Sample size was determined based on logistic regression. The recommended sample size for each group was at least 10 observations per estimated parameter.26 Since this study included 15 predictors, the minimum sample size for each group was 150. There were two outcome category groups: controlled and uncontrolled blood pressure groups so the total sample size was 300. To allow for incomplete data on some participants, 60 participants (approximately 20% of the sample) were added resulting in a final sample size of 360.