Using Incidence And Prevalence As Proportions Of Disease Recurrence, Essay.

Module 1

Imagine that you are providing advice to a State Minister for Health on a new policy to mitigate childhood obesity.  Would you use incidence or prevalence data to support your policy and why? 

Now imagine that you are providing advice on how Australia should manage an outbreak of Coronavirus.  Would you present him/her with incidence or prevalence data to support your policy and why? 

example of the how to respond:

The ideas of prevalence and incidence are used as proportions of disease recurrence. The incidence of disease speaks to the rate of event of new cases emerging in a given time frame in a particular population. The prevalence of illness speaks to the recurrence of existing cases in a characterized population at a specific point of time. A use of these ideas to the given situations would help in figuring out which information ought to be utilized to help the proposed arrangements. The primary situation is tied in with prompting the State Minister for Health on another policy to relieve childhood obesity. I would utilize  prevalence data to help my strategy since prevalence evaluates the likelihood of the population being influenced by obesity at that particular time including over a wide span of cases(past and present cases). Likewise, prevalance information is helpful in considering the burden of disease and proposing health related policies.

The second situation is tied in with prompting the Australian Government on the best way to deal with the episode of Coronavirus. I would utilize incidence information to help my arrangement since it gauges the quantity of new instances of Coronavirus disease happened in a predetermined population in a particular era. It communicates the danger of what number of individuals would get influenced by the viral contamination. Along these lines, helping in proposing a strategy to deal with the outbreak of viral contamination relying upon whether the rate is high or low.

Bottom of Form

What study designs could be used to explore the relationships between work-related factors and mental health? Different designs might be more useful for exploring different relationships. Please suggest a proposed observational study design for a study which considers the relationship between work overload and mental health. Why did you choose this study design?

example of the how to respond:

Observational  study design can be used to explore relationship between work related factors and mental health .  A cross sectional study design can be best to explore the relationship between work overload and mental health because the researcher can measure the outcome and exposure at the same time of study and multiple variables can also be measured. Furthermore , the cross sectional design  examines the relationships between disease and other variables that exists in the defined population. 

Incidence and Prevalence

With your experience and background, think of an intervention that you will like to test by using randomized controlled trial design. Please address these:

Title of your research:

Intervention:

Comparator (placebo/active component):

Allocation concealment:

Sequence generation (Random/non-random):

Blinding: (Single/Double/Triple):

example of the how to respond:

Title of your research: Panadol osteo is more effective than regular Panadol as a baseline pain relief for post-surgical patients.

Intervention: Only patients with total knee replacements at the same hospital will be involved in this trial. They will be randomly divided into two groups, some will be given Panadol TDS and others will be given Panadol Osteo TDS. None of these patients should not be allergic to either Panadol or Panadol Osteo.

Comparator (placebo/active component): Panadol vs. Panadol Osteo

Allocation concealment: Each patient’s name will be written on an individual, half folded piece of paper, and the whole number of patients involved will be then divided into two equal numbers and placed into two envelopes.

The shape, colour and taste of both Panadol and Panadol Osteo will be similar.

Sequence generation (Random/non-random): One envelop containing patients’ names will be marked ‘1’ and the other will be marked ‘2’.

Blinding: (Single/Double/Triple): Single – The participants will not know which medications they are given. Staff will monitor the pain level and duration that each patient experiences in order to determine whether Panadol Osteo is more effective than Panadol.

Considering the methods by which surveillance data are collected, what elements of the social context or community in which you live create barriers to or facilitate effective disease surveillance? Feel free to draw from your personal and professional experiences.

example of the how to respond:

Most methods of surveillance require a level of willing engagement with the healthcare system. My work has been largely with vulnerable or invisible communities who do not usually engage health care. In communities who are reluctant to engage this presents a significant challenge in monitoring health and disease. One example is the prison population, where interventions to reduce the spread of blood-born viruses have been initiated following the discovery that infection rates of viruses such as Hep C are 30% higher than in the general population. These interventions aim to encourage prisoners to minimise risky behaviour and engage in testing and treatment. If only a small percentage are willing to be tested, it is very difficult to assess the scope of the problem or the effectiveness of interventions. In instances like this, the interventions are often aimed at increasing the willingness to engage, and they are assessed by monitoring the uptake percentage of screening and other health initiatives.

Module 2

Providing access to in-prison medical care, and using opportunistic and multi-phasic approaches to screening can both facilitate surveillance in this population.

I was really interested to explore various models of why people do or don’t engage health promoting behaviours and how this can be influenced at an individual or broader social level. The underlying theory about how and why people engage has a huge impact on the type of health interventions used. Eg are we aiming to change attitudes in the hope this will change behaviour? Are we providing a trigger to action? Are we providing models to imitate? Reducing convenience barriers? Increasing perceived threat? Increasing a sense of self efficacy? 

It was interesting to see how different models weighted different aspects of behaviour or favoured different methods of influence or control, some perceiving people as rational agents, others as primarily operating according to perceptions of social acceptance, and the way some interventions focused on individual behavioural changes while others looked at broader social and access issues.

In the prison population I’ve observed that health literacy, ease of access, a sense of self worth, and previous positive experiences with health care professionals were characteristics of people willing to engage. A high level of perceived psychological risk (for example fear of physical touch in medical settings by people who had experienced severe trauma; issues of racism - 27% of prisoners identify as Aboriginal or Torrens Strait Islander; shaming for sexuality, gender, or lifestyle choices; cultural and language barriers), combined with a low level of perceived threat, a low outcome expectancy, and health care engagement as a culturally deviant behaviour were characteristics of those reluctant to engage. If health care professionals are conflated with other authority figures who are perceived to be corrupt or punitive people will also be reluctant to engage.

A second challenge in gathering accurate health data can be for communities or subgroups who do engage health care but are not easily identified through their records alone - for example transgender and non-binary people. Their status as members of the subgroup can’t easily be obtained from medicare records and the like, which can make it difficult to identify their data in order to assess their specific health needs.

Surveillance in sub-groups like this can be facilitated by providing specialist medical services that voluntarily identify and report tagged data, or by adding identifying information to the general data collected by health services. Peer based and advocacy groups often want to facilitate these processes to validate the needs of their community. However they are also often very sensitive to issues of privacy and protection - for example many trans activists and advocacy groups have suggested that trans people opt out of the MyHealthRecord given the broad access it will afford to highly sensitive personal data that can threaten people’s employment if leaked. Opt in research (active surveillance) exploring health in populations such as this may be a more effective approach as they a)are clearly for the benefit of that community and b)have much lower risks of revealing information in ways that would do harm.

Observational and Experimental Study Designs

Surveillance in the mental health arena has a unique set of challenges such as the lack of diagnostic specificity, the risk of stigma associated with early detection and early intervention efforts (eg the social cost of being identified as being ‘at risk of psychosis’ may act as a stressor and therefore a risk factor that makes psychosis more likely), the gap between experiencing symptoms and a person’s capacity to function or quality of life (fewer symptoms may not be associated with increases in the latter), and again, challenges with people being willing to engage health care to the extent that some distressed people attempt suicide before disclosing distress to a health professional.

In a screening program for early breast cancer detection, 750 women were encouraged to examine their breasts regularly for lumps, abnormal hardness,

swelling and tenderness, a process called Breast-Self Exam (BSE). 360 women reported abnormal lumps (+ve BSE result) and were referred for Biopsy

(confirmatory test), with 230 confirmed breast cancer cases after Biopsy. 390 women reported no lumps, abnormal hardness, swelling or tenderness during

their breast-self exam (-ve BSE result). But after visiting their GPs for other reasons, 20 of the 390 women who did not report any lumps, abnormal hardness,

swelling or tenderness (-ve BSE result) were determined to have breast cancer (Biopsy confirmed).

Determine the sensitivity and specificity of the Breast-Self Exam (BSE) screening test

example of the how to respond:

I have followed instruction given in the PPT; According to that following are my calculations: 

a = true positives (test positive for the disease and really have the disease)

b = false positives (test positive for the disease but do not actually have the disease)

c = false negatives (test negative for the disease but actually have the disease)

d = true negatives (test negative for the disease and really do not have the disease)

Sensitivity = probability of a positive test in people with the disease = a/(a+c)

Specificity = probability of a negative test in people without the disease = d/(b+d)

Sensitivity  = a/(a+c) = 230/(230+20)=  230/250  =  0.92= 92% 

Specificity = d/(b+d) =370(130+370)= 370/500= 0.74=74%

Using the CASP tool for case-control that can be found in Topic 1 discussion, appraise the following paper (hyperlink). You can discuss the points that you found good or bad, e.g. bias found if the method used is not validated: you can suggest a better method with justification.

Critical Appraisal on Cohort study 

Using the CASP tool for case-control that can be found in Topic 1 discussion, appraise the following paper (hyperlink). You can discuss the points that you found good or bad, e.g. bias found if the method used is not validated: you can suggest a better method with justification.

Systematic review 

Have a good read with some of the examples of systematic review and meta-analysis. Pay attention on the outline as described in my lecture slides.

Prevalence and incidence are a common phenomenon in epidemiology and disease investigation assessment impact. Prevalence measures a disease condition over a period of time either at a given point in time of periodic prevalence.  Periodic prevalence provides a better measure of the disease with its load case having new cases and dates between the time frames. It is often more meaningful when reporting the number of cases as a fraction of the total population. Incidence measures the rate of new or diagnosed cases of the diseases. It is beneficial when reported as a fraction of the general populations, (Rotham, Greenland & Lash, 2008; Woodward, 2013).

In this case, policy formulations are best formulated based on prevalence rates of obesity. This gives the actual observation of all the live cases during the time of assessments. Prevalence estimation is key and plays a crucial role in policy formulation. This will inform assessment on the number of the population likely to face obesity

The second scenario entails the number of the of corona-virus outbreak incidence in Australia offering meaningful information of the disease occurrence trend. Incidences report on such diseases establish disease occurrence at a particular point in time. This will be crucial in offering an assessment of the status of the disease in the population, thus offering a better approach to the management of the coron-avirus outbreak.

Observational studies are designs which offer a description of patterns of disease occurring in various setups. The descriptive study design will be beneficial in this scenario so as to assess the association of work-related factors and mental health, (Von Elm et al., 2007). Descriptive studies are crucial in providing knowledge about workload and mental health. This design is beneficial in public health fields in assessing segments of populations whom education and prevention programs can be targeted and further aid in the allocation of resources to mitigate the health impact being observed.

Title of your research: assessment of new drugs regime offers better nursing outcomes than generic drugs in cancer management for cancer patients diagnosed with colon cancer. Intervention: patients diagnosed with cancer with not less than 3 months of medication history.

The comparator (placebo/active component): administration of new drug regime and generic drug treatment option for cancer

Allocation concealment: the patients will be given a unique number which identifies then both groups are treated equally and the two groups separated ready for treatment allocation. The control and cancer group patients will be offered the same treatment options which are similar in shape, colour, and size which acts as a placebo.

Incidence and Prevalence

Sequence generation (Random/non-random): random selection of the study subjects will apply to be applicable in this study assessment  

Blinding: The participants will be single-blinded as they will not know which medications they have been provided. The nursing person in charge will monitor and document in the checklist patient progress and feedback to assess health outcomes.

True positive a=360; this refers to the positives which were correctly labeled as having the disease

False positive b=230; these entail the negatives which were incorrectly labeled by the tests.

False negatives c=390; these entails the positives which were wrongly labeled as negatives

True negatives d=20; these are true negatives which were correctly labeled by the tests.

Sensitivity = this is a measure of actual positives having the disease which are correctly identified.

Specificity = this refers to the proportion of actual negatives measurement which is correctly identified

 Sensitivity = A/(A+C) X100

= 360/(360+390)%

= 48%

Specificity = D/(D+B)X100

= 20/(20+230)%

=  80%

Disease surveillance is an epidemiological event which the diseases are monitored in terms of how it is spread, monitored and established. Main critical role of disease surveillance is to predict, observe and minimize the harm caused due to the outbreak, epidemic and encase of a pandemic situation and further to increase knowledge on the factors which might aggravate the occurrence of the disease. it is further a continuous process of assessing the occurrence of diseases and health-related events. It offers an appropriate and immediate intervention for controlling the disease. it further entails an ongoing assessment of the collection, assessment, and interpretation of information obtained from data from public health actions. Disease notification systems play a crucial role in disease surveillance. It timely reports on the occurrence of a disease using the designated tools. Disease surveillance has been used for effective prevention and managing diseases and utilized especially in controlling epidemic diseases. Effective disease and notification system allow for the detection of outbreaks which prompt an immediate intervention for the reduction of morbidity and mortality case, (Kulldorff, 2001).

Mandatory reporting has been entrenched in the disease reporting notification protocols. World Health Organization has laid in place mandatory requirements for reporting the following causes as they occur; plaque, cholera, yellow fever, typhus, and relapsing fever. Disease surveillance thus entails the collection of information, assessment, and interpretation. The collected information can be utilized in various ways; they can be used to evaluate control and prevention of health measures, monitoring changes of infectious agents, aid in planning and resource allocation to a particular disease and identification of high risks populations. For an effective collection of surveillance information, the information being sought needs to be standard.

Module 2

 Assessment of vector-borne diseases in my field of expertise portrays a global threat of emergence of diseases such as malaria and Zika viruses due to rapid urbanization and movement of people in the urban set ups. The vector-borne disease accounts for an estimate of about 17% of all infectious diseases which results in an increased burden of disease-causing over a million deaths annually, (WHO, 2017). The occurrence of this disease is occasioned by complex factors such as environmental changes like the changing climates which have a significant impact on disease transmission.

The vector-borne disease has been observed to re-emerge in urban settings as cases have been observed especially rise in Aede borne diseases such as dengue, zika and chikungunya diseases. Urban challenges have portrayed to be a significant factor in the spread of this diseases due to unplanned development of urban setups and increase globalization (Simons, Farrar, Nguyen, Willis & Dengue, 2012).

Observed challenges in urban disease surveillance system have shown a lack of awareness among the different stakeholders. Improved understanding by the people. Enhancing behavior change among the urban residents in identifying and controlling breading sites for the mosquito is key crucial engagement in the management of vector-borne disease surveillance and managing occurrences and prevalence rates. Thus utilization of effective tools for collecting assessment and information dissemination is a key factor. Further innovative of new tools of combating the disease due to increased resistance and residual identification of infections proves to be the biggest barriers in managing and enhancing vector born disease surveillance in the urban settings.

Case study appraisal by Parashar et al., (2000)

1. Did the study address clearly focused issue; Yes

The paper addressed an assessment on the outbreak of encephalitis which occurred between the years 1998-1998 in Malaysia and it was linked to para myoxivirous Nipah which had an infection on beings, human, dogs, and cats. The study focused on the issue clearly focussing on the effects of a virus was causing on the population at larger. Most patients in the study were farmers and were characterized by respiratory and neurologically symptoms which were observed from pig farmers. The virus of interest was Nipah virus which is closely linked to the Hendra virus associated with disease outbreaks on horses and humans in Australia.

2. Did the authors use an appropriate method; Yes

The study used case-control study with case-patients being defined as persons with serological evidence having Nipah Infection. Inclusion as case-patients was used to recruit patients hospitalized with encephalitis. Control subjects were obtained using two sets of subjects that is community farm and controls and case farm controls. Thus the study utilized case-control assessment of the subjects to assess the subjects, fitting the model of case-control study designs.  

3. Were the cases recruited in an acceptable manner; Yes

Observational and Experimental Study Designs

The study patients were recruited accurately with a selection of the cases from the community set up while the controls selected from community subjects. Case farm control s were selected from farming activities associated with the infection

4. Were controls selected in an acceptable manner; Yes

The controls were selected in an acceptable manner; this was done using two sets of controls from the community and case farm controls. The community farm controls were further used to identify the characteristics of farms which the humans inhabited. Case farm cases were identified based on the associated farming activities.

5. Were exposures accurately measured; Yes

Exposure methodologies were selected using the computation of odds ratio and comparing the exposures between cases and case farm controls were performed in stratified analysis. The comparators were measured using stratified analysis from the stratum for the cases and case-control from the farms.

6. Were the groups treated equally and potential confounders assessed

Stratification was performed on the study subjects. The treatment was performed equally with farm characteristics being adjusted for potential confounders were adequately adjusted in the study.

7. Treatment effect

The treatment was performed on the cases and comparable assessment was performed on controls. The odds ratio was performed on the study subjects to assess the association of the disease and its occurrence. Adjusted was made on the farm activities which showed positive association on odds ratio.

8. The precision of treatment effects

The treatment tested for IgM and the IgG antibodies were tested in the laboratory. Hendra virus antigens were tested in the lab before usage, this was cross-reacted on the Nipah Antibodies were utilized. A 95% CI interval was used in the study.

9. Believe on the results; yes

The results revealed an association of human Nipah infection and with pig’s environment because most of the patients were pig farmers due to isolation from the infected pigs.

10. Benefits of the results; No

The results are beneficial in that it was able to disease outbreak occurrence early enough. Those persons having close contact with pigs were high at risks of developing the disease. Further, the results showed high risks farms activities which had a positive effect on the disease.

11. How the results for other evidence of the study; No

The study was a case-control study investigating a disease outbreak. There was no comparable studies and evidence to support the study results.

The study by Low, Chiew & Ho (2015), assessed and evaluated five biomarkers which include neopterin, thrombomodulin, vascular endothelial growth factor-A, soluble vascular cell adhesion molecule 1 and pentraxin 3 in assessing dengue clinical outcomes. in this prospective study, the assessment of confounding factors was not taken into consideration in the study. The study did not elaborate on how the confounding factors were accounted in obtaining the association of the biomarkers and occurrence son dengue fever clinical outcomes.

Module 3

The study further aimed at comparing the results obtained with others obtained from the other studies in the literature review. The result obtained was compared with other systematic reviews and case-control studies undertaken previously being highlighted in the discussion section of the study.  However, the results could not be generalized to the general population due to various limitations highlighted in the study. In the study, the key limitations which hinder generalization of the results include, the inclusion criteria could not be inclusive, the study used low sample size for the study participants and the setting of the study was undertaken in a hospital thus could favor diseases cases and not represent the general population.  

Thus this shortcomings depicted in the research, make the study not to be reliable in assessing the critical aspects of the study. Some of the data collection methods strategies were faced with hiccup challenges limiting the general ability and thus rendering the study results not the reliable.

Randomized control study assessment by Cohen et al., (2012)

Domain	Judgment support	Judgment
Selection bias
Random sequence	Patients were selected randomly	There were no selection biases in the study
Allocation concealment	Double blinding of the participants was performed	Concealment of the subjects was done using double blinding.
Performance bias
Participants blinding	The subjects were assessed using the completion of the 5 item questionnaire tool.	Proper assessments of the study participants were done
Detection bias
Blinding of outcome assessment	The outcome in the study was double-blinded with randomization effect being undertaken in the study.	The outcome of the study effectively assessed.
Attrition bias
Outcome of data	Outcome measures used in the study were the frequency of coughing used as the primary measure while secondary outcomes were measured using frequency in cough severity.	Outcome data assessed using appropriate parameters
Reporting bias
Selective reporting	There was no reporting done selectively on the subjects in the study.	Reporting was done effectively and wholly and not subjects were subjected to selectively.

References:

Cohen, H. A., Rozen, J., Kristal, H., Laks, Y., Berkovitch, M., Uziel, Y., ... & Efrat, H. (2012). Effect of honey on nocturnal cough and sleep quality: a double-blind, randomized, placebo-controlled study. Pediatrics, peds-2011.

Kulldorff, M. (2001). Prospective time periodic geographical disease surveillance using a scan statistic. Journal of the Royal Statistical Society: Series A (Statistics in Society), 164(1), 61-72.

Low, G. K. K., Gan, S. C., & Ho, S. C. (2015). Biomarkers in differentiating clinical dengue cases&58; A prospective cohort study. Journal of Coastal Life Medicine, 3(12), 967-970.

Parashar, U. D., Sunn, L. M., Ong, F., Mounts, A. W., Arif, M. T., Ksiazek, T. G., ... & Othman, G. (2000). Case-control study of risk factors for human infection with a new zoonotic paramyxovirus, Nipah virus, during a 1998–1999 outbreak of severe encephalitis in Malaysia. The Journal of infectious diseases, 181(5), 1755-1759.

Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern epidemiology.

Simmons, C. P., Farrar, J. J., van Vinh Chau, N., & Wills, B. (2012). Dengue. New England Journal of Medicine, 366(15), 1423-1432.

Von Elm, E., Altman, D. G., Egger, M., Pocock, S. J., Gøtzsche, P. C., Vandenbroucke, J. P., & Strobe Initiative. (2007). The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. PLoS medicine, 4(10), e296.

WHO. Vector-borne disease. Geneva: World Health Organization; 2017. https://www.who.int/mediacentre/factsheets/fs387/en/. Accessed 10 Nov 2018.

Woodward, M. (2013). Epidemiology: study design and data analysis. Chapman and Hall/CRC.