Data analysis
Data were analyzed using SPSS version 18 (IBM SPSS®Statistics for Windows; IBM Corp, Armonk, New York, USA). Both descriptive and inferential statistics were applied for the data analysis. The 95% confidence intervals (CIs) for each mean were also calculated. Chi-square was used to compare the incidence of hyperkalemia between different factors. Univariate and multivariate logistic regression analyses were conducted to determine the association between risk factors and development of co-trimoxazole-induced hyperkalemia and compute adjusted and unadjusted odd ratios (ORs). The factors included in the multivariate logistic regression analysis were: age, gender, total daily dose (the once and twice daily doses of the double strength (DS) tablet 800/160 mg) and the co-administered medications. The level of statistical significance was defined as p≤ 0.05.