An examiner wants to study two groups of infants for 50 each, CPAP and double tests were performed, in 30 infants CPAP was positive and in 20 bubble test was positive, what should be the test used in this case?
**Core Concept**
The examiner is trying to determine the best test to use for diagnosing a condition in infants, where CPAP (Continuous Positive Airway Pressure) and bubble tests have already been performed. The goal is to identify the most sensitive and specific test to confirm the diagnosis in the remaining infants.
**Why the Correct Answer is Right**
To determine the best test, the examiner needs to calculate the sensitivity and specificity of each test. The bubble test has a higher specificity since it was positive in 20 out of 50 infants, indicating that it is less likely to produce false positives. On the other hand, the CPAP test has a higher sensitivity since it was positive in 30 out of 50 infants, indicating that it is more likely to detect true positives. However, since the examiner wants to confirm the diagnosis in the remaining infants, a test with high specificity is more desirable to avoid false positives.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because high sensitivity is not the primary concern in this scenario. While the CPAP test has a high sensitivity, it also has a high false positive rate, which would lead to unnecessary further testing and potential harm to the infants.
* **Option B:** This option is incorrect because high specificity is not the only factor to consider. The bubble test has a high specificity, but it also has a lower sensitivity, which means it may miss some true positives.
* **Option C:** This option is incorrect because it does not provide a clear direction for the examiner. The examiner needs a specific test, not a general approach.
**Clinical Pearl / High-Yield Fact**
When faced with a diagnostic dilemma, it is essential to consider both the sensitivity and specificity of the tests available. A test with high specificity is more desirable when the goal is to avoid false positives, while a test with high sensitivity is more desirable when the goal is to detect all true positives.
**Correct Answer: D.**