Excerpt: The conclusions by Zhang et al. (2015) were notable, but the support for the conclusions was not particularly strong because of two issues. The first weakness is that although some studies have found correlations between self-efficacy and pain, the study did not consider the possibility that it is symptom distress that affects self-efficacy in colorectal cancer patients. Rather, it was assumed only that self-efficacy caused reduced symptom effects instead of a reverse or mutual relationship. The study did not consider the possibility that low self-efficacy in those with high symptom distress was actually caused by the distress itself, which is a plausible explanation. In fact, Chiarotto et al. (2014) found that cancer patients on pain medication have higher rates of self-efficacy, which would appear to show that distress reduces self-efficacy, rather than the other way around, as assumed in the above study.