Medres LE1

What is medical research? | A. Administrative reporting of hospital finances and staffing. | B. Personal judgment about treatment without systematic investigation. | C. Systematic investigation of health questions to improve care and public health. | D. Routine recording of patient symptoms without a research question.

C. Systematic investigation of health questions to improve care and public health.

What does basic research study? | A. Biological mechanisms and processes. | B. Treatment effects and health outcomes in human participants. | C. Patient experiences and meanings through interviews. | D. Healthcare access and service delivery across populations.

A. Biological mechanisms and processes.

What does clinical research study? | A. Molecular pathways only in laboratory systems. | B. Health and interventions in humans. | C. Chemical properties only in cell-free experiments. | D. Gene functions only in nonhuman laboratory models.

B. Health and interventions in humans.

What did James Lind study? | A. Dietary treatments for diabetes; insulin was beneficial. | B. Placebo treatments for rheumatism; quassia was compared. | C. Antibiotic treatments for tuberculosis; streptomycin was beneficial. | D. Dietary treatments for scurvy; citrus was beneficial.

D. Dietary treatments for scurvy; citrus was beneficial.

What is the main principle of the Nuremberg Code? | A. Mandatory participation and restrictions on withdrawal. | B. Voluntary informed consent and the right to withdraw. | C. Public benefit overriding all participant autonomy. | D. Physician consent replacing participant consent.

B. Voluntary informed consent and the right to withdraw.

What does the Declaration of Helsinki address? | A. Rules for pooling effect sizes across clinical trials. | B. Ethical principles for medical research involving humans. | C. Standards for indexing medical articles in databases. | D. Criteria for grading the certainty of review evidence.

B. Ethical principles for medical research involving humans.

What are the three main research ethics principles? | A. Respect for persons, statistical power, and novelty. | B. Randomization, blinding, and allocation concealment. | C. Respect for persons, beneficence, and justice. | D. Feasibility, precision, and scientific relevance.

C. Respect for persons, beneficence, and justice.

What does respect for persons mean? | A. Distribute research burdens and benefits fairly. | B. Minimize harm and improve the benefit-to-risk balance. | C. Select participants according to ease of recruitment alone. | D. Respect autonomy, obtain consent, and protect vulnerable participants.

D. Respect autonomy, obtain consent, and protect vulnerable participants.

What does beneficence mean? | A. Distribute participation opportunities and benefits fairly. | B. Minimize harm and seek a favorable benefit-to-risk balance. | C. Prioritize scientific benefit regardless of participant harm. | D. Protect autonomous decisions and voluntary withdrawal.

B. Minimize harm and seek a favorable benefit-to-risk balance.

What does justice mean in research? | A. Fair distribution of research burdens and benefits. | B. Independent consent and voluntary withdrawal from research. | C. Reduction of harm through favorable benefit-to-risk balance. | D. Identical interventions for everyone regardless of eligibility.

A. Fair distribution of research burdens and benefits.

What was a major ethical problem in the Tuskegee study? | A. Deception and withholding effective treatment. | B. Premature publication before completing data analysis. | C. Failure to randomize participants between two effective treatments. | D. Failure to calculate sample size before recruitment.

A. Deception and withholding effective treatment.

What is an independent variable? | A. The predictor, exposure, or intervention being examined. | B. The probability threshold used to reject a hypothesis. | C. The response measured after exposure or intervention. | D. The numerical summary of a study's uncertainty.

A. The predictor, exposure, or intervention being examined.

What is a dependent variable? | A. The criterion used to select eligible participants. | B. The predictor or intervention being examined. | C. The statistic chosen to summarize precision. | D. The measured outcome.

D. The measured outcome.

In a study of sleep and memory, what is the independent variable? | A. Memory retention. | B. Sleep duration. | C. Change in recall performance. | D. Memory test score.

B. Sleep duration.

In a study of sleep and memory, what is the dependent variable? | A. Memory retention. | B. Sleep duration. | C. Average nightly sleep hours. | D. Assigned sleep-duration group.

A. Memory retention.

What is nominal data? | A. Equal-interval measurements without a true zero. | B. Equal-interval measurements with a true zero. | C. Ranked categories with unequal or unknown spacing. | D. Categories without ranking.

D. Categories without ranking.

What measurement scale is blood type? | A. Ordinal. | B. Ratio. | C. Nominal. | D. Interval.

C. Nominal.

What is ordinal data? | A. Categories without any ordering. | B. Equal-interval measurements with a true zero. | C. Ranked categories without necessarily equal spacing. | D. Equal-interval measurements without a true zero.

C. Ranked categories without necessarily equal spacing.

What measurement scale is a satisfaction rating? | A. Interval. | B. Ratio. | C. Nominal. | D. Ordinal.

D. Ordinal.

What is interval data? | A. Categories without ordering. | B. Numerical data with equal intervals but no meaningful true zero. | C. Ordered categories without necessarily equal spacing. | D. Equal-interval measurements with a meaningful true zero.

B. Numerical data with equal intervals but no meaningful true zero.

What measurement scale is Celsius temperature? | A. Interval. | B. Ordinal. | C. Nominal. | D. Ratio.

A. Interval.

What is ratio data? | A. Numerical data with equal intervals and a meaningful true zero. | B. Equal-interval measurements without a meaningful true zero. | C. Categories without ranking. | D. Ranked categories without necessarily equal spacing.

A. Numerical data with equal intervals and a meaningful true zero.

What measurement scale is weight? | A. Ordinal. | B. Nominal. | C. Ratio. | D. Interval.

C. Ratio.

Does a zero on a rating scale automatically make it ratio data? | A. No; a zero alone does not establish meaningful ratios. | B. Yes; any numerical scale starting at zero is ratio data. | C. Yes; assigning numbers guarantees equal intervals and meaningful ratios. | D. No; any scale containing zero must be nominal data.

A. No; a zero alone does not establish meaningful ratios.

What is discrete quantitative data? | A. Countable numerical values, such as number of admissions. | B. Unranked categories, such as blood type. | C. Measurements along an uninterrupted range, such as weight. | D. Ranked categories, such as satisfaction levels.

A. Countable numerical values, such as number of admissions.

What is continuous data? | A. Ordered categories, such as satisfaction ratings. | B. Unranked categories, such as citizenship. | C. Countable whole-number values, such as admissions. | D. Measurements along a range, such as weight or blood pressure.

D. Measurements along a range, such as weight or blood pressure.

What does qualitative research explore? | A. Numerical differences between group means using statistical tests. | B. Experiences, meanings, and situations through descriptions. | C. Effect sizes pooled statistically across clinical trials. | D. Event probabilities and risk ratios through numerical analysis.

B. Experiences, meanings, and situations through descriptions.

What does quantitative research analyze? | A. Interview themes without numerical measurement or statistical analysis. | B. Personal impressions without organized data collection. | C. Numerical measurements and counts using statistics. | D. Experiences and meanings primarily through narrative interpretation.

C. Numerical measurements and counts using statistics.

What do descriptive studies do? | A. Test predefined exposure-outcome relationships as their main purpose. | B. Assign treatments randomly to establish intervention effects. | C. Pool effect sizes from previously published trials. | D. Describe disease by person, place, and time; generate hypotheses.

D. Describe disease by person, place, and time; generate hypotheses.

What do analytical studies do? | A. Only document an unusual patient's clinical course. | B. Only describe cases by person, place, and time. | C. Only list database sources without analyzing relationships. | D. Test relationships between factors and outcomes.

D. Test relationships between factors and outcomes.

What is a case report? | A. A description of several patients with shared features. | B. A follow-up of exposed and unexposed groups. | C. A comparison of cases and controls for prior exposure. | D. A description of one patient or unusual clinical event.

D. A description of one patient or unusual clinical event.

What is a case series? | A. A randomized comparison of intervention and control. | B. A description of several patients with similar features. | C. A description of one unusual patient. | D. A comparison of cases and controls for earlier exposure.

B. A description of several patients with similar features.

What is a major limitation of case reports and case series? | A. Inability to describe unusual clinical features. | B. Usually no comparison group and limited generalizability. | C. Mandatory randomization that limits recruitment. | D. Excessively long follow-up required for every report.

B. Usually no comparison group and limited generalizability.

What is a cross-sectional study? | A. Selects by disease status and compares previous exposures. | B. Measures exposure and outcome at one point in time. | C. Randomly assigns treatment and compares outcomes. | D. Classifies exposure and follows future outcomes.

B. Measures exposure and outcome at one point in time.

Which design commonly measures prevalence? | A. Prospective cohort study. | B. Cross-sectional study. | C. Randomized controlled trial. | D. Case-control study.

B. Cross-sectional study.

What is a major limitation of cross-sectional studies? | A. Outcome information must always come from future follow-up. | B. The temporal order of exposure and outcome is often unclear. | C. Random allocation always prevents real-world application. | D. Exposure can never be measured.

B. The temporal order of exposure and outcome is often unclear.

What is a case-control study? | A. Classifies people by exposure and follows subsequent outcomes. | B. Measures exposure and outcome at one time. | C. Randomly assigns an intervention before observing outcomes. | D. Selects people by outcome and compares their prior exposures.

D. Selects people by outcome and compares their prior exposures.

Which design is useful for rare diseases? | A. Randomized controlled trial. | B. Case-control study. | C. Cross-sectional study. | D. Prospective cohort study.

B. Case-control study.

What biases are important in case-control studies? | A. Allocation concealment failure and unblinded random assignment. | B. Recall bias and selection bias. | C. Publication bias and funnel-plot asymmetry. | D. Random-sequence generation failure and treatment crossover.

B. Recall bias and selection bias.

What is a cohort study? | A. Randomly assigns people to an intervention. | B. Classifies people by exposure and compares subsequent outcomes. | C. Selects people by disease status and compares past exposure. | D. Measures prevalence during a single survey.

B. Classifies people by exposure and compares subsequent outcomes.

Which design can measure incidence? | A. Cross-sectional prevalence survey. | B. Case-control study. | C. Cohort study. | D. Case series.

C. Cohort study.

What is a prospective cohort study? | A. Classifies exposure now and follows outcomes into the future. | B. Uses historical records to trace exposure to completed outcomes. | C. Measures exposure and outcome only at one time. | D. Selects cases and controls and compares previous exposures.

A. Classifies exposure now and follows outcomes into the future.

What is a retrospective cohort study? | A. Classifies current exposure and follows new outcomes into the future. | B. Uses historical records to follow exposure to outcomes that already occurred. | C. Selects participants by outcome and compares earlier exposure. | D. Measures all participants during one current survey.

B. Uses historical records to follow exposure to outcomes that already occurred.

How does a retrospective cohort differ from case-control? | A. Both always select participants by current disease status. | B. Both require random assignment to exposure groups. | C. Cohort selects by outcome; case-control selects by exposure. | D. Cohort selects by exposure; case-control selects by outcome.

D. Cohort selects by exposure; case-control selects by outcome.

What is attrition? | A. Loss of participants to follow-up. | B. Selective publication of favorable studies. | C. Systematic differences during participant recruitment. | D. Incorrect recollection of earlier exposure.

A. Loss of participants to follow-up.

What is a randomized controlled trial? | A. Measures exposure and outcome during one survey. | B. Classifies naturally occurring exposure and follows outcomes. | C. Selects cases and controls and compares exposure history. | D. Randomly assigns an intervention and compares outcomes with a control group.

D. Randomly assigns an intervention and compares outcomes with a control group.

What does randomization help reduce? | A. All random error through elimination of sampling variation. | B. Selection bias and confounding through balance on average. | C. All attrition by guaranteeing complete follow-up. | D. All publication bias by requiring favorable results.

B. Selection bias and confounding through balance on average.

Which design is usually strongest for testing treatment efficacy? | A. Cross-sectional study. | B. Case-control study. | C. Case series. | D. Randomized controlled trial.

D. Randomized controlled trial.

Which design studies obesity prevalence in a city now? | A. Cross-sectional study. | B. Retrospective cohort study. | C. Case-control study. | D. Randomized controlled trial.

A. Cross-sectional study.

Which design compares past smoking in cancer cases and controls? | A. Prospective cohort study. | B. Cross-sectional study. | C. Case-control study. | D. Randomized controlled trial.

C. Case-control study.

Which design follows vaccinated and unvaccinated people for new disease? | A. Case series. | B. Cohort study. | C. Case-control study. | D. Cross-sectional study.

B. Cohort study.

What does a comparison test ask? | A. Whether a single patient's experience is unusual. | B. Whether a study's allocation was concealed. | C. Whether groups differ. | D. Whether a database contains duplicate titles.

C. Whether groups differ.

What does correlation assess? | A. Whether variables are related. | B. Whether a treatment was randomly allocated. | C. Whether a relationship must be causal. | D. Whether every group has identical means.

A. Whether variables are related.

What does regression assess? | A. Whether a literature search contains duplicate records. | B. Whether all variables must be unrelated. | C. Whether exposure was concealed during recruitment. | D. How an outcome relates to one or more predictors.

D. How an outcome relates to one or more predictors.

Does correlation or regression alone prove causation? | A. No; an association alone does not establish causation. | B. Yes; correlation proves causation when there are more than two groups. | C. Yes; regression adjustment eliminates every possible source of bias. | D. Yes; a significant association alone establishes causation.

A. No; an association alone does not establish causation.

Which test compares means of two independent groups? | A. One-sample t-test. | B. Unpaired t-test. | C. Repeated-measures ANOVA. | D. Paired t-test.

B. Unpaired t-test.

Which test compares two paired measurements? | A. One-way ANOVA. | B. Unpaired t-test. | C. Paired t-test. | D. One-sample t-test.

C. Paired t-test.

Which test compares a sample mean with a reference value? | A. Unpaired t-test. | B. One-sample t-test. | C. Paired t-test. | D. One-way ANOVA.

B. One-sample t-test.

Which test compares three or more independent group means? | A. Paired t-test. | B. One-way ANOVA. | C. Repeated-measures ANOVA. | D. One-sample t-test.

B. One-way ANOVA.

Which test compares three or more related measurements? | A. Unpaired t-test. | B. One-way ANOVA. | C. Repeated-measures ANOVA. | D. Kruskal-Wallis test.

C. Repeated-measures ANOVA.

What is the nonparametric alternative to an unpaired t-test? | A. Friedman test. | B. Kruskal-Wallis test. | C. Mann-Whitney U test. | D. Wilcoxon signed-rank test.

C. Mann-Whitney U test.

What is the nonparametric alternative to a paired t-test? | A. Friedman test. | B. Mann-Whitney U test. | C. Kruskal-Wallis test. | D. Wilcoxon signed-rank test.

D. Wilcoxon signed-rank test.

What is the nonparametric alternative to one-way ANOVA? | A. Friedman test. | B. Mann-Whitney U test. | C. Kruskal-Wallis test. | D. Wilcoxon signed-rank test.

C. Kruskal-Wallis test.

What is the nonparametric test for three or more related measurements? | A. Kruskal-Wallis test. | B. Wilcoxon signed-rank test. | C. Friedman test. | D. Mann-Whitney U test.

C. Friedman test.

What does two-way ANOVA examine? | A. Two factors and their interaction. | B. Two measurements from the same participant only. | C. Three related measurements using ranks only. | D. One sample mean compared with a reference value.

A. Two factors and their interaction.

What distinguishes parametric from nonparametric methods? | A. Whether outcomes are considered clinically important. | B. Their statistical assumptions; nonparametric methods often use ranks. | C. Whether the study was registered before recruitment. | D. Whether the sample resembles its target population.

B. Their statistical assumptions; nonparametric methods often use ranks.

What is evidence-based medicine? | A. Using research evidence, clinical expertise, and patient values to guide care. | B. Using clinical experience alone without appraising research. | C. Using research evidence alone while ignoring patient preferences. | D. Using patient preference alone regardless of evidence or expertise.

A. Using research evidence, clinical expertise, and patient values to guide care.

What are the three Es of evidence-based medicine? | A. Expectations, extraction, and estimation. | B. Expertise, ethics, and exposure. | C. Evidence, expertise, and expectations. | D. Evidence, efficiency, and eligibility.

C. Evidence, expertise, and expectations.

What does expectations refer to in evidence-based medicine? | A. Patient preferences, concerns, and values. | B. The investigator's prediction of statistical significance. | C. The expected number of articles retrieved by a search. | D. The journal's requirements for manuscript formatting.

A. Patient preferences, concerns, and values.

What are the three core skills of evidence-based medicine? | A. Acquire, appraise, and apply evidence. | B. Extract, standardize, and pool outcomes. | C. Randomize, blind, and conceal allocation. | D. Compile, deduplicate, and screen records.

A. Acquire, appraise, and apply evidence.

What five steps are listed in the appraisal lecture? | A. Acquire, Abstract, Allocate, Analyze, Author. | B. Ask, Allocate, Adjust, Analyze, Approve. | C. Assess, Ask, Acquire, Appraise, Apply. | D. Assess, Assign, Audit, Analyze, Accept.

C. Assess, Ask, Acquire, Appraise, Apply.

What does directness assess? | A. Whether the effect estimate is statistically precise. | B. Whether study methods adequately control bias. | C. Whether the study matches the clinical question. | D. Whether treatment is affordable in the patient's setting.

C. Whether the study matches the clinical question.

What does validity assess? | A. Whether methods and results are credible and bias is controlled. | B. Whether the patient prefers one intervention over another. | C. Whether the study question exactly matches the clinical problem. | D. Whether treatment is affordable and acceptable to the patient.

A. Whether methods and results are credible and bias is controlled.

What does applicability assess? | A. Whether the journal has a high citation count. | B. Whether the article has a sufficiently recent publication date. | C. Whether evidence fits the patient and setting. | D. Whether statistical analysis alone proves causation.

C. Whether evidence fits the patient and setting.

What does individualizing results mean? | A. Excluding all studies with unfavorable outcomes. | B. Replacing evidence with the patient's preferences alone. | C. Using the pooled estimate unchanged for every patient. | D. Adjusting interpretation for the patient's characteristics and baseline risk.

D. Adjusting interpretation for the patient's characteristics and baseline risk.

What is shared decision-making? | A. Letting statistical significance determine treatment automatically. | B. Applying research conclusions without discussing trade-offs. | C. Discussing evidence and trade-offs with the patient to choose care. | D. Choosing treatment solely from the clinician's preference.

C. Discussing evidence and trade-offs with the patient to choose care.

What does a diagnostic accuracy study assess? | A. How well a test identifies disease compared with a reference standard. | B. How a disease progresses over a long follow-up period. | C. Whether an intervention improves outcomes under controlled conditions. | D. How often an intervention causes adverse events.

A. How well a test identifies disease compared with a reference standard.

What is a reference standard? | A. The newest test being evaluated for possible clinical use. | B. The average result of all tests regardless of validity. | C. The best available method for determining disease status. | D. The least expensive test available in the clinic.

C. The best available method for determining disease status.

Which design commonly assesses diagnostic accuracy? | A. Case-control study of past occupational exposure only. | B. Cross-sectional comparison of an index test and reference standard. | C. Randomized trial of two drug treatments only. | D. Case series describing patients with positive tests only.

B. Cross-sectional comparison of an index test and reference standard.

What is screening? | A. Testing asymptomatic people for disease before symptoms appear. | B. Following diagnosed patients to estimate survival. | C. Monitoring treated patients for adverse reactions. | D. Testing symptomatic patients to explain an existing complaint.

A. Testing asymptomatic people for disease before symptoms appear.

Why is diagnostic accuracy different from screening benefit? | A. Screening must also improve important outcomes and account for harms. | B. Any accurate test automatically reduces population mortality. | C. Screening benefit is measured only by reference-standard agreement. | D. Screening benefit depends only on the number of positive results.

A. Screening must also improve important outcomes and account for harms.

What are possible harms of screening? | A. Complete follow-up, better precision, and reduced confounding. | B. Randomization, allocation concealment, and blinded assessment. | C. True negatives, earlier treatment, and lower mortality. | D. False positives, overdiagnosis, anxiety, and unnecessary procedures.

D. False positives, overdiagnosis, anxiety, and unnecessary procedures.

What is prognosis? | A. The effect of treatment under ideal controlled conditions. | B. The presence of disease during a single prevalence survey. | C. The accuracy of a test compared with a reference standard. | D. The likely course and outcomes of a disease over time.

D. The likely course and outcomes of a disease over time.

Which design is commonly used for prognosis? | A. Case series without follow-up. | B. Case report. | C. Cohort study. | D. Cross-sectional prevalence survey.

C. Cohort study.

What is efficacy? | A. How frequently studies with positive results are published. | B. How well an intervention works under controlled conditions. | C. How accurately a test identifies a disease. | D. How well an intervention works in routine clinical practice.

B. How well an intervention works under controlled conditions.

What is effectiveness? | A. How well an intervention works under ideal controlled conditions. | B. How well an intervention works in usual practice. | C. How closely an index test matches a reference standard. | D. How strongly exposure is recalled by cases.

B. How well an intervention works in usual practice.

What do harms studies assess? | A. Diagnostic accuracy against a reference standard. | B. Population prevalence during a single survey only. | C. Adverse events and unintended effects of interventions. | D. Therapeutic benefit under optimal conditions only.

C. Adverse events and unintended effects of interventions.

What is post-marketing surveillance? | A. Monitoring interventions after release for rare or long-term harms. | B. Monitoring database retrieval during a literature search. | C. Testing a drug's benefit only before regulatory approval. | D. Registering a systematic review before screening.

A. Monitoring interventions after release for rare or long-term harms.

What is a systematic review? | A. An explicit, structured search, appraisal, and synthesis of relevant studies. | B. Statistical pooling without a systematic search or appraisal. | C. An informal overview without predefined study-selection methods. | D. A randomized experiment conducted on newly recruited patients.

A. An explicit, structured search, appraisal, and synthesis of relevant studies.

What is a meta-analysis? | A. Narrative description of a single unusual patient. | B. Independent screening of titles and abstracts. | C. Prospective monitoring of an exposed patient group. | D. Statistical combination of compatible study results.

D. Statistical combination of compatible study results.

Must every systematic review contain a meta-analysis? | A. Yes; pooling is required even when the studies are incompatible. | B. Yes; statistical pooling is required to make any review systematic. | C. No; a review can synthesize evidence without statistical pooling. | D. Yes; including two or more studies always requires pooling.

C. No; a review can synthesize evidence without statistical pooling.

What does PEO stand for? | A. Patient, Effectiveness, Observation. | B. Protocol, Exposure, Odds. | C. Population, Evaluation, Objective. | D. Population, Exposure, Outcome.

D. Population, Exposure, Outcome.

What does PICO stand for? | A. Patient, Index, Causation, Objective. | B. Protocol, Intervention, Confidence, Observation. | C. Population, Intervention, Comparison, Outcome. | D. Population, Incidence, Cohort, Odds.

C. Population, Intervention, Comparison, Outcome.

What does T add to PICOT? | A. Test accuracy. | B. Time period. | C. Trial registration. | D. Treatment allocation.

B. Time period.

What is a primary outcome? | A. Any outcome reported only after analysis is complete. | B. An additional outcome unrelated to the main study objective. | C. The main outcome the study is designed to assess. | D. The outcome with the smallest p value regardless of the protocol.

C. The main outcome the study is designed to assess.

What is a secondary outcome? | A. The outcome used to decide who enters the study. | B. An outcome selected only because it is statistically significant. | C. The single main outcome the study is designed to assess. | D. An additional outcome providing further information.

D. An additional outcome providing further information.

What does FINER stand for? | A. Factual, Interesting, Normalized, Explicit, Reliable. | B. Focused, Indexed, Novel, Experimental, Randomized. | C. Feasible, Interesting, Novel, Ethical, Relevant. | D. Feasible, Important, Numerical, Efficient, Reproducible.

C. Feasible, Interesting, Novel, Ethical, Relevant.

What makes a research question feasible? | A. Adequate participants, expertise, resources, time, and manageable scope. | B. Its findings have never been discussed before. | C. Its results are expected to reach statistical significance. | D. Its answer could directly change clinical policy.

A. Adequate participants, expertise, resources, time, and manageable scope.

What makes a research question novel? | A. It protects participants within acceptable ethical limits. | B. It confirms, refutes, or extends prior findings. | C. It influences health policy or patient management. | D. It can be completed with available participants and resources.

B. It confirms, refutes, or extends prior findings.

What makes a research question relevant? | A. It extends a previously studied scientific finding. | B. It produces a small p value in every analysis. | C. Its answer may influence practice, policy, or future research. | D. It can be completed within the available budget.

C. Its answer may influence practice, policy, or future research.