Working title - "MALE INFERTILITY AND E-CIGARETTE TRENDS ACROSS EUROPEAN UNION (EU): AN ECOLOGICAL STUDY"
Working title - "MALE INFERTILITY AND E-CIGARETTE TRENDS ACROSS EUROPEAN UNION (EU): AN ECOLOGICAL STUDY"
Background/Context
E-cigarettes were invented in 2003 and for the longest time, vaping was heralded as a safer and much more enjoyable alternative to smoking. The lifetime and current prevalence of e-cigarettes vaping in men globally are 22% and 12%, respectively. According to Kapan et al in 2020, in European countries, there is a higher prevalence of e-cigarette use among males, adolescents and young adults, smokers of conventional cigarettes, and former smokers. Current smokers of conventional cigarettes showed the highest prevalence for the use of e-cigarettes, ranging from 20.4% to 83.1%, followed by ex-smokers, which ranges from 7% to 15%. It has been documented for decades that tobacco smoking has a detrimental impact on fertility, but do e-cigarettes affect fertility? For men in particular, the connection between tobacco and infertilityis hard to ignore. According to GBD based research in 2023, male infertility is defined asthe inability to achieve conception within one year of unprotected intercourse. Studies indicate that male factors alone account for approximately 2030% of infertility cases; at least 30 million men worldwide are infertile with the highest rates in Africa and Eastern Europe, according to times. Many animal-based studies have shown effects of e-cigarettes on the male reproductive system. These data have suggested that vaping leads to pathological alterations of the cells, tissues, and organs of the male reproductive system.
Justification/rationale
According to Debbie et al in 2023, Electronic cigarettes (e-cigarettes) are often considered a safe substitute for conventional cigarette cessation. They contain nicotine, and the addition of flavourings increases the toxicity of e-cigarette vapour in a significant manner. The effects of these toxicants on male reproduction are well established in conventional cigarette smokers. Although toxins were measured at much lower levels in e-cigarette aerosols compared to smoke from a conventional cigarette, there are concerns about their potential impact on male reproduction. Ecological studies are useful in creating a hypothesis and also when investigating the impact of exposures or interventions on health outcomes across different geographical areas or populations. In this case, the study aims to analyse the correlation between e-cigarette trends and male infertility rates across the European Union Countries.
Research Objective(s)
Population: Males >15 years of age residing in EU countries between 1990 and 2019Exposure: E-cigarette use
Comparison: no comparison groups (historical).Outcome: Male infertility
The objective of this ecological study is to determine if there is any correlation between male infertility and E-cigarette usage among men of >15 years across the EU countries from 2012-2019.Methodology (study design, population and setting)
A comprehensive literature review of peer-reviewed journal articles will be undertaken following a systematic search strategy based on pre-defined eligibility criteria drawn on the PECO format related to male infertility, e-cigarette usage, and their possible underlying causal pathways to identify potential confounders. This ecological study will be conducted using data from two sources. Data will be analysed from Global burden of disease (www.healthdata.org) for prevalence of male infertility and smoking for age groups >15 from year 2012-2019 and the data from Eurobarometer (www.europa.eu/eurobarometer/) on E-cigarettes usage of the same age groups and year under study. In the Eurobarometer database, electronic cigarette use is typically measured through survey questions that assess individuals' self-reported behaviours and attitudes towards e-cigarette use but they generally aim to gather information on the prevalence and patterns of e-cigarette use among the surveyed population. The following statistical analysis will be planned with the aggregated data. Employing a linear regression model with the male infertility prevalence as the dependent variable and the e-cigarette usage as the independent variable. Each data point in the model will represent a specific EU country during a particular year. A suitable regression method will be used to estimate the coefficients of the regression equation which will help establish the relationship between male infertility and e-cigarette usage rates, accounting for the variability across the EU countries. Furthermore, if other predictor variables at the country level are identified and data is available, they may be added to the regression model. This will help improve the estimation of coefficients and enhance the overall understanding of the relationship between male infertility and e-cigarette usage rates across EU countries.
The quality of the regression model will be examined by the goodness-of-fit measures. These metrics will indicate how well the model explains the variations in male infertility rates based on e-cigarette usage rates. The results of the linear regression analysis, including the significance and direction of the regression coefficients will determine if there is a statistically significant relationship between male infertility and e-cigarette usage rates among men aged >15 across the EU countries. Visualizations, such as scatter plots, to depict the relationship between male infertility prevalence rates and e-cigarette usage rates across the EU countries over the study period will be created. The results will be interpreted from the statistical analysis, including the strength, direction, and statistical significance of the regression.
The above study will also discuss the considerable limitations with the ecological studies and any additional contextual factors or potential confounding variables like age, socioeconomic status and other health-related behaviours like alcohol consumption etc. which may influence the observed association between male infertility prevalence rates and e-cigarette usage rates among men aged >15 years across the EU countries from 2012-2019.
Ethical Considerations
Ethical consideration not required as this study is based on open datasets where the data is freely available to download.
