An observational study is the most suitable study design for analyzing the relationship between BMI and asthma. Thus, cohort or prospective studies would be appropriate, as they extend over a considerable period. In this type of study, researchers observe changes and the time sequences in which events occur. These qualities make the studies suitable, and entail drawing

Nevertheless, in any research, concern for selection bias will always occur. A prospective design allows data for known confounders. For this reason, the results are significantly definitive and informative. The study may raise ethical questions if a section of the sample population has dementia. Additionally, being overweight could carry a degree of negative impact and could offended people. Finding the required sample size to take part in an extended research could prove problematic. . This association should be explored using longitudinal designs with the critical statistical power. In addition, the information should be adequate, while measuring weight and height should not be self-reported.
In prospective cohort studies, researchers conceive and design studies, recruit the potential samples, and collect baseline data on the subjects before any of the subjects have shown signs of the issue under investigation. Thereafter, the subjects are followed for a considerable period to ascertain if they show signs of the outcome of interest. For this particular design, the selection should entail people who are not obese, but show signs of developing the condition over time. Those chosen must be willing and ready to take part in the study for an extended period of time. The results of this study may be a true reflection of the effect of the exposure under investigation. However, it is possible that the findings could be due to a different explanation. For example, it could be due to random errors, bias, or confounding, which produces false results (Pearce, Checkoway, & Kriebel, 2007).

This research proposal aims to investigate the most appropriate study design for exploring the relationship between body mass weight (BMI) and asthma. There exists a considerable knowledge gap in the association between BMI and asthma. Consequently, intervention measures may not be accurate or appropriate. For this reason, the study is appropriate, as it will help determine the precise association between the two so that intervention measures are carried out from an informed position(Xu, B. et all, 2002).

Possible modifiers in a study investigating the relationship between BMI and asthma could be lifestyle choices. For example, the lack of exercise, smoking, drinking, and living in environments with unclean breathing air or exposure to pathogenscan all be factors that increase the possibility of asthma. The research will avoid this by examining the respondents intensely to ensure the reliabilityof the results (Braback et al., 2013).

Determining whether BMI has a correlation with asthma is incredibly difficult. For example, it may be difficult to establish whether individuals in the control group are unexposed, or if in some cases, they may fail to recall past exposure. Nevertheless, this problem could be overcome by ensuring a thorough analysis of the outcome in relation to exposure. It is easy to determine the participants, BMI, and then compare the results with their asthma status (Ungvari et al, 2012).