This is a cross sectional study on patients receiving renal replacement therapy in Trinidad and Tobago. Patients diagnosed with end stage renal disease can be placed on different treatment modalities. These include: haemodialysis, peritoneal dialysis and renal transplantation. Trinidad and Tobago have all three forms of renal replacement therapy.

1) Inclusion criteria

The study population included all patients on renal replacement therapy for at least 3 months and patients 18 years and older. A minimum interval of 3 months is necessary for patient recovery and return to daily life activities after initiation of renal replacement therapy [6] [10] [11] .

The diagnosis of end stage renal disease was made with the National Kidney Foundation practice guidelines [20] using an estimated glomerular filtration rate of ≤15 mls/min/1.73 m².

2) Exclusion criteria

Patients excluded were persons less than 18 years and persons receiving renal replacement therapy for <3 months.

The sample size was obtained using a 95% confidence interval, a margin of error of 0.0025 and a percentage estimation of 0.5. This gives a minimal sample size of 384 patients on renal replacement therapy: 26 peritoneal dialysis patients, 323 haemodialysis patients (262 private and 61 public) and 35 renal transplant recipients.

Haemodialysis and peritoneal dialysis are undertaken at our public institutions. Public hospitals alone manage all peritoneal dialysis patients. Private facilities also offer haemodialysis and most patients are funded by the government through the external patient programme. Renal transplantation is accessed through our National Organ Transplant Unit, in the public sector at no cost to the patient.

The subjects were recruited from both public and private institutions from October 2015 to October 2016. Peritoneal dialysis patients were recruited from our public hospitals where this type of dialysis is done. Haemodialysis patients were recruited from private and public facilities across Trinidad. The public facilities included San Fernando General Hospital, Eric Williams Medical Sciences Complex, Port of Spain General Hospital, Scarborough Hospital and Sangre Grande General Hospital. The renal transplant patients were recruited from the National Organ Transplant Unit at the Eric Williams Medical Sciences Complex. The mode of renal replacement therapy for each patient in our population is physician and patient dependent with the nephrologist deciding on the best mode of therapy. Some of the factors affecting choice of therapy in our setting include: financial circumstances, adherence to therapy, age and complications of therapy.

The renal transplantation population consists of a total of 108 successful living kidney transplant recipients from the inception of the National Organ Transplant unit in January 2006 to December 2015. Of this renal transplant population, 100 patients met the inclusion criteria and were included in the study. There are about 90 patients on peritoneal dialysis across Trinidad and Tobago, 80 patients met inclusion criteria and were subjects in this study.

The haemodialysis population presently is approximately over 1000 patients. Among the haemodialysis patients, stratified random sampling was done among private facilities. In October 2015 there were a total of 16 private haemodialysis centres that participated in the government’s extended patient programme. These private facilities for sampling purposes were divided into geographical locations using their distribution within each regional health facility of Trinidad and Tobago. These included the North Central Regional Health Facility, North West Regional Health Facility and South West Regional Health Facility. The ratio of distribution was 1:1:2 respectively. Private facilities were therefore sampled by stratified random sampling using these ratios. The haemodialysis patients within the facilities were obtained by convenience sampling. A total of 13 centres were sampled in this study which included all the public centres and 8 private centres.

A demographics questionnaire was employed which gathered information on age, ethnicity, and length of time on renal replacement therapy, employment, income, social support, medical history, substance use, weight, height and previous hospitalizations. Employment, body mass index and medical conditions were classified using the International Standard Classification of Occupations of the United Nations [21] , the World Health Organization Global Database on Body Mass Index [22] and the International Statistical Classification of Diseases and Related Health Problems 10^th Revision [23] respectively. Body mass index for obese patients was further categorized for persons of Asian (25 kg/m²) and Afro-Caribbean descents (27 kg/m²) [24] .

Ethical approvals and permissions were obtained for all sampled facilities. Approvals from the ethics committees from the respective regional health facilities were obtained. The University of the West Indies, Research Ethics Committee also granted their approval for this project.

Data collection commenced October 2015 and was completed in October 2016. Strict confidentiality of information was maintained throughout this study. The purpose of the study and content of questionnaires was explained fully to patients before the interview. Informed consent from all participants in this study was obtained. Questionnaires were administered in an interview-based format to patients.

Statistical Package for the Social Sciences (SPSS) version 24 was used for statistical analysis. Inter-collector reliability was tested periodically.

There were a total of 530 patients on renal replacement therapy in this study between October 2015 and October 2016. Of these, 350 were on haemodialysis, 80 were on peritoneal dialysis and 100 were kidney transplant recipients. Thirty eight percent of all patients were between 56 to 65 years of age (Table 1). 52.5% were male and 47.5% were female (Table 2). The Indo Trinidadian population accounted for 51% of the subjects (Figure 1).

Sixty four percent of patients were found to be obese (Table 3). In a study by Tillin et al, that followed over 2500 persons, body mass index cut off levels of 25 in persons of Asian descent and 27 in those of African Caribbean descents posed equivalent risks to those of European descent with a cut off value of 30 [24] . These values were used in this study for persons of these descents.

The diagnosis of chronic kidney disease was made when patients were already at end stage renal disease requiring intervention in 84.2% of persons. Primary hypertension and/or diabetes mellitus were reported as the reason for chronic kidney disease in 72% of the population on renal replacement therapy.

Sixty seven percent of haemodialysis patients had permanent catheters as their primary access site for dialysis. Among these patients, 51% were told they were hospitalized for investigation and treatment of catheter related blood stream infections.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation. ¹T.Tillin, N. Sattar, I.F Godsland, A.D Hughes, N. Chaturvedi et al. Ethnicity-specific obesity cut-points in the development of type 2 diabetes-a prospective study including three ethnic groups in the United Kingdom. Diabet Med. 2015; 32: 226-234.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation; N/A-not applicable.

Seven percent of transplant recipients reported a diagnosis of post-transplant erythrocytosis. Eleven reported a diagnosis of new onset Diabetes Mellitus after transplant. Nineteen percent of transplant patients reported distressing symptoms when responding to the kidney transplant questionnaire. The most distressing symptoms were those related to infections. Other symptoms reported included dyspnoea, headaches and altered bowel habit.

Thirty four percent of the renal transplant recipients had been transplanted for more than 5 years compared to 8% of haemodialysis patients and 12.5% of peritoneal dialysis patients who were on their respective forms of renal replacement for more than 5 years (Table 4).

After starting renal replacement therapy, 30.5% of haemodialysis patients had 2 or more hospitalizations, 7.5% of peritoneal dialysis patients and 6% of renal transplant recipients had 2 or more hospitalizations post renal replacement therapy. The common reasons for hospitalizations reported among haemodialysis patients were catheter related blood stream infections (41.4%) and fluid overload secondary to chronic renal failure (37.7%).

Sixty seven percent of haemodialysis patients were using more than 10 medications compared to a smaller proportion of peritoneal dialysis and transplant recipients, 7.5% and 6% respectively (Table 5). Alcohol consumption and cigarette use are shown in Table 6 and Table 7.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

In the entire population of patients, 17.7% were single and 54.7% were married (Table 8). 51.1% of patients were Christian, 33.8% were Hindu and 11.5% were Muslim (Table 9).

A greater proportion of transplant recipients completed or was completing tertiary level education (Figure 2). After receiving renal replacement therapy for end stage renal disease, 21.7% of haemodialysis patients in the 18 to 65 years age

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

group reported that they were able to return to work or obtain employment because of starting renal replacement therapy. Among the same age group, 36.25% of the peritoneal dialysis patients and 63% of the renal transplant recipients were able to return to work or obtain employment. 65% of renal transplant recipients were employed (Table 10). The renal transplant recipients had a greater proportion of positions as managers or professionals (Table 11).

Among the haemodialysis patients 20% were either current or prior recipients of social welfare, 20% of the peritoneal dialysis patients received or previously received social welfare and 2% of the transplant recipients were either prior or present recipients of social welfare. Fifty nine percent of haemodialysis patients reported they earned $1000 TT (Trinidad and Tobago) dollars or less each month, 32.5% of the peritoneal dialysis patients earned within this bracket while 27% of transplant patients reported this monthly income (Table 12).

Figure 3 shows that among all groups of patients, the person having the most

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation. ¹International Standard Classification of Occupations of the United Nations. ISCO 08. http://www.ilo.org/public/english/bureau/stat/isco/

HD-haemodialysis, PD-peritoneal dialysis, T-renal transplantation.

influence on a patient when deciding on a modality of renal replacement therapy was the patient’s physician (85.4% haemodialysis, 85% peritoneal dialysis, 71% transplant) . On assessing patients’ knowledge and understanding of their present therapy, 61.5% of patients said they felt completely knowledgeable about their present therapy (Table 13).

Among all patients in our study, 72% were diabetic and/or hypertensive. In the transplant recipients, 39% were diabetic and/or hypertensive and 27% reported chronic glomerulonephritis as the aetiology of their kidney failure. This study showed that the diagnosis of chronic kidney disease was made when patients were at end stage renal disease requiring intervention in 84.2% of persons. These numbers may possibly be even higher since some patients diagnosed with end stage renal disease do not wish for any therapy and are managed conservatively.

Again, this emphasizes the need for public awareness and education on controlling the risk factors associated with lifestyle diseases.

Eighty percent of transplant patients, 32.5% of haemodialysis patients and 81.25% of peritoneal dialysis patients were using between 4 and 10 medications. Sixty seven percent of haemodialysis patients were using greater than 10 medications. A greater proportion of patients using 10 medications or less were in the transplant (94%) and peritoneal dialysis (92.5%) groups. Patients on haemodialysis may have more comorbidities than patients on other modalities hence the need for a greater number of medications. There were 62.5% of type 2 diabetics among patients on haemodialysis (HD) in this study. Forty eight percent of patients on peritoneal dialysis (PD) were type 2 diabetics and 11% of renal transplant recipients were type 2 diabetics. The proportion of patients who were hypertensive was greater in the dialysis group (HD: 76.3%, PD: 73.5%, T: 39%). Furthermore, patients on haemodialysis usually require supplementation of calcium, vitamin D, erythropoietin and phosphate binders. This may mean that patients on this form of renal replacement therapy will inevitably be on a greater number of medications than others.

Sixty six percent of patients with arteriovenous fistulas or grafts were more than 55 years. Seventy seven percent of patients with arteriovenous fistulas or grafts were more than 45 years. One study has shown that younger patients on haemodialysis have better quality of life scores [26] . In this study, 15.5% of the patients on haemodialysis aged between 18 to 35 years had arteriovenous fistulas or grafts. Patients who were on haemodialysis for a longer time, possibly were able to obtain an arteriovenous fistulas or graft before others because of the length of time waiting in the hospital system.

It has been well recognized in many studies that arteriovenous fistulas and arteriovenous grafts are associated with fewer complications and an improved quality of life for patients on long term haemodialysis [27] . In a study of 1563 patient on haemodialysis, patients with arteriovenous fistulas reported greater physical activity and energy, better emotional and social well-being, fewer symptoms, better sleep, less effect of dialysis and burden of kidney disease [28] .

Adipose tissue provides more tumour necrosis factor alpha soluble receptors that attenuate the adverse effects of tumour necrosis factor. Overweight individuals have higher lipoprotein concentrations, which counteract the inflammatory effects of circulating endotoxins [29] . Reductions in total body fat are associated with decreased humoral immunity [30] . Overweight and obese individuals have a higher absolute amount of muscle mass. This increased amount of lean tissue might confer an additional protective edge during times of catabolism which is common in haemodialysis patients [31] [32] [33] .

Fadem et al showed that external influences such as physician’s recommendations affected how patients choose a therapy and disclosed a general preference for physician-based education [34] . In this study, the patient’s physician had the greatest influence on renal replacement therapy choice. Patients with a greater knowledge and understanding of their present therapy may feel more empowered to make decisions and directly contribute and initiate other aspects of management like lifestyle modifications, adherence with medications and follow up visits at clinic.

Educating patients on available options of renal replacement plays a pertinent role in assisting patients with managing chronic kidney disease and the comorbidities associated with it. There are studies that have shown a general lack of knowledge and understanding of the options available for renal replacement therapy [35] [36] [37] [38] . It was found that 74.7% of patients with a good level of knowledge and understanding of renal replacement therapy attained at least a secondary level of education.

The selection of patients for each modality of renal replacement therapy may differ because of the specific requirements of each therapy. All modes of renal replacement are available to our population through the public sector.

Renal transplantation is a mode of renal replacement that requires a thorough pre-emptive evaluation of cardiac and vascular status. In our transplant unit, patients are extensively managed and assessed by the transplant surgeon, vascular surgeon, nephrologists, transplantation coordinator, dietician, dentist, psychiatrist, social worker and an ethics committee over several months before the transplantation procedure. Adequate optimization of each patient and all comorbidities are stringently managed by expert care. Pre-transplantation counselling is expansive and potential recipients whether on the live or cadaveric waiting list have several lecture sessions with their transplant coordinator and social worker. The pre-transplantation experience differs vastly from persons starting other forms of renal replacement.

When compared to patients on dialysis, haemodialysis is a more feasible option than peritoneal dialysis. There are very few contraindications to haemodialysis when patients are diagnosed with end stage renal disease. It is readily available in the acute setting and is the least time consuming of the three modalities of renal replacement therapy, requiring at least a temporary catheter to initiate therapy. Peritoneal dialysis however needs greater medical evaluation and assesses patients for conditions that may predispose them to developing peritonitis. Peritoneal dialysis also demands a patient to have a certain minimal standard of living to properly perform this therapy in a home setting. As such, patients are routinely evaluated and cleared by their medical social worker prior to commencing peritoneal dialysis. In order to achieve the full therapeutic goals of peritoneal dialysis patients are fully counselled and educated on this form of renal replacement therapy. The recognition of complications and management of comorbidities is highlighted and reinforced by peritoneal dialysis nurses regularly. Patients on peritoneal dialysis and those receiving renal transplants may be more motivated and empowered in managing their kidney disease than haemodialysis patients. Social support networks are needed for all patients on renal replacement but because of the selectivity of each mode, patients on haemodialysis possibly have the least social support.

Of the three modalities of renal replacement therapy, renal transplantation may be the most selective. This highly specific selection of patients on each modality was reflected in this study. There were 62.5% of type 2 diabetics among patients on haemodialysis (HD), 48% on peritoneal dialysis (PD) and 11% receiving renal transplants (T). Hypertension was greater in the dialysis group (HD: 76.3%, PD: 73.5%, T: 39%). Thirty four percent of renal transplant recipients had their transplants for >5 years compared to 8% of haemodialysis patients and 12.5% of peritoneal dialysis patients. Thirty percent of patients aged 18 to 35 years were renal transplant recipients, followed by 15% of peritoneal dialysis patients and 14.5% of patients on haemodialysis. This may suggest that younger patients and those with fewer comorbidities are likely to be selected as renal transplant candidates. Our transplant patients were also more likely to be employed and earning in the higher income brackets. This could be because of upward mobility secondary to an improved quality of life after transplantation or potential recipients initially belonging to higher socioeconomic groups than patients on other modes of renal replacement therapy.

Our transplantation programme in Trinidad and Tobago is government funded and referral based. Donors both living, and deceased must meet specific criteria for eligibility. Worldwide, other transplantation centres may have the added bias of selection of patients based on socioeconomic status since privately, access to transplantations may be greater in persons with insurance or those in the higher income brackets. In a report analysing the data of 600,000 patients listed in the United Network for Organ Sharing database (UNOS) from 2000 to 2013, transplant centres allowed listing of patients at multiple centres. This was initially allowed to facilitate patients from rural areas. However, the practice eventually favoured wealthier patients because they were able to afford registration at multiple sites making them more likely to be transplanted than someone in greater need of transplantation [39] .

All transplantation centres should be ethical in their selection of patients for transplantation and should be subjected to regular auditing of transplanted candidates.

Thirty four percent of transplant recipients had allografts for more than 5 years, the remaining 66% of patients were transplanted for 5 years or less. This may mean that the survival of transplant recipients may be better than patients on other modes of renal replacement. Furthermore, when current time period on therapy was analysed, 19% of patients with renal transplants had their grafts for greater than 10 years, followed by 2.3% of patients on haemodialysis and 1.3% of patients on peritoneal dialysis There are studies that have shown an improvement in morbidity and mortality with renal transplantation over dialysis [40] [41] .

Sixty three percent of transplant recipients, 21.71% of HD patients and 32.5% of PD patients between the ages of 18 and 65 years were able to return to work or obtain employment after initiating renal replacement therapy. In a prospective study done 20 years ago on cost utility of renal transplantation in Canada, it was found that over two years, transplantation was both less costly and more effective than dialysis. Employment opportunities were the greatest for transplant patients also [10] .

Our transplantation programme in Trinidad and Tobago established only 10 years ago is small compared to other transplantation units with a maximum of only 2 live donor transplantations being done monthly and deceased donor renal transplantations taking place on availability and criteria fulfilment. In this study, out of the 100 renal transplant patients meeting the inclusion criteria, 24 were recipients from deceased donors. With larger transplantation programmes, cost per transplantation may be reduced.

Our dialysis centres assess each patient and regulates each dialysis prescription to achieve good clearances. However, this study did not assess objectively adequacy of haemodialysis for each patient by analysing clearances among haemodialysis and peritoneal dialysis patients. The patients in this study all had end stage renal disease and were on renal replacement therapy. Other patients not on renal replacement were not assessed. In addition, patients in the other stages of chronic kidney disease were not studied. These groups are an area for future research.