Environmental health Epidemiology - Assignment Example

Environmental Health Epidemiology Identifying Potential Sources Of Bias In This Study Bias in a clinical research study can be referred to any sort of systematic error, which results in presenting inappropriate estimations about the association prevailing between a disease and its exposure (Blumenthal & Fleisher, 2001). In relation to the provided study, it can be affirmed that the clinical research of investigating the development of leukemia associated with occupational exposures to benzenes basically has three types of potential sources of bias.

These sources can be apparently noted as selection, detection and performance of identifying individuals working in a facility with the existence of excessive benzene exposure. 2. Process to Address Potential Sources of Bias in Future StudiesThe sources of bias that have identified in the study can substantially increase the risk of estimating appropriate value of the association prevailing between leukemia and benzene exposure. In order to effectively deal with this particular critical situation, the process of masking or blinding of each individual participants involved with the provided study will certainly aid in controlling the potential risks emerging from varied bias sources (Higgins & Green, 2011). 3. Calculating Measures Based on the Screening Test ResultsSensitivity (TPR)TPR=TP/PTPR=TP/(TP+FN) = 214/(214+90) =0.

70Prevalence of Excessive Benzene ExposurePrevalence = Σ Condition positive / Σ Total population = 214/1832 =0.12Specificity (SPC)SPC=TN/NSPC=TN/( FP+TN) =29/(90+29) =0.24Positive Predictive Value (PPV)PPV= Σ True positive / Σ Test outcome positive =214 / 0.070 =3057Negative Predictive Value (NPV)NPV = Σ True negative / Σ Test outcome negative = 29 / 00.24 = 120.8Accuracy (ACC)ACC = Σ True positive + Σ True negative / Σ Total populationACC = 214 + 29 / 1832 = 214.024. ConclusionBased on the results studied in the screening program, it can be ascertained that the calculations provide appropriate results regarding the participants who are subjected to excessive benzene exposure.

According to the values identified in the aforesaid calculation, it is determined that the results significantly demonstrated the need of framing a new diagnostic test, which would enable the assessors to define appropriate outcomes. One of such outcomes can be determining the number of positive along with negative participants and the individuals who are subjected towards excessive benzene exposure.ReferencesBlumenthal, U. J., & Fleisher, J. M. (2001). Epidemiology: a tool for the assessment of risk.

Water Quality: Guidelines, Standards and Health, 135-160.Higgins, J. P. T., & Green, S. (2011). Introduction to sources of bias in clinical trials. Retrieved from http://handbook.cochrane.org/chapter_8/8_4_introduction_to_sources_of_bias_in_clinical_trials.htm