OAT Scientific Reading Comprehension 4 — Questions and Answers
Question 1: A passage presents two competing hypotheses about macular degeneration. The author concludes that Hypothesis B is better supported. Based on the passage, a student should:
- Accept Hypothesis B as the passage's conclusion while recognizing it may be revised with new evidence (Correct answer)
- Reject both hypotheses because science is always uncertain
- Accept whichever hypothesis matches information learned in class
- Conclude that the author has a bias favoring Hypothesis B
Correct answer: Accept Hypothesis B as the passage's conclusion while recognizing it may be revised with new evidence
Scientific conclusions are provisional and passage-based reasoning requires accepting the author's supported conclusion while acknowledging the nature of scientific inquiry.
Question 2: A methods section states: 'Tear osmolarity was measured using osmometry with an intraclass correlation coefficient (ICC) of 0.94.' The ICC value primarily indicates:
- High measurement reliability and consistency across repeated measurements (Correct answer)
- The instrument has 94% accuracy compared to a gold standard
- 94% of subjects produced reliable measurements
- The correlation between tear osmolarity and dry eye severity is 0.94
Correct answer: High measurement reliability and consistency across repeated measurements
ICC near 1.0 indicates excellent test-retest or inter-rater reliability of the measurement instrument.
Question 3: A passage states that lens accommodation amplitude follows a 'monotonically decreasing function' with age. This means:
- Accommodation amplitude decreases consistently with every increase in age, never increasing (Correct answer)
- Accommodation amplitude fluctuates unpredictably with age
- Young patients have the lowest accommodation amplitude
- Accommodation amplitude decreases then plateaus after age 40
Correct answer: Accommodation amplitude decreases consistently with every increase in age, never increasing
A monotonically decreasing function never increases; it either decreases or stays constant at each step.
Question 4: A passage compares observational data showing higher rates of glaucoma in patients using a certain medication. A limitation noted by the authors is 'indication bias.' This refers to:
- Patients prescribed the medication may already have higher disease risk, confounding the association (Correct answer)
- Researchers were biased toward observing glaucoma in the medication group
- The indication for the medication was incorrectly recorded in medical charts
- Patients with glaucoma were excluded from the study
Correct answer: Patients prescribed the medication may already have higher disease risk, confounding the association
Indication bias occurs when a drug is prescribed to sicker patients, making the drug appear harmful even if it is not.
Question 5: A passage includes a Kaplan-Meier survival curve comparing two treatments for preventing visual field loss. The curve that stays higher for a longer period represents:
- The treatment associated with better survival (longer time to visual field loss) (Correct answer)
- The treatment that caused faster disease progression
- The treatment used in a smaller sample
- The control group in all cases
Correct answer: The treatment associated with better survival (longer time to visual field loss)
In a survival curve, higher curves indicate more participants remaining event-free, representing better outcomes.
Question 6: A passage reports a systematic review and meta-analysis of 15 randomized trials on ocular hypertension treatment. Compared to a single RCT, the meta-analysis primarily offers:
- Greater statistical power and more precise effect estimates by pooling data across studies (Correct answer)
- More detailed information about individual patient responses
- Elimination of all confounding variables from the combined studies
- A more recent and updated version of one of the 15 studies
Correct answer: Greater statistical power and more precise effect estimates by pooling data across studies
Meta-analyses pool data from multiple studies, increasing sample size and statistical power while producing more precise overall estimates.
Question 7: A passage discusses a dose-response relationship between UV light exposure and cataract formation. The presence of a dose-response relationship is considered important evidence because:
- It supports a causal relationship between exposure and outcome (Correct answer)
- It proves that UV light is the sole cause of cataracts
- It eliminates the need for a control group
- It shows the minimum effective UV dose for cataract prevention
Correct answer: It supports a causal relationship between exposure and outcome
A dose-response relationship (more exposure = more effect) is one of Bradford Hill's criteria supporting causality.
OAT Scientific Reading Comprehension 4
A passage presents two competing hypotheses about macular degeneration.
The author concludes that Hypothesis B is better supported.
Based on the passage, a student should: