Category: Statistics

Stat Methods Med Res. 2024 Apr 3:9622802241242323. doi: 10.1177/09622802241242323. Online ahead of print.

ABSTRACT

Understanding whether and how treatment effects vary across subgroups is crucial to inform clinical practice and recommendations. Accordingly, the assessment of heterogeneous treatment effects based on pre-specified potential effect modifiers has become a common goal in modern randomized trials. However, when one or more potential effect modifiers are missing, complete-case analysis may lead to bias and under-coverage. While statistical methods for handling missing data have been proposed and compared for individually randomized trials with missing effect modifier data, few guidelines exist for the cluster-randomized setting, where intracluster correlations in the effect modifiers, outcomes, or even missingness mechanisms may introduce further threats to accurate assessment of heterogeneous treatment effect. In this article, the performance of several missing data methods are compared through a simulation study of cluster-randomized trials with continuous outcome and missing binary effect modifier data, and further illustrated using real data from the Work, Family, and Health Study. Our results suggest that multilevel multiple imputation and Bayesian multilevel multiple imputation have better performance than other available methods, and that Bayesian multilevel multiple imputation has lower bias and closer to nominal coverage than standard multilevel multiple imputation when there are model specification or compatibility issues.

PMID:38567439 | DOI:10.1177/09622802241242323

Med Pr. 2024 Apr 3:185593. doi: 10.13075/mp.5893.01522. Online ahead of print.

ABSTRACT

BACKGROUND: COVID-19 vaccines for public use were approved at the turn of 2020 and 2021. The level of vaccination coverage against COVID-19 in Poland is one of the lowest in Europe. Despite scientific studies there are people who are afraid of vaccinations and spread false information about them. Vaccinations against COVID-19 allowed us to learn about the attitudes of people who decided to be vaccinated, which can be used to improve the effectiveness of the infectious diseases prevention in the work and public environment. The aim of the study was to analyze the main reasons determining a decision to get vaccinated against COVID-19.

MATERIAL AND METHODS: The study was carried on among all the people who decided to be vaccinated against COVID-19 in Nofer Institute of Occupational Medicine in Łódź. All vaccinated people completed an anonymous survey containing questions related to the most important factors, which encouraged them to undergo this vaccination.

RESULTS: The study involved 945 people vaccinated against COVID-19. Statistical significance was revealed between 3 different reasons (one’s own health, stress-free work, safe travelling and easier access to entertainment) for getting vaccinated and age, gender and a form of employment. The authors also found statistical significance of the correlation between the age, gender, education and form of employment of the respondents and the reason for choosing the specific vaccine product.

CONCLUSIONS: Despite evidence presented by scientists about the effectiveness and safety of vaccinations, many people refused and still refuse to receive the vaccine. In order to increase the readiness of the population for vaccinations against COVID-19 and subsequent ones, if there is a need to limit new epidemics, the following should be done: introduce activities to raise health awareness, intensify strategies and campaigns aimed at increasing public trust in available vaccines against COVID-19, devolop individualized messages that contribute to vaccine hesitancy.

PMID:38567412 | DOI:10.13075/mp.5893.01522

Postgrad Med. 2024 Apr 3:1-12. doi: 10.1080/00325481.2024.2333233. Online ahead of print.

ABSTRACT

BACKGROUND: There is an ongoing debate regarding the comparative merits of splenectomy (SP) and splenic preservation in the surgical management of gastric cancer. This systematic review and meta-analysis aims to shed light on potential differences in survival outcomes and postoperative complications associated with these two procedures.

METHOD: An exhaustive literature search was conducted across multiple databases, namely PubMed, Embase, Cochrane Library, and Web of Science. We utilized a random-effects model via RevMan 5.4 software to conduct a meta-analysis of the hazard ratios (HRs) and risk ratios (RRs) associated with SP and spleen preservation. Subgroup analyses were based on various attributes of the included studies. We employed funnel plots to assess publication bias, and sensitivity analysis was conducted to gauge the stability of the combined results. Both funnel plots and sensitivity analysis were performed using Stata 12.

RESULT: Our research incorporated 23 observational studies and three randomized controlled trials, involving a total of 6,255 patients. SP did not yield superior survival outcomes in comparison to splenic preservation, a conclusion that aligns with the combined results of the randomized controlled trials. No statistically significant difference in survival prognosis was observed between SP and splenic preservation, irrespective of whether the patients had proximal gastric cancer or proximal gastric cancer invading the stomach’s greater curvature. SP exhibited a higher incidence of all postoperative complications, notably pancreatic fistula and intraabdominal abscesses. However, it did not significantly differ from splenic preservation in terms of anastomotic leakage, incision infection, intestinal obstruction, intra-abdominal bleeding, and pulmonary infection. No significant difference in postoperative mortality between SP and splenic preservation was found. Funnel plots suggested no notable publication bias, and sensitivity analysis affirmed the stability of the combined outcomes.

CONCLUSION: Despite the lack of significant differences in certain individual complications and postoperative mortality, the broader pattern of our data suggests that SP is associated with a greater overall frequency of postoperative complications, without providing additional survival benefits compared to splenic preservation. Thus, the routine implementation of SP is not advocated.

PMID:38567398 | DOI:10.1080/00325481.2024.2333233

Eur Sociol Rev. 2023 Oct 6;40(2):226-241. doi: 10.1093/esr/jcad062. eCollection 2024 Apr.

ABSTRACT

Lesbian, gay and bisexual people are disadvantaged in terms of health and socio-economic status compared with heterosexual people, yet findings pertaining to educational outcomes vary depending on the specific identity and gender considered. This study delves into these unexplained findings by applying a social-stratification lens, thereby providing an account of how intergenerational educational mobility varies by sexual identity. To accomplish this, we use representative data from five OECD countries and a regression-based empirical specification relying on coarsened exact matching. We find that gay and lesbian people have higher educational attainment than heterosexual people in all five countries and that these higher levels of education stem from greater rates of upward educational mobility among gay/lesbian people. There were, however, few differences between heterosexual and bisexual people. Variation across countries emerged when analyses were stratified by gender, with higher rates of upward mobility observed for gay men in Australia, Chile, the United Kingdom, and the United States and lesbian women in Australia and Germany. Overall, our results align with previous claims that education can be a strategy for gay/lesbian people to avoid actual or anticipated discrimination. However, variation in these patterns across groups suggests that other mechanisms may also be at play.

PMID:38567380 | PMC:PMC10984377 | DOI:10.1093/esr/jcad062

Nephrol Dial Transplant. 2024 Apr 2:gfae079. doi: 10.1093/ndt/gfae079. Online ahead of print.

ABSTRACT

BACKGROUND AND HYPOTHESIS: It remains unclear if the relation of chronic kidney disease (CKD) with cognitive dysfunction is independent of blood pressure (BP). We evaluated kidney function in relation to premorbid BP measurements, cerebral small vessel disease (CSVD) and incident mild cognitive impairment (MCI) and dementia in Framingham Offspring Cohort participants.

METHODS: We included Framingham Offspring participants free of dementia, attending an examination during midlife (exam cycle 6, baseline) for ascertainment of kidney function status, with brain MRI late in life (exam cycles 7-9), cognitive outcome data and available interim hypertension and blood pressure assessments. We related CKD (estimated glomerular filtration rate < 60 ml/min/1.73m2) and albuminuria (urine albumin-to-creatinine ratio ≥ 30 mg/g) to CSVD markers and cognitive outcomes using multivariable regression analyses.

RESULTS: Among 2604 participants (mean age 67.4 ± 9.2, 64% women, 7% had CKD and 9% albuminuria), albuminuria was independently associated with covert infarcts (adjusted OR, 1.55 [1.00-2.38]; P = 0.049) and incident MCI and dementia (adjusted HR, 1.68 [1.18-2.41]; P = 0.005 and 1.71, [1.11-2.64]; P = 0.015, respectively). CKD was not associated with CSVD markers but was associated with higher risk of incident dementia (HR, 1.53 [1.02-2.29]; P = 0.041), While albuminuria was predictive of the Alzheimer’s disease subtype (Adjusted HR = 1.68, [1.03-2.74]; P = 0.04), CKD was predictive of vascular dementia (Adjusted HR, 2.78, [1.16-6.68]; P = 0.023).

CONCLUSIONS: Kidney disease was associated with CSVD and cognitive disorders in asymptomatic community dwelling participants. The relation was independent of premorbid BP, suggesting that the link between kidney and brain disease may involve additional mechanisms beyond blood pressure related injury.

PMID:38565317 | DOI:10.1093/ndt/gfae079

Comp Med. 2024 Apr 2. doi: 10.30802/AALAS-CM-24-000007. Online ahead of print.

ABSTRACT

Giardia duodenalis and Cryptosporidium spp. are zoonotic protozoal pathogens, spread by a fecal-oral route, which can infect a wide range of hosts including but not limited to dogs and humans. Giardia was recently estimated to be present in 37% to 50% of kennel-housed dogs. Cryptosporidium infections in kennel-housed dogs have been reported in 7% to 21% of the population. The goal of this study was to define demographic factors and fecal scores associated with positive screening test cases of Giardia and Cryptosporidium in kennel-housed laboratory dogs in the state of Texas. Fecal samples were collected from 153 clinically normal laboratory dogs at an academic research facility and a local laboratory dog supplier. We used 3 diagnostic tests evaluated in parallel to determine test positivity to each organism: a human point-of-care coproantigen test, a direct immunofluorescent assay, and an in-house polymerase chain reaction. Dogs were significantly more likely to test positive for Giardia (45%) than Cryptosporidium (7%) (P < 0.01). Dogs that were 18 mo of age or younger had 3 times the odds (P = 0.009) of subclinical Giardia infection compared with older dogs. We found no significant relationship between age and Cryptosporidium prevalence. Dogs with hard feces (fecal score 1-2) at the time of screening had 0.34 times lower odds (P = 0.049) of testing positive for Giardia than dogs with normal feces, but no statistically significant relationship was found between fecal score and Cryptosporidium-positive test status. With these findings, we demonstrated the value of considering age and fecal score when choosing which dogs to screen for subclinical Giardia. Additional studies with larger sample sizes should be conducted to determine the relationship between age and fecal score and subclinical Cryptosporidium infection.

PMID:38565307 | DOI:10.30802/AALAS-CM-24-000007

Eur J Cardiothorac Surg. 2024 Apr 2:ezae132. doi: 10.1093/ejcts/ezae132. Online ahead of print.

ABSTRACT

Individual patient data (IPD) meta-analyses build upon traditional (aggregate data) meta-analyses by collecting IPD from the individual studies rather than using aggregated summary data. Although both traditional and IPD meta-analyses produce a summary effect estimate, IPD meta-analyses allow for the analysis of data to be performed as a single dataset. This allows for standardization of exposure, outcomes, and analytic methods across individual studies. IPD meta-analyses also allow the utilization of statistical methods typically used in cohort studies, such as multivariable regression, survival analysis, propensity score matching, uniform subgroup and sensitivity analyses, better management of missing data, and incorporation of unpublished data. However, they are more time-intensive, costly, and subject to participation bias. A separate issue relates to the meta-analytic challenges when the proportional hazards assumption is violated. In these instances, alternative methods of reporting time-to-event estimates, such as restricted mean survival time should be used. This statistical primer summarizes key concepts in both scenarios and provides pertinent examples.

PMID:38565280 | DOI:10.1093/ejcts/ezae132

JNCI Cancer Spectr. 2024 Apr 2:pkae026. doi: 10.1093/jncics/pkae026. Online ahead of print.

ABSTRACT

Women with high mammographic density (MD) have an increased risk of breast cancer. They may be offered contrast-enhanced mammogram (CEM) to improve breast cancer screening performance. Using a cohort of women receiving CEM, we evaluated whether conventional and modified MD measures were associated with breast cancer. Sixty-six cases with newly diagnosed unilateral breast cancer were frequency-matched on age to 133 cancer-free controls. On low-energy cranio-caudal CEMs (equivalent to standard mammogram), we measured quantitative MD using CUMULUS software at the conventional intensity threshold (“Cumulus”) and higher-than-conventional thresholds (“Altocumulus”, “Cirrocumulus”). The measures were standardized to enable estimation of odds per age- and adiposity-adjusted standard deviation (OPERA). In multivariable logistic regression of case-control status, only the highest-intensity measure, Cirrocumulus, was statistically significantly associated with breast cancer (OPERA = 1.40, 95% CI 1.04-1.89). Conventional Cumulus did not contribute to model fit. For women receiving CEM, Cirrocumulus MD might better predict breast cancer than conventional quantitative MD.

PMID:38565262 | DOI:10.1093/jncics/pkae026

CMAJ. 2024 Apr 1;196(12):E394-E409. doi: 10.1503/cmaj.230878.

ABSTRACT

BACKGROUND: Most studies of disparities in birth and postnatal outcomes by parental birthplace combine all immigrants into a single group. We sought to evaluate heterogeneity among immigrants in Canada by comparing birth and postnatal outcomes across different immigration categories.

METHODS: We conducted a population-based retrospective study using Statistics Canada data on live births and stillbirths (1993-2017) and infant deaths (1993-2018), linked to parental immigration data (1960-2017). We classified birthing parents as born in Canada, economic-class immigrants, family-class immigrants, or refugees, and evaluated differences in preterm births, small-for-gestational-age (SGA) and large-for-gestational-age (LGA) births, stillbirths, and infant deaths among singleton births by group.

RESULTS: Among 7 980 650 births, 1 715 050 (21.5%) were to immigrants, including 632 760 (36.9%) in the economic class, 853 540 (49.8%) in the family class, and 228 740 (13.4%) refugees. Compared with infants of Canadian-born birthing parents, infants of each of the 3 immigrant groups had higher risk of preterm birth, SGA birth, and stillbirth, but lower risk of LGA birth and neonatal death. Compared with infants of economic-class immigrants, infants of refugees had higher risk of early preterm birth (0.9% v. 0.8%, adjusted risk ratio [RR] 1.08, 95% confidence interval [CI] 1.01-1.15) and LGA birth (9.2% v. 7.5%, adjusted RR 1.12, 95% CI 1.10-1.15), but lower risk of SGA birth (10.2% v. 11.0%, adjusted RR 0.92, 95% CI 0.90-0.94), while infants of family-class immigrants had higher risk of SGA birth (12.2% v. 11.0%, adjusted RR 1.01, 95% CI 1.00-1.02). Risk of stillbirth, neonatal death, and overall infant death did not differ significantly among immigrant groups.

INTERPRETATION: Heterogeneity exists in outcomes of infants born to immigrants to Canada across immigration categories. These results highlight the importance of disaggregating immigrant populations in studies of health disparities.

PMID:38565234 | DOI:10.1503/cmaj.230878

Perfusion. 2024 Apr 2:2676591241244983. doi: 10.1177/02676591241244983. Online ahead of print.

ABSTRACT

INTRODUCTION: We set out to investigate whether the use of Histidine-Tryptophan-Ketoglutarate (HTK) solution or del Nido cardioplegia is linked to an increased incidence of postoperative acute kidney injury (AKI) in patients undergoing coronary artery bypass surgery (CABG).

METHODS: A retrospective study was carried out at our center, with a total of 478 patients included in the analysis. Among them, 268 patients were administered the del Nido solution (DN) while 210 patients received the HTK solution. The primary focus of this study was to assess the occurrence of postoperative AKI and the need for renal replacement therapy (RRT). Multivariable logistic regression was used to examine the relationship between the type of cardioplegia used and adverse kidney outcomes. Additionally, serum levels of sodium, potassium, and ionized calcium were monitored during cardiopulmonary bypass (CPB).

RESULTS: The incidence of AKI was significantly higher in the HTK group compared to the DN group [(48/220 (21.81%) vs. 24/186 (12.90%), p = .049], although the rate of RRT did not show a statistically significant difference (9/48, 18.75% vs. 6/24, 25%, p = .538). Multivariate logistic regression analysis revealed that HTK was a significant risk factor for AKI. Furthermore, serum sodium and calcium levels were found to decrease following HTK cardioplegic infusion. Conclusion: Our study provides compelling evidence of the impact of cardioplegic solutions on postoperative AKI rates. It underscores the importance of optimizing cardiac arrest protocols. These findings warrant further prospective investigations into the influence of cardioplegic solutions on electrolyte imbalances and postoperative AKI rates.

PMID:38565217 | DOI:10.1177/02676591241244983