Multiple measurements of depression predict mortality in a longitudinal study of chronic hemodialysis outpatients

BACKGROUND

The medical risk factors associated with increased mortality in hemodialysis (HD) patients are well known, but the psychosocial factors that may affect outcome have not been clearly defined. One key psychosocial factor, depression, has been considered a predictor of mortality, but previous studies have provided equivocal results regarding the association. We sought to determine whether depressive affect is associated with mortality in a longitudinal study of end-stage renal disease (ESRD) patients treated with HD, using multiple assessments over time.

METHODS

Two hundred ninety-five outpatients with ESRD treated with HD were recruited from three outpatient dialysis units in Washington D.C. to participate in a prospective cohort study with longitudinal follow-up. Patients were assessed every six months for up to two years using the Beck Depression Inventory (BDI), age, serum albumin concentration, Kt/V, and protein catabolic rate (PCR). A severity index, previously demonstrated to be a mortality marker, was used to grade medical comorbidity. The type of dialyzer with which the patient was treated was noted. Patient mortality status was tracked for a minimum of 20 and a maximum of 60 months after the first interview. Cox proportional hazards models, treating depression scores as time-varying covariates in a univariable analysis, and controlling for age, medical comorbidity, albumin concentration, and dialyzer type and site in multivariable models, were used to assess the relative mortality risk.

RESULTS

The mean (+/- SD) age of our population at initial interview was 54.6 +/- 14.1 years. The mean PCR was 1.06 +/- 0.27 g/kg/day, and the mean Kt/V was 1.2 +/- 0.4 at baseline, suggesting that the patients were well nourished and dialyzed comparably to contemporary U.S. patients. The patients' mean BDI at enrollment was 11.4 +/- 8.1, in the range of mild depression. Patients' baseline level of depression was not a significant predictor of mortality at 38.6 months of follow-up. In contrast, when depression was treated as a time-varying covariate based on periodic follow-up assessments, the level of depressive affect was significantly associated with mortality in both single variable and multivariable analyses.

CONCLUSIONS

Higher levels of depressive affect in ESRD patients treated with HD are associated with increased mortality. The effects of depression on patient survival are of the same order of magnitude as medical risk factors. Our findings using both controls for factors possibly confounded with depressive affect in patients with ESRD and time-varying covariate analyses may explain the inconsistent results of previous studies of depression and mortality in ESRD patients. Time-varying analyses in longitudinal studies may add power to defining and sensitivity to establishing the association of psychosocial factors and survival in ESRD patients. The mechanism underlying the relationship of depression and survival and the effect of interventions to improve depression in HD outpatients and general medical inpatients should be studied.

Interdialytic weight gain and survival in hemodialysis patients: effects of duration of ESRD and diabetes mellitus

BACKGROUND

Medical mortality determinants in end-stage renal disease (ESRD) patients treated with hemodialysis (HD) are well known. More recently, associations have been established between the dose of dialysis administered and patient survival. We showed in a prospective study that both dialyzer type and patient compliance with the dialysis prescription were independently associated with survival. Although several parameters of dialytic technique and patient compliance are associated with differential survival in patients with ESRD treated with HD, the association of interdialytic weight gain (IWG) with survival is unclear. No study has assessed the relationship between IWG and mortality in HD patients, controlled for multiple medical risk factors. The aim of our study was to determine whether IWG was associated with survival in patients with ESRD treated with HD, controlling for multiple medical and dialytic risk factors.

METHODS

We prospectively conducted an observational, longitudinal, multicenter study of 283 urban HD patients to determine the relationship of IWG with several dialytic parameters and patient survival. Medical risk factors such as demographic indices and comorbid conditions were assessed. We studied Kt/V, the protein catabolic rate (PCR), serum albumin and anthropometric measurements, behavioral compliance indices, dialyzer characteristics, and serum electrolyte concentrations, and correlated these with IWG. In addition, the duration of dialysis was assessed in HD patients with and without diabetes mellitus. Cox proportional hazards models assessed the relative mortality risk of increased IWG, controlling for variations in medical comorbidity and other mortality determinants.

RESULTS

The mean (+/- SD) age of our population was 54.6 +/- 14.1 years, and the mean time they were treated with HD was 30.4 +/- 46.9 months. The mean IWG was 1.54 +/- 0.71% dry wt/day. Correlations were found between increased IWG and younger age, and lower midarm circumference, and increased Kt/V, PCR, and serum potassium concentration. The mean follow-up period was 48.9 +/- 10.6 months. An increase in IWG was associated with a significantly increased relative mortality risk in diabetic ESRD patients treated with HD when variations in age, comorbidity, serum albumin concentration, and dialyzer type and site were controlled. There was, however, no association of increased mortality risk with increased IWG in the larger population of patients without diabetes. In further analyses, the increased mortality risk associated with increased IWG was found to be present only in patients with diabetes mellitus who had recently started HD therapy for ESRD.

CONCLUSION

IWG is correlated with several nutritional and dialytic variables and with parameters that predict survival in HD patients. Increased IWG is independently associated with decreased survival of diabetic ESRD patients treated with HD, after adjusting for variation in other medical risk factors. The population of incident diabetic HD patients is particularly susceptible to increased risk associated with increased IWG. The mechanisms underlying these results are obscure, but IWG might be associated with poorer survival in this population if it were linked to worsened hypertension, cardiovascular stress, or poorer glycemic control. Interventions to improve compliance with IWG in incident diabetic HD patients are warranted.

Immunologic function and survival in hemodialysis patients

BACKGROUND

Although the medical determinants of mortality in patients with end-stage renal disease (ESRD) treated with hemodialysis (HD) are well appreciated, the contribution of immunologic parameters to survival in such patients is unclear, especially when variations in age, medical comorbidity and nutrition are controlled. In addition, although dysregulation of cytokine metabolism has been appreciated in patients with ESRD, the association of these parameters with outcomes has not been established. Recently, the type of dialyzer used in patients' treatment has been associated with survival, but the mechanisms underlying these findings, including their immune effects, have not been established. We conducted a prospective, cross-sectional, observational multicenter study of urban HD patients to determine the contribution of immunological factors to patient survival. We hypothesized increased proinflammatory cytokines would be associated with increased mortality, and that improved immune function would be associated with survival.

METHODS

Patients were assessed using demographic and anthropometric indices, Kt/V, protein catabolic rate (PCR) and immunologic variables including circulating cytokine [interleukin (IL)-1, IL-2, IL-4, IL-5, IL-6, IL-12, IL-13 and tumor necrosis factor (TNF)-alpha] levels, total hemolytic complement activity (CH50), and T cell number and function. A severity index, previously demonstrated to be a mortality marker, was used to grade medical comorbidity. A Cox proportional hazards model, controlling for patients' age, severity index, level of serum albumin concentration, dialyzer type and dialysis site was used to asses relative survival risk.

RESULTS

Two hundred and thirty patients entered the study. The mean (+/- SD) age of the population was 54.4 +/- 14.2 years, mean serum albumin concentration was 3.86 +/- 0.47 g/dl, mean PCR was 1.1 +/- 0.28 g/kg/day, and mean Kt/V 1.2 +/- 0.3. Patients' serum albumin concentration was correlated with levels of Kt/V and PCR, and their circulating IL-13 and TNF-alpha levels, but negatively with their circulating IL-2 levels, T-cell number and T-cell antigen recall function. T-cell antigen recall function correlated negatively with PCR, but not Kt/V. There was no correlation of any other immune parameter and medical or demographic factor. Immune parameters, were all highly intercorrelated. Mean level of circulating cytokines in HD patients were in all cases greater than those of a normal control group. There were few differences in medical risk factors or immune parameters between patients treated with different types of dialyzers. After an almost three-year mean follow-up period, increased IL-1, TNF-alpha, IL-6, and IL-13 levels were significantly associated with increased relative mortality risk, while higher levels of IL-2, IL-4, IL-5, IL-12, T-cell number and function, and CH50 were associated with improved survival. The difference in survival between patients treated with unmodified cellulose dialyzers and modified or synthetic dialyzers approached the level of statistical significance, but there were no differences in levels of circulating cytokines between these two groups.

CONCLUSIONS

Higher levels of circulating proinflammatory cytokines are associated with mortality, while immune parameters reflecting improved T-cell function are associated with survival in ESRD patients treated with HD, independent of other medical risk factors. These factors may serve as markers for outcome. The mechanism underlying the relationship of immune function and survival, and the effect of interventions to normalize immune function in HD patients should be studied.

Psychosocial factors, behavioral compliance and survival in urban hemodialysis patients

BACKGROUND

The medical risk factors associated with increased mortality in hemodialysis (HD) patients are well known, but the psychosocial factors that may affect outcome have not been clearly defined. Psychosocial factors could affect mortality through interaction with parents' nutrition or their compliance with the dialysis prescription. We conducted a prospective, longitudinal, multicenter study of urban HD patients to determine the contribution of compliance and psychosocial factors to patient survival.

METHODS

Patients were assessed using indices of social support, patient's assessments of their well-being, including illness effects (IEQ), and satisfaction with life (SWLS), the Beck Depression Inventory (BDI), serum albumin concentration, Kt/V and protein catabolic rate (PCR). Behavioral compliance was measured three ways: percent time actually dialyzed per treatment compared to prescribed time (shortening behavior); percent sessions attended (skipping behavior) and total integrated time compliance (% TCOMP). A severity index, previously demonstrated to be a mortality marker, was used to grade medical comorbidity. The typed of dialyzer the patient was treated with was noted. A Cox proportional hazards model, controlling for age, medical comorbidity, albumin concentration and dialyzer type was used to assess relative mortality risk of variations in psychosocial factors and behavioral compliance.

RESULTS

A total of 295 patients (60.8% of those eligible) agreed to participate. The mean ( +/- SD) age of our population was 54.6 +/- 14.1 year, mean PCR was 1.06 +/- 0.27 g/kg/day, and mean Kt/V 1.2 +/- 0.4, suggesting the patients were well nourished and adequately dialyzed. The patients' mean BDI was 11.4 +/- 8.1 (in the range of mild depression). Patients' SWLS was similar to that of a group of patients without chronic illness. After a 26 month mean follow-up period, higher levels of perceived social support, improved perception of the effects of illness and increased behavioral compliance were significantly associated with decreased relative mortality risk (0.8, 0.77, and 0.79, respectively), controlled for variations in patients' age, severity of illness, serum albumin concentration and dialyzer type. Variations in depression and Kt/V were not predictors of mortality during the observation period.

CONCLUSIONS

Lower levels of social support, decreased behavioral compliance with the dialysis prescription, and increased negative perception of the effects of illness are independently associated with increased mortality in ESRD patients treated with HD. The effects are of the same order of magnitude as medical risk factors. Such effects may be attributable to a relationship between a patients' perception of social support and effects of illness and behavior, with other factors such as the provision of better medical care in patients with larger social networks. The mechanism underlying the relationship of psychosocial factors and compliance and survival, and the effect of interventions to improve perception of illness, and increase social support and compliance with the dialysis prescription in HD patients should be studied.

Engagement of African American families in research on chronic illness: a multisystem recruitment approach

Our multisystem approach addressed the recruitment of African American families with a chronically, physically ill member. The approach focused on the social transactions between the family, the healthcare team, and the research staff, and the influence of these transactions on family recruitment. This multisystem approach included three core strategies: defining the membership of families in a culturally appropriate fashion and engaging those members; engaging the healthcare team; and building and maintaining the skills and morale of the research staff. A description of a longitudinal family health study and potential sources of recruitment biases is provided. Descriptive and bivariate analyses examined the effectiveness of the recruitment approach. A focus groups explored the reciprocal process of family protectiveness that both facilitated and hindered family recruitment and the research staff's alliance with families and the dialysis staff. Discussion focuses on the family health study's recruitment rate, sampling biases, and methods for improving the effectiveness of the multisystem recruitment approach.

Psychologic functioning, quality of life, and behavioral compliance in patients beginning hemodialysis

Psychologic and demographic characteristics have been shown to correlate with behavioral compliance in studies of prevalent hemodialysis (HD) patients. Few data, however, exist on the psychologic characteristics or their relationship to compliance in patients initiating HD treatment, or incident patients. Our previous work with prevalent HD patients showed an interrelationship among social support, perception of the effects of illness, and depression measured by a standardized depression index and a cognitive depression index deleting somatic symptoms. To compare psychosocial and behavioral compliance parameters in incident and prevalent patients, 99 incident HD patients undergoing dialysis for less than 6 months were assessed by using a variety of questionnaires. The patients' mean standardized depression index score was in the range of mild depression. There was no difference in mean age, Karnofsky functional status, perception of effects of illness or standardized or cognitive depression scores between incident patients and 149 prevalent patients treated with HD for 6 to 246 months. Satisfaction with life scores and perception of sexual adjustment were better, but Kt/V (quantitative measure of the amount of dialysis provided) and protein catabolic rate were lower in incident than in prevalent patients. Social support and perception of illness scores correlated with depression measures in incident patients, findings that were similar to prevalent patients. Incident (as did prevalent) patients showed striking bivariate correlations between the psychosocial and depression variables, but fewer correlations between psychologic and compliance measures. Both standard compliance parameters, such as mean predialysis serum phosphorus and potassium concentration, and behavioral compliance were better in incident than in prevalent patients. Worsened sexual adjustment, functional status, and increased severity of illness were correlated with improved behavioral compliance in incident patients. Behavioral compliance styles correlated with different social support and severity of medical illness variables in incident and prevalent patients, when assessed by multiple linear regression analysis. These different patterns suggest the existence of different mechanisms of adaptation in the groups. Measures focused on increasing delivery of dialysis and enhancing social support in urban African-American patients starting HD therapy may be useful in improving compliance with the dialysis prescription, and indirectly improving survival.

Staff security and work pressure: contrasting patterns of stability and change across five dialysis units

Differences among clinical care units in social dynamics and social organization are associated with differences in the clinical course of patients with a range of chronic illness. These differences are also associated with well-being of staff members. Recent attention has focused on understanding these differences among units with an eye towards correcting deficiencies and enhancing strengths of clinical care units. The current study sought to delineate the effect of social and organizational dynamics unique to each unit on staff perceptions of the security of their relationships with other staff and their perceived work pressure. The unit as a major source of differences among staff subjects was compared with the impact of ethnic identity, of work in the morning shift vs other shifts, and of professional role. Results confirmed that unit membership was, by far, the most important correlate of staff perceptions of the unit, particularly those concerning security of relationships with others and perceived work pressure. Moreover, the results suggested that unit differences in perceived security were due to differences among units in long standing turmoil within the unit or long standing problematic ties between the unit and the larger institution which controls it. However, perceived work pressure seems more transient and may reflect the challenge of shorter-term fluctuations in the demands of patient care.

Aspects of quality of life in hemodialysis patients

The proper means of measuring quality of life in chronically ill patients is unclear. Because different measures may assess varied aspects of patients' experience and because they may be interrelated in different ways, the relationship between several of these quality-of-life measures, including indices of psychological well-being, social support, and severity of illness in ESRD patients treated with hemodialysis (HD), was prospectively assessed. In addition, it was determined whether patients' assessment of quality of life, along any dimension, was related to patient compliance in three urban HD units, in a population largely composed of African-American patients. Severity of illness scores correlated with both attendance and compliance with the dialysis prescription. Karnofsky scores correlated inversely with age, depression, social environment, and level of severity of illness, as expected, but not with behavioral compliance measures. Social support scores correlated with perception of illness, depression, satisfaction with life, and adjustment to illness scores, but not with behavioral or standard compliance measures. Perception of illness scores correlated with depression, social support, adjustment to illness, and satisfaction with life scores, but not with Karnofsky ratings, severity scores, or standard and/or behavioral compliance measures. Social environment scores correlated with almost all assessed variables, with the exception of anthropometric measurements, predialysis phosphorus levels, and behavioral compliance measures. Satisfaction with life scores (a global, subjective measure of quality of life) correlated with advancing age, level of social support, severity of illness, and the presence of a relationship, but were not correlated with Karnofsky scores. These data suggest that quality of life in patients treated with HD must be measured in several ways. The Psychological Adjustment to Illness Scale Social Environment score may be a useful, generalizable adjunct measure of quality of life in HD patients, in addition to the Satisfaction With Life Scale. Quality of life and perception of the effects of illness are not necessarily associated with functional ability in HD patients. These findings must be considered where making decisions about the discontinuation of HD treatment.

Behavioral compliance with dialysis prescription in hemodialysis patients

The relationship between compliance and outcome is poorly understood, partially because there has been no gold standard for measuring compliance in hemodialysis patients. To investigate interrelationships between psychological, medical, and compliance factors, hemodialysis (HD) patients were studied with the Beck Depression Inventory, and a subset, the Cognitive Depression Index, the Perception of Illness Effects scale, and the Multidimensional Scale of Perceived Social Support. Behavioral compliance was measured in three ways: (1) percent time compliance (signifying "shortening behavior"); (2) percent attendance (signifying "skipping behavior) (3) percent total time compliance, assessing patients' time on dialysis normalized for prescribed time, including all shortenings and absences. Standard compliance indicators (predialysis serum potassium and phosphorus concentrations and interdialytic weight gain) were also analyzed. The patients' mean Beck Depression Inventory was in the range of mild depression. The prevalence of depression was 25.5%. Both depression indices correlated with Perception of Illness Effects scale scores. In general, social support was related to both measures of depression and perception of illness effects. Total time compliance was 95.8 +/- 5.0%. Younger patients were more likely to skip treatments compared with older patients. Time compliance comprised a wide spectrum, with most patients relatively compliant, whereas a small proportion received far less than their prescribed dialysis. Skipping and shortening behaviors did not correlate, suggesting that these constitute two separate types of noncompliant behaviors. Time compliance parameters did not correlate with potassium levels or interdialytic weight gain, but did correlate with phosphorus levels. Interrelationships between behavioral compliance measures and other parameters varied between units and patients of different gender. Finally, behavioral compliance patterns were stable over months in patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Sexual function and mental distress status of patients with end-stage renal disease on hemodialysis

There were changes in the sexual functioning of the patient with ESRD after starting hemodialysis. This was marked by decrease in the sex urge, the frequency of intercourse, and the level of satisfaction. The majority of the male patients reported some amount of morning erection, indicating reasons other than physiologic reasons for their sexual dysfunction. The level of mental distress was very low, and younger patients may suffer from a higher level of mental stress. Intervention through individual counseling and sex therapy may be beneficial to most of these patients.