Kidney Disease Questionnaire Research Articles

Relationship between hemoglobin level and quality of life in anemic patients with chronic kidney disease receiving epoetin alfa

ABSTRACTObjectives: To evaluate the relationship between hemoglobin (Hb) level and quality of life (QOL) in anemic patients with non-dialysis chronic kidney disease receiving epoetin alfa.Patients and methods: A post-hoc analysis using data from a multicenter, open-label, prospective study of epoetin alfa for anemia in patients with chronic kidney disease not on dialysis was conducted. The relationship between Hb and QOL was analyzed using correlation and longitudinal analyses, the latter adjusting for sample selection bias. The Linear Analog Scale Assessment (LASA) and the Kidney Disease Questionnaire (KDQ) subscales were used to measure QOL. The impact of an incremental 1 g/dL increase in Hb level on LASA and KDQ scores was determined using an incremental analysis.Results: A total of 1183 and 1044 patients formed the study populations for the LASA and KDQ analyses, respectively. There was a positive and significant relationship between Hb levels and QOL ( p < 0.05). Using non-linear regression analysis, we characterized the sigmoid-shape of the relationship between Hb levels and QOL scores. Hemoglobin change was a statistically significant determinant of QOL improvement for both LASA and KDQ scales ( p < 0.05). The model predicted that, based on a 2 unit change in Hb, the greatest incremental QOL improvement per unit of Hb increase occurred when Hb was in the range of 11 to 12 g/dL.Conclusions: This study demonstrates that, beyond the well-known relationship between Hb increases and QOL improvements, the maximal incremental gain in QOL occurred when Hb reached 11 to 12 g/dL. This suggests that treating anemic patients with non-dialysis chronic kidney disease until their Hb level reaches 12 g/dL will result in the greatest QOL improvement per Hb unit increase. The analyses were conducted based on an open-label study of epoetin alfa and could be further validated using a randomized, controlled trial, comparing incremental gains in QOL associated with treatment initiation at varying levels of Hb across arms.

Cultural adaptation and validation of the "Kidney Disease and Quality of Life - Short Form (KDQOL-SF™ 1.3)" in Brazil

The objective of the present study was to translate the Kidney Disease Quality of Life -- Short Form (KDQOL-SF 1.3) questionnaire into Portuguese to adapt it culturally and validate it for the Brazilian population. The KDQOL-SF was translated into Portuguese and back-translated twice into English. Patient difficulties in understanding the questionnaire were evaluated by a panel of experts and solved. Measurement properties such as reliability and validity were determined by applying the questionnaire to 94 end-stage renal disease patients on chronic dialysis. The Nottingham Health Profile Questionnaire, the Karnofsky Performance Scale and the Kidney Disease Questionnaire were administered to test validity. Some activities included in the original instrument were considered to be incompatible with the activities usually performed by the Brazilian population and were replaced. The mean scores for the 19 components of the KDQOL-SF questionnaire in Portuguese ranged from 22 to 91. The components "Social support" and "Dialysis staff encouragement" had the highest scores (86.7 and 90.8, respectively). The test-retest reliability and the inter-observer reliability of the instrument were evaluated by the intraclass correlation coefficient. The coefficients for both reliability tests were statistically significant for all scales of the KDQOL-SF (P < 0.001), ranging from 0.492 to 0.936 for test-retest reliability and from 0.337 to 0.994 for inter-observer reliability. The Cronbach's alpha coefficient was higher than 0.80 for most of components. The Portuguese version of the KDQOL-SF questionnaire proved to be valid and reliable for the evaluation of quality of life of Brazilian patients with end-stage renal disease on chronic dialysis.

Health-related quality of life outcomes after kidney transplantation

With the improvements in short and long term graft and patient survival after renal transplantation over the last two decades Health-Related Quality of Life (HRQL) is becoming an important additional outcome parameter. Global and disease specific instruments are available to evaluate objective and subjective QOL. Among the most popular global tools is the SF-36, examples of disease specific instruments are the Kidney Transplant Questionnaire (KTQ), the Kidney Disease Questionnaire (KDQ) and the Kidney Disease-Quality of Life (KDQOL). It is generally accepted that HRQL improves dramatically after successful renal transplantation compared to patients maintained on dialysis treatment but listed for a transplant. It is less clear however which immunosuppressive regimen confers the best QOL. Only few studies compared the different regimens in terms of QOL outcomes. Although limited in number, these studies seem to favour non-cyclosporine based protocols. The main differences that could be observed between patients on cyclosporine versus tacrolimus or sirolimus therapy concern the domains of appearance and fatigue. This may be explained by two common adverse effects occurring under cyclosporine therapy, gingival hyperplasia and hair growth. Another more frequently occurring side effect under calcineurin inhibitor therapy is tremor, which may favour CNI free protocols. This hypothesis, however, has not been formally evaluated in a randomised trial using HRQL measurements.In summary HRQL is becoming more of an issue after renal transplantation. Whether a specific immunosuppressive protocol is superior to others in terms of HRQL remains to be determined.

General or Disease Specific Questionnaire? A Comparative Study in Hemodialysis Patients

Objective. Today questionnaires developed to assess important outcome measures such as health-related quality of life are widely used. In this study we evaluated the construct validity of the Nottingham Health Profile (NHP) and the reliability of its Turkish version in hemodialysis patients. Methods. In a sample of patients on renal dialysis (n = 94) the quality of life is measured by the NHP. The validity of this questionnaire is evaluated by using the Kidney Disease Questionnaire (KDQ) in the same patient group. The NHP is administered twice to each patient, at dialysis intervals two weeks apart. Results. NHP scores at both administrations are similar in both assessments. Pearson's correlation coefficients range from 0.61 to 0.84. Cronbach's alpha coefficients for the NHP sections range between 0.64 and 0.79. The alpha coefficients for three of the NHP scales (energy, sleep and social isolation) are well below 0.7. In the KDQ the mean values obtained for the five dimensions are: 4.2 ± 1.5 for physical symptoms, 4.8 ± 1.7 for fatigue, 4.9 ± 1.9 for depression, 4.2 ± 1.2 for relationship with others, and 4.8 ± 1.5 for frustration. In general the correlation between the dimensions of the NHP and KDQ is good and the correlation coefficients varies from 0.18 to 0.73. Clinical validity is assessed by examining the correlation between the results obtained for the two questionnaires (components of the NHP and KDQ) and hemoglobin level, number of the co-morbid conditions and educational level. Conclusions. The NHP is shown to have construct validity when used in patients with end-stage renal disease (ESRD) in Turkey. The application of the NHP in patients with ESRD is easy, fast and the questions are not difficult to understand. The multiple-degree scoring in the KDQ causes a complexity in answering. The correlation between the dimensions of the NHP and KDQ is good. Our results show better correlations between disease specific questionnaires and clinical parameters.

Intravenous l-carnitine increases plasma carnitine, reducesfatigue, and may preserve exercise capacity in hemodialysis patients

Exercise capacity in patients with end-stage renal disease (ESRD) remains impaired despite correction ofanemia. Carnitine insufficiency may contribute to impaired exercise and functional capacities in patients with ESRD. Two randomized placebo-controlled trials were conducted to test whether intravenous l-carnitine improves exercise capacity (assessed by maximal rate of oxygen consumption [VO2max]) and quality of life (measured by the Kidney Disease Questionnaire [KDQ]) in patients with ESRD. In study A, patients were administered l.-carnitine, 20 mg/kg (n = 28), or placebo (n = 28) intravenously at the conclusion of each thrice-weekly dialysis session for 24 weeks. In study B, a dose-ranging study, patients were administered intravenous l-carnitine, 10 mg/kg (n = 32), 20 mg/kg (n = 30), or 40 mg/kg (n = 32), or placebo (n = 33) as in study A. The prospective primary statistical analysis evaluated changes in VO2max in each study and specified that changes in the KDQ were assessed only in the combined populations. l-Carnitine supplementation increased plasma carnitine concentrations, but did not affect VO2max in either study. Because change in VO2max showed significant heterogeneity, a secondary analysis using a mixture of linear models approach on the combined study populations was performed. l-Carnitine therapy (combined all doses) was associated with a statistically significant smaller deterioration in VO2max (-0.88 ± 0.26 versus −0.05 ± 0.19 mL/kg/min, placebo versus l-carnitine, respectively; P = 0.009). l-Carnitine significantly improved the fatigue domain of the KDQ after 12 (P = 0.01) and 24 weeks (P = 0.03) of treatment compared with placebo using the primary analysis but did not significantly affect the total score (P = 0.10) or other domains of the instrument (P > 0.11). Carnitine was well tolerated, and no drug-related adverse effects were identified. Intravenous l-carnitine treatment increased plasma carnitine concentrations, improved patient-assessed fatigue, and may prevent the decline in peak exercise capacity in hemodialysis patients. VO2max in the primary analysis and other assessed end points were unaffected by carnitine therapy.

Long-Term Knowledge Retention following Predialysis Psychoeducational Intervention

Background/Aims: Early identification and predialysis psychoeducation are gaining acceptance. Although research supports the immediate value of predialysis interventions, long-term benefits remain unknown. We examined long-term knowledge retention following a psychoeducational intervention. Methods: 47 progressive renal failure patients completed the Kidney Disease Questionnaire at baseline and 18, 30, 42, and 54 months after initiating renal replacement therapy (RRT; the ‘longitudinal’ sample). A larger cohort provided data at one or more of these points (n = 132, 117, 101, and 70 at 18, 30, 42, and 54 months, respectively; the ‘cross-sectional’ sample). Results: Initial knowledge gains among psychoeducation recipients were followed by a significant knowledge advantage for three groups throughout follow-up. Patients who received predialysis psychoeducation either before or after starting dialysis demonstrated superior Kidney Disease Questionnaire scores as compared with those identified before the initiation of RRT who received the usual standard of practice. Patients identified after the initiation of RRT and who received standard education, however, demonstrated the same level of knowledge retention as produced by psychoeducation. The results were identical across the longitudinal and cross-sectional samples. Conclusions: Patient education produces important benefits in end-stage renal disease, but the incremental value of early intervention remains to be demonstrated.

Formal literature review of quality-of-life instruments used in end-stage renal disease

Although quality-of-life assessment is an important complement to conventional clinical evaluation, there are limited opportunities for researchers in end-stage renal disease (ESRD) to examine evidence for a range of quality-of-life measures. To better understand how quality of life has been conceptualized, measured, and evaluated for ESRD, we conducted a structured literature review. Eligible articles were identified from a MEDLINE search, expert input, and review of references from eligible articles. A standardized instrument was created for article review and included type of measure, instrument development process, study sample characteristics, quality-of-life domains, and reliability and validity testing. From 436 citations, 78 articles were eligible for final review, and of those, 47 articles contained evidence of reliability or validity testing. Within this set, there were 113 uses of 53 different instruments: 82% were generic and 18% were disease specific. Only 32% defined quality of life. The most frequently assessed domains were depression (41%), social functioning (32%), positive affect (30%), and role functioning (27%). Testing was completed for test-retest reliability (20%), interrater reliability (13%), internal consistency (22%), content validity (24%), construct validity (41%), criterion validity (55%), and responsiveness (59%). Few articles measuring quality of life in ESRD defined quality-of-life domains or adequately described instrument development and testing. Generic measures, such as the Sickness Impact Profile, and disease-specific measures, such as the Kidney Disease Questionnaire, had been tested more thoroughly than others. Standardized reporting and more rigorous testing could help researchers make informed choices about instruments that would best serve their own and their patients’ needs.

Knowledge of disease and dietary compliance in patients with end-stage renal disease.

Noncompliance is a common problem in patients with end-stage renal disease. In this study, we assessed the relationship between knowledge of disease and dietary compliance in a cohort of 56 dialysis patients. Based on a health belief model of adherence, we predicted that dialysis patients who knew more about kidney disease and its treatment would be more complaint than those who knew less about these matters. We also examined the relationship between dietary compliance and patients' emotional well-being. We used a composite measure of compliance consisting of serum K, P, and interdialytic weight gain. A 30-item "Kidney Disease Questionnaire" was used to assess patients' knowledge of their illness. Contrary to prediction, compliers did not score higher on the knowledge questionnaire; in fact, the observed correlation of .32 was in the opposite direction. In the same vein, we found no relationship between compliance and emotional well-being. These results, although somewhat surprising, add to a growing body of research which indicates that medical compliance involves more than educating patients about the mechanisms and treatment of their illness.

KNOWLEDGE OF DISEASE AND DIETARY COMPLIANCE IN PATIENTS WITH END-STAGE RENAL DISEASE

Noncompliance is a common problem in patients with end-stage renal disease. In this study, we assessed the relationship between knowledge of disease and dietary compliance in a cohort of 56 dialysis patients. Based on a health belief model of adherence, we predicted that dialysis patients who knew more about kidney disease and its treatment would be more compliant than those who knew less about these matters. We also examined the relationship between dietary compliance and patients' emotional well-being. We used a composite measure of compliance consisting of serum K, P, and interdialytic weight gain. A 30-item “Kidney Disease Questionnaire” was used to assess patients' knowledge of their illness. Contrary to prediction, compilers did not score higher on the knowledge questionnaire; in fact, the observed correlation of .32 was in the opposite direction. In the same vein, we found no relationship between compliance and emotional well-being. These results, although somewhat surprising, add to a growing body of research which indicates that medical compliance involves more than educating patients about the mechanisms and treatment of their illness.

Time of diagnosis of chronic renal failure and assessment of quality of life in haemodialysis patients.

Time of diagnosis of chronic renal failure ani predialysis care may be important factors related to the quality of life of patients on dialysis treatment. We evaluated the quality of life of 113 haemodialysis patients who had a late (< or = 1 month before starting dialysis, n = 53) or early (> or = 6 months, n = 60) diagnosis of chronic renal failure. At the time of the survey patients had been on dialysis for a median duration of 55 days (range 1-109). Quality of life was measured by the Kidney Disease Questionnaire (KDQ), including five dimensions with scales ranging from 1.0 to 7.0 (1.0 = more impairment): the health and life satisfaction indices (higher score = more dissatisfied), functional status (Karnofsky scale), and the time trade-off technique. Mean scores of quality of life measures were worse in the late- than in the early-diagnosis group. A significant difference (P < 0.05) was observed in the depression (4.46 +/- 1.45 vs 5.23 +/- 1.36), relationships with others (3.95 +/- 1.31 vs 4.53 +/- 1.31) and frustration (4.08 +/- 1.51 vs 5.21 +/- 1.34) dimensions of the KDQ. and in life satisfaction (4.11 +/- 1.92 vs 3.32 +/- 1.57). Functional status declined compared to 1 year before dialysis, particularly in the late-diagnosis group. Among the elderly patients, the magnitude of the difference was more pronounced, (including in the physical symptoms item of the KDQ). Our findings demonstrate that late diagnosis of chronic renal failure and the consequent lack of predialysis care adversely affect the quality of life of haemodialysis patients. Early diagnosis and regular predialysis care should be encouraged to improve the quality of life during dialysis treatment.

Postdialysis fatigue

To clarify the demographic and clinicolaboratory features of postdialysis fatigue (PDF), we enrolled 85 patients on maintenance hemodialysis in a cross-sectional study using validated questionnaires and chart review. Forty-three patients complained of fatigue after dialysis. On formal testing using the Kidney Disease Questionnaire, the PDF group had statistically greater severity of fatigue and somatic complaints than the group of patients without subjective fatique ( P = 0.03 and 0.04, respectively). On a scale measuring intensity of fatigue (1 = least to 5 = worst), the PDF group average was 3.4 ± 1.2. PDF subjects reported that 80% ± 25% of dialysis treatments were followed by fatigue symptoms. In 28 (65%) of patients, the symptoms started with the first dialysis treatment. They reported needing an average of 4.8 hours of rest or sleep to overcome the fatigue symptoms (range, 0 to 24 hours). There were no significant differences between patients with and without PDF in the following parameters: age; sex; type of renal disease; presence of diabetes mellitus, heart disease (congestive, ischemic), or chronic obstructive lung disease; blood pressure response to dialysis; type or adequacy of dialysis regimen; hematocrit; electrolytes; blood urea nitrogen; creatinine; cholesterol; albumin; parathyroid hormone; ejection fraction; and use of antihistamines, benzodiazepines, and narcotics. In the fatigue group, there was significantly greater use of antihypertensive medications known to have fatigue as a side effect ( P = 0.007). Depression was more common in the fatigue group by Beck Depression score (11.6 ± 8.0 v 7.8 ± 6.3; P = 0.02). We conclude that (1) postdialysis fatigue is a common, often incapacitating symptom in patients on chronic extracorporeal dialysis; (2) no routinely measured parameter of clinical or dialytic function appears to predict postdialysis fatigue; and (3) depression is highly associated with postdialysis fatigue, but the cause-effect relationship is unclear.

Outcome measurement in kidney disease.

The effects of chronic kidney disease have been difficult to quantify using traditional measures of mortality and biological processes. New approaches to the quantification of outcomes in kidney disease are required. A wide variety of methods have become available and are now in use in some studies. Psychometric approaches, such as the Sickness Impact Profile and the Kidney Disease Questionnaire, have been shown to be responsive to change in some clinical studies. In order to estimate the cost-effectiveness of investments in kidney disease, decision theory approaches are required. We argue that these decision theory approaches should be given serious consideration for inclusion in clinical trials and in the US Renal Data System.

Epoetin: a pharmacoeconomic review of its use in chronic renal failure and its effects on quality of life.

Epoetin (recombinant human erythropoietin) is an effective treatment for the anaemia of patients with chronic renal failure. It is well tolerated, and the risk of adverse effects that are caused by too rapid a correction of anaemia, for example hypertension, can be reduced in most cases by lower starting dosage regimens. Epoetin improves the quality of life of anaemic patients with end-stage renal disease (ESRD), and significant improvements in most parameters of the Kidney Disease Questionnaire, the Sickness Impact Profile and the Nottingham Health Profile have been reported by patients. However, acquisition costs of epoetin are high, thereby adding a considerable cost to ESRD therapy despite a reduction in blood transfusion requirements. Notwithstanding, although cost-effectiveness studies have indicated that epoetin is associated with higher costs of therapy, cost-benefit analysis indicates that these costs can be reduced markedly with low-dose regimens and may be completely recovered if patients regain employment.

Erythropoietin for anaemia in haemodialysis patients: results of a maintenance study (The Canadian Erythropoietin Study Group)

Most published studies of recombinant human erythropoietin (rHuEpo) have been of limited duration and in small patient populations. The present study examines the long-term effects of rHuEpo in 98 haemodialysis patients treated for up to 18 months. All patients had completed a 6 month placebo-controlled study of rHuEpo. Patients previously on placebo (group 1; n = 31) received rHuEpo at an initial dose of 50 U/kg thrice weekly with subsequent dose adjustments to maintain haemoglobin (Hb) in the range 105-120 g/l. Patients previously on rHuEpo (group 2; n = 67) continued on their usual dose with adjustments made to maintain Hb at 105-120 g/l. Haematological parameters were measured every 2 weeks. Quality of life, assessed by a disease-specific kidney disease questionnaire (KDQ), was measured every 6 months. Mean Hb in group 1 increased from 74.2 +/- 11.4 g/l at baseline to 112.9 +/- 12.6 g/l after 12 months of rHuEpo therapy. After 12 weeks of rHuEpo therapy Hb in groups 1 and 2 was indistinguishable. Hb remained constant in both groups throughout the period of follow-up. Mean rHuEpo dose requirements were similar in both groups. At the end of the study the mean intravenous rHuEpo dose in group 1 patients was 176.6 +/- 154.4 and in group 2 patients was 210.0 +/- 144.0 U/kg per week. Access failure was increased during rHuEpo therapy in patients with synthetic grafts (46% versus 7% failures compared to fistulae; P less than 0.001). Group 1 patients receiving rHuEpo had a significant increase in diastolic but not systolic blood pressure despite a 32% increase in overall antihypertensive prescriptions.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of generic and specific quality-of-life measures in hemodialysis patients treated with erythropoietin

The effect of recombinant human erythropoietin (EPO) on the quality of life and exercise capacity of 118 hemodialysis patients was assessed in a randomized, double-masked placebo-controlled trial. Patients were randomized into three groups: 1) placebo, 2) EPO to achieve a hemoglobin of 95-110 g/L and 3) EPO to achieve a hemoglobin of 115–130 g/L. Patients were followed for six months. Quality of life was assessed using a disease-specific measure [the Kidney Disease Questionnaire (KDQ)] and two generic measures [Sickness Impact Profile (SIP) and the Time Trade Off (TTO)]. The KDQ contains five dimensions. Functional capacity was assessed with a Six-Minute Walk test (SMW) and an Exercise Stress Test (EST). The mean hemoglobin at six months was 74, 102, and 117 gm/l in groups one, two and three, respectively. There was a marked improvement in quality of life with EPO therapy, but no difference between groups 2 and 3. The outcome measure that was the most responsive to change was the KDQ ( P < .001 for the fatigue and physical symptoms dimensions). The aggregate global ( P <.02) and physical ( P = .005) scores of the SIP improved with EPO therapy, the psychosocial score did not. There was no improvement in the TTO. There was an improvement in the EST ( P = .02) but not in the SMW. The reproducibility of the outcome measures in placebo-treated patients varied between 0.80 and 0.98 (intra-class correlation coefficient). The correlation among the outcome measures at six months was statistically significant in most cases, as was the correlation of change scores between baseline and six months.

Association between recombinant human erythropoietin and quality of life and exercise capacity of patients receiving haemodialysis. Canadian Erythropoietin Study Group.

To determine whether recombinant human erythropoietin improves the quality of life and exercise capacity of anaemic patients receiving haemodialysis. A double blind, randomised, placebo controlled study. Eight Canadian university haemodialysis centres. 118 Patients receiving haemodialysis aged 18-75 with haemoglobin concentrations less than 90 g/l, no causes of anaemia other than erythropoietin deficiency, and no other serious diseases. Patients were randomised to three groups to receive placebo (n = 40), erythropoietin to achieve a haemoglobin concentration of 95-110 g/l (n = 40), or erythropoietin to achieve a haemoglobin concentration of 115-130 g/l (n = 38). Erythropoietin was given intravenously thrice weekly, initially at 100 units/kg/dose. The dose was subsequently adjusted to achieve the target haemoglobin concentration. All patients with a serum ferritin concentration less than 250 micrograms/l received oral or intravenous iron for one month before the study and as necessary throughout the trial. Scores obtained with kidney disease questionnaire, sickness impact profile, and time trade off technique; and results of six minute walk test and modified Naughton stress test. The mean (SD) haemoglobin concentration at six months was 74 (12) g/l in patients given placebo, 102 (10) g/l in those in the low erythropoietin group, and 117 (17) g/l in those in the high erythropoietin group. Compared with the placebo group, patients treated with erythropoietin had a significant improvement in their scores for fatigue, physical symptoms, relationships, and depression on the kidney disease questionnaire and in the global and physical scores on the sickness impact profile. The distance walked in the stress test increased in the group treated with erythropoietin, but there was no improvement in the six minute walk test, psychosocial scores on the sickness impact profile, or time trade off scores. There was no significant difference in the improvement in quality of life or exercise capacity between the two groups taking erythropoietin. Patients taking erythropoietin had a significantly increased diastolic blood pressure despite an increase in either the dose or number of antihypertensive drugs used. Eleven of 78 patients treated with erythropoietin had their sites of access clotted compared with only one of 40 patients given placebo. Patients receiving erythropoietin were appreciably less fatigued, complained of less severe physical symptoms, and had moderate improvements in exercise tolerance and depression compared with patients not receiving erythropoietin. At the doses used in this trial there was a higher incidence of hypertension and clotting of the vascular access in patients treated with erythropoietin.

The kidney disease questionnaire: A test for measuring patient knowledge about end-stage renal disease

Two studies report on the development of the Kidney Disease Questionnaire (KDQ) as a test for measuring patient knowledge about end-stage renal disease and its treatment. The KDQ is available in a 26-item version or as two parallel 13-item tests. Psychometric evaluations indicate that all versions show high levels of reliability. Initial validity tests are also promising. The KDQ is able to discriminate individuals well informed about kidney disease and its treatment from those who are not so well informed. It is also sensitive to the effects of an experimental education program and to ESRD-related knowledge that is acquired as a result of starting dialysis. Data and issues related to the administration, readability, demographic correlates, and a French translation of the KDQ are also presented and discussed.