A comparison of qualitative and quantitative research methods used to assess knowledge of foot care among people with diabetes.

Many diabetes-related pathologies, especially among neuropathic patients, are potentially avoidable. Prevention, however, requires appropriate knowledge and understanding. To assess our ability to effect change in behaviour we need adequate tools to measure not only knowledge but also understanding and change of behaviour. To assess individuals' knowledge and beliefs towards diabetic footcare, we used both quantitative and qualitative methods: a structured questionnaire composed of 20 questions was completed by the respondent, followed by a semi-structured interview conducted by the chiropodist. Results from the structured questionnaire were inconsistent with those from the interviews (Wilcoxon test, p < 0.008). The former demonstrated an average knowledge score of 45% while performance during the interview generated data which suggested poorer knowledge levels. Respondents who correctly identified a series of statements regarding diabetic footcare within the questionnaire could not then apply this knowledge meaningfully when interviewed. A structured questionnaire may not be the best means of assessing patients' knowledge and understanding. We need not only to improve patient education regarding footcare, but also to improve our means of measuring patient knowledge and understanding, more accurately to assess the success or otherwise of our interventions.