Epidemiological data analysis

Process analysis looks at the logical sequence in a model where for instance the forecast for a product can be derived from a set of reasonably hard data (such as epidemiological data sets, perhaps of disease incidence, prevalence or death rates). Knowing the numbers of patients suffering from a particular disease such as stress urinary incontinence (SUI), one can state various assumptions which are either fact-based or logical and from this produce a forecast (see Figure 1.2). 

Woodward, M., 2005, Epidemiology Study design and data analysis, 2nd Edition, Chapman Hall/CRC. 

Several species and populations from other Anopheles complexes have been discriminated based on CHC patterns. Examples include all five species of the An. quad-rimaculus complex (Carlson et al., 1997), some species of the An. maculipennis complex (Phillips et al., 1990a), malaria-vector and non-vector forms of the An. maculates complex (Kittayapong et al., 1990, 1993), and An. Stephensi strains susceptible or resistant to DDT and malathion (Anyanwu et al., 1993, 1997). CHCs have been used in combination with isoenzyme analysis to successfully differentiate populations of An. darlingi (Rosa-Freitas et al., 1992). All these findings demonstrate that hydrocarbon analysis is a powerful tool for distinguishing mosquito species and populations. This is particularly important for disease vectors, since it can facilitate interpretation of epidemiological data and assist implementation of control measures. 

Hill WJ, Ferguson WS. 1979. Statistical analysis of epidemiological data from a chromium chemical manufacturing plant. J Occup Med 21 103-106. 

Thielemans, A. and Massart, D.L., The use of principal component analysis as a display method in the interpretation of analytical chemical, biochemical, environmental, and epidemiological data, Chimia, 39, 236-242, 1985. 

Recognition of Unusual Patterns. Recognition of unusual patterns requires a population-based or epidemiological approach to data analysis and interpretation. What would constitute an unusual pattern of disease occurrence Essentially, it is a cluster that does not fit. A cluster is an aggregation of cases of a disease or other health-related condition... which are closely grouped in time and place (CDC, 1992, p. 429). Again, baseline information is needed for comparison to evaluate what is unusual. 

Based on an analysis of the epidemiologic data, EPA calculated that lifetime continuous exposure to asbestos air concentrations of 0.0001 fiber/mL could result in up to 2-4 cancer deaths (lung cancer or mesothelioma) per 100,000 people. This air concentration is within reported ranges of ambient air levels (0.00001 to 0.0001 fiber/mL). The EPA analysis has been extensively discussed and reviewed in the scientific literature. EPA is in the process of reviewing and possibly updating their cancer risk estimates for asbestos. 

Starr TB, Cause C, Youk AO, Stone R, Marsh GM, and Collins JJ (2004) A risk assessment for occupational acrylonitrile exposure using epidemiology data. Risk Analysis 24(3) 587-601. 

Axelrad, D. A., Bellinger, D. C., Ryan, L. M., Woodruff, T. J. (2007). Dose-response relationship of prenatal mercury exposure and IQ an integrative analysis of epidemiologic data. Environ. Health Perspect. 115 609—615. 

---