Power is the probability that a study will reject the null hypothesis. difference between the null and alternative hypotheses. level of significance, and the null vs. alternative difference. a numeric example of power and sample size estimation for the one-sample case.
During the procedure the patient is unconscious and unaware of the need to urinate. After the procedure, however, it may not be safe for the patient to walk. They may be too sick to take care of their own bathroom needs or their surgeon may feel that a catheter is best for their particular recovery.
A urinary catheter tube drains urine from your bladder. You may need a catheter because you have urinary incontinence (leakage), urinary retention (not being able to urinate), prostate problems, or surgery that made it necessary. Clean intermittent catheterization can be done using clean techniques.