I need help from the experts... my research will be conducted in health facilities that deals with tuberculosis patients. the study population is among TB patients newly diagnosed in health facilities. I planned to conduct a quasi-experimental study to assess the effectiveness of intervention in improving adherence to anti-tuberculosis medication where the outcome variable is dichotomous (adhered/ non adherence) based on calculation of percentage of medication ingested. intervention will be conducted at 8 weeks, with pre and post test evaluation. How do I calculate the sample size?