Strengths and limitations
colorectal cancer, distortions like recall
COLORECTAL CANCER
The study population was clearly defined due to the survivors’ participation in an earlier RCT [Being aware of potential distortions like recall and hindsight bias [We applied a data-driven approach to categorize patients’ responses to open-ended questions, used a pair of independent raters that have been trained in the category system and had a third methodologist available to reach consensus and establish a high degree of interrater congruence. This objective, data-driven method to analyse verbal data avoids the subjectivity of a purely “qualitative analysis”. Nevertheless, each category will contain a range of similar but of course not entirely identical perspectives. However, the high congruence with regards to content between the frequencies of the different categories and the frequencies of the most common words within the patients’ answers is an indicator of a high degree of objectivity.There are also some limitations: As a consequence of using a mailed survey instead of face-to-face interviews, the qualitative answers were sometimes short and enquiry for further explanation was not possible. On the other hand, a mailed survey has the advantage of a lower likelihood of social desirability than in interviews, the avoidance of an interviewer’s possible influence, and the accessibility of a larger sample of participants. Furthermore, it has to be acknowledged that out of the original 220 patients enrolled in the RCT, only n = 96 were available for this analyses. This certainly had an impact on relative distribution of answer categories. Thus, our results represent the perspectives of colorectal cancer patients who have still been alive at the time of this follow-up study and were also willing to participate.