Mail follow-up of chronic diseases in northeast Thailand

The use of mailed questionnaires to follow patients with chronic diseases was investigated in 650 patients from 16 provinces of northeastern Thailand who sought care at the University Hospital. The overall response rate to the first mail follow-up was 73.2%. If all three mail follow-ups were considered, up to 86.6% of all patients responded. The demographic variables appeared to be similar between the respondents and the non-respondents. Cancer and deterioration of disease status had an adverse effect on the response rate. Utilization of peripheral health centres to supplement mail follow-up in these sub-populations was suggested. Almost 78% of 650 patients were followed and interviewed to assess the validity of mailed response. The percentages of respondents and non-respondents who were followed were almost identical. Of the 504 patients followed, 92% were located. The successful location was over 98% for the respondents and only 54% for non-respondents. The agreement of some parameter such as death and survival time after discharge was very high between mail and intensive follow-up data. Less distinctive events had lower agreement rates. Some precautionary notes were voiced and the possibility of extension of mail follow-up in collection of information and supervision of health care was suggested.