Introduction
Epidemiological studies involve a variety of health determinants and therefore, require a compound procedure of collecting and analyzing their data. Usually, there are several stages of collecting data and analyzing it, as scientists have to ensure that parameters match the overall intention of the study. The method settled for by epidemiologists in any study will depend on the physiologic processes that characterize the disease risk studied (Checkoway, Pearce, & Kriebel, 2004).
Exposure and Dose Modeling
Exposure dose relations studies investigate the uptake of the toxics and their clearance from the body. Fewer complex studies dealing with a two-way analysis largely rely on the cumulative exposure methods to their results. These results are comfortable to interpret, relative to those from other methods, and allow for easy comparison with previous studies. Under cumulative exposure method, the researcher assumes that disease risk corresponds to the dose exposure. Here, reliance is on biological hypotheses or empirical weighting for exposure histories. Time induction analysis offers a way to investigate and quantify risk exposures that take many years to be manifest. Another method is the temporal dynamic of exposure and risk, which relies on biological processes.
A new method, known as dosimetric, makes it possible to calculate the relationship of exposure and risk. The dosimetric method moves beyond the assumption that risk corresponds to the cumulative exposures of the victim. Instead, it offers the ability to analyze instances where exposure is not uniform throughout the study period. It does this by enabling them to include factors that interact biologically with the effect modifiers, besides offering an exposure profile of the victim. The dosimetric model has three steps namely; model structure development, estimation of parameters and validation, which includes an analysis of its sensitivity.
Hughes et al. (1998) used the cumulative exposure method to measure an exposure-response relationship of crystalline silica and radiographic opacities. The method allowed the researchers to conduct the inquiry using results from a previous study that had similar estimates. They successfully developed their discussion of the exploration results by comparing different parameters measured. Buchanan, Miller and Soutar (2002) use a variation of the dosimetric method. Here, the scholars examine the possible effect of variances in concentration of the quartz and the risk of silicosis. The method allows the investigators to conclude that exposure time and concentration, work as independent factors leading to the development of silicosis. They are able to offer a detailed revelation of additional parameters influencing the exposure-response relation.
A distinction between the two studies above is that Hughes et al. (1998) looked at an area of study within epidemiology whose variables were novel at the time of study. On the other hand, Buchanan, Miller and Soutar (2002) examined additional parameters within a specific study whose prior results had been analyzed using the cumulative exposure method. The dissimilar methods came in handy for different types of studies. As explained by Checkoway, Pearce and Kriebel (2004), occupational epidemiologists study complex and dynamic physiologic processes to explain exposure-response relationships. The additional uniqueness of diseases studied makes it necessary to have weighting mechanisms that minimize the risk of exposure miscalculation while using the various methods mentioned above.
Conclusion
Epidemiological studies begin with a careful choice of parameters and these depend on the agent studied. Scholars examine the underlying physiologic functions, which later enlighten their choice of explicit mathematical weighting function. The appropriate method used in the final exploration will depend on the findings of the examination and the whether the inquiry should present simple, average or cumulative exposure measures.
References
Buchanan, D., Miller, B. G., & Soutar, C. A. (2003). Quantitative relations between exposure to respiable quartz and risk of silicosis. Occupational Environment Medicine, 60, 159-164.
Checkoway, H., Pearce, N., & Kriebel, D. (2004). Research methods in occupational epidemiology (2nd ed.). New York, NY: Oxford University Press.
Hughes, J. M., Weill, H., Checkoway, H., Jones, R. N., Henry, M. M., Heyer, N. J., et al. (1998). Radiograhic evidence of silicosis risk in the diatomaceous earth industry. Ami Respir Crit Care Med, 158, 807-814.