Noninvasive Positive-Pressure Ventilation In COPD

Which car do you want?

Which car do you want?

Which study do you choose? And Why?

Therapy(single trial) Is this evidence valid? Is this valid evidence important? Can we apply this valid, important evidence in caring for our patient?

Validity Randomization Randomization concealment Similarity at the start Long and complete follow up Intention to treat analysis Blindness-patient, clinician, study personnel Equal treatment except experimental Tx.

Importance Relative risk reduction(RRR) Absolute risk reduction(ARR) (CER-EER)/CER Absolute risk reduction(ARR) CER-EER Number needed to treat(NNT) 100/ARR Magnitude and precision of Tx. effect

Applicability Patient’s difference Feasibility of Tx. Potential Benefit and Harm from Tx. Our patient’s value and expectation