The literature shows that effective Online Patient Education (OPE) site can provide significant benefits to patients with a chronic disease. What remains unclear is which design features make OPE site effective, and which benefits can OPE actually provide. This paper addresses this by i) identifying 29 design features of effective OPE site ii) identifying 13 potential benefits and iii) statistically assessing the validity of both features and benefits using empirical data. The design features were initially classified as: patient tailored information, interactivity, user friendliness, content, and interpretability as necessary design features while the benefits were grouped as health benefits or social benefits. Following pilot testing, 141 patients and carers rated both design features and benefits. An exploratory factor analysis (EFA) was carried out and changes were made to both the design features and the benefits, resulting in more parsimonious and better organized sets of features and benefits.