How to cite this article: Álvarez-Rangel LE, Cruz-Santiago J, Meza-Jiménez G, Bernáldez-Gómez G, Ledesma-González VM, Camacho-Hernández F, Rodríguez-Rodríguez A, Aguilar-Martínez C. Modification of Health-related quality of life in kidney transplant recipients. Rev Med Inst Mex Seguro Soc. 2015;53 Supl 1:S66-73.
Received: October 22nd 2014
Accepted: March 6th 2015
Luis Enrique Álvarez-Rangel,a José Cruz-Santiago,a Guillermo Meza-Jiménez,a Germán Bernáldez-Gómez,a Víctor Manuel Ledesma-González,a Fernando Camacho-Hernández,b Arturo Rodríguez-Rodríguez,b Carolina Aguilar-Martínezb
aUnidad de Trasplantes
bDepartamento de Nefrología
Hospital de Especialidades “Dr. Antonio Fraga Mouret”, Centro Médico Nacional La Raza, Distrito Federal, México
Communication with: Luis Enrique Alvarez-Rangel
Teléfonos: (55) 5782 1088 y (55) 5724 5900, extensión 23270
Background: The assessment of health-related quality of life is essential to renal replacement therapies. We conducted a study to evaluate the change in quality of life at 6 and 12 months after renal transplantation and compared with healthy population and general population.
Methods: A prospective study in 278 renal transplant recipients using the SF-36 survey at 0, 6 and 12 months after transplantation. The results were compared with those obtained in healthy population (kidney donors) and general population. Student t test was employed for comparisons of means. A value of p < 0.05 was considered statistically significant.
Results: The quality of life before transplantation was lower than that observed in healthy population and the general population (p < 0.001). At 6 months of transplantation significant improvement over the baseline measurement (p < 0.001) in the 8 domains and the two composite scales was obtained, but at 12 months, an additional benefit was not observed. The quality of life of recipients at 12 months of transplant was lower only in the concept of general health (p = 0.035) compared with healthy population. However, it was higher than general population in physical and mental composite scales (p = 0.013 and p = 0.001 respectively).
Conclusions: The health related quality of life improved significantly at 6 and 12 months after renal transplantation, achieving equated healthy population and general population.
Keywords: Health related quality of life, Renal transplant, Nephrology.
Patients with chronic kidney failure experience a severe reduction in their lifestyle that includes physical and mental activity limitations.1-5 Therefore, health-related quality of life (HRQOL) is considered a fundamental point in the evaluation of renal replacement therapies. It is a multidimensional construct that includes at least three domains: physical functioning, psychological functioning, and social functioning; these can be modified by the disease and treatment.3 In renal transplant this is an increasingly important indicator because it reflects the patients' perception of their health status before and after treatment. To evaluate it, one can use generic instruments (SF-36),6 instruments specific to chronic kidney disease (Kidney Disease Quality of Life [KDQOL]),7 or instruments specific to renal transplantation (ReTransQol).8
Generic instruments have the main advantage being useful in various clinical settings and the ability to make comparisons with the healthy population or the general population. The SF-36 survey is a generic instrument has been previously validated in the general Mexican population9,10 and those with chronic kidney failure.11-14 For this reason, it may be useful for assessing quality of life in renal transplant recipients.
Multiple studies have demonstrated the superiority of the quality of life with kidney transplant compared to patients with any kind of dialysis therapy.1,3,15-21 Some others have included comparison of transplant recipients with the general population,1,15,22-25 and very few have used a group of healthy people for comparison. This is important because the general population does not always have the same social, economic, and cultural context as kidney transplant recipients; moreover, the general population is not necessarily a healthy population.
In Mexico, health-related quality of life for kidney transplant recipients has been little studied. In this regard we conducted a study to establish the changes in quality of life at 6 and 12 months after kidney transplantation, and to compare it with the healthy population and the general population.
A prospective study was performed in the Unidad de Trasplante Renal of the UMAE Hospital de Especialidades “Dr. Antonio Fraga Mouret” of the Centro Médico Nacional La Raza during the period from January 1st 2007 to June 30th 2010. The generic instrument for measuring health-related quality of life (SF-36) was used. The questionnaire was administered to 3 groups of patients:
The group of kidney transplant recipients included all patients transplanted in our hospital during the period mentioned, the questionnaire was administered to them the day before the kidney transplant (baseline measurement) and measurement was repeated at 6 and 12 months during their follow-up in the outpatient clinic. The healthy population group included kidney donors who agreed to participate during the same period; they were taken as a healthy population because during the study protocol for donation they demonstrated absence of chronic degenerative diseases; they had the additional advantage of belonging to the same social, economic, and cultural context as recipients, as they are usually their relatives, spouses, or friends; we applied the same questionnaire the day before nephrectomy. The general population group included people outside the institution, chosen at random, who were accompanying patients in the outpatient area; they received the same questionnaire as donors and recipients, but only once during the study.
The answers obtained by the SF-36 generic instrument were coded for the construction of 8 health concepts or domains (physical function [PF], physical role [PR], bodily pain [BP], general health [GH], vitality [VT] social function [SF], emotional role [ER] and mental health [MH]), as well as two composite scales (physical component scale [PCS] and mental component scale [MCS]). The results are expressed on a scale of 0 (worst health) to 100 (best health).
Comparisons were made between surveys of recipients at 0, 6, and 12 months after kidney transplantation. Then comparisons were made of recipients’ results at 6 and 12 months with the results of the general population and healthy population.
The data collected were analyzed using SPSS version 17. The results are expressed as means ± standard deviation for scalar variables, and simple frequencies with proportions for categorical variables. Comparisons of means between groups were made using Student's t test. A p < 0.05 was considered significant.
The study was approved by the research committee of our hospital and all patients were included after signing informed consent.
Baseline measurement of health-related quality of life was made with 278 kidney transplant recipients (246 [88.5%] from living donor, and 32 [11.5%] from deceased donor) with a mean age of 27.16 ± 8.94 years, 163 (58.6%) male. During follow-up, 221 and 118 recipients completed the SF-36 survey at 6 and 12 months, respectively. For the group of healthy individuals 159 kidney donors were included, and the general population group included 219 people accompanying patients during their appointments. Demographic and baseline clinical characteristics of the three groups can be seen in Table I.
|Table I Demographic and clinical baseline characteristics of recipients, healthy population, and general population|
|n= 278||n= 159||n= 219|
|mean ± SD||mean ± SD||mean ± SD|
|Age||27.16 ± 08.94||40.20 ± 09.86 *||29.77 ± 16.72|
|Weight||59.48 11.43 ±||64.18 ± 08.47 *||—|
|Height||01.61 ± 00.09||01.59 ± 00.08||—|
|Body mass index||22.72 ± 03.37||25.12 ± 02.42 *||—|
|No. cases (%)||No. cases (%)||No. cases (%)|
|Female||115 (41.4%)||100 (62.9%) *||129 (58.9%) *|
|Male||163 (58.6%)||59 (37.1%) *||90 (41.1%) *|
|Serum creatinine||12.27 ± 04.06||00.87 ± 00.17 *||—|
|Hemoglobin||10.05 ± 02.29||14.89 ± 01.47 *||—|
|Serum albumin||04.14 ± 00.44||0435 ± 00.33 *|
|*p< 0.05 with regard to recipients|
The SF-36 survey done the day before the transplant evaluates the quality of life in peritoneal dialysis or hemodialysis therapy. The results of the baseline survey were lower than those observed in the healthy population and the general population (p < 0.001) in the 8 domains and the two composite scales (Figure 1).
Figure 1 Health-related quality of life in patients with chronic kidney failure in renal replacement therapy with peritoneal dialysis and hemodialysis: comparison with healthy population (kidney donors) and general population
Figure 2 shows how at 6 months from transplantation significant improvement was obtained compared to the baseline measurement (p < 0.001) in all 8 domains and the two composite scales. However, at 12 months no additional benefit was documented. The differences between the measurements taken at 6 and 12 months after transplantation were not significant in any of the health concepts or composite scales (Table II). The healthy population group obtained better scores than the general population on the concepts of bodily pain (p = 0.004), general health (p < 0.001) and vitality (p = 0.002).
Figure 2 Change in health-related quality of life at 6 and 12 months from kidney transplantation
|Table II Results of health-related quality of life in kidney recipients (0, 6, and 12 months), healthy population,and general population|
|Concept||Recipient: month 0
(mean ± SD)
|Recipient: month 6
(mean ± SD)
|Recipient: month 12
(mean ± SD)
(mean ± SD)
(mean ± SD)
|Physical function||64.12±24.93 *||86.38 ± 14.14||89.32 ± 11.60||90.91 ± 13.80&||88.75 ± 14.80|
|Physical role||34.08±38.25 *||80.20 ± 29.79||84.98 ± 28.12||78.95 ± 34.60||83.28 ± 28.35|
|Bodily pain||69,75±27.48 *||88.82 ± 16.77||91.17 ± 13.48||87.69 ± 17.80||82.11 19.82 ±&$Β|
|General health||48.24±23.24 *||69.84 ± 17.53||72.21 ± 18.52||76.57 ± 15.61&$||67.34 ± $20.07$Β|
|Vitality||56.95±25.77 *||84.48 ± 14.86||83.95 ± 14.66||81.45 ± 13.79&||75.92 ± 19.94&$Β|
|Social function||59.70±27.48 *||88.01 ± 16.63||87.44 ± 16.61||85.06 ± 18.31||81.63 ± 19.58&$|
|Emotional role||53.57±36.86 *||86.27 ± 23.30||86.44 ± 26.23||81.34 ± 31.29||80.97 ± 30.26&|
|Mental health||63.32±22.93 *||82.28 ± 14,92||83.12 14.17 ±||79.69 ± 16.03||78.78 ± 19.10&$|
|Physical component scale||54.05±23.14 *||81.31 ± acid):15.22%||84.42 ± 12.88||83.53 ± 1520||80,37 ± 16.50$|
|Mental component scale||58.39±23.81 *||85.26 ± 13.69||85.24 ± 13.68||81.89 ± 15.93&||79.33 ± 18.21&$|
|*p< 0.05 for recipients at 6 and 12 months, healthy population, and general population
&p< 0.05 for recipients at 6 months
&p< 0.05 for recipients at 12 months
bp< 0.05 for general population
The results at 6 months from transplant were lower than the healthy population group in the concepts of physical function and general health (p = 0.002 and p < 0.001, respectively) but were higher in the concept of vitality (p = 0.041) and the mental component scale (p = 0.032). In contrast, the results of transplant recipients at 6 months were higher than those obtained by the general population in the concepts of bodily pain (p < 0.001), vitality (p < 0.001), social function (p < 0.001), emotional role (p = 0.040), mental health (p = 0.033), and the mental component scale (p < 0.001).
Figure 3 shows how quality of life of recipients at 12 months after transplantation was lower only in the concept of general health (p = 0.035) compared with the healthy population; in the rest of the concepts of health and composite scales, no significant differences were observed. However, the results were higher than the general population in the physical and mental composite scales (p = 0.013 and p = 0.001 respectively).
Figure 3 Comparison of health-related quality of life in kidney transplant recipients at 6 and 12 months with results from healthy population (kidney donors) and general population
Transplant is considered the kidney replacement therapy of choice in patients with chronic renal failure because their results are superior to those obtained with peritoneal dialysis or hemodialysis, both in terms of patient survival and quality of life.26 In our study the health-related quality of life in patients with chronic renal failure prior to transplantation was lower in all eight health concepts and the two composed scales as compared to the healthy population and the general population. These results show the great impact of chronic kidney disease on quality of life, even in cases where patients are on peritoneal dialysis or hemodialysis therapy.1-16 Similar findings have been reported by other groups.1-5 This is probably because solute clearance is not the sole determinant of quality of life, as demonstrated by the ADEMEX study.11 Multiple factors impact on the quality of life of patients in renal replacement therapies, including: age, gender, anemia, nutritional status, morbidity, socioeconomic status, unemployment, and medication side effects.11,27,28
The improvement in quality of life is significant from the first 6 months after transplantation; however, further improvement at one year is not achieved. This suggests that the benefit of kidney transplantation on quality of life is mainly established during the first six months and is similar to that reported by other groups.22,25 Ponton et al. established that quality of life after transplantation oscillates during the period between 7 and 36 months. In the first three, there is a phenomenon described by patients as "rebirth", then the quality of life shows a decrease at 6 months after transplantation, and finally improves to achieve stability at one year.29
The improvement in the quality of life of kidney transplant recipients was so significant in our study as to be comparable to that observed in the general population in all health concepts, and even higher in the two composite scales. Our results are similar to those reported by other authors.16,21,22,25 Ogutmen et al. compared 302 kidney transplant recipients with 64 hemodialysis patients, 207 peritoneal dialysis patients, and 278 normal subjects. The transplant was the renal replacement therapy with the best quality of life, and the results were not different from those obtained by the normal control group.16 Even in studies in which the recipients have not achieved similar scores to those of the general population, the benefit to physical and mental function is remarkable. Aasebo et al. applied the SF-36 questionnaire to 131 young adult transplant recipients and compared with the results of 2360 individuals from the general population. Although the recipients had a score lower than that of the general population in seven of the eight health concepts and the two composite scales, they reported greater participation in cultural or athletic activities, and most were satisfied with their work and achieved college education at higher rates than the general population.30
In our series, the recipients at 6 months after transplantation got better results than the general population on the concepts of bodily pain, vitality, social function, emotional role, mental health, and the mental component scale. However, the general population group was also worse than the healthy population on the concepts of bodily pain, general health, and vitality. For this reason, the use of the general population control group may be wrong, because they do not always have the same social, economic, and cultural context as kidney transplant recipients; moreover, the general population is not necessarily a healthy population. Therefore, comparison with a known healthy population is necessary. Kidney donors are patients who are presumed healthy because they have participated in a study protocol in which they have not shown any chronic degenerative diseases, and also they have the added advantage of sharing the same socio-economic conditions of the receiver because they usually have a family or friendship relationship. Considering the limitations discussed of the general population group, in our study a group of healthy people (donors) was included for comparison. Only the perception of general health was higher in the healthy population when compared transplant recipients at one year; there were no differences in the other health concepts and the two composite scales.
Improving quality of life during the first year after transplantation is important for the long-term outcome. High scores in physical and mental function at 3 months from transplant predict better patient and graft survival at 10 years.31 Molnar et al. showed that for every 10-point increase in physical composite scale, the risk of mortality decreases by 18%.32 The decline in physical function increases the risk of mortality and graft failure at 12 years from transplantation.33 The limitations of this work may include the use of a generic instrument for assessing quality of life. However, despite not being specific for patients with chronic kidney failure, it allowed us to make comparisons with the general population and the healthy population. The SF-36 questionnaire has been used and validated internationally both in the general population, in kidney transplantation, and in chronic kidney disease. In Mexico, it has been used in major studies in patients with chronic renal failure such as ADEMEX.11
The health-related quality of life significantly improved at 6 and 12 months after renal transplantation, achieving equivalence with the healthy population and the general population.
Conflict of interest statement: The authors have completed and submitted the form translated into Spanish for the declaration of potential conflicts of interest of the International Committee of Medical Journal Editors, and none were reported in relation to this article.