PATIENTS AND METHODS
Patients were recruited from the Department of Nuclear Medicine in China-Japan Union Hospital, Changchun, China, from September 2015 to June 2016. Inclusion criteria were as follows: 1) planning for RIT with a definitive total thyroidectomy record and pathological report; 2) patients from 18 years to 70 years; 3) normal electrocardiography (ECG) and blood pressure. Exclusion criteria included the following: 1) a history of RIT; 2) having metastasis to other organs; 3) having other types of cancer, cardiovascular diseases, endocrine diseases, or mental disorder; 4) declining to participate in this study. This study was approved by the local independent ethics committees and the institutional review boards of China-Japan Union Hospital, Changchun, China, and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all included patients.
Design and random assignment
This study was a two-arm randomized controlled trial. The sample size was estimated by G*Power version 3.1 program with a power (1–β) of 80% and a significance level of 5%. Using an effect size of 0.59 which was reported by related studies, we established that a minimum sample size of 94 patients was required. Allowing for 20% loss to follow-up of sample, 120 patients were randomized 1:1 into the MBSR intervention group or the usual care (UC) group. The allocation sequence was generated by random permuted block randomization (with a block size of 4) conducted using a computer-based system and concealed in sequentially numbered envelopes. Patients were blinded to study hypotheses and had no knowledge of the content of the group to which they were not assigned. The research staff were not blinded to the randomization or patient outcome. The UC group underwent admission education, medication guidance, isolation protection education, and discharge guidance, as they were conventionally performed for these patients. As for the MBSR group, we designed a timetable starting 8 weeks before RIT hospitalization (Figure 1), after which they would become a radioactive source. For these patients, in addition to routine guidance, a brief overview of the MBSR program, emphasizing the 8-week session schedule, was given 8 weeks before RIT hospitalization. All sessions were based on the original 8-week MBSR program that was developed by Kabat-Zinn12 and were adjusted according to the corresponding conditions (Table 1). Each session also included group discussions and individual reports to create an interactive learning environment. The MBSR program was provided by a psychologist who was qualified in delivering mindfulness skills. Prior to the study, we also performed an 8-week pilot feasibility MBSR program with eight patients. The pilot study was designed to help provide the psychologist practice in running the program under clinical supervision and to resolve any potential practical problems.
(To view a larger version of Figure 1, click here.)
(To view a larger version of Table 1, click here.)
The assessments were conducted at three time points, which were the initial baseline that was immediately before the start of MBSR (T1), immediately after RIT hospitalization was concluded (T2), and 3 months after RIT hospitalization (T3).
QoL questionnaire (QLQ)
QoL was assessed using the QoL Questionnaire Core 30 Items (QLQ-C30) of the European Organization for Research and Treatment of Cancer (EORTC), which is a validated, self-reported, cancer-specific measure of QoL, with high functional scores and low symptom scores representing better functioning. It has been translated and validated in 81 languages and is used in more than 3,000 studies worldwide. It consists of five functional dimensions (eg, physical, emotional, cognitive, social, and role), three symptomatic dimensions (including pain, fatigue, and nausea), and other dimensions, such as insomnia, appetite, and economic burden. The scoring has been linearly transformed to a 0–100 scale according to the EORTC scoring manual.
Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale (SAS)
The level of depression and anxiety was assessed by the Zung SDS and the Zung SAS, respectively. Each scale contains 20 items based on a 0–4 scale, with a higher score indicating a higher level of anxiety or depression. The possible range of scores was 0–80 for each scale.
Statistical analysis was performed using MedCalc software (version 17.4.4; Broekstraat, Mariakerke, Belgium). Comparisons of categorical variables were performed with either chi-squared test or Fisher’s exact test as appropriate. Student’s t-test was used for normally distributed continuous variables, and the Mann–Whitney U test was used for non-normally distributed continuous variables. Linear mixed models were used to assess the interaction between patients’ assignment (UC group vs MBSR group) and time (T1, T2, and T3) in relation to QoL, SDS, and SAS scales, testing whether the rate of scale change varied by study assignment. Linear mixed models were also used to account for baseline differences. P<0.05 was considered to indicate statistical significance for all analyses. Cohen’s d was calculated for the evaluation of effect size.