Category: Statistics

Open Heart. 2021 Dec;8(2):e001850. doi: 10.1136/openhrt-2021-001850.

ABSTRACT

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a well-established risk factor for cardiovascular disease, with ethnic and regional differences noted. With the recent surge of research within this field, we re-examine the evidence associating NAFLD with subclinical atherosclerosis, and investigate potential regional differences.

METHODS: This is a systematic review and meta-analysis. PubMed and EMBASE were systematically searched for publications from January 1967 to July 2020 using standardised criteria. Original, observational studies investigating the association between NAFLD and either carotid intima-media thickness (CIMT) and/or coronary artery calcification (CAC) were included. Key outcomes included differences in mean CIMT, the presence of increased CIMT, the presence of CAC and the development/progression of CAC. Pooled ORs and pooled standard differences in means were calculated using random-effects models. Between-study heterogeneity was quantified using the Q statistic and I². Subgroup analyses stratified by region of study (Asian vs Western) were also conducted.

RESULTS: 64 studies involving a total of 172 385 participants (67 404 with NAFLD) were included. 44 studies assessed the effect of NAFLD on CIMT, with the presence of NAFLD associated with increased CIMT (OR 2.00, 95% CI 1.56 to 2.56). 22 studies assessed the effects of NAFLD on CAC score, with the presence of NAFLD associated with the presence of any coronary calcification (OR 1.21, 95% CI 1.12 to 1.32), and the development/progression of CAC (OR 1.26, 95% CI 1.04 to 1.52). When stratified by region, these associations remained consistent across both Asian and Western populations (p>0.05). The majority (n=39) of studies were classified as ‘high quality’, with the remaining 25 of ‘moderate quality’.

CONCLUSIONS: There is a significant positive association between various measures of subclinical atherosclerosis and NAFLD, seen across both Western and Asian populations. These results re-emphasise the importance of early risk evaluation and prophylactic intervention measures to preclude progression to clinical cardiovascular disease in patients with NAFLD.

PMID:34933963 | DOI:10.1136/openhrt-2021-001850

Clin Med Res. 2021 Dec;19(4):161-168. doi: 10.3121/cmr.2021.1654.

ABSTRACT

Objective: Characterization of COVID-19 in the Latinx community is necessary for guiding public health initiatives, health system policy, clinical management practices, and improving outcomes. Our aim was to describe the socioeconomic background and clinical profile of patients with COVID-19 at a large public hospital in Los Angeles to improve health disparities leading to poor outcomes during the pandemic.Design, Setting and Participants: A single center retrospective cross-sectional study of all patients with a positive polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who presented to Los Angeles County (LAC)+University of Southern California (USC) Medical Center between March 15, 2020 and April 30, 2020.Methods: We describe patient characteristics, socioeconomic factors, laboratory findings, and outcomes of the first 278 patients to present to LAC+USC Medical Center with COVID-19.Results: Patients self-identified as Hispanic (82.4%) or non-Hispanic (17.6%). Hispanic patients presented later from symptom onset (6 days vs 3 days, P = 0.027) and had higher post-intubation mortality (40.9% vs. 33.3%, P = 1), intensive care unit (ICU) mortality (31.1% vs. 22.2%, P = 0.87), and overall mortality (11.1% vs 10.2%, P = 1). However, the difference in admission rates, mechanical ventilation rates, and overall mortality rates were not statistically significant. A majority of patients, 275/278 (98.9%), reported residency ZIP codes in areas of higher population density, higher percentage of Latinx, born outside the United States, lower median income, and lower high school graduation rate when compared to the rest of Los Angeles County. Regression analysis within the Hispanic cohort found that age, history of hypertension, history of diabetes, lactate dehydrogenase (LDH), and C-reactive protein (CRP) were predictors of mechanical ventilation and mortality.Conclusion: We show the Latinx community has been disproportionally affected by the pandemic in Los Angeles and we identified multiple socioeconomic and clinical characteristics that predispose this population to COVID-19 infection. This study highlights the need for change in local and national strategies to protect vulnerable communities during public health outbreaks.

PMID:34933948 | DOI:10.3121/cmr.2021.1654

BMJ Evid Based Med. 2021 Dec 21:bmjebm-2021-111746. doi: 10.1136/bmjebm-2021-111746. Online ahead of print.

ABSTRACT

The disproportionate focus on statistical significance in reporting and interpreting clinical research studies contributes to publication bias and encourages selective reporting. This highlights a need for alternative approaches that clearly communicate the uncertainty in the data, enabling researchers to provide a more nuanced interpretation of clinical research findings.Our purpose in this article is to introduce the density strip method as one potential approach that might act as a bridge between data visualisation for descriptive purposes and formal statistical inference. We build on existing theory, translating it to the applied research context to illustrate its utility to clinical researchers.We achieve this by considering an exemplar clinical trial, Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial (MS-SMART). MS-SMART was a multiarm randomised placebo-controlled trial of three potentially neuroprotective drugs in secondary progressive MS. We illustrate through MS-SMART the potential of the density strip as an effective visualisation of the distribution of clinical trial outcomes and as a complementary approach to aid the interpretation of formal, inferential, statistical analysis.We conclude by summarising the advantages and disadvantages of the density strip methodology and provide suggestions for its potential extensions and possible further uses.

PMID:34933930 | DOI:10.1136/bmjebm-2021-111746

BMJ Evid Based Med. 2021 Dec 21:bmjebm-2021-111836. doi: 10.1136/bmjebm-2021-111836. Online ahead of print.

ABSTRACT

Registration of health and medical research is an effective way of improving the transparency and credibility of evidence. Registration involves pre-specifying the research objectives, design, methods and analytic plan on a publicly accessible repository before conducting the study. Registration can reduce bias and improve the transparency and credibility of research findings. Registration is mandated for clinical trials, but it is also relevant to systematic reviews, observational and preclinical experimental research. This paper describes how researchers can register their research and outlines possible barriers and challenges in doing so. Widespread adoption of research registration can reduce research waste and improve evidence-informed clinical and policy decision making.

PMID:34933926 | DOI:10.1136/bmjebm-2021-111836

BMJ Evid Based Med. 2021 Dec 21:bmjebm-2021-111788. doi: 10.1136/bmjebm-2021-111788. Online ahead of print.

ABSTRACT

OBJECTIVES: To determine if and to what degree asthma may predispose to worse COVID-19 outcomes in order to inform treatment and prevention decisions, including shielding and vaccine prioritisation.

DESIGN: Systematic review and meta-analysis.

SETTING: Electronic databases were searched (October 2020) for clinical studies reporting at least one of the following stratified by asthma status: risk of infection with SARS-CoV-2; hospitalisation, intensive care unit (ICU) admission or mortality with COVID-19.

PARTICIPANTS: Adults and children who tested positive for or were suspected to have COVID-19.

MAIN OUTCOME MEASURES: Main outcome measures were the following stratified by asthma status: risk of infection with SARS-CoV-2; hospitalisation, ICU admission or mortality with COVID-19. We pooled odds ratios (ORs) and presented these with 95% confidence intervals (CI). Certainty was assessed using GRADE (Grading of Recommendations, Assessment, Development and Evaluations).

RESULTS: 30 (n=112 420) studies were included (12 judged high quality, 15 medium, 3 low). Few provided indication of asthma severity. Point estimates indicated reduced risks in people with asthma for all outcomes, but in all cases the evidence was judged to be of very low certainty and 95% CIs all included no difference and the possibility of increased risk (death: OR 0.90, 95% CI 0.72 to 1.13, I²=58%; hospitalisation: OR 0.95, 95% CI 0.71 to 1.26; ICU admission: OR 0.96, 95% CI 0.75 to 1.24). Findings on hospitalisation are also limited by substantial unexplained statistical heterogeneity. Within people with asthma, allergic asthma was associated with less COVID-19 risk and concurrent chronic obstructive pulmonary disease was associated with increased risk. In some studies, corticosteroids were associated with increased risk, but this may reflect increased risk in people with more severe asthma.

CONCLUSIONS: Though absence of evidence of a clear association between asthma and worse outcomes from COVID-19 should not be interpreted as evidence of absence, the data reviewed indicate that risks from COVID-19 in people with asthma, as a whole, may be less than originally anticipated.

PMID:34933924 | DOI:10.1136/bmjebm-2021-111788

Gut. 2021 Dec 21:gutjnl-2021-324915. doi: 10.1136/gutjnl-2021-324915. Online ahead of print.

ABSTRACT

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) represents a new inclusive definition of the whole spectrum of liver diseases associated to metabolic disorders. The main objective of this study was to compare patients with MAFLD and non-MAFLD with hepatocellular carcinoma (HCC) included in a nationally representative cohort.

METHODS: We analysed 6882 consecutive patients with HCC enrolled from 2002 to 2019 by 23 Italian Liver Cancer centres to compare epidemiological and future trends in three subgroups: pure, single aetiology MAFLD (S-MAFLD); mixed aetiology MAFLD (metabolic and others, M-MAFLD); and non-MAFLD HCC.

RESULTS: MAFLD was diagnosed in the majority of patients with HCC (68.4%). The proportion of both total MAFLD and S-MAFLD HCC significantly increased over time (from 50.4% and 3.6% in 2002-2003, to 77.3% and 28.9% in 2018-2019, respectively, p<0.001). In Italy S-MAFLD HCC is expected to overcome M-MAFLD HCC in about 6 years. Patients with S-MAFLD HCC were older, more frequently men and less frequently cirrhotic with clinically relevant portal hypertension and a surveillance-related diagnosis. They had more frequently large tumours and extrahepatic metastases. After weighting, and compared with patients with non-MAFLD, S-MAFLD and M-MAFLD HCC showed a significantly lower overall (p=0.026, p=0.004) and HCC-related (p<0.001, for both) risk of death. Patients with S-MAFLD HCC showed a significantly higher risk of non-HCC-related death (p=0.006).

CONCLUSIONS: The prevalence of MAFLD HCC in Italy is rapidly increasing to cover the majority of patients with HCC. Despite a less favourable cancer stage at diagnosis, patients with MAFLD HCC have a lower risk of HCC-related death, suggesting reduced cancer aggressiveness.

PMID:34933916 | DOI:10.1136/gutjnl-2021-324915

J Nucl Med Technol. 2021 Dec 21:jnmt.120.261893. doi: 10.2967/jnmt.120.261893. Online ahead of print.

ABSTRACT

Background: There is limited data on the head-to-head comparison of ^99mTc-pyrophosphate (PYP) and echocardiographic strain imaging in the assessment of transthyretin (TTR) cardiac amyloidosis. Methods: At Mayo Clinic Arizona, patients that had undergone both a ^99mTc-PYP scan and transthoracic echocardiogram (TTE) within a 90-day period were retrospectively identified for chart review and strain imaging analysis. Patients were divided into two groups according to their ^99mTc-PYP results (PYP+ and PYP -) for the comparison. A standard 17-segment model was used for segmental, regional and global longitudinal strain comparison. A p-value of <0.05 was deemed as significant. Results: A total of 64 patients were included, the mean age was 75.1 ± 13.0 years and 57(89.1%) were male. Comparing the PYP+ to the PYP- group, the left ventricular global longitudinal strain was significantly worse (PYP+ vs. PYP-: -10.5 ± 2.6 vs. -13.1 ± 4.1, P = 0.003). PYP+ patients also had worse regional basal strain (-4.6 ± 2.6 vs. -8.8±4.0, p<0.001) and a trend of worse mid-ventricular strain (-9.6 ± 4.0 vs. -11.7± 4.4, P = 0.07), however, no statistical difference in apical region (-17.6 ± 4.73 vs. -19.0 ± 6.46, P = 0.35). This is consistent with an apical sparing pattern shown by the relative apical longitudinal strain index (1.3 ±0.5 vs. 1.0 ± 0.3, P = 0.008). Segment to segment analysis demonstrated significant difference in strain between PYP+ and PYP- segments in 4 segments: basal inferior (P = 0.006), basal anterolateral (P = 0.01), apical septal (P = 0.002) and apical inferior (P = 0.001). Left ventricular diastolic dysfunction was significantly different with 17 (77.3%) patients in group PYP+ versus 15 (36.6%) in PYP- participants (P = 0.002). Conclusion: Our study suggested that PYP uptake is related to overall worse LV segmental, regional and global longitudinal strain function, as well as diastolic function compared to patients without PYP uptake. This provides important data for clinicians to know the echocardiographic function features related to ^99mTc-PYP uptake and can serve as a hypothesis-generating study for future investigators.

PMID:34933921 | DOI:10.2967/jnmt.120.261893

Br J Ophthalmol. 2021 Dec 21:bjophthalmol-2021-320211. doi: 10.1136/bjophthalmol-2021-320211. Online ahead of print.

ABSTRACT

BACKGROUND: The choroid is densely innervated by all parts of the autonomic nervous system and further harbours a network of local nerve cells, the intrinsic choroidal neurons (ICN). Their function in ocular control is currently unknown. While morphological data assume a role in intraocular pressure regulation, we here test if increased pressure on isolated choroids may activate ICN.

METHODS: Donor tissue was transferred into a pressurisable tissue culture chamber, and nasal and temporal choroid halves incubated for 1 or 4 hours, with pressures set to 15 or 50 mm Hg, followed by qRT-PCR expression analysis of the ICN-specific markers VIP, UCN, NOS1, UCH-L1. POL2-normalised data in the different pressure settings, incubation times and localisations were statistically analysed.

RESULTS: The presence of the ICN-specific markers VIP, UCN, NOS1, UCH-L1 was confirmed using immunohistochemistry, and mRNA of all markers was detected in all experimental conditions. Marker analysis revealed no significant changes of mRNA expression levels between 15 and 50 mm Hg in the different incubation times. When comparing all samples over all experimental conditions, a significant increase of VIP and NOS1 mRNA was detected in temporal versus nasal choroids.

CONCLUSION: In this functional analysis of human ICN in vitro, higher amounts of VIP and NOS1 mRNA were detected in the temporal choroid, that is, the choroidal site with ICN accumulation. Further, our data indicate that elevated pressure is apparently not able to trigger ICN responses via the investigated markers. Alternative markers and stimuli need to be investigated in upcoming studies in order to unravel ICN function.

PMID:34933896 | DOI:10.1136/bjophthalmol-2021-320211

BMJ Open Diabetes Res Care. 2021 Dec;9(Suppl 1):e002204. doi: 10.1136/bmjdrc-2021-002204.

ABSTRACT

INTRODUCTION: Access to care is essential for patients with diabetes to maintain health and prevent complications, and is important for health equity. New York State’s Health Homes (HHs) provide care management services to Medicaid-insured patients with chronic conditions, including diabetes, and aim to improve quality of care and outcomes. There is inconsistent evidence on the impact of HHs, and care management programs more broadly, on access to care.

RESEARCH DESIGN AND METHODS: Using a cohort of patients with diabetes derived from electronic health records from the INSIGHT Clinical Research Network, we analyzed Medicaid data for HH enrollees and a matched comparison group of HH non-enrollees. We estimated HH impacts on several access measures using natural experiment methods.

RESULTS: We identified and matched 11 646 HH enrollees; patients were largely non-Hispanic Black (29.9%) and Hispanic (48.7%), and had high rates of dual eligibility (33.0%), Supplemental Security Income disability enrollment (49.1%), and multiple comorbidities. In the 12 months following HH enrollment, HH enrollees had one more month of Medicaid coverage (p<0.001) and 4.6 more outpatient visits than expected (p<0.001, evenly distributed between primary and specialty care). There were also positive impacts on the proportions of patients with follow-up visits within 7 days (4 percentage points (pp), p<0.001) and 30 days (6pp, p<0.001) after inpatient care, and on the proportion of patients with follow-up visits within 30 days after emergency department (ED) care (4pp, p<0.001). We did not find meaningful differences in continuity of care. We found small positive impacts on the proportion of patients with an inpatient visit and the proportion with an ED visit.

CONCLUSIONS: New York State’s HH program improved access to care for Medicaid recipients with diabetes. These findings have implications for New York State Medicaid as well as other providers and care management programs.

PMID:34933873 | DOI:10.1136/bmjdrc-2021-002204

CMAJ Open. 2021 Dec 21;9(4):E1195-E1204. doi: 10.9778/cmajo.20200283. Print 2021 Oct-Dec.

ABSTRACT

BACKGROUND: Despite their popularity, the efficacy of interventions targeting gut microbiota to improve depressive symptoms is unknown. Our objective is to summarize the effect of microbiome-targeting interventions on depressive symptoms.

METHODS: We conducted a systematic review and meta-analysis. We searched MEDLINE, Embase, PsycINFO, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews and the Cochrane Controlled Register of Trials from inception to Mar. 5, 2021. We included studies that evaluated probiotic, prebiotic, synbiotic, paraprobiotic or fecal microbiota transplant interventions in an adult population (age ≥ 18 yr) with an inactive or placebo comparator (defined by the absence of active intervention). Studies must have measured depressive symptoms with a validated scale, and used a randomized controlled trial study design. We conducted a random effects meta-analysis of change scores, using standardized mean difference as the measure of effect.

RESULTS: Sixty-two studies formed the final data set, with 50 included in the meta-analysis. Probiotic, prebiotic, and synbiotic interventions on depressive symptoms showed statistically significant benefits. In the single studies evaluating each of fecal microbiota transplant and paraprobiotic interventions, neither showed a statistically significant benefit.

INTERPRETATION: Despite promising findings of benefit of probiotic, prebiotic and synbiotic interventions for depressive symptoms in study populations, there is not yet strong enough evidence to favour inclusion of these interventions in treatment guidelines for depression. Critical questions about species administered, dosage and timing relative to other antidepressant medications remain to be answered.

STUDY REGISTRATION: PROSPERO no. 143178.

PMID:34933877 | DOI:10.9778/cmajo.20200283