Read the attached paper from the British Medical Journal titled “Maternal Overweight and Obesity in Early Pregnancy and Risk of Infant Mortality: A Population Based Cohort Study in Sweden”.
Answer the following questions. There are 10 questions and a total of 25 marks are available for this assignment. Marks allocated to each question are clearly shown in parentheses. The recommended time to complete the assignment is 3 hours. Answer each question in not more than 100-150 words. Unnecessarily long answers will be penalized. Use Font size 11. Do not type outside the boxes provided. Do not cut and paste. Adjusted the provided space after each question to fit your answer.
|The study aimed to investigate the associations between maternal overweight and obesity and infant mortality outcomes. Study researchers adjusted odds ratios for seven confounders. Briefly explain and discuss the justification for controlling each confounder in the analysis (3 marks). Note: You may need to search on PubMed to find the associations between these variables.Although the researchers adjusted the odds ratios for parity, birth spacing was not included in the adjusted model. Briefly discuss whether you think the researchers should have adjusted the odds ratios for the inter-pregnancy interval(s) (2 marks). Note: You may need to search on PubMed to find the associations between birth spacing and both the exposure variable and the outcome variable.In many European countries, mothers continue to smoke during pregnancy. Briefly discuss how smoking habits were measured in this study and the validity of these estimates (2 marks)Discuss whether you think the strength of the association between maternal overweight/obesity and infant mortality may have been affected by information bias related to the exposure variable (3 marks)Review Table 1 and briefly discuss why you think the rates of infant, neonatal and post-neonatal mortality declined from 1992-1996, 1997-2000, 2001-2005, 2006-2010 (3 marks)Study authors report that the population attributable fraction (PAF) related to maternal overweight/obesity was 11% and 7% for smoking. Interpret and discuss the public health significance of the reported PAF (3 marks).The authors report that the study findings may have been influenced by residual confounding. Define the term residual confounding and discuss the potential role of residual confounding in the context of this study (2 marks)One method to minimize potential residual confounding is to use a within-siblings study (or sibship) design or sibling control analysis. Briefly discuss how sibling control analysis can be used to decrease potential residual confounding in observational epidemiological studies (2 marks). Note: your answer does not need to be related to the context of this study; rather, observational epidemiological studies in general.Briefly discuss the public health implications of the study findings for female UAE Nationals (or other female GCC nationals) (2 marks). Consider the public health interventions during preconception planning and the periconception period, the first antenatal appointment, and throughout pregnancy.Briefly discuss the challenges and opportunities for conducting this study in the UAE (or another GCC country of your choice; 3 marks). Consider the sources of data and linkage between registries/databases required for the exposure variable, outcome variable, and confounding variables.Answer:A confounder is an external influence that changes the effect of dependent and independent variable under a study. The extraneous influence of a confounding variable influences the outcome of an experimental design increasing the probability of producing inaccurate results. It was therefore important to control each confounder in the analysis to reduce the effect of the confounding effects on the study. Controlling each confounder during the study ensured that the results of the study reflect actual relationship between the variables studied. Confounding is a threat to the validity of inferences made concerning cause and effect justifying the need to control each confounding variable.|
|Answer:Evidence from meta-analyses and systematic reviews indicate that child spacing has effects on child outcomes. Preceding inter-pregnancy intervals that are 24 months infant mortality. Similarly birth spacing shorter than 36 months is associated with increased risk of child mortality under the age of five years. The effect of birth spacing on infant mortality was a potential confounding variable in the study of maternal overweight and obesity and the risk of infant mortality. Therefore, the researchers should have adjusted the odds rations for inter-pregnancy intervals to reduce the influence of the potential confounders on their study, promoting the validity of study results.|
|Answer:The study hypothesized that maternal smoking increased the risk of infant mortality. The smoking habit was measured through estimations done by calculating the population attributable fraction (PAF) using a specific formula. Most information on maternal information was missing during the study and therefore, the researcher had to rely on PAF investigate the number of infant deaths attributed to maternal smoking. PAF is a widely used measure in assessing the public health impact of exposures in populations and therefore is associated with valid estimates in various studies. Therefore, the study produced valid estimates on infant mortality rates attributed to maternal smoking. It is important though to note that PAF is based on assumptions that may be problematic observational data but is necessary for making translational inferences for public health.|
|Answer:The study found a strong association between maternal overweight or obesity and infant mortality. However, the authors agree that although they were able to adjust the BMI related risks for several maternal characteristics, they cannot exclude the possibility of residual social confounding. This suggests that there is a great possibility of information bias related to exposure variable which could have the strong association between maternal overweight and infant mortality. The fact that study did not control maternal smoking confounder provides the evidence that the study was influenced by information bias. Information bias is associated with incorrect estimation of the real effect of an exposure on the outcome. This could explain the strong association between maternal overweight or obesity and infant mortality in this study.|
|Answer:The rate of infant, neonatal, and post-neonatal mortality was higher from 1992-1996, as compared to the next years. In the early 1990s, antenatal steroids and surfactant had not been introduced. The therapies are effective in saving pre-term births. This explains why the infant mortality death was higher in between 1992 and 1996. Since then more research has been done on causes of infant mortality deaths yielding various strategies of saving infants associated the decline of with rates of infant, neonatal and post-neonatal mortality. In addition, the uniform and free antenatal and paediatric health services have improved infant health reducing infant mortality over years.|
|Answer:According to the study, population attributable fraction (PAF) related to maternal overweight/obesity was 11% and 7% for smoking. This means that maternal overweight and obesity causes 11% of infant mortality while smoking causes 7% of infant mortality. Therefore, maternal overweight or obesity and smoking cause infant mortality. If the population was not exposed to these situations, that is maternal overweight or obesity and smoking, then the 11% and 7% infant deaths would not have occurred. This report significant too the population as it warns on negative effects such exposure to their health. The reported PAF shows that maternal overweight or obesity and smoking increases the risk of infant mortality.|
|Answer:Residual confounding occurs when a confounding variable is measured with some error or measured imperfectly. The adjustment using the measure with some errors does not remove the confounding variable effect completely. For example a certain study found that maternal smoking results in a lower risk of having Down Syndrome birth. Errors and imperfect measures led to the misleading conclusion. Residual confounding in this study, has a potential role of yielding misleading conclusions which can put the lives of mothers and infants at an increased risk of danger. Wrong conclusions drawn from erroneous and imperfect measure s lead to wrong interpretations which are associated with greater risks. A wrong interpretation can increase the rate of infant mortality instead of reducing it, the initial purpose of such studies.|
|Answer:The appropriate measuring of potential confounding factors apart from exposure and outcome in a study helps in controlling them in an analysis. A within-siblings study reduces the potential residual confounding due to the characteristics that remain fixed between pregnancies. Residual conforming occurs when there is a range of exposure. The limited range of exposure reduces the chances of error decreasing the potential residual confounding in observational epidemiological studies. Additionally, siblings in stable families share stable aspects of family context and half their genome. Siblings’ differences in family context are potential confounders that increase the potential residual confounding. The absence of such confounders reduces potential residual confounding in observational epidemiological studies.|
|Answer:The study findings indicate that maternal overweight or obesity contributes to infant mortality. For the UAE females, it is important to control body weight to reduce or avoid infant mortality. Although practices such as smoking are not common among these females, overweight and obesity are common and should be controlled to save infants. Various public health interventions are useful in reducing infant mortality rate. Before conception, women should ensure that they have the proper weight. After conception, women should attend an antenatal appointment and other appointments during the pregnancy period to be enlightened on what practices to engage in and which ones to avoid to reduce the risk of harming the baby.|
|Answer:In UAE, more hospitals and healthcare facilitates have been established enabling women to have easy access to healthcare. This means that majority of women have their information on exposure variable, confounding variables, and outcome variable in the hospitals. The documents give researchers an opportunity to conduct similar studies in UAE. Services such as the first antenatal visits, national identification numbers, and the register of the total population provide necessary information for the study. However, it is not long since women in this region started enrolling into higher institutions, therefore finding information on the level of education, a confounding variable can be challenging during similar studies.|