Clinical trials also known as?

In population-based studies, the issue is often health promotion and disease prevention rather than treatment of an existing disease.

can provide the strongest evidence for evaluating treatments and interventions.

It is done under controlled conditions. It is very expensive.

Community health nurse conduct experimental studies to determine the effectiveness of community health practices e.g. efficacy of different health education methods and communication methods etc.

Several types of _____ error or bias and all of them can impact the validity of study results.

Common bias are: Selection and Information bias.

Common bias are: Selection and Information bias:

forms of potential bias in systematic error ?

Common bias are: Selection and Information bias:

Such things as how the study design is selected, how subjects are selected, how information is collected, how the study is carried out, or how the study is interpreted by investigators are all forms of potential bias.

Occurs when the selected subjects in a sample are not representative of the population of interest. As a result,this selection of subjects can make it appear (falsely) that there is or is not an association between an exposure and an outcome.

Nonprobability sampling (nonrandom sampling) is strongly associated with selection bias.

Selection Bias:

Occur with studies using convenience samples or volunteers.

Selection Bias:

Occur when one applies different eligibility criteria to the cases and controls.

Selection Bias:

Occur when people of certain characteristics drop out of a group at a different rate.

______ these types of error through careful assessment of subject selection and eligibility criteria, and monitoring of characteristics in the populations of interest are critical for successful research and program implementation.

______ these types of error through careful assessment of subject selection and eligibility criteria, and monitoring of characteristics in the populations of interest are critical for successful research and program implementation.

Deals with how information or data are collected for a study.

This includes the source of data that are collected, such as hospital records, outpatient charts, or national databases.

Many of these types of data are not collected for research purposes; so they may be incomplete, inaccurate, or contain information that is misleading.

This can complicate data analysis as the information abstracted from these sources may be incorrect and can lead to invalid conclusions.

Information Bias:

occur when an instrument is not sensitive enough to measure small differences between groups (e.g., blood pressure measurements taken using the wrong cuff size).

Information Bias:

a control may be recorded as a case or a case is classified as having an exposure or exposures that he or she did not actually have.

Information Bias:

happens when subjects are asked to remember or recall events from the past.

Information Bias:

occurs when a subject may not report a certain exposure as he or she may be embarrassed or not want to disclose certain personal information.

occurs when it appears that a true association exists between an exposure and an outcome, but in reality, this association is confounded by another variable or exposure.

There are many examples of _________, such as age, gender, and socioeconomic status.

occurs when a study is performed, and it appears from the study results that an association exists between an exposure and an outcome, when, in fact, the association is actually between the confounder and the outcome.

Recognition of _________ requires a basic understanding of the relationship between an exposure and a disease or an outcome, and can also be identified by performing a stratified analysis first.

Once ______ are determined, then these variables can be removed.

are considered inherently strong because of their rigorous design.

Random selection of a sample and random assignment to groups are objective methods that can be used to prevent bias and produce comparable groups.

Random assignment helps to minimize bias by ensuring that every subject has an equal chance of being selected and that results are more likely to be attributed to the intervention.

The random assignment of subjects to different treatment groups helps to ensure that study groups are similar in the characteristics that might affect results (e.g., age, gender, ethnicity, and general health).

Both the subjects and the investigators are blinded, that is, unaware of which group is receiving the experimental treatment or intervention.

In which the subjects are unaware of which group they are in, can be used.

Strength of ?

Lower likelihood of confounding variables

Strength of ?

Minimize bias in treatment assignment

Strength of ?

Able to control intervention or treatment

Strength of ?

Able to identify confounding and address in the study

Strength of ?

Able to control exposure

Strength of ?

Able to calculate relative risk and incidence rates

Strength of ?

Can study multiple outcomes

Strength of ?

Inexpensive (2 answers)

Strength of ?

Shorter time to completion

Strength of ?

Able to study variables with long latency or impact periods

Strength of ?

Provides a means to compare groups

Strength of ?

Able to calculate odds ratios

Strength of ?

Able to study rare or fatal diseases

Strength of ?

Can study multiple exposures

Strength of ?

Able to calculate prevalence of population studied

Strength of ?

Assesses exposures and outcomes at one time

Strength of ?

Provides a snapshot of study population

Weaknesses of ?

Labor intensive (2 answers)

Weaknesses of ?

Costly (2 answers)

Weaknesses of ?

Lengthy (2 answers)

Weaknesses of ?

Sometimes impractical or unethical to conduct

Weaknesses of ?

Risk of bias and confounding variables

Weaknesses of ?

Sometimes unable to measure or determine exposure

Weaknesses of ?

Selection bias (2 answers)

Weaknesses of ?

Measurement error

Weaknesses of ?

Recall bias

Weaknesses of ?

Cannot assess risk (2 answers)

Weaknesses of ?

Risk of confounding variables

Weaknesses of ?

Cannot control for or identify the significance of potentially important variables

How screening is done?

____ aimed at the Presumptive Identification of a Disease

test is positive (abnormal) --> One can only presume that the disease may be present.

initself,isnotsufficient to establish a positive diagnosis of disease.

Measure blood pressure at every diabetes related visit

Full fasting lips profile (TC, HDL-C, TG and calculated LDL-C) every 1-3 years (more frequently if treatment is initiated)

Annual random urine albumin to creatinine ratio

Annual serum creatinine and calculated creatinine clearance in those without nephropathy and at least every 6 months in those with nephropathy

Dilated eye exam by experienced healthcare professional

type1: annually

type2: every 1-2 years, starting at diagnosis of diabetes

Examples of screening tests?

Examples of screening tests?

Measurement can lead to ? (2 answers)

When a screening test is _______ ,a referral is made for follow-up diagnostic testing to confirm whether, in fact, the disease is present.

Screening for individuals : attempts to identify previously unrecognized disease in individuals who may present to the HC provider for health maintenance checks, or for an unrelated complaint.

Screening for populations

Recommendations for periodic screening of adults in the general population include hypertension, lipid disorders, obesity, colorectal cancer,..

Nurses and patients may also use family history to determine which screening tests are needed or appropriate.

e.g.healthfair

Application of screening tests to a large population.

Is often costly

May better to do on targeting selected populations known to be at high risk.

The ability of the screening test to distinguish correctly between persons with and those without the disease.

If a screening test is 100% valid, it would never have a false-positive or false-negative reading.

Results would be always positive in people who had the disease and negative in people who did not.

is measured using sensitivity and specificity.

Ability of a screening test to identify correctly the persons who have the disease.

it represents the proportion of persons with the disease whom the test identifies as positive.

True positive(TP): when the disease is correctly identified.Ø False negative(FN): a test with poor sensitivity will miss cases; people will be incorrectly told that they are free of disease.

Sensitivity: when the disease is correctly identified.

Sensitivity: a test with poor sensitivity will miss cases; people will be incorrectly told that they are free of disease.

No. of true positive test results / No. of people with disease (No. of TP+FN)

The greater the number of false negative test results (the larger the no. of persons with disease who have not been identified), the lower the sensitivity of the screening test.

The ability of the screening test to identify persons who are normal or without the disease and who correctly test negative when screened.

True negative: persons do not have the disease, and the test findings are normal.

False positive: persons do not have the disease, but their screening test results is positive for disease

persons do not have the disease, and the test findings are normal.

persons do not have the disease, but their screening test results is positive for disease

No. of true negative test results / No. of people without the disease (No. of TN+FP)

Has the disease + positive

Has the disease + Negative

Does not have the disease + Negative

Does not have the disease + Positive

______ tests are not considered to be diagnostic.

wouldbe100%sensitiveand specific. Thiscombinationisnotlikely. Hence,screeningtestarenotusedtoconfirma diagnosis positively.

Refers to the consistency or reproducibility of test result over time and in between examiners.

A test is reliable when it gives consistent results when administered at different times by different persons.

The nursing process is usually used by CHN to plan and implement ______ programs that benefit the community being served.

Determine the need for a screening program by identifying the at risk population.

Determine the resources available (Funding, cost, personnel, equipment, facilities, support of leaders).

Avoid replicating existing screening programs.

Assess the appropriate site and time.

Establish program goals that are meaningful to the community.

Set priorities.

Include key persons in the planning process.

Design easy-to-use forms to documenting screening results, include normal parameters, counseling and referral information.

Advertise the program

Identify and train screeners

Set up the site

Consider space needs

Be ready for case finding

Feed the workers and the participants

Plan to follow up

To justify continued program funding and operation.

To improve service delivery.

To determine the impact of the program on community health.

refers to actual end results of the program.

focuses on actual program performance

• An essential component of screening programs.

Process of directing persons to resources to meet needs.

Hand Hygiene

Ideal characteristics: all right except ?

• Questionnaire

• Blood test

• Mammography

Cost-effective?

The case of PKU and neonatal screening.

The cost of disease management justifies the cost of screening.

• Medicalstaff/epidemiologists -> Meet screening criteria

• Consumers

Consider: Mammography & Pap smear

• Screeningshoulddonoharm

• Are side effects are acceptable?

the degree to which the measurement represents the true value of the attribute that is being measured.

Reliable? Valid?