreatitis (PEP) has been studied but results have been conflicting.

AIMS: To evaluate the benefit of using combination prophylaxis in preventing PEP.

METHODS: A literature search was performed using Scopus, PubMed/MEDLINE, and Cochrane databases in May 2021. Randomized controlled trials (RCTs) involving adults patients who underwent ERCP and received EI versus SI were eligible for inclusion. The pooled effect was expressed as odds ratio (OR) to assess the rate of PEP, severity of PEP, and specific adverse events. The results were pooled using Reviewer Manager 5.4 software.

RESULTS: Six RCTs involving 4016 patients were included in the final analysis. The EI group did not demonstrate any significant benefit over SI group in preventing PEP (OR = 1.00, 95% CI [0.68, 1.45], P = 0.98), irrespective of gender or the epinephrine concentration used. The tests for subgroup differences were not statistically significant with P-values of 0.66 and 0.28, respectively. The addition of topical epinephrine to rectal NSAID did not improve the rate of moderate to severe PEP (OR = 0.94, P = 0.86) or PEP in high-risk patients (OR = 1.14, 95%, P = 0.73). The rates of infection, including cholangitis and sepsis (OR = 0.63, P = 0.07), gastrointestinal bleeding (OR = 1.25, P = 0.56) and procedure-related death (OR = 0.71, P = 0.59) were similar between both groups.

CONCLUSION: The addition of topical epinephrine did not demonstrate any benefit over rectal NSAID alone in preventing PEP or reducing other procedure-related adverse events.

PMID:35695971 | DOI:10.1007/s10620-022-07518-4

Environ Monit Assess. 2022 Jun 13;194(7):498. doi: 10.1007/s10661-022-10011-0.

ABSTRACT

Studies on historical patterns of climate variables and climate indices have attained significant importance because of the increasing frequency and severity of extreme events worldwide. While the recent events in the tropical state of Kerala (India) have drawn attention to the catastrophic impacts of extreme rainfall events leading to landslides and loss of human lives, a comprehensive and long-term spatiotemporal assessment of climate variables is still lacking. This study investigates the long-term trend analysis (119 years) of climate variables at 5% significance level over the state using gridded datasets of daily rainfall (0.25° × 0.25° spatial resolution) and temperature (1° × 1° spatial resolution) at annual and seasonal scales (south-west monsoon, north-east monsoon, winter and summer). Five trend analysis techniques including the Mann-Kendall test (MK), three modified Mann-Kendall tests and innovative trend analysis (ITA) test were performed in the study. It is evident from the trend analysis results that more than 83% of grid points were showing negative trends in annual and south-west monsoon season rainfall series (at a mean rate of 39.70 mm and 28.30 mm per decade respectively). All the trend analysis tests identified statistically significant increasing trends in mean and maximum temperature at annual and seasonal scales (0.10 to 0.20 °C/decade) for all grids. The K-means clustering algorithm delineated 59 grid points into five clusters for annual rainfall, illustrating a clear geographical pattern over the study area. There is a clear gradient in rainfall distribution and concentration inside the state at annual as well as seasonal scales. The majority of annual rainfall is concentrated in a few months of the year. That may lead the state vulnerable to water scarcity in non-rainy seasons.

PMID:35695969 | DOI:10.1007/s10661-022-10011-0