Quality of Sleep and Quality of Life in Renal Transplantation Patients M.M. Eryilmaz, C. Ozdemir, F. Yurtman, A. Cilli, and T. Karaman ABSTRACT Introduction. Sleep and sleep-related disorders are common among end-stage renal disease patients. In the general population and hemodialysis patients, insomnia impairs health-related quality of life (HRQOL). The aims of this study were to examine the prevalence of sleep problems among renal transplantation patients and the relationship between the quality of sleep and the HRQOL. Methods. Pittsburgh Sleep Quality Index (PSQI) for measuring quality of sleep, WHOQOL-BREF for quality of life, and Beck Depression Inventory (BDI) were applied to 100 renal transplant patients. Results. Thirty (30%) subjects were “poor sleepers” (global PSQI ⬎ 5). Poor sleepers were younger (mean age: 31 vs 37); less educated (mean years of education: 7.80 vs 9.55), and more depressed (mean BDI scores 13.63 vs 7.18). There were significant inverse correlations between global PSQI and physical health (r ⫽ ⫺0.31; P ⬍ .001) and psychological state (r ⫽ ⫺.20; P ⫽ .04) with a significant correlation with BDI scores (r ⫽ .36; P ⬍ .001). The BDI score (P ⬍ .001) was the only significant factor of physical health, psychological state, and social functioning. BDI score (P ⬍ .001) and education (P ⬍ .022) were significant predictors of environmental conditions. Conclusion. Sleep problems are not as common among transplant as dialysis patients, but still higher than the general population. Poor sleep seems to be a part of depressive symptomatology. Severity of depression and lower education were more negatively effective factors on the quality of life of these patients than the quality of sleep.
ATIENTS WITH end-stage renal disease (ESRD) have the treatment opportunities of hemodialysis (HD), peritoneal dialysis (PD), or renal transplantation (Tx). For 2002, the prevalence of the ESRD cases needing renal replacement therapy (RRT) in Turkey was 395.0 (pmp) with an incidence of 70 (pmp).1 RRT was performed by 61.8% HD, 11.1% PD, and 27.0% renal Tx.1 Sleep and sleep-related disorders (SRDs) are common in ESRD patients.2– 4 Some clinical trials have investigated the relationship between disordered sleep and the healthrelated quality of life (HRQOL) among hemodialysis and other chronically ill patients, they have described quality of sleep as an independent factor in HRQOL, showing SRDs to impair HRQOL in HD patients.5–7 Other studies have shown that SRDs such as restless leg syndrome and sleep apnea-hypopnea syndrome disappeared shortly after renal Tx, but quality of sleep/sleep disorders have not yet been adequately investigated in the posttransplant period.8,9 Among the treatment choices Tx has overwhelming
importance in terms of patient survival, HRQOL, and cost-effectiveness. Many studies have reported in the shortand long-term post–renal rTx periods an improved HRQOL, which is an important outcome parameter.10 –12 A review of the literature shows that HRQOL may be affected by sociodemographic variables, chronic illnesses, psychiatric and physical conditions (depression, stroke, anxiety, anemia, malnutrition, uremia, etc), as well as quality and related disorders of sleep.5,6,13 The aim of this study was to investigate the prevalence of sleep problems among ESRD patients treated with renal Tx
From the Department of Psychiatry (M.M.E., C.O., F.Y., T.K.) and Chest Diseases and Sleep Unit (A.C.), Akdeniz University School of Medicine, Antalya, Turkey. Address reprint requests to: Mr. M. Mehmet Eryilmaz, Department of Psychiatry, Akdeniz University Hospital, Dumlupinar Bulvari Kampus, Antalya, 07058 Turkey. E-mail: [email protected]
0041-1345/05/$–see front matter doi:10.1016/j.transproceed.2005.03.084
© 2005 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
Transplantation Proceedings, 37, 2072–2076 (2005)
QUALITY OF SLEEP AND QUALITY OF LIFE
to examine the effective variables of quality of life after transplantation.
SUBJECTS AND METHODS This cross-sectional study of 115 renal Tx recipients recruited those who had received a graft at least 6 months prior. Patients were excluded if they were ⬍18 years of age, had ⬍5 years of education, or refused to participate. The remaining patients completed a semistructured interview scale that evaluated the demographic data, clinical specifications, and comorbid conditions together with WHOQOL-BREF14; Pittsburgh Sleep Quality Index (PSQT),15 and Beck Depression Inventory (BDI) 16 on a voluntary basis. Quality of life was measured by the WHOQOL-BREF,14 a 26-item self-administered brief questionnaire, which was derived from the 100-item parent WHOQOL-100. It covers domains of physical capacity, psychological state, social functioning, and environment. One item from each of the 24 facets of the original WHOQOL-100 was included, together with an additional two items from the overall quality of life and general health facets. Patients scored the questions over a range of 1 to 5 points.14 The validity and reliability study of the Turkish version of the WHOQOL-BREF was assessed by Fidaner et al.17 The Cronbach ␣ coefficient for all items was between 0.53 and 0.83, namely, quite a high level of internal consistency.17 Quality of sleep was measured using the PSQI,15 a self-administered questionnaire that assesses sleep quality during the previous month. It contains 19 self-rated questions yielding seven components: subjective sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbance, use of hypnotic medications, and daytime dysfunction. Each component is scored from 0 to 3, yielding a global PSQI score between 0 and 21, with higher scores indicating a lower quality of sleep. The PSQI is useful to identify good and poor sleepers. A global PSQI score ⬎ 5 indicates that a person is a “poor sleeper” if he or she has severe difficulties in at least two areas or moderate difficulties in more than three areas.15 The reliability and validity study of the Turkish version of the PSQI was evaluated by Agargun et al,18 who found the Cronbach ␣ coefficient PSQI to be 0.804 for all items, namely, a high level of internal consistency. The Cronbach ␣ coefficient for all seven components of the of PSQI Turkish version were 0.88, 0.87, 0.92, 0.91, 0.84, 0.67, and 0.35.18 Variables such as age, sex, education, cause and time of renal disease, time on dialysis, number of transplants (some patients had been received kidney more than once because of graft loss), time after transplantation, comorbidity, social security, socioeconomic level, and medication of the patients were determined by interview, chart review and medical records. Depression was also measured by BDI,16 patients with 17 or more scores were accepted as depressive. The statistical analysis was performed using Statistical Package Software System (SPSS) for Windows, release 10.0. Spearman correlation coefficients were used to evaluate associations between continuous variables. Student t test was used to compare the means of normally distributed variables between good sleepers and poor sleepers. The Mann-Whitney U test was used for variables that were not normally distributed. Differences among categorical variables were analysed using the 2 test on two-tailed Fisher exact test as appropriate. The level of significance was ␣ ⫽ 0.05 for all comparisons. Multiple linear regression with forward stepwise selection (␣ ⫽ 0.05) was performed to identify factors that were independently associated with subscales of the WHOQOL scores.
Among the 115 patients available to enter the present study, 15 did not meet the inclusion criteria. The remaining 100 subjects composed the study population. The characteristics of the 100 subjects are shown in Table 1. Eighteen of them had a second renal allograft because of the graft loss and three, a third one. The mean (SD) global and component PSQI scores are shown in Table 1. Thirty (30%) of 100 subjects were poor sleepers (global PSQI ⬎ 5). There were significant inverse correlations between global PSQI and physical health (r ⫽ ⫺.31; P ⬍ .001), psychological state (r ⫽ ⫺ .20; P ⫽ .04), and a significant positive correlation with BDI scores (r ⫽ .36; P ⬍ .001). The mean global PSQI score was not different for females and males patients, who did or did not live alone versus with a partner. There were strong correlations between poor sleepers, PSQI scores and age (P ⬍ .01), education (P ⫽ .028), and severity of depression (P ⬍ .001). Poor sleepers were younger (mean age: 31 vs 37); less educated (mean years of education: 7.80 vs 9.55), and more depressed (mean BDI scores 13.63 vs 7.18). The comparisons of the good sleepers (global PSQI ⬍ 5) and poor sleepers (global PSQI ⱖ 5) WHOQOL scores are shown in Fig 1. The differences of all domains WHOQOL-BREF scores were statistically significant between the groups (P ⫽ .01, P ⫽ .03, P ⬍ .01, P ⫽ .01, Table 1. Characteristics of the 100 Subjects Included in the Study Variables
Age (years) Education (years) Male Single Unemployed Living donor Comorbidity Duration of disorder (months) Duration of dialysis (months) Duration after rTx (years) Depressed (BDIⱖ17) All patients (BDI) Quality of sleep Global PSQI Subjective sleep quality Sleep latency Sleep duration Sleep efficiency Sleep disturbance Use of sleep medications Daytime dysfunction Quality of life Physical health Psychological state Social functioning Environmental conditions
36.1 (11.3) 9 (3.5) 65 36 33 63 23 46.90 (45.0) 18.8 (20.0) 4.2 (5.1) 14 9.1 (7.7) 4.64 (2.47) 0.81 (0.66) 1.20 (0.99) 0.64 (0.73) 0.30 (0.90) 1.12 (0.90) 0.10 (0.48) 0.45 (0.61) 70.62 (14.95) 69.76 (15.34) 68.64 (16.29) 65.81 (14.64)
Tx, renal transplantation; PSQI, Pittsburgh Sleep Quality Index; BDI, Beck Depression Inventory.
ERYILMAZ, OZDEMIR, YURTMAN ET AL
shown in Table 1. The cutoff points of WHOQOL-BREF have not been determined for the Turkish version yet, so it was not possible to calculate them for Tx patients, but we estimated that all domains of WHOQOL-BREF were nearly equal as the normal controls. The correlations between WHOQOL-BREF domains and the other continuous variables are shown in Table 2. There was a significant inverse correlation between global PSQI score and Physical Health (PH); (P ⬍ .01), Psychological State (PS); (P ⬍ .05), and Environmental Condition (EC): (P ⫽ .05). There was no significant correlation between our samples’ sociodemographic variables (age, time on dialysis, renal disorder time, etc) and WHOQOLBREF domains except for education. Education was significantly correlated with EC (P ⬍ .01) and PH (P ⫽ .02). Furthermore, BDI scores had the strongest correlation with the all domains of WHOQOL-BREF scores (Table 2). Finally, in the multivariate analysis, the BDI score was the only significant factor for physical health, psychological state, and social functioning (P ⬍ .001). The significant predictors of the environmental conditions were the BDI score (P ⬍ .001) and education (P ⬍ .022). The BDI score remained as a significant predictor for all domains of the WHOQOL-BREF-TR after controlling for age, sex, global PSQI, time on dialysis, duration after Tx, and the other variables. The results of the analysis of regression are shown in Table 3.
Fig 1. Comparisons of the mean scores of the components of WHOQOL-BREF between good (o, n ⫽ 69) and poor (, n ⫽ 30) sleepers of PSQI. PSQI, Pittsburgh Sleep Quality Index; PH, Physical Health; PS, Psychological State; SF, Social Functioning; EC, Environmental Conditions. *P ⫽ .01; **P ⫽ .03; ***P ⫽ .01.
The prevalence of poor sleep in the present study was 30%, a pretty high level when compared to 15% to 25% prevalence among the general population sleep lower than the patients with ESRD who were treated with the hemo– peritoneal dialysis. For example the prevalence of sleepwake complaints reported by previous studies in hemodialysis patients was 50% to 80%.2– 4 To the best of our
respectively). There were no statistically significant differences between good and poor sleepers and the other variables. The mean scores of WHOQOL-BREF domains are
Table 2. Correlations Between Variables and WHOQOL-BREF-TR Domains PH Variables
Age Education Disorder time Time on dialysis Post-Tx time Global PSQI SSQ Sleep latency Sleep duration Sleep efficiency Sleep disturbance USM DD BDI
⫺.15 .23 .05 .12 ⫺.14 ⫺.30 ⫺.27 ⫺.07 ⫺.14 ⫺.36 ⫺.31 ⫺.02 ⫺.23 ⫺.40
.13 .02 .57 .21 .10 ⬍.01 ⬍.01 .44 .14 .11 ⬍.01 .83 .02 ⬍.01
.04 .18 .16 .14 ⫺.09 ⫺.20 ⫺.16 ⫺.00 ⫺.00 ⫺.15 ⫺.16 ⫺.11 ⫺.26 ⫺.64
.65 .06 .10 .14 .32 .04 .11 .94 .96 .12 .10 .27 .01 ⬍.01
⫺.00 .01 .00 .01 ⫺.10 .15 ⫺.11 .05 .01 .22 .13 .04 .23 ⫺.41
.98 .86 .93 .92 .31 .12 .24 .57 .88 .02 .18 .64 .01 ⬍.01
.03 .29 .18 .14 ⫺.09 ⫺.19 ⫺.16 ⫺.07 ⫺.05 ⫺.12 ⫺.09 ⫺.10 ⫺.15 ⫺.41
.75 .01 .06 .16 .37 .05 .09 .45 .57 .20 .35 .32 .13 ⬍.01
Tx, transplantation; PSQI, Pittsburgh Sleep Quality Index; SSQ, Subjective Sleep Quality; USM, Use of Sleep medications; DD, daytime dysfunction; BDI, Beck Depression Inventory; PH, Physical Health; PS, Psychological State; SF, social functioning; EC, Environmental Conditions;r, correlation coefficient.
QUALITY OF SLEEP AND QUALITY OF LIFE
Table 3. Multiple Linear Regression Models With Outcome Variables: WHOQOL-BREF Domains PH
Intercept Age Sex Education PSQI BDI
77.7 ⫺0.18 0.07 0.15 ⫺0.18 ⫺0.77
⬍.01 .05 .44 .11 .06 ⬍.01
81.3 ⫺0.00 ⫺0.02 0.05 0.03 ⫺1.26
⬍.01 .95 .76 .55 .72 ⬍.01
76.5 ⫺0.03 ⫺0.02 0.07 ⫺0.01 ⫺0.86
⬍.01 .72 .76 .43 .91 ⬍.01
64.2 ⫺0.08 0.16 0.88 ⫺0.04 ⫺0.69
⬍.01 .49 .19 .02 .61 ⬍.01
␤, regression coefficient; PH, Physical Health; PS, Psychological State; SF, Social Functioning; EC, Environmental Conditions; PSQI, Pittsburgh Sleep Quality Index; BDI, Beck Deppression Inventory.
knowledge this is the first study to investigate the quality of sleep with a validated instrument in renal Tx patients, so we were unable to compare our results with any previous study. The prevalence of poor sleepers among Tx patients was significantly higher than that of the general population for most the items of the PSQI, namely, subjective sleep quality, sleep latency, and duration. The findings of the present study suggest that Tx reduces the high frequency of sleep and related disorders among patients (30% vs 75%). Our results also extend the results of the some single researches that have reported that sleep complaints (eg, OSA and RLS) disappeared after Tx.8,9 Previous studies that investigated relationship between sleep disorders and HRQOL found that insomnia is independently associated with a significant decrease in overall quality of life for patients with chronic illness.6 Similar results were replicated among a specific group of chronic illness such as ESRD.5 Iliescu et al5 found strong associations between quality of sleep and life among 89 HD patients after controlling for other physical and mental predictors of HRQOL. For example, mental HRQOL was associated with subjective sleep quality, sleep disturbance, use of sleep medications, and daytime dysfunction. Physical HRQOL was associated with sleep efficiency, sleep disturbances, use of sleep medications, and daytime dysfunction. At the end, poor sleepers had lower HRQOL in all domains. In the present study, Tx patients showed similar strong associations between WHOQOL-BREF domains and global subscale scores of the PSQI. Global PSQI was strongly associated with PH, PS, and BDI. Subjective sleep quality, sleep disturbance, and daytime dysfunction were associated with PH, while PS showed a strong association with daytime dysfunction. Additionally poor sleepers scored nearly 10 points lower in all domains of WHOQOL-BREF than good sleepers (Fig 1.) In the present study, the depression rate (BDI scores ⱖ 17 for the Turkish version) of Tx patients was 14%, which was high compared to the general population. It is well known that even after a successful transplant, patients live with much stress factors: immunosuppressive drug side effects; adaptation to a new life; fear of rejection; and stress. These factors continue to limit the effectiveness of renal transplantation, possibly causing a predisposition to depression.13 These factors may be useful to understand the high
severity of depression in this group of our study sample. However, for the total group of the sample, the mean rate of the BDI scores (the mean rate: 9.1 [7.7]) was so high as the cutoff point predicting the presence of depression. In our study, there was a strong negative correlation between severity of depression and HRQOL as described before in the comprehensive review of Valderabbano et al.13 Our findings about sleep quality and its effect on the HRQOL are similar to previous studies that demonstrate insomnia to be an independent predictor of HRQOL. But in the multivariate analysis, our findings were distinct from studies that found sleep to be an independent factor for the HRQOL in HD and chronically ill patients.5,6 In the present study depression was the single predictor that affected all domains of WHOQOL-BREF. It seems that sleep complaints occurred as part of the symptomatology of depression. Severity of depression (BDI scores) had the strongest association with PSQI and all domains of the WHOQOL-BREF. This difference might be explained at least in part that, among HD patients ESRD directly influences sleep quality leading to impaired HRQOL. On the other hand, in Tx patients, sleep problems may improve or disappear with a functional graft.8,9 In renal transplant patients, sleep quality becomes less important predictor of HRQOL; depression and education appear to be more effective factors to determine HRQOL. The other sleep problems depend on the severity of depression. In this view our results replicated the findings of previous studies, which reported the importance of sleep in HD patients on a reverse angle. This study has several limitations. First the data were provided from self-reports of sleep-related phenomena. Sleep disturbances are measured most accurately with polysomnography. However, we chose a sleep quality measure that has been validated and compared with polysomnography and widely used in the studies in this area. Second, we did not measure anxiety and did not rule out other psychiatric disorders through a psychiatric interview. We chose to measure the severity of depressive symptoms with an instrument that is widely used and validated in the Turkish population. The cutoff point of the BDI for determining a major depressive disorder could have been too liberal. We did not exclude the group of patient who had higher scores than the cutoff point. Additionally BDI is a
measurement for the severity of the depressive mood, not a diagnostic tool for patients with major depressive disorders. Third, this study was cross-sectional in nature. Whether depressive symptomatology and sleep-related complaints persist after treatment for major depression needs to be ascertained in longitudinal research. Fourth, determining the other variables such as anxiety, creatinine level, used immunosuppressant therapy, life habits, conditioned arousal, and daytime napping, and their effects on the HRQOL would be desirable and may be subjects for future investigation for the Turkish Tx patients. In conclusion, the results of this study suggest that poor sleep is not common among Tx patients as much as dialysis patients, but still higher than the general population, and that quality of sleep is not an independent predictor of HRQOL of the Tx patients because of the recovery of sleep disorders. Severity of the depressive symptomatology was the single predictor of all domains of the HRQOL, education seemed to be an another effective factor for living conditions that are a component of HRQOL. Our study reports that Tx is a strong treatment choice for the healing of the sleep and related disorders in ESRD patients, but clinicans should be careful about the rest of the patients who still have sleep complaints that seem to be related to the effects of depression. Additional studies are needed to examine treatments, such as sleep medications, antidepressives, education, and psychotherapy as well as to evaluate potential confounders such as sexual life disorders, life habits, anxiety, daily stress, caffeine, and alcohol for their effects on HRQOL in the posttransplant period. REFERENCES 1. Turkey National Hemodialysis, Transplantation and Nephrology Registry Report, 2002 2. Holley JL, Nespor S, Rault R: A comparison of reported sleep disorders in patients on chronic hemodialysis and continuous peritoneal dialysis. Am J Kidney Dis 19:156, 1992
ERYILMAZ, OZDEMIR, YURTMAN ET AL 3. Walker S, Fine A, Kryger MH: Sleep complaints are common in a dialysis unit. Am J Kidney Dis 26:751, 1995 4. Williams SW, Toll CS, Zong B, et al: Correlates of sleep behaviour among hemodialysis patients. Am J Nephrol 22:18, 2002 5. Iliescu EA, Coo H, McMurray MH, et al: Quality of sleep and health related quality of life in haemodialysis patients. Nephrol Dial Transplant 18:125, 2003 6. Katz DA, Mc Horney CA: The relationship between insomnia and health related quality of life in patients with chronic illness. J Fam Pract 51:229, 2002 7. Sanner BM, Tepel M, Eser M, et al: Sleep-related breathing disorders impair quality of life in haemodialysis recipients. Nephrol Dial Transplant 17:1260, 2002 8. Winkelmann J, Stautner A, Samtleben W, et al: Long-term course of restless legs syndrome in dialysis patients after kidney transplantation. Movement Disorders 17-5:1072, 2002 9. Auckley DH, Schmidt-Nowara W, Brown LK: Reversal of sleep apnea-hypopnea syndrome in end stage renal disease after kidney transplantation. Am J Kidney Dis 34:739, 1999 10. Dew MA, Switzer GE, Goycoolea S, et al: Does transplantation produce quality of life benefits? Transplantation 64:1261, 1997 11. Franke GH, Heemann U, Kohnle M, et al: Quality of life in patients before and after kidney transplantation. Psychol Health 14:1037, 2000 12. Gudex CM: Health-related quality of life in end-stage renal failure. Qual Life Res 4:359, 1995 13. Valderrabano F, Jofre R, Lopez-Gomez JM: Quality of life in end-stage renal disease patients. Am J Kidney Dis 38:443, 2001 14. The WHOQOL Group: Development of the World Health Organization WHOQOL-brief quality of life assessment. Psychol Med 28:551, 1998b 15. Buyssee DJ, Reynolds CF 3rd, Monk TH, et al: The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res 28:193, 1989 16. Hisli N: Beck depresyon envanterinin üniversite ög˘rencileri için geçerlig˘i, güvenirlig˘i. Psikoloji Dergisi 7:13, 1989 17. Fidaner H, Elbi H, Fidaner C, et al: WHOQOL-100 ve WHOQOL-BREF’in psikometrik özellikleri. 3P Dergisi 7:23, 1999 18. Agargun MY, Kara H, Anlar O: Pittsburgh uyku kalitesi indeksi’nin geçerlig˜i ve güvenirlig˜i. Türk Psikiyatri Dergisi 7:107, 1996