A:

1. The nurse reviews the patient's medical history and notes

that he has been prescribed several medications for his

COPD, including a long-acting beta-agonist (LABA), an

inhaled corticosteroid (ICS), and a short-acting

bronchodilator (SABA). The nurse wants to evaluate the

effectiveness of these medications for the patient. Which of

the following sources of evidence would provide the most

reliable and valid information for this purpose?

a) A systematic review of randomized controlled trials

(RCTs) that compare different combinations of COPD

medications

b) A narrative review of observational studies that describe

the outcomes of COPD patients using different medications

c) A case report of a single patient who had a positive

response to a specific combination of COPD medications

d) A clinical practice guideline that summarizes the

recommendations for COPD management based on expert

opinion

Answer: A. A systematic review of RCTs is the highest

level of evidence for evaluating the effectiveness of

interventions, as it synthesizes the results of multiple

studies that have minimized bias and confounding factors.

A narrative review, a case report, and a clinical practice

guideline are lower levels of evidence, as they may not be

based on rigorous methods, may not be generalizable to

other patients, or may not reflect the current state of