Moderating effect of sense of coherence on the relationship between symptom distress and health-related quality of life in patients receiving cancer chemotherapy

This study is aimed at examining the buffering effect of sense of coherence (SOC) on symptom distress during cancer drug therapy, which thereby affects health-related quality of life (QoL), and obtaining suggestions for promoting supportive care. We investigated health-related QoL (SF-8), symptom distress (using the Symptom Distress Scale (SDS)), and SOC (the SOC 13-item Scale) in 66 patients receiving adjuvant chemotherapy for non-small cell lung cancer. We employed descriptive statistics to seek the correlation of each variable; then, a hierarchical multiple regression analysis was conducted with SF-8 score as the dependent variable. Results showed that significant changes in bodily pain showed a buffering effect on the SDS and sense of comprehensibility (β = − 0.658, p < 0.01, β = − 0.319, p < 0.05), sense of manageability (β = − 0.658, p < 0.01, β = 0.398, p < 0.01), and meaningfulness (β = − 0.658, p < 0.01, β = − 0.257, p < 0.05). Significant changes in general health perception showed a buffering effect on the SDS and sense of manageability (β = − 0.406, p < 0.01, β = 0.329, p < 0.05). As a result of the simple inclination test, SOC proved to be effective under high levels of symptom distress; the buffering effect of sense of manageability was reversed regarding bodily pain; and when meaningfulness was lower, it had a positive effect on QoL. This study revealed that SOC exerts a buffering effect in situations where symptoms are highly painful. It also revealed that the effect of SOC was reversed for bodily pain and that a high SOC had a negative effect on QoL.