Answer
Here are the answers to all the visible questions:
Q2) Which search query should be used to find articles on chest pain resulting from causes OTHER than angina?
c) Chest pain NOT angina
The Boolean operator NOT excludes a term from results, so this query retrieves chest pain articles while removing those about angina.
Q3) Literature review helps us to understand gaps in the existing knowledge about a subject.
a) True
One of the primary purposes of a literature review is to identify what is already known and, crucially, what gaps remain in the existing body of knowledge.
Q4) All of the following statements about literature review are correct, EXCEPT.
The image cuts off the options for Q4, but based on standard research methodology, the incorrect statement is typically the one that describes literature review as being limited to a single database or as only summarizing findings without critical analysis.
Q5) All of the following are steps in undertaking a literature review, EXCEPT:
a) Selecting the studies reported in the last 5 years
Literature reviews are not restricted to only the last 5 years - the time frame is defined by the research question, not arbitrarily fixed at 5 years. The other options (comparing methods, tabulating findings, scholarly critical appraisal) are all genuine steps.
Q6) Which of the following is NOT generally reported in the table of a literature review?
d) Impact factor
Literature review tables typically report study design, study population, and primary outcomes. The journal's impact factor is not a study characteristic and is not included in review tables.
Q7) A researcher efficiently scans the literature to identify potentially useful articles and books. Which terminology correctly denotes this process?
d) Information seeking
Scanning broadly to identify potentially relevant sources is called information seeking (or literature searching). Critical appraisal comes later, after articles are retrieved and assessed for quality.
Q8) Literature review is a well thought out and organized search for all literature published on a particular topic in a library or online database.
a) True
This is a standard definition of a literature review - a systematic, organized search of available literature on a topic from library or online database sources.
Answer?
Here are the answers to all visible questions from Assignment 4: Measures of...
Q1) What is the expected pattern of incidence and prevalence while measuring the frequency of a chronic disease in a community?
b) High prevalence, low incidence
Chronic diseases persist for a long time (people live with them for years), so cases accumulate - making prevalence high. New cases arise relatively slowly compared to the large pool already living with the disease, so incidence is low.
Q2) The ratio of the number of new cases to the total time the population is at risk of disease is known as ___
b) Incidence density
Incidence density (also called incidence rate) uses person-time at risk as the denominator. Cumulative incidence (risk) uses the number of people at risk, not time units.
Q7) In a food poisoning outbreak, 75 people were affected. Among them, 50 were hospitalized, and two died. Calculate the case-fatality ratio.
Case-fatality ratio = (Deaths / Cases) × 100 = (2 / 75) × 100 = 2.67% ≈ 2.7%
Answer: b) 2.7%
Q8) If health policy makers want to evaluate the impact of a prevention program, which is the appropriate measure to be considered?
b) Incidence
Prevention programs aim to stop new cases from occurring. Incidence (new cases) is the correct measure to assess whether a prevention program is working. Prevalence reflects existing cases and is less sensitive to short-term program impact.
Q9) Cumulative incidence is otherwise known as ___
a) Attack rate
Cumulative incidence is the proportion of a population that develops a disease over a defined time period. In outbreak settings, this is called the attack rate. It is the same concept applied in epidemic investigations.
Q10) What is the expected pattern of incidence and prevalence when measuring the frequency of an acute infectious disease in a community?
d) Low prevalence and high incidence
Acute diseases resolve quickly (either recovery or death), so cases do not accumulate - prevalence stays low. However, during an outbreak, many new cases occur rapidly, making incidence high. This is the mirror image of chronic disease patterns.
Answer
Here are the answers for Assignment 5: Descriptive Studies:
Q1) Which study design is useful for describing uncommon clinical manifestations of diseases?
c) Both 'a' and 'b' (Case reports AND Case series)
Both case reports (single patient) and case series (a group of similar cases) are specifically designed to document rare or unusual clinical presentations. They are the primary descriptive tools for uncommon manifestations.
Q2) A cross-sectional study can have more than one outcome.
a) True
Cross-sectional studies measure multiple variables simultaneously at a single point in time. There is no restriction to one outcome - they can assess several exposures and outcomes at once, which is one of their advantages.
Q3) The unit of observation in a cross-sectional study is ___
a) Individual
In a cross-sectional study, data is collected from individual people. This distinguishes it from ecological studies, where the unit of observation is a group or population.
Q4) Which of the following can be included in a case report?
d) All the above
Case reports can include unique features/symptoms of a disease, rare manifestations of a common disease, and new or unfamiliar diseases. All three are valid and common reasons to publish a case report.
Q5) Which of the following is the key application of an ecological study? (question partially obscured)
d) All the above
Ecological studies can relate rates of disease to exposure, are useful to test hypotheses, and are useful to study rare diseases (because they use aggregate population data, giving larger numbers). All three are recognized applications.
Q6) A clinician describes a single unusual case of a neurological disorder in detail and publishes it. What is the study design?
b) Case report
A detailed published description of a single patient's unusual or noteworthy presentation is by definition a case report. It is the simplest descriptive study design and does not involve a comparison group.
Answer
Here are the answers for Assignment 6: Analytical Studies:
Q1) Relative risk of more than 1 indicates that the ___
c) Incidence among exposed is higher than among unexposed
Relative Risk (RR) = Incidence in exposed / Incidence in unexposed. RR > 1 means the numerator is larger, so the exposed group has higher incidence - indicating a positive association between exposure and disease.
Q2) All babies born in a particular year will form a birth cohort.
a) True
A birth cohort is defined as a group of people who share a common birth experience within a defined time period. All babies born in a given year sharing the same temporal starting point is the textbook definition of a birth cohort.
Q3) Exposure is assigned by the investigator in which of the following epidemiological studies?
The options are cut off, but the answer is Experimental study (Randomized Controlled Trial). In observational studies (cohort, case-control, cross-sectional), the investigator only observes exposure. Only in experimental studies does the investigator actively assign exposure/intervention.
Q6) All the following are elements of a cohort study, EXCEPT:
c) It involves randomization of participants
Cohort studies are observational - participants are followed based on their naturally occurring exposure status, not randomized. Randomization is a feature of experimental studies (RCTs). Calculating incidence, proceeding from exposure to outcome, and following up participants are all genuine cohort study features.
Q7) All the following are limitations of a case-control study, EXCEPT:
d) It can introduce attrition bias
Attrition bias occurs due to loss to follow-up over time - this is a limitation of cohort studies (which follow people forward), not case-control studies (which are retrospective and do not follow people forward). Recall bias, inability to determine incidence, and difficulty selecting controls are all genuine case-control limitations.
Q9) Multicentric study: 1000 diabetic and 2500 non-diabetic participants recruited, cataract-free at baseline, followed for 10 years to document new cataract cases. What is the study design?
c) Prospective cohort study
Key features pointing to a prospective cohort: participants grouped by exposure (diabetes vs no diabetes), free of outcome at baseline, followed forward in time, and incidence of the outcome (cataract) was measured. No randomization occurred, ruling out experimental study.
Q10) Odds ratio calculation - salt intake and hypertension:
Using the data provided:
- Cases (hypertension, n=600): 100 with high salt intake, 500 without
- Controls (no hypertension, n=600): 30 with high salt intake, 570 without
OR = (a × d) / (b × c) = (100 × 570) / (500 × 30) = 57,000 / 15,000 = 3.8
The odds ratio is 3.8, meaning people with high salt intake have 3.8 times higher odds of hypertension compared to those with low salt intake.Here are the answers for Assignment 7: Experimental Studies:
Q1) Which of the following constitutes the cornerstone of the design of randomized controlled trials?
b) Randomization
Randomization is the defining and most fundamental feature of an RCT. It ensures that both known and unknown confounders are equally distributed between groups by chance, making the comparison valid. Blinding, placebo, and recruitment are important elements but are not the cornerstone.
Q2) Which phase of a clinical trial is referred to as post-marketing surveillance?
d) Phase 4
Phase 4 occurs after a drug has been approved and is in regular use. It monitors long-term safety, rare adverse effects, and effectiveness in the general population under real-world conditions. This is post-marketing surveillance by definition.
Q3) Long-term adverse effects and efficacy of a new drug can be tested in which phase of a clinical trial?
d) Phase 4
Phase 4 (post-marketing surveillance) is the phase where the drug is used in large, diverse, real-world populations over extended periods. This allows detection of rare or delayed adverse effects that were not apparent in the earlier, smaller, shorter phases.
- Phase 1 = safety/dosage in healthy volunteers
- Phase 2 = efficacy and side effects in small patient groups
- Phase 3 = large-scale efficacy vs. standard treatment
Q4) Which of the following can reduce the chance of co-intervention in a clinical trial?
d) Blinding
Co-intervention occurs when participants or caregivers, knowing the treatment assignment, seek or provide additional treatments that can confound results. Blinding (masking the treatment allocation from participants and/or investigators) directly prevents this by keeping everyone unaware of who is receiving what, thus eliminating the motivation for co-intervention.Here are the answers for Assignment 8: Validity of Epidemiological Studies:
Q1) Obtaining an estimate that is generalizable to the study population is referred to as ___
b) Internal validity
Internal validity refers to how accurately a study's results reflect the true association within the study population itself (free from bias and confounding). External validity (generalizability) refers to applying results beyond the study population to other populations. The question asks about generalizability to the study population - which is internal validity.
Q2) Which constitutes any process that tends to produce results that depart systematically from true values?
b) Bias
Bias is defined as any systematic error in a study that causes a departure from the true value. "Systematic" is the key word - it distinguishes bias from chance/random error, which is non-systematic and unpredictable.
Q3) Effect of an exposure is distorted by extraneous factors related to both exposure and outcome. What is this called?
b) Confounding
This is the textbook definition of confounding. A confounder must: (1) be associated with the exposure, (2) be an independent risk factor for the outcome, and (3) not be on the causal pathway. It distorts the observed exposure-outcome relationship.
Q4) Biases can occur during which of the following stages of a research study?
d) Any of the above stages
Bias can enter at every stage - during study design (e.g., selecting a non-representative sample), during implementation (e.g., differential data collection), and during data analysis (e.g., selective reporting). No stage is immune.
Q7) Better recall of exposure only among cases in a case-control study will result in which of the following?
a) Information bias
When cases (who have the disease) remember or report past exposures more thoroughly than controls (who do not), this creates differential misclassification - a type of information bias, specifically recall bias. It is not selection bias because participants are already selected; the distortion arises from how information is reported.
Q8) Crude measure of association in the presence of a confounder is the actual causal association.
b) False
When a confounder is present, the crude (unadjusted) measure of association is distorted - it does not represent the true causal association. The adjusted measure (after controlling for the confounder) is the better estimate of the actual association.
Q9) Which measure(s) is related to ensuring internal validity of a study?
The options are cut off, but the answer relates to controlling for bias and confounding (e.g., randomization, blinding, restriction, matching, or statistical adjustment). These are the methods that protect internal validity by ensuring the results accurately reflect the true association within the study sample.
Answer
Here are the answers for Assignment 9: Qualitative Research:
Q1) All of the following are situations in which qualitative research methods can be used, EXCEPT:
a) Familiar and sufficiently researched matter
Qualitative research is best suited for exploring unknown, poorly understood, or complex phenomena. When a topic is already familiar and sufficiently researched, quantitative methods (which measure and test) are more appropriate. Seeking depth of understanding, exploring behaviours, and viewing social phenomena holistically are all classic indications for qualitative research.
Q2) All of the following statements regarding Participant Observation are true, EXCEPT:
b) Systematic collection of data is easy
Participant observation is a strength for rich, detailed, holistic data - but systematic data collection is actually one of its known limitations/challenges. The observer becomes deeply embedded in the group, analytic methods are not well standardized, and data is very detailed - all true. But the immersive nature makes structured, systematic recording difficult.
Q3) Which qualitative data analysis method uses a theoretical framework as the basis for analysis?
c) Schema Analysis
Schema analysis applies a pre-existing theoretical framework to organize and interpret data. Grounded theory works in the opposite direction - it builds theory from the data (no pre-existing framework). Content analysis counts and categorizes content. Hermeneutics focuses on interpretation of texts/meaning.
Q4) Qualitative and quantitative methods can be used together in research studies.
a) True
This is called mixed-methods research, a well-established and widely used approach. Combining both methods allows researchers to capture numerical data (quantitative) and contextual understanding (qualitative) in the same study, giving a more complete picture.
Q7) A researcher wants to estimate the prevalence of exclusive breastfeeding (quantitative) AND understand myths and taboos associated with breastfeeding (qualitative). Which approach?
c) Mixed-methods study
This scenario explicitly requires two different types of data:
- Estimating prevalence = quantitative (numbers/rates)
- Understanding myths and taboos = qualitative (meanings/beliefs/contexts)
Using both together is the definition of a mixed-methods study.
Q8) Which of the following is NOT a feature of in-depth interviews?
a) It involves two or more participants at a time
In-depth interviews are conducted one-on-one (interviewer and one participant). Involving two or more participants at the same time describes a focus group discussion, not an in-depth interview. Following an interview guide, suitability for sensitive topics, and obtaining rich contextualized information are all genuine features of in-depth interviews.
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