Lung transplantation is a viable therapeutic option for patients with end-stage lung disease. The focus of interest has shifted from advances in surgical techniques to improved quality of life for the transplant recipient. A prospective longitudinal repeated measures design was used to determine the impact of lung transplantation on quality of life and life satisfaction. Using 4 measurement points (before transplantation, after 8 weeks, and after 6 and 12 months), 61 patients were followed from before to 1 year after successful lung transplantation. Quality of life was measured using 2 generic (SF-36, Quality of Life Profile for Chronic Diseases) and 1 lung- specific (Saint George’s Respiratory Questionnaire) questionnaires. All dimensions of the health-related scores improved significantly after transplantation, except bodily pain. Patients reported the most significant improvements until 6 months after transplantation. Lung transplantation had no influence on social functioning or role emotional. The Saint George’s Respiratory Questionnaire ratings showed similar significantly better scores for transplant recipients at 6 months, and stagnations for most dimensions afterward. (Progress in Transplantation. 2004;14:331-336)
Health-related quality of life (QOL) has increasingly been accepted as a supplementary outcome measure for patients after lung transplantation. The focus of interest in clinical investigations regarding lung transplantation has changed from surgical technical advances to improved QOL for the individual. In preliminary studies, different approaches to measure these advances in QOL have been used to identify predictors of QOL and adjustment after lung transplantation. Previous studies that focused on these changes in QOL after lung transplantation generally report improvements in patients’ perceptions of QOL and life satisfaction.1-10 The results of clinical studies measuring QOL after lung transplantation are limited by small sample sizes,1-4,6,11 retrospective study designs with only 1 measurement point,5,6,12,13 and little or no information about the progress after transplantation for the individual.5,12,13 Studies on the QOL of lung transplant candidates and recipients generally report improvements in QOL following lung transplantation.1,7,8,14 However, comparisons between the studies and published results are difficult because of different study designs, patient populations, and measurement instruments used.2,5,9,10,15-18
From a methodological perspective, the best way to focus on improvements of QOL after lung transplantation is to follow patients by using a prospective longitudinal design with different measurement points, including initiation data before transplantation. Craven et al13 and Lanuza et al1 followed patients prospectively from candidacy on the waiting list until 6 months after transplantation, using 3 measurement points. In both studies, authors concluded that patients experience improved physical and psychological strengths, and that patients report a better global health satisfaction. Ten Vergert and colleagues7 administered the same set of questionnaires to patients from before to 19 months after successful lung transplantation. Improvements occurred about 4 months after transplantation in regards to mobility, energy, sleep, and activities of daily living dependency, and were maintained in the following 15 months.
QOL is multidimensional. Health-related QOL can be divided into a physical, psychological, and a social component of health. These 3 components are interrelated; each dimension can be assessed in 2 ways: (1) objective assessment of overall functioning (eg, 6-minute walk test for physical abilities) and (2) subjective assessment of patients’ perceptions regarding QOL-related scoring. Therefore, tools measuring patients’ perceptions of QOL should address all of these 3 dimensions adequately.5,8,10,12,14
To determine the impact of lung transplantation on QOL and life satisfaction, the same patient group was followed from before transplantation to 1 year after successful transplantation. Patients’ beliefs in their ability to improve their QOL were assessed to identify hypothetical barriers for improvement in individuals.
Methods
A prospective, longitudinal repeated measures design was used. Each part of the study was approved by the Ethics Committee at the Hanover Medical School. Data were collected before transplantation, 8 weeks after surgery (single or bilateral), and 6 and 12 months after transplantation. Lung transplant recipients (N = 61) were recruited exclusively as candidates on the waiting list during outpatient visits or during pretransplant hospital stays. Demographic data and diagnoses are shown in Tables 1 and 2. After written informed consent was obtained, patients completed a battery of questionnaires (Quality of Life Profile for Chronic Diseases [PLC], SF-36, and Saint George’s Respiratory Questionnaire [SGRQ]) measuring QOL and life satisfaction. In addition, a half-structured interview focused on patients’ beliefs that potentially influence QOL was conducted. For each patient, the second measurement point was 8 weeks after successful lung transplantation, followed by examinations at 6 and 12 months after transplantation. Patients were asked to complete the same set of questionnaires at each time point. Datasets from patients who died after transplantation or withdrew informed consent were excluded from this analysis: 2 patients withdrew their informed consent because of moves and follow-ups in other transplant centers, 4 patients died after transplant surgery (22-67 days), and 1 person died (after 157 days) between measurement points 2 and 3.
Quality of Life Profile for Chronic Diseases
The PLC19 is a German self-rating questionnaire and contains 40 Likert-scale questions, consisting of the following 3 components: (1) physical component of QOL-scale of physical functioning; (2) psychological components of QOL, (a) scale of negative moods, (b) scale of positive moods, and (c) scale of psychological functioning; and (3) social components of QOL, (a) scale of social well being and (b) scale of social functioning. The data are presented for the 3 components on a scale from 0 to 4, with higher scores indicating a higher perceived health-related QOL. The scale of negative moods needs to be repolarized, with higher scores indicating less negative moods. Validity and reliability for this instrument have been assessed for 8 clinical studies in chronic patient populations, and for a representative normative sample (n = 2047),20 showing that the internal consistency and the discrimination of the instrument were satisfactory.20,21
Table 1 Demographic data
Table 2 Diagnoses of lung transplant candidates
Internal consistency values measured with Cronbach α range between .72 and .89 for all subscales.21 For testing the construct validity, the level of significance was set at .01. Intercorrelation matrices showed moderate and strong correlation coefficients between .45 and .72 (all P = .0001).21 The scales of the PLC questionnaire showed close correlations to the similar scales of the SF-36 questionnaire (r between .6 and .8; P = .0001).
SF-36
The Medical Outcomes SF-36 is a general health status survey18,21- 23 and contains 36 Likert-scale questions; it assesses 8 dimensions of health: physical functioning, role limitations caused by physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations caused by emotional problems, and mental health. The SF-36 has been extensively validated for use in healthy groups, as well as in populations with acute and chronic diseases. Each dimension is scored separately, and scores are transformed to a 0 to 100 scale, with higher scores indicating a more satisfactory health status. The instrument has previously been validated in patients with chronic obstructive pulmonary disease,17,18 and has been used in the lung transplant population.2,6,8,10,14,24
Saint George’s Respiratory Questionnaire
The SGRQ is a lung-specific questionnaire capturing aspects of health-related QOL that are more specific for patients with respiratory problems.6,25,26 SGRQ contains 50 items with 76 weighted responses. The questionnaire consists of 3 components: (1) symptoms, measuring distress due to respiratory symptoms, related to the frequency of symptoms; (2) activities, effects of disturbance to mobility and physical activity; and (3) impacts, assessing the psychosocial impact of the disease. In addition, a total score is calculated by summing all positive responses in the 3 components and expressing the result as a percentage of weights for all items in the questionnaire. Each response has a unique empirically derived “weight” on a 0 to 100 scale, and the maximum possible weights that could be obtained represent the worst possible state by the patient. The SGRQ was validated for use in the lung transplant population with acceptable reliability scores.6,25,26
Interviews
The half-structured interviews were based on the Illness Beliefs Model,27 which focuses on illness beliefs and perceptions of self- efficacy by patients and their relatives that influence outcome and prognosis of chronic diseases.
Statistical Parameters
Descriptive statistical parameters suc\h as means and standard deviations were obtained for all continuous variables, and percentages were calculated for nominal variables for the study sample as a whole. Correlations were tested by calculating Kendall tau rank correlation coefficients for ordinal data. To detect statistically significant differences between the measurement points, paired t tests for related groups were used. All calculations have been realized by the SPSS 11.0 (Statistical Package for Social Sciences, SPSS Inc, Chicago, Ill) software. The level of significance was set at .05.28
Figure 1 The progression of perceived quality of life after lung transplantation using the Quality of Life Profile for Chronic Diseases. Datapoints are mean values.
Results
The questionnaires and interviews were completed by 61 eligible patients, age 20 to 63 years (mean 47, median 49 years). Fifty- three patients (87%) received a bilateral lung transplant, and 8 patients ( 13%) received a single lung transplant. The majority of the sample received social support from family (66%) and friends (74%).
As shown in Figures 1 and 2, patients rated their general QOL levels very low on all subscales (PLC and SF-36) during their candidacy for lung transplantation on the waiting list. The reported capabilities (PLC and SF-36) improved significantly from before transplantation to 6 months after transplantation (P = .0001), but stagnated afterward for most dimensions of QOL. Following the physical components of QOL (PLC) patients perceived statistically significant improvements for measurement points at 8 weeks, 6 months, and 12 months (P = .010, P = .003, and P = .042, respectively). Negative moods were reduced at 12 months after transplantation (P = .006), whereas the positive moods increased with the highest peak at 8 weeks after transplantation (P = .0001). Social components of QOL using the PLC were showing significant changes 6 months (P = .040) and 12 months after transplantation (P = .005).
Figure 2 The progression of perceived quality of life after lung transplantation using the SF-36. Datapoints are mean values.
These results were validated by significant improvements regarding the SF-36 subscales physical functioning (P = .028) and role physical (P = .049) at 6 months after transplantation. These 2 scales were scored close to 0 before transplantation. The scale for general health (SF-36) shows significant improvements reported by the patients for all measurement points following transplantation (P = .01). The SF-36 subscales for role physical and emotional, general, and for mental health perceptions stagnated or decreased between months 6 and 12 after transplantation. The progress with 4 measurement points for perceived QOL after lung transplantation is shown in Figures 1 and 2. The results shown in Figure 3 show statistically significant decreases in all SGRQ dimensions: symptoms (P = .005), impacts (P = .012), activities (P = .0001), and the total score (P = .0001) at month 6 following lung transplantation.
Patients’ perceptions of improvement of QOL after lung transplantation are supported by the interview results. Patients described their central concept of suffering before lung transplantation as increasing dyspnea and the related anxiety of dying before an organ is available. Consistent with the patients’ perceptions, dyspnea is largely responsible for the decrease in physical abilities and contact capabilities before transplantation. Patients with higher perceptions of internal self-efficacy reported better levels of QOL (P = .001). Patients with higher scores on health-related life satisfaction indicated that 3 interrelated factors influenced positive outcome and survival: medicine, family support, and themselves.
Conclusion
Patients on the waiting list for lung transplantation report dramatic restrictions in all dimensions of QOL, with lowest scoring in the physical subscales. These findings occur consistently within general (PLC, SF-36) and lung-specific (SGRQ) questionnaires. We found that successful lung transplantation has a large impact on QOL and its health-related dimensions. Lung transplantation significantly improves the subjects’ overall function and satisfaction regarding QOL, and has evolved to a viable treatment option for patients with end-stage lung diseases. Although lung transplant recipients report better general, physical, and psychological functioning, individuals’ self-estimations of these parameters differ greatly. Positive beliefs concerning abilities to influence the course of their therapy correlate with higher scores in perceived QOL.
Significant changes occur between all measurement points and for all dimensions (physical, psychological, and social), except the SF- 36 subscales social functioning and role emotional. Both subscales intercorrelate significantly (P = .003) at all measurement points (Table 3).
Figure 3 The progression of perceived quality of life after lung transplantation using the Saint George Respiratory Questionnaire. Datapoints are mean values.
Table 3 Changes in quality of life for all subscales between the measurement points-t test for paired samples*
These results do not correspond with other study results.2,6,10,14 A possible explanation could relate to the interview findings; patients reported changes regarding role definitions between the core family members (eg, changes of role definitions within the partnership) occurring within the time frame between 6 and 12 months after lung transplantation. Perceived improvements regarding physical functioning correspond with the patients’ activities to reintegrate themselves into social systems such as the family system. Successful adaptations from the patients’ point of view are related to higher scoring in regards to social and emotional QOL as well as life satisfaction.
These findings are consistent with earlier reports on QOL outcomes of lung transplant recipients.2,5,6,10 Mac Naughton et al2 report similar results as shown above and compare their data with estimations of a normative sample. They conclude that regardless of the overall improvements following transplantation, lung transplant recipients range one third under the normative population regarding overall QOL. These conclusions have also been confirmed by a research group from Norway.6
Further research should focus on the development of interventional nursing strategies to improve QOL after successful lung transplantation and identify potential barriers for improvement. Researchers need to identify which behaviors and characteristics are shared by lung transplant recipients who have successful clinical and QOL outcomes after transplantation.
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Christiane Kugler, RN, MSN, Martin Strueber, MD, Uwe Tegtbur, MD, Jost Niedermeyer, MD, Axel Haverich, MD, PhD
Hanover Medical School, Hanover, Germany
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Copyright North American Transplant Coordinators Organization Dec 2004
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