11 e-Letters

published between 2020 and 2023

  • To improve validity in population-based prospective cohort study: comment on the article by Wei et al.

    An article by Wei et al. reported the death of a child associated with an increased risk of incident atrial fibrillation (AF). The association was observed when the cause of death was both cardiovascular and non-cardiovascular diseases.1 These findings provide a valuable addition to the literature; however, some issues were not addressed by the authors.
    First, several clinical risk factors are associated with incident AF, including concurrent medication, illegal drugs, obesity, sleep apnea, and hyperthyroidism.2-4 For example, we previously reported that insulin users had a higher risk of incident AF than non-users among the elderly patients’ cohort (1.58 odds ratio (OR); 95% confidence interval (CI): 1.37–1.82). Patients with dipeptidyl peptidase 4 inhibitor (OR 0.65; 95% CI: 0.45–0.93) intake had a lower risk of developing AF when compared with non-users.4 However, while associated evaluations were not presented, Wei et al. did not exclude individuals with these risk factors. Consequently, confounding effects may have contributed to the significant effects causing incident AF, thus, omitting these effects may improve study validation outcomes.
    Second, the study initially enrolled 2,740,028 participants in the unexposed group and 64,216 participants in the exposed group at baseline, but missing data between groups (50.1% vs. 79.6%) were examined in further analyses. These missing data potentially affected data credibility in mediation analyses.5 Consequent...

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  • Discrepancies in Mental Health Impacts

    While the data that this article studied and the results that were produced show a change in the mental health status and medication behaviors of Portugal, it does not support the change in mental health status captured in much of the literature around the world. When the COVID-19 virus was declared a pandemic, there was global unrest. It is natural for people to feel fear, anxiety, and panic in the face of an unknown pandemic (Usher, Durkin, & Bhullar, 2020). The article addresses some of the discrepancies between the literature coming out that has been showing increases in anxiety and depressive symptoms in the Discussion section. However, these discrepancies do not align with the data presented in the paper. Further explanation and research is needed as to why rates of some prescription medications to manage mental health symptoms are declining when there is evidence showing that mental illnesses have increase as a result of the pandemic.
    The article discussed a reduction of prescriptions for anxiolytics, sedatives, and hypnotics in children, adolescents, and elderly women. These medications would address the symptoms of anxiety, stress, and other symptoms that a global pandemic may cause (Javed, Sarwer, Soto, & Mashwani, 2020). The authors suggested that perhaps people have been going to see the doctor less frequently due to quarantines and fear of contracting the virus. However, some of the medications are long-term, so it does not make sense that, duri...

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  • The importance of ethnicity and race variables in epidemiology and public health

    The authors, Cifuentes MP, Rodriguez-Villamizar LA, Rojas-Botero ML, et al [1], present an article that, owing to a lack of rigor in the creation and application of ethno-racial categories, ends up employing an analysis method that, although intended to allow proving inequalities, ends up disguising or attenuating them.

    Raj Bhopal published a seminal article in this journal in 2004 demonstrating the importance of ethnicity and race variables in epidemiology and public health. Bhopal pointed out that, at a minimum, researchers should explain their understanding of the concepts of race or ethnicity and the classification they use, even more so when we know that they need development in terms of geographic specificity, scope, and precision for different contexts [2]. Similar recommendations are made by Janeth Mosquera in her analysis about the use of the ethnic-racial category in the research published by the three most important scientific journals of Public Health in Colombia [3].

    The paper does not present a comprehensive and helpful description of the categories that assist the reader in understanding the ethnic-racial composition of the Colombian population and correctly analyze the regularly available data for public health surveillance. The Colombian surveillance system employs the census ethnic-racial categories. Among these Census categories, the "white-mestizo" used by the authors is not defined and thus is not used for public health surveill...

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  • ICNIRP Response to: John William Frank “Electromagnetic fields, 5G and health: what about the precautionary principle?”

    Frank’s essay contains several statements about 5G, its relation to the radiation protection science, and related to this, ICNIRP’s guidance and integrity more generally. ICNIRP considers this to be seriously inaccurate and in need of correction for the sake of both scientific accuracy and development of effective public health policy. However, due to journal word limits we must restrict our response to Frank’s misleading claims about ICNIRP’s integrity (for full response see https://www.icnirp.org/en/activities/news/index.html).

    Frank’s essay accuses ICNIRP of unmanaged conflict of interests, and uses this accusation to attempt to throw doubt on ICNIRP’s scientific evaluations. However, ICNIRP has a very rigorous procedure to avoid conflicts of interest (https://www.icnirp.org/en/about-icnirp/commission/index.html), and Frank did not provide any evidence in support of his statement - he merely referred to ‘persistent allegations’ from the Swedish epidemiologist Lennart Hardell. For example, Frank repeats claims made by Hardell that “ICNIRP’s membership includes over-representation of vested interests, especially the giant multinational telecommunications firms who are heavily invested in the roll out of 5G systems internationally”, and no supporting evidence was provided by either author. To be clear, there are no industry r...

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  • Antidepressants and suicidality

    Hengartner et al. conducted a meta-analysis on suicide risk with selective serotonin reuptake inhibitors (SSRI) and other new-generation antidepressants in adults (1). Although the pooled relative risks (RRs) of SSRI for suicide risk including suicide and suicide attempt in patients with depression and in patients with all indications did not reach the level of significance, the pooled RR (95% confidence intervals [CIs]) of any new-generation antidepressant for suicide risk in patients with depression and in patients with all indications were 1.29 (1.06-1.57) and 1.45 (1.23-1.70), respectively. The authors presented information on the different suicide risk between SSRI and other new-generation antidepressants , and I present additional information regarding the relationship.

    First, Sharma et al. conducted a meta-analysis on the association of SSRI and serotonin-norepinephrine reuptake inhibitors with suicidality and other mental indicators (2). Although the pooled odds ratios (ORs) of antidepressant treatment for suicidality and aggression did not reach the level of significance in adults, the pooed ORs (95% CIs) of antidepressant treatment for suicidality and aggression were 2.39 (1.31-4.33) and 2.79 (1.62-4.81) in children/adolescents. The suicide risk differed in different generations, and suicide risk estimation should be conducted by stratification with generation and type of anti-depressants.

    Second, Hengartner and Plöderl reported that odds ratios (OR...

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  • Role of presymptomatic transmission of COVID-19: evidence from Beijing, China- A Response

    We read with interest, intrigue and concern the findings reported in this short report. if the findings are validated from larger and multicentric data this may have huge implications in the way we trace and isolate the COVID-19 contacts. Pre symptomatic transmission from index cases 5 days prior to the onset of symptoms is a huge logistical nightmare in terms of containment strategies. This would imply at practical impossibility and futility of these strategy especially in setting of cluster or community transmission. This also highlights the virtues of basic but universal measures like physical distancing, hygiene and use of mask at all times under specific settings.

  • Back to the topic: high cardiovascular mortality in Russia

    The question “Why does Russia have such high cardiovascular (CV) mortality rates?”1 can be answered by a pathologist who practiced during the Soviet time.2 Since then, the quality of post mortem examinations has decreased especially during the 1990s: autopsies were sometimes made perfunctorily. The deterioration in anatomic pathology and the health care in general during the 1990s coincided with the increase in the registered CV mortality. A tendency to over-diagnose CV diseases is generally known to exist also for people dying at home and not undergoing autopsy. If a cause of death is not entirely clear, it has been usual to write on a death certificate: “Ischemic heart disease with cardiac insufficiency” or a similar formulation.2 Concerning the relatively high CV mortality in Russia, it should be commented that irregular treatment of hypertension,3 diabetes and other chronic diseases continues to be a problem. Considering the above, the differences between Norwegian and Russian cohorts1 can be better understood. The levels of serum lipids were comparable between Russia and Norway being slightly higher in the latter possibly due to better nutrition. Interestingly, N-terminal pro-b-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-cTnT), and high-sensitivity C-reactive protein (hsCRP) were higher in Russia.1 It can be reasonably assumed that average levels of these markers inversely correlate with a nation’s health reflected by the life expecta...

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  • Are Associations Between Television Viewing and Mortality Due to Confounding?

    We read with great interest the report from Hamer and colleagues that examined the hypothesis that associations between television (TV) viewing and mortality from heart disease (HD) are due to confounding (1). They employed a negative control approach (2) and report evidence of associations between TV viewing and HD mortality (HR=1.09 [1.06, 1.12] per 1 hr/day increase in TV) and accidental deaths (the negative control outcome; HR=1.06 [0.98, 1.15]) after adjusting for age, sex, smoking, education, and prevalent HD (1)

    The positive association between TV and accidental deaths was interpreted as evidence that the TV-HD mortality association was due to confounding. Although key study limitations were noted including a small number of accidental deaths and limited adjustment for confounding, the authors concluded that “observed associations between TV and HD are likely to be driven by confounding”. Although we agree that confounding is a worrisome threat to the internal validity of epidemiologic studies, we believe that the conclusion in the Hamer report is overstated.

    A critical additional strategy to understand bias due to confounding, one that was not employed in the current study, is to examine relevant results from published studies conducted in different study populations using different methods. (2) We previously reported results in two studies that examined associations for accidental deaths and HD mortality with TV viewing (3) and leisure-time sitti...

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  • PACE may increase consumer consciousness of calorie consumption but at the price of understanding healthy eating and mental health

    Dear Editor,
    The authors of “Effects of physical activity calorie equivalent food labelling to reduce food selection and consumption: systematic review and meta-analysis of randomized controlled studies” make a strong claim that PACE food labeling can increase consumer consciousness of calorie consumption and therefore caloric reduction, but perhaps this concept deters true understanding of "healthful eating" and may have larger health implications for those with disordered eating.
    There is a growing knowledge that that not all calories are created equal. Different foods may not only have different effects on hunger and satiety but also insulin production, gut microbiome interactions, and de novo lipogenesis in the liver (1). While not all consumers need this level of understanding, but without a basic acknowledgement of food’s qualities- like fats, fiber, sugar, ect- the consumer is lead to believe that calories are the most important determinant in what makes food “healthful.” With PACE food labeling, a consumer is led to believe that an ice cream cone and a handful of nuts, both of which could amount to 200 calories, are “equal.” However, in this comparison, only the nuts are possibly advantageous to people with diabetes and cardiovascular disease (2).
    Stripping foods down to solely their caloric energy through PACE food labeling could inadvertently foster unhealthy relationships with food. As stated in the article, PACE labeling could be use...

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  • PACE - Not the Nation's Quick Fix

    Dear Editor,

    Much has been published in the news as of late about the effects of physical activity calorie equivalent (PACE) food labelling in order to reduce the nation’s calorie consumption. These labels aim to identify how many minutes of physical activity are required to burn off the calories in a particular food item. A systematic review and meta-analysis, by researchers at Loughborough University, found that food labelling may reduce the number of calories consumed compared with food that was not labelled or other types of food labelling (1).
    This was supported by the UK Royal Society for Public Health which had already advocated for PACE to replace the current labelling system (2). Overall, it found this technique could lead to a reduction of 100 calories per day combined with an increase in physical activity.

    Many nutritionists have been quick to criticise, stating that it loses sight of the fact that food goes beyond calories and is fundamental for social aspects of life (3). Additionally, the nutritional content of food might be neglected. For example, it might be easier to “burn off” a chocolate bar than something with much more nutritious such as nut butters or a banana. This could result in people picking the easier but not necessarily the “healthier option.” Digestion is complex and although foods such as nuts and oats might be high in calories, their content results in slower processing and digestion. This allows people to feel fuller fo...

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