In this study, the levels of distress and anxiety of PTC patients after receiving CBT-HEP intervention gradually and significantly relieved with the extension of time. Although the level of depression was also gradually decreased, but there was no statistically significant difference between the post-intervention and the six-month follow-up. In patients who did not receive CBT-HEP intervention, only distress and depression were significantly relieved during a certain period of time. The post-intervention questionnaire was administered prior to posttreatment whole-body iodine imaging. At this time, worry about the effectiveness of treatment and the discomfort of prolonged freedom restriction may be the main causes of increased anxiety and depression before discharge. In addition, when comparing the two groups of patients, the CBT-HEP intervention was effective and rapid in helping PTC patients to reduce their distress, anxiety and depression. However, when using chi-square tests to validate the results, CBT-HEP was found to be ineffective in alleviating depression, possibly because some patients' PHQ-9 scores decreased, but they were still higher than or equal to 5, which cannot be defined as depression remission.
In the critical factor analysis of distress and quality of life for all participants, women, living alone, hypothyroidism, negative emotions, tingling in the hands/feet, concern about treatment effectiveness and radiation safety were found to be the main factors leading to severe distress. Severe distress, hypothyroidism, and hoarseness were the main factors leading to decreased quality of life. In addition, most PTC patients suffer from severe insomnia and fatigue. In practice, personalized care for patients with the above characteristics, such as CBT-HEP intervention, can help PTC patients improve their quality of life as much as possible given the limited medical resources in China.
Relatively few studies have been conducted on interventions to alleviate psychological problems in thyroid cancer patients. A study  implemented in 60 patients with thyroid cancer found that psychological and behavioral intervention was effective in reducing patients' anxiety and depression. A study  conducted on 120 patients with thyroid cancer found that mindfulness-based stress reduction could also significantly alleviate the anxiety and depression of patients. Another studies [13, 14] using a psychological nursing intervention also found that psychological distress, depression and anxiety could be significantly reduced. All of the above studies are generally consistent with the findings of this paper. We cannot say that CBT-HEP intervention is necessarily superior to the above interventions, but we have innovatively added scientific knowledge to our intervention, which may have a longer lasting positive impact on patients given the limited nursing resources in China.
Some studies have found that gender , negative emotions [9, 25, 26], and hypothyroidism  would significantly affect the DT score and quality of life in patients with thyroid cancer, which is consistent with our research results. However, some studies thought age  and employment status  would significantly affect the DT score or that any demographic variables were not associated with DT scores in patients with thyroid cancer . These outcomes are inconsistent with our research results. The reasons for the inconsistency may be related to the different ethnicities of these studies and the different independent variables included in the multifactorial analysis. In addition, our study found a novel point that patients' concerns about the effects of 131I treatment and radiation safety can lead to severe distress. We should be aware that most patients in China have a low level of education and are unable to actively access the correct and relevant information, so it is necessary to convey relevant knowledge to patients in China.
Regarding the quality of life of patients with thyroid cancer, a previous study  suggested that role function was the best and the cognitive function was the worst for thyroid cancer patients, which is consistent with this study. Some studies [29, 30] found that in the field of symptoms, fatigue was the most serious, followed by insomnia, which is slightly different from the findings of this study. The reasons for the inconsistency may be related to different lifestyles and races. The above article  also found occupation, education, income, marital status, physical activity, fruit intake, and type of surgery could significantly affect the quality of life of patients with thyroid cancer, which is not entirely consistent with this study. We did not find that marital status, physical activity, fruit intake, or type of surgery could significantly affect the quality of life. This may be because the independent variables included in the two studies were different; for example, we included hoarseness, hypothyroidism and DT scores, which could lead to inconsistent findings.
There are many limitations in this trial, such as: the small sample included in this trial; it was a single-center trial; the type of pathology included was single, only PTC; the independent variables included in the analysis were not comprehensive enough, for example, variables such as economic income and exercise were not included; in the intervention trial, the follow-up period was too short.
As the number of thyroid cancer patients increases, their quality of life is an issue that cannot be ignored. Our research can raise awareness of this issue, and medical staff can use the new psychological intervention method to help thyroid cancer patients relieve their psychological problems and improve their quality.