A quasi-experimental pre-posttest control group design, with purposive sampling, was used to recruit participants from the Endocrinology department of a hospital in southern Taiwan from January to May of 2014. The inclusion criteria were (i) being at least 20 years old at the time of recruitment (ii) having no cognitive impairment and severe complications, (iii) being able to express opinions in either Mandarin or Taiwanese, and (iv) having a diagnosis of diabetes. To ensure participants' anonymity, all questionnaires were marked with an encryption code to facilitate data analysis, but with no personal identifiers.