Analysis of Anxiety and Influencing Factors in Kidney Transplant Recipients and General Public During the COVID-19 Pandemic

Background

SARS-CoV-2, an RNA virus transmitted through the respiratory tract, has sustained its global presence since its initial identification in China in 2019. Research has demonstrated a correlation between the prevalence of SARS-CoV-2 and an elevated incidence of major depression and anxiety [1]. Anxiety was more elevated than depression.

Due to long-term immunosuppressive medication, suppressed immune function, and high comorbidity in kidney transplant recipients, COVID-19 pose a 4–10 times greater risk of fatality within this specific population compared to the general population [2]. Given the high morbidity and mortality rates and low health-related quality of life [3] in kidney transplant recipients, it is imperative to give special consideration to their mental well-being. Few studies have examined the psychological state of kidney transplant patients during the COVID-19 epidemic, especially in China. This peak of COVID-19 infection was more concentrated, strained healthcare resources, and meant that kidney transplant patients would have frequent recurrent COVID-19 infections in the future, which had a greater psychological impact on people. Although the mental health of kidney transplant patients is often overlooked, we believe it is important to understand the psychological state of these patients during this peak period of COVID-19 transmission, because kidney transplant patients may be worse off psychologically than the general public.

We used a currently widely used self-measurement scale for anxiety invented in 1971 called the Self-Rating Anxiety Scale (SAS) [4]. In this study, the anxiety of kidney transplant patients was assessed and compared with the general public through the SAS scale. The influencing factors affecting anxiety in kidney transplant patients and the general public were also analyzed. Our goal was to better understand the anxiety status of kidney transplant patients at the beginning of the COVID-19 Omicron variant pandemic and to provide targeted psychological interventions in the follow-up.

Material and Methods

STUDY POPULATION:

This retrospective study investigated data obtained from 203 kidney transplant recipients and 53 individuals from the general population who participated in an online survey questionnaire. All kidney transplant recipients who were regularly followed up in our center and individuals from the general population who completed the questionnaire were included in the study. Individuals with incomplete responses were excluded from the study.

DATA COLLECTION:

Data collection was carried out through online survey questionnaires, which can be completed on a mobile device or computer. The link to the questionnaire was distributed by means of a doctor-patient communication group in the chat software or by scanning a code at the outpatient clinic visit. The survey was conducted from December 14^th to 16^th, 2022.

STUDY VARIABLES:

Gender, age, BMI, smoking history, chronic illnesses, time since transplantation, kidney function, COVID-19 vaccination status, history of prior COVID-19 infection, and the SAS anxiety self-evaluation scale were collected in this study. Individuals answered a maximum of 54 questions in this questionnaire.

SAS SCALE:

The SAS scale was used to evaluate anxiety levels across all cohorts. We calculated the total score by summing the scores assigned to each of the 20 items contained within the SAS scale (with 5 of them processed in reverse). The total score was multiplied by a factor of 1.5, and the integer component was taken as the standard score. Based on the standard score, anxiety levels were then classified as mild (50–59 points), moderate (60–69 points), or severe (70 points or higher).

STATISTICAL METHODS:

Continuous variables were reported as median (interquartile range), and categorical variables were analyzed using the χ² test. The t test was used for between-group comparisons of continuous variables, and the chi-square (χ²) test was used for between-group comparisons of categorical variables. Nonparametric tests were used for between-group comparisons of ordered categorical variables. P values less than 0.05 were considered statistically significant.

Results

BASELINE:

To elucidate the primary factors influencing anxiety levels among patients, we conducted a retrospective analysis of the baseline characteristics of 203 kidney transplant recipients and 53 individuals from the general population during the initial phases of the COVID-19 pandemic. The Cronbach’s alpha coefficient for the SAS questionnaire was determined to be 0.815 for the 256 kidney transplant recipients and general populations.

Table 1 shows the baseline characteristics of the kidney transplant recipients and general populations. The general population exhibited a statistically significant younger age compared to the kidney transplant recipients (P<0.001). Moreover, the prevalence of diabetes and cardiovascular disease was significantly lower in the general populations (P<0.001 and P=0.013, respectively). In terms of COVID-19 vaccination, 92.5% of individuals from the general populations and 10.3% of the kidney transplant recipients had received at least 1 dose of the COVID-19 vaccine, with a significant difference between the 2 groups. Furthermore, the 2 groups demonstrated a significant dissimilarity in terms of COVID-19 infection rates (P<0.001).

ANXIETY LEVELS IN KIDNEY TRANSPLANT RECIPIENTS AND GENERAL POPULATION:

Figure 1 presents the anxiety grading and scores of the kidney transplant recipients and individuals from the general population. Among the 203 kidney transplant recipients, 28 (13.8%) individuals exhibited varying degrees of anxiety, with a SAS score of 40.5±9.04. Of these, 21 individuals experienced mild anxiety, whereas 4 experienced moderate anxiety and 3 experienced severe anxiety. Among the 53 individuals from the general population, 9 individuals (17.0%) had varying degrees of anxiety, with a SAS score of 39.64±10.73. Of these, 6 individuals had mild anxiety, 2 had moderate anxiety, and 1 had severe anxiety.

Our finding indicates no significant difference in anxiety grading (P=0.557) or SAS scores (P=0.593) between the kidney transplant recipients and individuals form the general population.

FACTORS AFFECTING PSYCHOLOGICAL ANXIETY IN KIDNEY TRANSPLANTATION AND GENERAL POPULATIONS:

We examined the impact of various factors on psychological anxiety levels in 203 kidney transplant recipients, as presented in Table 2. The influence of different factors on SAS scores were evaluated. Among the total kidney transplant recipients, 65 individuals were infected with COVID-19, and no statistically significant difference was observed in the SAS score (P=0.080) or anxiety levels (P=0.083) between infected and uninfected patients. There was no significant difference in scores between the senior group aged over 60 years and the group under 65 years old (P=0.313). The 12 cases of second transplants and 31 cases of living donor transplants had no significant impact on SAS scores (P=0.512, 0.890). The mean eGFR of kidney transplant patients was 91.92±33.14 (95% CI: 87.33–96.50) mL/(min*1.73 m2). We found no linear correlation between eGFR and SAS scores. We divided the patients into 2 groups based on the time of transplantation at the 1-, 5-, and 10-year marks, respectively, and compared their SAS scores. We found no significant effect of transplantation time on SAS scores at these 3 time points (P=0.948,0.444,0.840). Additionally, 10 patients received immune shock therapy, such as ATG, hormones, and rituximab, within 6 months, and the SAS scores of these 10 patients were not significantly different from the others (P=0.829).

We also analyzed the impact of various factors on the psychological anxiety in the general population consisting of 53 cases. It was observed that females had significantly higher standard scores and anxiety level grading than males. Among females, 5 cases displayed mild anxiety, 1 case of moderate anxiety, and 1 case of severe anxiety. In contrast, among male participants, there was 1 case each of moderate and severe anxiety (P=0.026). The standard score was 43.22±12.03 in females and 36.90±8.88 in males (P=0.032). Furthermore, individuals with chronic respiratory diseases showed elevated levels of anxiety following the current wave of the epidemic. Among the 53 cases in the general population, 2 individuals had chronic respiratory disease, and their standard scores were 57 and 60 for mild and moderate anxiety, respectively. This distinction in anxiety classification (P=0.023) and standard score (P=0.010) was found to be statistically significant when compared to the group without respiratory disease. Infection with COVID-19 had no significant impact on patients’ scale standard scores (P=0.539) or anxiety ratings (P=0.356). Furthermore, age, BMI, diabetes mellitus, cardiovascular disease, and the number of vaccinations had no significant impact on patient anxiety levels. Regression analysis revealed that respiratory disease was an independent risk factor for patient anxiety scores.

Discussion

STUDY LIMITATIONS:

There are many limitations to this study. The first is that the online questionnaire approach of this study produces bias in the survey population. Both kidney transplant patients and individuals in the general public were significantly younger in this study. Despite the current popularity of the internet and smart devices, older people still have difficulty using smart devices, which led to the lack of data from the older age group in our study. Some studies have shown that age is an influential factor in individual anxiety, with younger people more likely to be anxious than older people [1]. Therefore, age bias may have had an impact on the results of our study. Although we attempted to increase the number of older participants by advising and instructing patients to complete the questionnaire in the outpatient clinic, this was clearly insufficient to correct for bias. In addition, because our investigation was conducted at the peak of COVID-19 infection, the vast majority of individuals presented with varying degrees of symptoms of infection, and we believe that more symptomatic individuals were less likely to participate in our investigation; therefore, our study included few critically ill patients, which is confirmed by the very low hospitalization and mortality rates in this study.

There are similar geographical limitations to our research. As our center is located in the northern region of China, the patients in the study were mainly from the northern region of China, while the number of patients from the southern region was small. Thus, our study was also geographically biased.

This study also suffers from insufficient sample size and follow-up. Since this study explored the psychological state at the beginning of the COVID-19 pandemic, we chose the time of the study to be around half a month into the outbreak. It was difficult to ensure an adequate sample size in a short period of time through online methods, so we also invited patients who were regularly prescribed immunosuppressants to complete the questionnaire at the clinic, although only for kidney transplant patients. Follow-up is also necessary. However, the follow-up of our survey is ongoing and not yet conclusive.

Conclusions

Our study found that the kidney transplant group had less anxiety than we expected during this peak of COVID-19 infection, even better than the general population, and was more stable. Therefore, we need to pay more attention to the treatment of infections and complications in kidney transplant patients in the future. However, there is still a need for continued attention to and support for the mental health of kidney transplant recipients.