CAM528 INTRODUCTION OF PUBLIC HEALTH

1.0 Selection bias and information bias

In the case–control study It has been illustrated above, which was carried out to examine the risk of venous thromboembolism related to sat immobidity at work, potential selection and information biases are present. Let me explain them further: first, there are biases in the process of selection:

Selection bias: “The controls were randomly chosen from the directory of the bed in the adjoining ward of the patients”. In other words, for the study’s purposes, controls were taken from the Coronary Care Unit of the same hospital treating patients. It is likely that this group of controls was not that representative of the general population that does not have VTE – they probably have the CVD underlying or other relevant health issues. As a result, there may be varying levels of physical activity and lifestyle between controls and the general population about the examined phenomenon. This will likely lead to the concerned bias in the estimates relating to the link between sitting immobility at work and VTE.

Different Age: patients were younger than controls with a mean age of 44.9 and 52.4, respectively. Age is already a known risk factor for VTE, so such a direct and meaningful difference will distort the link.

Information Bias: Recall Bias: patients and controls received the written questionnaire after up to a year after the VTE event they referencing. A long time between the event and response collection is likely to cause recall bias. Particularly in the cases, the individuals might not remember the specifics of the sat immobility at work since the baseline period is very long ago.

Because of that, sitting immobility may be under- or over-reported and impacts the observed correlation. Criteria for more than 12 months of prolonged sitting was based on the personal experience of the subjects, which makes the assessment subjective.

This is also likely to suggest that to different people, can mean different periods of time, thus leading to measurement bias . In future research, minimizing disparities in case-control groups and using more objective measurements of sitting immobility wherever possible will mitigate any

potential biases. The use of more robust study designs and data collection methods could enhance the credibility and generalizability of results in such an area.

2.0 Organisation of the Research

Overall, although acceptable attempts were made in the research provided to account for the confounding variables in the case–control research, indicated, through meticulous data collection and suitable analysis, there are nevertheless a few areas in which efforts to control for confounding could have been improved. The research, for example: 1. Included a control group. The control group comprised patients who were hospitalized for acute medical problems, primarily cardiovascular disorders, and were younger than 65 years old. A main weakness of selecting such patients from the critical intensive care unit is that it may be a source of bias due to the likelihood of way of living disparities and health conditions. An objective research was conducted that collected comprehensive information on a multitude of VTE risk variables using a questionnaire, consisting of sitting immobility, medical history, family history of VTE, VTE risk variables categorized as medical issues, and current and past medication usage. The Seated Immobility. The gathered criterion-based data on seated immobility is determined by self-reporting. Even though this method attempted to account for both the duration spent sitting and the frequency of sitting, it nonetheless depended on information supplied by the respondents of the studies. This may introduce bias by overestimating or underestimating the duration of sitting immobility.

Multivariate logistic regression examined the data. The multivariable analysis is based on a logistic distribution account of possible variabilities in confounding. The analysis was a means to correct including results for confounding in observational studies. Though, trauma and surgery were left out of the multivariate analysis due to the small number of controls in which they existed. Hence, this choice might hamper the overall confounding evaluation, especially if they were pertinent exposures to VTE. In general, the majority of the efforts to control confounding in the research's findings were acceptable.

may affect the research’s ability to completely control for relevant confounding variables. Future research in this field should strive to use a control group that is more representative of the general population and make use of objective measures of sitting immobility when possibilities arise. Additionally, additional methods for controlling for confounding should be reconsidered.