KMU Past Paper Practice

Question:

A nephrologist notices several patients presenting within three months with a similar unusual renal syndrome after using the same unregulated herbal preparation. He publishes the clinical findings of all 12 patients without including a comparison group. Which study design best describes this report?

Options:

Correct Answer:
Case series

Explanation: A case series describes several patients with a similar condition or exposure without a formal comparison group and is mainly useful for describing patterns and generating hypotheses.

Question:

A researcher studies ten years of hypertension admissions using hospital records that were originally collected for routine patient care. How should the information used in this research be classified?

Options:

Correct Answer:
Secondary data

Explanation: The information already existed before the present research and was collected for another purpose, so it is secondary rather than newly collected primary data.

Question:

Investigators prepare a complete numbered list of all eligible households in a town and use a computer-generated random-number sequence to select households for a health survey. Which sampling method is being used?

Options:

Correct Answer:
Simple random sampling

Explanation: Selection is made directly from the complete sampling frame by a random process, giving eligible units a defined chance of selection.

Question:

A health service offers testing for a disease only to workers with a recognized occupational exposure that places them at substantially increased risk. Which screening approach is being used?

Options:

Correct Answer:
Selective screening

Explanation: Selective or high-risk screening targets groups with a greater probability of disease rather than screening the whole eligible population.

Question:

During one community health visit, asymptomatic adults undergo blood-pressure measurement, blood glucose testing and visual assessment as part of the same programme. Which type of screening does this represent?

Options:

Correct Answer:
Multiphasic screening

Explanation: Multiphasic screening applies several screening tests during the same screening encounter to assess more than one health condition.

Question:

After a wedding meal, public-health investigators identify the guests who consumed a particular dish and determine the proportion who developed acute gastroenteritis during the following day. Which epidemiological measure is most appropriate?

Options:

Correct Answer:
Attack rate

Explanation: An attack rate is a short-term incidence proportion used to describe how many people at risk develop disease during an outbreak or similar defined exposure episode.

Question:

A six-month community survey counts every person who had depression at any time between January and June, including those already affected in January and those diagnosed later in the interval. Which measure is being estimated?

Options:

Correct Answer:
Period prevalence

Explanation: Period prevalence includes all individuals who had the condition at any time during the specified interval, whether disease was present at the start or developed later.

Question:

A district report calculates deaths among residents aged 60–69 years during one year and uses the total district population aged 60–69 years as the denominator. Which mortality measure has been calculated?

Options:

Correct Answer:
Age-specific death rate

Explanation: Both numerator and denominator are restricted to the same age group, making this an age-specific rather than crude mortality measure.

Question:

A provincial programme offers the same screening test to all adults within a defined eligible age range without first separating them according to individual risk factors. Which screening approach does this represent?

Options:

Correct Answer:
Mass screening

Explanation: Mass screening is offered broadly to a defined population group rather than being limited to individuals selected because of increased risk.

Question:

A published report describes 18 patients who developed the same neurological syndrome after a suspected environmental exposure. The investigators suggest the exposure may be associated with the syndrome. Which feature most limits their ability to estimate the strength of this association?

Options:

Correct Answer:
Absence of a comparison group

Explanation: A case series lacks a suitable unexposed or unaffected comparison group, so it can suggest a hypothesis but cannot reliably quantify an exposure–disease association.

Question:

A researcher records environmental temperature in degrees Celsius for each study location. Equal numerical differences have equal meaning, but zero degrees Celsius does not represent complete absence of temperature. Which measurement scale best applies?

Options:

Correct Answer:
Interval scale

Explanation: An interval scale has equal intervals between values but lacks a true absolute zero, as illustrated by temperature measured in degrees Celsius.

Question:

Body weight is recorded in kilograms during an epidemiological survey. The measurement has equal intervals and a meaningful zero, allowing statements such as one value being twice another. Which scale is most appropriate?

Options:

Correct Answer:
Ratio scale

Explanation: Ratio-scale measurements have equal intervals and a true zero, so meaningful ratios between values can be interpreted.

Question:

To estimate vaccination coverage, investigators randomly select 20 villages from a district and then survey every eligible household within each selected village. Which sampling technique is best represented?

Options:

Correct Answer:
Cluster sampling

Explanation: Naturally occurring groups such as villages are selected first, and individuals within those selected clusters are then studied.

Question:

A hospital-based study enrolls every patient who fulfills the eligibility criteria and presents to the outpatient clinic during the study period until the required sample size is reached. Which sampling method is being used?

Options:

Correct Answer:
Consecutive sampling

Explanation: Consecutive sampling includes each eligible participant encountered in sequence during a defined period until the desired sample is obtained.

Question:

An investigator plans to recruit 100 participants, specifying in advance that 50 should be men and 50 women. Individuals are then approached non-randomly until each target number is filled. Which sampling method is being used?

Options:

Correct Answer:
Quota sampling

Explanation: Quota sampling sets predetermined numbers for specified categories but selects individuals within those categories without a probability-based random process.

Question:

In a multicentre survey, different teams initially use slightly different methods to measure blood pressure. The investigators want to minimize systematic measurement differences between study sites. Which action is most appropriate?

Options:

Correct Answer:
Standardize measurement procedures and train observers

Explanation: Standardized definitions, equipment use and observer training reduce systematic differences in measurement and therefore help prevent information bias.

Question:

During a case-control study, an interviewer knows which participants are cases and repeatedly asks the cases more detailed questions about previous occupational exposure than the controls. Which error is most directly introduced?

Options:

Correct Answer:
Interviewer bias

Explanation: Knowledge of disease status changes how exposure information is obtained, causing a systematic difference in measurement between cases and controls.

Question:

Investigators compare average dietary salt consumption and average hypertension prevalence across 25 districts. No individual person’s salt intake is linked directly with that person’s blood pressure status. Which study design is being used?

Options:

Correct Answer:
Ecological study

Explanation: Both exposure and outcome are measured at the district or group level rather than being linked within individual participants, which defines an ecological design.

Question:

A public-health team deliberately introduces a structured health-education programme in selected communities and compares subsequent outcomes with communities receiving the standard programme. Which broad category of epidemiological study does this represent?

Options:

Correct Answer:
Experimental study

Explanation: The investigators actively assign an intervention and then compare outcomes, distinguishing an experimental study from purely observational designs.

Question:

A health report states that among notified cases of a condition there were 240 male cases and 120 female cases, and expresses this relationship as 2:1. Which basic form of epidemiological measurement is being used?

Options:

Correct Answer:
Ratio

Explanation: A ratio compares one quantity directly with another; unlike a proportion, the numerator does not need to be contained within the denominator.