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| Journal of the New Zealand Medical Association,
04-April-2003, Vol 116 No 1171
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|
Quality of life before and after heart, lung and liver
transplantation
Sarah Beilby, Rona Moss-Morris and Liz Painter
Heart, lung and liver transplantations are increasingly
common interventions that have become the treatment of choice for end-stage
cardiac, respiratory or liver disease in New Zealand. Clinic data from the Heart
and Lung Transplant Unit at Green Lane Hospital and the New Zealand Liver
Transplant Unit at Auckland Hospital at the time this study was conducted
(September 2001), showed that 136 heart transplants had been performed in New
Zealand since 1987, 52 lung transplants since 1994, and 96 liver transplants
since 1998.
Survival statistics compiled from the clinical data suggest
that heart recipients in New Zealand have a one-year survival rate of 86%, and a
five-year survival rate of 75%. Refinements in organ procurement and
preservation have resulted in a gradual improvement in the survival rates for
lung transplant patients, with recent clinic data suggesting a one-year survival
rate of 80%, and a two-year survival rate of 66%. A 2002 review of the first
four years of liver transplantation in New Zealand showed that the outcomes for
liver transplant patients are particularly optimistic. They have a one-year
survival rate of 94%, and three-year survival rate of
87%.1 The one-year New Zealand survival rates
are equivalent to international UNOS data for heart transplantation, and are
superior for lung and liver
transplantation.2
As survival rates following transplantation have improved,
focus has shifted towards assessing the success of transplant surgery not only
in terms of survival rates but also in terms of the recipients’ quality of
life. The World Health Organization definition of quality of life is ‘a
state of complete physical, mental and social wellbeing and not merely the
absence of disease’.3 Quality of life has
gained importance as an outcome measure, especially because of the intense
resource allocation and cost that transplantation
demands.4 The literature suggests that during
the organ-waiting period patients experience significant difficulties, including
high levels of emotional distress, and physical and functional
disability.5–8
Following transplantation, most patients appear to enjoy a
dramatic improvement in quality of life. Improvements in physical functioning
are often accompanied by improvements in psychological functioning, although
problems persist for some patients.6,8–10
One of the limitations of the research to date is that most studies have
examined quality of life outcomes at one to two years post-transplant only. This
is despite the fact that survival rates, particularly for heart and liver
transplantation, are well over 50% even at 5–10 years after
transplantation.11–13 Few studies have
compared the differences in quality of life status among the transplant groups.
There is some evidence that although performance improves after heart, lung and
liver transplantation, the trajectories may not be the same and liver recipients
may enjoy slightly better health-related quality of life than their heart or
lung counterparts.14,15 Furthermore, while
transplant recipients may experience dramatic improvements in physical
functioning following transplantation, their functioning level may not
approximate to that of the general population, even for liver
recipients.16–18
The current study recruited all heart, lung and liver
recipients still living in New Zealand, and all patients currently on the
waiting list for one of these transplants. The purpose of the study was to
compare quality of life between pre- and post-transplant groups, and between
each of the three patient groups post-transplant. To determine the extent to
which quality of life is affected by transplants in general, the study also
aimed to compare quality of life scores in post-transplant patients with New
Zealand normative data. Finally the study aimed to look at the effects of time
since transplant on patients’ quality of life. This was the first study to
evaluate quality of life outcomes in transplant patients in New
Zealand.
MethodsEthical approval for this study
was granted by the Health Funding Authority Northland to Franklin. All patients
currently on the waiting list for a transplant and surviving transplant
recipients at the Heart and Lung Transplant Unit at Green Lane Hospital and the
New Zealand Liver Transplant Unit at Auckland Hospital were invited to complete
a questionnaire. At the time of this study, this amounted to 45 patients on the
waiting list and 179 transplant recipients. Questionnaires were either given to
patients at clinics or sent in the mail. Non-responding patients were sent a
reminder letter in the mail after six weeks. The questionnaire assessed quality
of life and demographic information.
The MOS 36-item Short-Form Health Survey (SF-36) was used to measure quality of life.19 This is a standardized general health survey that can be used across general and patient populations. It has been revised and developed over a number of years and has excellent validity and reliability. It measures quality of life across eight domains including physical functioning (the ability to perform everyday tasks such as climbing stairs, dressing and lifting objects), role-physical (the impact of physical health on the performance of everyday roles), general health, bodily pain, vitality, social functioning, role-emotional (the impact of emotional health on the performance of everyday roles) and psychological wellbeing. Scores are standardized to range between 0 and 100 for each of the subscales. Normative data for the New Zealand population are available, allowing for the comparison of quality of life between transplant patients and the general population.20 Data were analysed using SPSS for Windows, version 10.0. Differences between the groups were tested using independent and single samples t-tests and Analysis of Covariance (ANCOVA). The relationship between time since transplant and quality of life was assessed using Pearson’s correlation coefficients. Because a number of analyses were conducted, statistical significance was set at the relatively stringent level of p <0.01. ResultsResponse
rate Completed questionnaires were returned by 34 pre-transplant patients
(72%) and 129 post-transplant patients (75%).
Demographic profile
Table 1 shows the patient characteristics in the pre-transplant sample. The
majority of patients were of European descent and the remainder identified
themselves as New Zealand Maori. The mean ages across the groups ranged from
43–50 years. Patients on the waiting list for a heart transplant were all
male, while the gender ratios in the lung and liver waiting-list groups were
more balanced.
Table 1. Demographic profile of patients on the waiting
list for a transplant
NB: Total numbers in each category vary due to
non-response to a question.
Table 2 shows the patient characteristics in the
post-transplant sample. Again, the majority of patients were of European
descent, and the mean ages were similar to the pre-transplant sample. There were
no Pacific Island people in the heart and lung transplant groups, but 7% of the
liver transplant group were of Pacific descent. The majority of patients in the
heart and liver transplant groups were male but there were more females in the
lung transplant group.
Table 2. Demographic profile of post-transplant
patients
NB: Total numbers in each category vary due to
non-response to a question.
Quality of life
Because the numbers in some of the patient groups were rather low, the initial
comparison of pre- and post-transplant quality of life included patients from
all three patient groups. Independent samples t-tests were used to compare the
mean SF-36 subscale scores across these groups. Table 3 shows that all the SF-36
subscale scores, except for bodily pain and role-emotional, were significantly
higher in the post-transplant group suggesting that there is a dramatic
improvement in quality of life following transplantation.
Table 3. SF-36 subscale mean scores in pre- and
post-transplant patients
To ascertain whether the same pattern of results occurred
within each of the patient groups, further analyses were run comparing pre- and
post-transplant patients in each of the groups. To a large extent, the results
remained consistent across the groups. However, while role-emotional scores were
not significantly different pre- and post-transplant in the heart or lung
groups, they were significantly improved in the liver group following
transplantation (pre-transplant: M = 40.74, SD = 43.39; post-transplant: M =
81.00, SD = 31.90; t(58) = -3.30, p = 0.01). Similarly, the post-transplant
liver group showed a significantly higher level of psychological wellbeing than
the pre-transplant liver group (t(57) = -3.09, p = 0.01), but there was no
significant difference in the heart pre- and post-transplant groups, and only a
marginally significant difference in the lung groups, (t(33) = -2.15, p =
0.03).
Single samples t-tests were conducted on the data collected
from the post-transplant group to investigate their quality of life in relation
to New Zealand normative data. These analyses suggested that transplant
recipients scored significantly lower than the New Zealand norms on physical
functioning (t(126) = -3.39, p = 0.00); role-physical (t(124) = -5.079, p =
0.000); social functioning (t(125) = -7.25, p = 0.00); and self-rated general
health (t(125) = -4.22, p = 0.00). On the other hand, mental health and vitality
scores were significantly higher among transplant recipients than the general
population (t(125) = 5.10, p = 0.00 and t(124) = 22.86, p = 0.00 respectively),
and role-emotional scores were not significantly different (t(124) = -0.42, p =
0.68). The SF-36 scores were all significantly lower in the pre-transplant
sample with the exception of mental health scores, which were not significantly
different to NZ normative data (t(33) = -0.39, p = 0.59).
Because liver transplants have been conducted in New Zealand
over the past four years only, it was only possible to compare the SF-36 scores
across post-transplant groups for patients who had transplants during this
period. This amounted to 24 heart patients, 50 liver patients, and 16 lung
patients. The analyses were conducted using ANCOVA, with gender entered as a
covariate. Gender was included as a covariate as, although the groups were
generally equivalent for age and ethnicity, the gender make-up in each of the
groups was significantly different. Table 4 shows that there were no significant
differences between the groups on any of the subscale scores, suggesting that
self-reported quality of life is equivalent across the groups up to four years
post-transplant. The effect of gender was also non-significant in all of the
analyses.
Table 4. Estimated marginal means controlling for
gender for SF-36 subscale scores across post-transplant patient groups
NB: Data included for transplants conducted in the past
4 years only.
To ascertain whether time since transplant affected
patients’ quality of life, we conducted Pearson’s correlation
coefficients between time since transplant and each of the SF-36 subscale
scores. These correlations were conducted for the total post-transplant sample
and for the post-transplant heart patients. The heart group included the widest
range of patients with patients having received a transplant from between one
year and 14 years prior to the study. None of the correlations was significant
in either the total sample or the heart group on its own, with correlations
ranging from 0.02 (p = 0.83) for vitality, to r = -0.24 (p = 0.07) for general
health. The majority of the correlations were less than 0.1, suggesting that
time since transplant accounts for little of the variance in self-reported
quality of life.
DiscussionConsistent with the literature, New
Zealand transplant recipients reported better physical and psychological
functioning than pre-transplant patients. The positive changes in psychological
functioning appeared to be particularly pronounced for the liver patients.
Although physical functioning improved following transplantation, it was found
to be worse than that of New Zealand normative data. This is also consistent
with previous research, which has found that physical functioning in transplant
recipients is worse than that of non-patient community
samples.16–18
A noteworthy finding is that transplant recipients reported
SF-36 mental health and vitality scores that were superior to those of the
normative data, a finding that has not been reported in previous research. This
finding may be explained by a social desirability bias, whereby transplant
recipients may have reported better psychological functioning than they actually
have. Alternatively, this finding may be explained by a contrast effect.
Transplant recipients are likely to perceive their quality of life more
positively than the general population because of the striking contrast between
terminal illness before transplantation and better functioning following
transplantation, thus accounting for a positive perception of
functioning.
The results of this study suggest that self-reported quality
of life is equivalent across the groups up to four years post-transplant. This
appears to be inconsistent with both the literature and medical opinion, which
posit that heart, and particularly liver transplant patients not only live
longer, but may enjoy slightly better health-related quality of life than lung
transplant patients.14,15 The results obtained
in this study suggest that patients’ perceptions of their quality of life
may be different to medical perceptions. Lung transplant patients’
perceptions of their quality of life may be determined by a contrast effect,
whereby their experience of the striking difference between respiratory
insufficiency pre-transplant and better functioning following transplantation
may account for why they report functioning equivalent to their heart and liver
counterparts.
This study has provided the groundwork for transplant
quality of life research in New Zealand and has added to the literature by
comparing quality of life outcomes with the general population and, where able,
across the transplant groups. It has also shown that time since transplant is
largely unrelated to SF-36 scores. This suggests that the quality of life gains
following transplant may be sustained over time. However, this was a
cross-sectional study, and clearly a longitudinal analysis is needed to confirm
whether patients’ perceptions of their quality of life differ over time or
remain stable. Longitudinal analysis may also be useful to compare the quality
of life benefits of heart, lung and liver transplantations over a longer time
period.
Author information:
Sarah Beilby, Clinical Health Psychologist, Burtons Healthcare; Rona
Moss-Morris, Senior Lecturer, Department of Health Psychology, University of
Auckland; Liz Painter, Clinical Psychologist, Transplant and Cardiac Services,
Green Lane Hospital, Auckland
Acknowledgements:
This research was supported by a Maurice & Phyllis Paykel Research
Scholarship in Health Sciences awarded to Sarah Beilby. Thanks to the transplant
patients who participated in this study and the staff at the Heart and Lung
Transplant Unit, Green Lane Hospital and the New Zealand Liver Transplant Unit
for their assistance and support.
Correspondence: Dr
Rona Moss-Morris, Health Psychology, Faculty of Medical and Health Sciences, The
University of Auckland, Private Bag 92019, Auckland. Fax: (09) 373 7013; email:
r.moss-morris@auckland.ac.nz
References:
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