Factors Associated With Physical Inactivity of Recipients of a Kidney Transplant: Results From the ADHERE BRAZIL Multicenter Study

Abstract

Objective

Physical activity is recommended for recipients of a kidney transplant. However, ADHERE BRAZIL study found a high prevalence (69%) of physical inactivity in Brazilian recipients of a kidney transplant. To tackle this behavior, a broad analysis of barriers is needed. This study aimed to identify factors (patient and transplant center levels) associated with physical inactivity among recipients of a kidney transplant.

Methods

This was a subproject of the ADHERE BRAZIL study, a cross-sectional, multicenter study of 1105 recipients of a kidney transplant from 20 kidney transplant centers. Using a multistage sampling method, patients were proportionally and randomly selected. Applying the Brief Physical Activity Assessment questionnaire, patients were classified as physically active (≥150 min/wk) or physically inactive (<150 min/wk). On the basis of an ecological model, 34 factors associated with physical inactivity were analyzed by sequential logistic regression.

Results

At the patient level, physical inactivity was associated with smoking (odds ratio = 2.43; 95% CI = 0.97–6.06), obesity (odds ratio = 1.79; 95% CI = 1.26–2.55), peripheral vascular disease (odds ratio = 3.18; 95% CI = 1.20–8.42), >3 posttransplant hospitalizations (odds ratio = 1.58; 95% CI = 1.17–2.13), family income of >1 reference salary ($248.28 per month; odds ratio = 0.66; 95% CI = 0.48–0.90), and student status (odds ratio = 0.58; 95% CI = 0.37–0.92). At the center level, the correlates were having exercise physiologists in the clinical team (odds ratio = 0.54; 95% CI = 0.46–0.64) and being monitored in a teaching hospital (undergraduate students) (odds ratio = 1.47; 95% CI = 1.01–2.13).

Conclusions

This study identified factors associated with physical inactivity after kidney transplantation that may guide future multilevel behavioral change interventions for physical activity.

Impact

In a multicenter sample of recipients of a kidney transplant with a prevalence of physical inactivity of 69%, we found associations between this behavior and patient- and center-level factors. At the patient level, the chance of physical inactivity was positively associated with smoking, obesity, and patient morbidity (peripheral vascular disease and hospitalization events after kidney transplantation). Conversely, a high family income and a student status negatively correlated with physical inactivity. At the center level, the presence of a dedicated professional to motivate physical activity resulted in a reduced chance of physical inactivity. A broad knowledge of barriers associated with physical inactivity can allow us to identify patients at a high risk of not adhering to the recommended levels of physical activity.

Introduction

For patients with stage 5 chronic kidney disease (CKD), kidney transplantation promotes increased survival and improves quality of life, in addition to being more cost-effective than other renal replacement therapies.^1,2 Recipients of a kidney transplant depend on continuous treatment, with periodic consultations, daily and regular use of medications, and active behavior modification in their care, including changes in lifestyle.^3–5 Of these behaviors, much attention is directed to the use of immunosuppressive agents, because the negative impact of lack of adherence to these drugs is well established.^4,6 Self-management after kidney transplantation also includes the promotion of health behaviors such as smoking cessation and being physically active as the posttransplant risk of cardiovascular diseases and cancer increases because of the side effects of immunosuppressive agents and pretransplant comorbidities.^3,6,7 Low levels of physical activity are a major modifiable risk factor for cardiovascular diseases and mortality in this population.^8–10

Physical inactivity (ie, lack of achievement of physical activity recommendations for health)^11,12 has a high prevalence worldwide, 1.6% to 71.2%, depending on the country.¹³ It is generally higher in women and at older ages.¹³ Importantly, it is a modifiable risk factor for chronic diseases.¹³ The prevalence of adequate physical activity is low among patients with CKD, especially in dialysis programs.^8,14 After kidney transplantation, although improvements in functional capacity occur, approximately 22% to 89% still remain physically inactive, depending on the classification used, for example, by direct methods or estimated through questionnaires.^8,14–16

The impact of physical inactivity of recipients of a kidney transplant has been the focus of a few research studies.^8,16 Low levels of physical activity are associated with a high prevalence of obesity and diabetes, high risk of cardiovascular events, and high cardiovascular and all-cause mortality.^9,16–20 Intervention studies focused on evaluating the effect of physical activity-promoting strategies found improved muscle and physical performance, as well as increased cardiorespiratory fitness, muscle strength, mobility, cardiovascular function, walking capacity, and quality of life.^18,21–26 Although there is increasing evidence regarding the reduction in cardiovascular risk in recipients of a kidney transplant after adopting regular physical exercises, the impact on the graft and patient survival remains undefined.^16,27 However, intervention studies with exercise training for increasing physical activity have involved small samples with a short follow-up and have usually evaluated only intermediate outcomes, such as physical performance.^24–26,28 In addition to the type, intensity, and duration of an exercise training program directed to recipients of a kidney transplant, the factors limiting the effectiveness of these interventions deserve better exploration.^16,19,28

Physical inactivity is the result of multilevel factors. Therefore, an ecological perspective considering patient-level, microlevel (health care professionals and social support), mesolevel (health care organization), and macrolevel (health care system) factors can be applied to understand physical inactivity.^29,30 Furthermore, most studies exploring factors associated with physical inactivity only focused on patient-level correlates, such as demographics (age and sex), disease patterns (time on dialysis) or morbidity (peripheral vascular disease), patient’s perceived barriers (fear of movement, lack of motivation, health concerns, and weather conditions), and psychological factors (depression).^{14,16,31–33} Therefore, a broad evaluation of the factors associated with the physical inactivity of recipients of a kidney transplant is needed, particularly at the center level.³¹ The evaluation of the center-level variables is essential to identify modifiable targets for facility-level intervention.

The ADHERE BRAZIL study, which included 1105 recipients of a kidney transplant from 20 Brazilian kidney transplantation centers, was primarily developed to evaluate adherence to immunosuppressive agents but also focused on other health behaviors, such as appointment attendance and physical inactivity.^34–36 We reported a high prevalence of physical inactivity (69%) in the ADHERE BRAZIL participants.³⁵ The objective of the present subanalysis of ADHERE BRAZIL was to identify multilevel determinants of physical inactivity of recipients of a kidney transplant.

Methods

Study Design

This study is a subproject of ADHERE BRAZIL, a multicenter cross-sectional study in Brazil, a country that has the second-highest number of kidney transplantations in the world. The ADHERE BRAZIL study was registered on the ClinicalTrials.gov website (NCT02066935) and in the Open Science Framework platform (https://osf.io/). We performed a secondary analysis of the available collected data. The methods of ADHERE BRAZIL were previously reported.³⁴

Sample Setting

The sample size of ADHERE BRAZIL was calculated using the Open Epi program for a population frequency study to evaluate lack of adherence to immunosuppressive agents.³⁴ Although it was not specifically calculated to assess the prevalence of physical inactivity (varies from 22% – 89%), the applied estimated prevalence of 50% resulted in the largest ideal sample size.^8,14–16

We applied a multistage sampling strategy by including a convenience sample of 20 from the 86 active Brazilian transplant centers, representing all regions of the country and having different levels of transplant activity, types of hospitals, and compositions of transplant teams. Inclusion criteria for transplant centers were: performed at least 10 kidney transplantations per year in the last 5 years before the study and consent form signed by the director of the center. Patients were randomly selected among those who attended routine visits. The inclusion criteria were aged of >18 years, >1 year since kidney transplantation, use of a measurable immunosuppressive agent, and signing of the informed consent form.³⁴ Patients without cognitive ability to answer the physical activity assessment tool were excluded.

Physical Inactivity

Physical activity was assessed using the Brief Physical Activity Assessment Tool.³⁷ This is a short self-report instrument consisting of 2 questions, transculturally adapted for use in Portuguese with satisfactory psychometric properties (κ coefficient = 0.41; agreement of 71% with accelerometer).^37,38 The questions are about the kind and frequency of physical activity. The patient was classified as physically active if engaged in physical activity for 150 minutes or more per week and as physically inactive if weekly physical activity was <150 minutes.^11,12,34

Factors Associated With Physical Inactivity

We followed an ecological model to select factors potentially associated with physical inactivity. This model proposes hierarchical relationships of interactions wherein the patients are influenced by factors beyond the patient characteristics, such as health care professionals, health services, and health policies^29,30 (Fig. 1). The variable selection for this substudy followed our theoretical assumptions³⁰ and empirical evidence regarding physical activity in patients with CKD, including recipients of a kidney transplant,^{14,16,19,20,31,32,39–42} as well as the available variables in the ADHERE BRAZIL dataset. The current substudy was limited to patient- and center-level (mesolevel) variables because of the absence of suitable variables at the microlevel and macrolevel in the overarching ADHERE BRAZIL study.

The following 23 patient-level variables were included: sociodemographic factors—age (years), sex (male vs female), education level (0–4, 4–8, 8–11, or >11 years of study), race (White vs not White), marital status (with vs without a stable partner), occupation (student vs not a student), family income (<1 reference salary [US $248.28 per month] vs >1), and religion (yes vs no); clinical factors—etiology of CKD, pretransplant treatment modality (hemodialysis, peritoneal dialysis, or preemptive transplantation) and its length (months), comorbidities (hypertension, diabetes, peripheral vascular disease, coronary artery disease, and heart failure), graft function (creatinine and estimated glomerular filtration rate), category of CKD, episodes of acute rejection, and number of hospitalizations after kidney transplantation (up to 3 vs >3); factors related to transplantation—transplant vintage (years; up to 5 years vs >5 years), type of donor (living vs deceased), and immunosuppressive agents; and behavioral factors—body mass index (up to 25, overweight [25–30], or obese [>30]), and smoking (yes vs no). Mesolevel (center-level) variables were (total of 11) as follows: center activity (number of transplants per year: low [0–50], moderate [50–150], or high [>150]), number of beds (up to 150, 150–500, or > 500), satisfaction with the number of professionals (score, 0–100), satisfaction with the structure of the waiting room (yes vs no), difficulty in accessing the center by public transportation (yes vs no), teaching hospital (hospital providing undergraduate medical education or postgraduate medical, nursing, or multiprofessional residency training), and specific professionals (exercise physiologist or physical therapist) dedicated to exercise in the team.^{14,16,19,20,31,32,39–42}

Data Collection

Data collection procedures have been previously described.³⁴ In brief, patient data were collected by a structured questionnaire applied by an interview by trained local research coordinators who also extracted clinical data from patient medical files using structured forms. Regarding center-level data, a nominated representative of the transplant center completed the structured questionnaire during the same period of patient data collection. All data collection was performed using the Research Electronic Data Capture (RedCap) system. The project was approved by the Ethics Research Board of the University Hospital of Federal University of Juiz de Fora (CAAE 27972914.1.1001.5133, approval number 691.120) and by the ethics research boards of the other participating centers.³⁴

Data Analysis

Variables are presented as percentages, mean and SD, and 95% CIs. We evaluated the association between physical inactivity and explanatory variables using simple logistic regression analysis and robust variance estimators, considering a possible clustering between centers. Subsequently, explanatory variables that met the following criteria were selected for multiple logistic regression analysis: an odds ratio of ≤0.75 or ≥1.25 and a P value of ≤.20.³⁶ Eleven variables were eligible for the multiple model, 9 at the patient level (marital status, being a student, family income, hypertension, peripheral vascular disease, posttransplant hospitalization, use of everolimus, obesity, and smoking) and 2 at the center level (teaching hospital with undergraduate students and presence of an exercise physiologist in the team).

The multivariate analysis also used the same binary logistic regression. A hierarchical approach was used, following the ecological model, for multilevel analysis. First, we analyzed the relationships between variables at the patient level (block 1) and physical inactivity. Then, variables with an odds ratio of ≤0.75 or ≥1.25 and a P value of ≤ .20 were selected for the next step. In the second step, the relationships between the patient-related variables selected from the first analysis added with the mesolevel variables (block 2) were analyzed and the final model was generated. A Hosmer-Lemeshow goodness-of-fit test was used to test model adequacy; P values of >.20 indicated a good model fit. All analyses were performed using STATA (version 15; StataCorp LLP, College Station, TX, USA).

Role of the Funding Source

The funders played no role in the design, conduct, or reporting of this study.

Results

In the sample of 1105 patients (Fig. 2), 58.5% were male, the mean age was 47.6 (SD = 12.6) years, and 51.4% were White. Most reported a stable partner (59.9%), had a family income higher than 1 reference salary (74.6%), and had at least 8 years of schooling (85.1%). Most patients underwent hemodialysis (93%) before transplantation and had undergone kidney transplantation at least 5 years ago (51.2%) from a deceased donor (65.2%). The graft function, as expressed by a glomerular filtration rate of 58.0 (SD = 0.75) mL/min/1.73 m², was good. Hypertension was frequent (72.2%), and 18.7% of patients were obese (Tab. 1). Patients were mainly from centers of low (38.2%) or moderate (36%) kidney transplantation activity and located in large hospitals (53.6%). Most centers had teaching activities, but less than half hired specific professionals for physical activity orientation (Tab. 1; Suppl. Table 1).

The final model of the multivariate analysis included 6 variables at the patient level and 2 at the mesolevel (transplant center). At the patient level, we found association with modifiable behavioral factors (obesity and smoking), nonmodifiable factors such as comorbidities (peripheral vascular disease and number of hospitalization events after transplantation), and socioeconomic factors (family income and occupation as a student). At the mesolevel, physical inactivity correlated to the composition of the multidisciplinary team and being monitored in a teaching hospital (Tab. 2).

Patients with a family income above 1 reference salary had a 34% reduction in the association with physical inactivity (odds ratio = 0.66; 95% CI = 0.48–0.90; P = .01), and in those who were students, the reduction was 42% (odds ratio = 0.58; 95% CI = 0.37–0.92; P = .019). Conversely, smokers were more than 2 times more likely to be physically inactive (odds ratio = 2.43; 95% CI = 0.97–6.06; P = .058), and obese patients were almost twice as likely to be physically inactive (odds ratio = 1.79; 95% CI = 1.26–2.55; P < .001). Patients with peripheral vascular disease were 3 times more likely to be physically inactive (odds ratio = 3.18; 95% CI = 1.20–8.42; P = .021), and those with more than 3 posttransplant hospitalizations were 1.5 times more likely to be physically inactive (odds ratio = 1.58; 95% CI = 1.17–2.13; P = .003). At the mesolevel, there was a negative association between physical inactivity and the presence of an exercise physiologist as a member of the team, which reduced the chance of the patient being physically inactive by 46% (odds ratio = 0.54; 95% CI = 0.46–0.64; P < .001). Conversely, when a patient was monitored in a medical undergraduate teaching hospital, the odds of that patient being physically inactive increased by almost 1.5 times (odds ratio = 1.47; 95% CI = 1.01–2.13; P = .041) (Tab. 2).

Discussion

Physical inactivity is a risk factor for poor outcomes after kidney transplantation.^9,16–20 By understanding physical inactivity from a multilevel perspective, we provide the basis for developing multilevel interventions to target this risk factor in care after kidney transplantation. This multicenter study strengthens the much-needed evidence base on physical inactivity using an ecological perspective addressing multilevel factors, thus moving beyond the most studied patient-related variables so far.^14,16,31,40 In addition to social, behavioral, and variables reflecting patient morbidity (patient variables), physical inactivity was associated with aspects of practices of the transplant center (exercise physiologists as part of the team and teaching hospital), thus indicating that both levels are related to physical inactivity. Notably, this was one of the largest studies that evaluated physical inactivity after kidney transplantation.^10,14,40 A strength of the present study is the representativeness of our multistage sample, which ensured the inclusion of different types of transplant centers regarding the number of transplants performed and location in areas with various socioeconomic characteristics.³⁴

At the patient level, recipients of a kidney transplant with a higher family income were less physically inactive, as described by other authors who observed an inverse association between income and sedentary time, both in recipients of a kidney transplant and in the general population.^39,43 Family income may reflect increased health control, including better adherence to treatment, dietary adequacy, and functional capacity, which may influence the level of physical activity of patients.^44,45 Being a student was also associated with a lower chance of physical inactivity. In general, this group is younger and performs more activities than full-time workers in routine life, whether through daily, sports or leisure activities, or commuting to the school.⁴⁶

As in the general population and for other chronic diseases, some factors that are not connected with the practice of regular exercise, such as smoking and obesity, were associated with physical inactivity.^42,47 However, few studies have evaluated the relationship between these factors and physical activity of recipients of a kidney transplant, with various results.^14,25,28,48 Masiero et al evaluated 6055 recipients of a kidney transplant and observed an association between obesity and the lowest level of self-reported physical activity.⁴⁰ In another study that evaluated the level of physical activity with an accelerometer, an increase in the body mass index of 1 point was associated with an increase in sedentary time of 2.66 min/d.³⁹

The presence of physical limitations, comorbidities, and fear of some type of damage to health are recognized as barriers to the practice of physical activity after kidney transplantation.^14,16,41 Peripheral vascular disease is a prevalent comorbidity in patients with CKD and was also associated with physical inactivity in our study, as reported by others.^14,49 In fact, ischemic symptoms in the lower limbs may limit exercise participation in patients with peripheral vascular disease. Gardner et al observed that patients with intermittent claudication had a shorter total walking time and fewer steps, especially at moderate- and high-intensity activities.⁴⁹ Nevertheless, frequent hospitalization after kidney transplantation, which reflects poor physical functioning and health status, was associated with physical inactivity.⁹ Both poor physical functioning and the number of comorbidities, another measure of health status, were closely associated with a sedentary lifestyle after kidney transplantation.^14,18,41

At the center level, a lack of expertise or specific advice and prescriptions by health care professionals about the need and possibility of physical exercises has been scarcely reported.^33,46,50 Patients who are monitored by teams in which there is an exercise physiologist have a lower chance of being physically inactive. The exercise physiologist, more than other health care professionals, recognizes the importance of physical activity assessment and knows how to guide the patient in an individualized and efficient way.⁵⁰ The importance of the presence of an exercise physiologist in the treatment of patients with CKD was reported in a recent study that evaluated adherence and the reasons for not participating in an intradialytic exercise program.⁵¹ The presence of an exercise professional increased patient adherence to an exercise program by more than 2 times compared to that for sessions without an exercise professional.⁵¹ Therefore, despite the limited number of exercise professionals in the centers that care for patients with CKD, the motivation and individualized prescriptions of physical exercise provided by these professionals represent a strategy for increasing the level of physical activity.^51,52 Unexpectedly, being treated in a medical undergraduate teaching hospital was a factor associated with physical inactivity. Considering the lack of evidence on this association, we can speculate that this result reflects a characteristic of these kind of hospitals, that is, to follow patients with highly complex disorders. Because of health care professionals’ limited time during consultations, the focus of care is on the optimization of immunosuppression, assessment of graft function, and adherence to immunosuppressive agents, and physical activity promotion is hardly prioritized.⁶

From a clinical point of view, this study found some modifiable factors that may contribute to the increase in the level of physical activity of recipients of a kidney transplant. Changes in lifestyle, namely, smoking cessation and weight reduction, may contribute to improvements in the level of physical activity, in addition to promoting a reduction in the risk for cardiovascular diseases.^6,27,47 Furthermore, increasing the level of physical activity is one of the pillars for the treatment of peripheral vascular disease and may reduce the number of complications in these patients.⁵³ Finally, the inclusion of an exercise physiologist in kidney transplantation centers may be a crucial and strategic measure to increase in the level of physical activity.^51,52

Limitations

Because of the cross-sectional nature of the present study, we cannot infer a causal relationship in the observed associations. However, the correlates are useful to identify patients at a greater risk of being physically inactive. The insights from the present study can inform future physical activity interventions directed to the characteristics of the target population and appropriated to the available resources. Although the use of self-report questionnaires to assess the level of physical activity has some limitations compared to direct objective measures, this is the most frequently applied and viable method for studies with large samples.^10,14,40 Because this study is a secondary data analysis, some well-recognized barriers to physical activity of recipients of a kidney transplant were not evaluated, for example, self-efficacy, depression, fear of movement, and immunosuppressive agent–related side effects.^{16,32,33,41,50} Moreover, the design of the ADHERE BRAZIL study did not include an assessment of other levels (eg, the microsystem and macrosystem levels). Further insights regarding variables at these not studied levels should be sought for to aid the design of suitable physical activity interventions adapted to them. However, despite the enormous potential benefits of physical activity to physical performance and graft outcomes, studies about correlates of physical inactivity after kidney transplantation are still incipient. Importantly, this study included one of the largest samples for this type of evaluation, and the basic epidemiological characteristics (age, sex, and type of donor) are similar to those of recipients of a kidney transplant worldwide.^10,14,40

In conclusion, physical inactivity of recipients of a kidney transplant is influenced by the characteristics of the patient and the kidney transplantation center where they are monitored. As identifying the correlates to physical inactivity is the first step to decrease this behavior, our results suggest the need for strategies directed not only at the patient level but also at kidney transplantation center practice.

Author Contributions

Emiliana Sertorio (Data curation, Formal analysis, Investigation, Methodology, Writing—original draft), Fernando Colugnati (Conceptualization, Formal analysis, Investigation, Methodology, Writing—original draft), Kris Denhaerynck (Conceptualization, Formal analysis, Investigation, Methodology, Writing—review & editing), Stefan De Smet (Conceptualization, Formal analysis, Investigation, Methodology, Writing—review & editing), Jose Medina (Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing—review & editing), Maycon Reboredo (Data curation, Formal analysis, Investigation, Methodology, Writing—original draft), Sabina De Geest (Conceptualization, Formal analysis, Investigation, Methodology, Project administration, Supervision, Writing—original draft), and Helady Sanders-Pinheiro (Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Supervision, Writing—original draft)

The ADHERE BRAZIL study team includes the following individuals: Alvaro Pacheco-Silva: Hospital do Rim e Hipertensão, Oswaldo Ramos Foundation, Nephrology Discipline, Federal University of São Paulo, São Paulo, Brazil. Paula F.C.B.C. Fernandes: Federal University of Ceará, Fortaleza, Brazil. Marilda Mazzali: State University of Campinas, Campinas, Brazil. Pedro A.M. Souza: Santa Casa de Misericórdia de Belo Horizonte, Belo Horizonte, Brazil. Roberto C. Manfro: Federal University of Rio Grande do Sul-Hospital das Clínicas de Porto Alegre, Porto Alegre, Brazil. Alvaro Pacheco-Silva: Hospital Israelita Albert Einstein, São Paulo, Brazil. Gustavo F. Ferreira: Santa Casa de Juiz de Fora, Juiz de Fora, Brazil. Elias David-Neto: State University of São Paulo-Hospital das Clínicas de São Paulo, São Paulo, Brazil. Valter D. Garcia: Santa Casa de Porto Alegre, Porto Alegre, Brazil. Carlos G.W.C. Marmanillo: Hospital Angelina Caron, Curitiba, Brazil. Silvia R. Cruz: Federal University of Para-Hospital Ofir Loyola, Belém, Brazil. Luciane M. Deboni: Fundação Prorim - Hospital Municipal de São José, Joinville, Brazil. Mário Abbud-Filho: Hospital de Base, São José Rio Preto, Brazil. Teresa C.A. Ferreira: Federal University of Maranhão - Hospital Universitário do Maranhão, São Luiz, Brazil. Maurício G. Pereira: Federal University of Rio Grande do Norte-Hospital Onofre Lopes, Natal, Brazil. Deise B.M. Carvalho: Hospital São Francisco de Assis da Providência de Deus, Rio de Janeiro, Brazil. Sergio Wyton: Hospital São João de Deus, Divinópolis, Brazil. Giuseppe C. Gatto: Hospital Universitário de Brasília, Brasília, Brazil. Rafael F. Maciel: Hospital Antonio Targino, Campina Grande, Brazil.

Acknowledgments

We thank the recipients of kidney transplants and the professionals involved in their care. Without them this study would not be possible.

Ethics Approval

The project was approved by the Ethics Research Board of the University Hospital of Federal University of Juiz de Fora (CAAE 27972914.1.1001.5133, approval number 691.120) and by the ethics research boards of the other participating centers.

Funding

E.S.S. received scholarships from the Coordination for the Improvement of Higher Education Personnel (CAPES) (financial code 001).

S.D.S. was financially supported by Research Foundation Flanders (FWO-SBO project number S006722N), C2-M KU Leuven grant (26M/21/001), and by B2023-Bijzonder Onderzoeksfonds 2023 KU Leuven research grant.

The study received internal grants from the Minas Gerais Institute of Studies and Research in Nephrology Foundation (IMEPEN) and research grants from Libbs Pharmaceutical Ltda. and Astellas Pharma Brazil Ltd. None of the internal grants have a grant number.

Clinical Trial Registration

The trial was registered on Clinicaltrials.gov (NCT02066935).

Data Availability

The data on which the analyses are based are available upon request on the Open Science Framework website at https://osf.io/zg97b/ and https://osf.io/qhmdg/.

Disclosure and Presentations

The authors completed the ICMJE Form for Disclosure of Potential Conflicts of Interest and reported no conflicts of interest.

The dissertation this paper is adapted from is posted on the UFJF Digital Institutional Repository of Scientific and Intellection Production (https://repositorio.ufjf.br/jspui/handle/ufjf/15345).

Part of this manuscript was presented orally at the American Transplant Congress 2022, June 4–8 2022, Boston, MA, USA.

References

Author notes