A Cognitive Behavioral Group Approach to Enhance Adherence to ...

Dialysis Therapies

A Cognitive Behavioral Group Approach to Enhance Adherence to Hemodialysis Fluid Restrictions: A Randomized Controlled Trial John Sharp, DClinPsy, Matt R. Wild, DClinPsy, Andrew I. Gumley, PhD, and Christopher J. Deighan, MD ● Background: Adhering to fluid restrictions represents one of the most difficult aspects of the hemodialysis treatment regimen. This report describes a randomized controlled trial of a group-based cognitive behavioral intervention aimed at improving fluid-restriction adherence in patients receiving hemodialysis. It was hypothesized that the intervention would improve adherence, measured by means of interdialytic weight gain (IWG), without impacting negatively on psychosocial functioning. Methods: Fifty-six participants receiving hemodialysis from 4 renal outpatient settings were randomly assigned to an immediate-treatment group (ITG; n ⴝ 29) or deferredtreatment group (DTG; n ⴝ 27). Participants were assessed at baseline, posttreatment, and follow-up stages. Treatment consisted of a 4-week intervention using educational, cognitive, and behavioral strategies to enhance effective self-management of fluid consumption. Results: No significant difference in mean IWGs was found between the ITG and DTG during the acute-phase analysis (F1,54 ⴝ 0.03; P > 0.05). However, in longitudinal analysis, there was a significant main effect for mean IWG (F1.76,96.80 ⴝ 9.10; P < 0.001) and a significant difference between baseline and follow-up IWG values (t55 ⴝ 3.85; P < 0.001), reflecting improved adherence over time. No adverse effects of treatment were indicated through measures of psychosocial functioning. Some significant changes were evidenced in cognitions thought to be important in mediating behavioral change. Conclusion: The current study provides evidence for the feasibility and effectiveness of applying group-based cognitive behavior therapy to enhance adherence to hemodialysis fluid restrictions. Results are discussed in the context of the study’s methodological limitations. Am J Kidney Dis 45:1046-1057. © 2005 by the National Kidney Foundation, Inc. INDEX WORDS: Adherence; compliance; interdialytic weight gain; hemodialysis; fluid; intervention; randomized controlled trial.

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ATIENTS RECEIVING hemodialysis frequently show difficulty adhering to treatment, which involves a complex and onerous behavioral regimen. Studies examining the prevalence of nonadherence to hemodialysis therapy suggest that many patients do not successfully follow diet, fluid-intake, and medication regimens, and that of these regimens, nonadherence to fluid intake is among the most common.1,2 Previous reports estimated that more than 50% of hemodialysis patients do not

From Psychological Medicine, Division of Community Based Sciences, University of Glasgow, Academic Centre, Gartnavel Royal Hospital; and Renal Unit, Glasgow Royal Infirmary, Glasgow, Lanarkshire, UK. Received October 4, 2004; accepted in revised form February 9, 2005. Originally published online as doi:10.1053/j.ajkd.2005.02.032 on May 3, 2005. Address reprint requests to Matt R. Wild, DClinPsy, Psychological Medicine, Division of Community Based Sciences, University of Glasgow, Academic Centre, Gartnavel Royal Hospital, 1055 Great Western Rd, Glasgow, Lanarkshire, G12 0XH, UK. E-mail: [email protected] © 2005 by the National Kidney Foundation, Inc. 0272-6386/05/4506-0010$30.00/0 doi:10.1053/j.ajkd.2005.02.032 1046

follow the fluid-restriction regimen.3 The established association between adherence and patient well-being4 suggests that the development of strategies aimed at improving adherence should be viewed as paramount in renal settings. An increasing amount of literature is dedicated to the investigation of psychological interventions, and there has been distinct variation in the approaches adopted.5 Traditionally, intervention studies have used behavioral strategies in their quest for adherence enhancement. However, the demonstrated benefits of multifaceted interventions6,7 have prompted contemporary trials to integrate additional psychotherapeutic techniques in the development of their intervention protocol. Cognitive theories of behavior change have been applied to the treatment of almost every chronic medical problem. These theories are based on the observation that people’s emotional problems are founded in a system of dysfunctional beliefs about themselves and the world surrounding them.8,9 Underlying beliefs are thought to influence individuals’ thoughts. Holding irrational beliefs often creates cognitive distortion that can lead to emotional disruption.

American Journal of Kidney Diseases, Vol 45, No 6 (June), 2005: pp 1046-1057

IMPROVING FLUID-RESTRICTION ADHERENCE

Nonadherent hemodialysis patients are especially likely to hold negative beliefs and attitudes regarding their treatment and consequently are more likely to engage in cognitive distortion. Previous research suggests that such distorted thinking styles may influence health-related behavior.10 Cognitive behavior therapy (CBT) aims to help patients identify dysfunctional cognitions, test them against reality, and alter them, thereby improving their emotional well-being and coping behavior. A CBT approach may be particularly beneficial for patients who, on the basis of experiencing multiple failures in attempting to manage fluid-intake restrictions, have little or no belief in their ability to cope adequately with the demands of the treatment regimen. Such individuals may have developed strong negative beliefs regarding their fluid management. Negative thoughts (eg, “My fluid restrictions are beyond my control.”) can result in negative feelings (eg, sadness, anger, hopelessness) and maladaptive health behaviors (eg, overdrinking), thereby reinforcing these problematic beliefs. Assisting patients to develop more realistic, self-helping beliefs by using CBT could enable them to cope more effectively with fluid restrictions inherent in the hemodialysis treatment regimen. Reviews of the existing literature suggest a need for improved methodological approaches in the current field.5 Previous studies typically have been constrained by such methodological weaknesses as the use of small sample sizes and lack of control groups. Few studies have attempted to apply a randomized controlled trial (RCT) design to their investigation. Some reports have highlighted the difficulties in adopting this design in renal outpatient settings.11,12 It was proposed that the social nature of hemodialysis units may promote diffusion of treatment across groups. However, through the adoption of alternative experimental design, it may be possible to circumvent such difficulties. This would be worthwhile because RCTs provide the best evidence on the efficacy of health care interventions.13 The present study reports on the effects of a newly developed cognitive behavioral intervention. The Glasgow University Liquid-Intake Program (GULP) aims to assist adult nonadherent hemodialysis patients to improve their fluid restriction self-management. Through the adoption

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of an RCT design, the study sought to answer 3 broad research questions: (1) Is GULP effective in improving adherence to hemodialysis fluid restrictions? (2) Are the foreseen improvements in fluid-restriction adherence accompanied by a detrimental impact on quality of life and emotional well-being? (3) Does GULP impact on attributions and health beliefs thought to be influential in mediating adherence to fluid restrictions? METHODS

Participants, Settings, and Locations Participants were recruited from 4 National Health Service outpatient hemodialysis units located in west and central Scotland, UK. Ethical approval was obtained from the relevant local research ethics committees. Renal nursing staff identified patients with a history of problematic fluidrestriction adherence, defined as an average daily interdialytic weight gain (IWG) of 2.5 kg or greater. Inclusion criteria were: (1) confirmed diagnosis of end-stage renal disease, (2) receiving hemodialysis 3 times weekly for at least 3 months, (3) at least 18 years of age, (4) living in a home setting, (5) willing to participate, (6) no severe cognitive disorders (eg, dementia), (7) no significant vision or hearing impairments, (8) ability to speak and/or read English, and (9) not currently receiving any additional psychotherapeutic treatment from another source.

Interventions GULP was conducted in a group format. Groups of participants were randomly assigned to an immediatetreatment group (ITG) or deferred-treatment group (DTG). Participation involved: (1) baseline prerandomization assessment, (2) 4-week treatment phase, (3) posttreatment assessment, and (4) follow-up assessment 10 weeks after treatment. The DTG received standard care for 4 weeks before starting treatment. The deferred entry to treatment condition permitted experimental control in the form of both an extended baseline and replication of the intervention effect. The intervention protocol was administered in a group format (3 to 8 people) for hour-long sessions once weekly for 4 weeks. Ten groups, including 5 ITGs and 5 DTGs, were facilitated by an appropriately supervised trainee clinical psychologist (J.S.) in renal outpatient settings. In view of the target population (patients who have difficulty adhering to treatment) and to minimize the risk for dropout, the intervention was designed to be brief and time limited. Educational components included conveying information relating to the importance of fluid restrictions. Behavioral techniques were shared to allow patients to acquire relevant self-monitoring skills, including controlling their environment, goal setting, and self-regulation. Cognitive components were included to encourage patients to identify associations between their thoughts, emotions, and behaviors. Patients were requested to complete thought records between sessions. This allowed patients to identify and gain insight into their own cognitive

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distortions and the impact of these thinking errors on their behavior. Patients were asked to evaluate the rationality and accuracy of their beliefs in an attempt to modify thoughts identified as maladaptive. Strategies were introduced to help patients manage the physiological symptoms of stress. All patients received a muscular relaxation tape for daily practice. The importance of effective social support networks was discussed. Suggestions were given on how to interact appropriately with others regarding the management of fluid consumption and gain optimal social support from significant others. The intervention was highly structured and formatted to allow for replication between groups. The therapist was guided by a facilitator’s manual to achieve this. Sessions were led by a therapist, although participants were encouraged to contribute throughout. Participants received a treatment manual, recording sheets, and an audiotape for homebased practice. Full details of the treatment procedures are available from the authors.

Outcomes The primary outcome measure with respect to the efficacy of GULP was IWG. Using regularly calibrated electronic scales that were zeroed before each use, renal nursing staff witnessed and recorded predialysis and postdialysis weight measurements of ITG participants during a 14-week period and DTG participants during an 18-week period. Emotional functioning was measured by using the Hospital Anxiety and Depression Scale (HADS).14 The HADS is a well-established, standardized, 14-item, self-report questionnaire. Its omission of somatic items makes it an appropriate measure for a chronically ill population. The measure rates the patient’s experience of anxiety- (7 items; score range, 0 to 21) and depression-related (7 items; score range, 0 to 21) symptoms within the past week. A lower score indicates better emotional well-being. The Short-Form 36 (version 2) Health Survey (SF36)15 measures 8 health concepts: physical functioning, role limitations caused by physical health problems, bodily pain, general health, vitality, social functioning, role limitations caused by personal or emotional problems, and mental health. A higher score indicates better healthrelated quality of life. On individual visual analogue scales, participants were requested to rate questions relating to health beliefs and attributions associated with fluid restrictions. These items were adapted from Friend et al.16 Health belief questions were: “To what extent do you believe excessive fluid consumption is hazardous to your health?,” “To what extent is it important for you to avoid excessive drinking?,” and “To what extent do you believe that restricting fluid intake will help you in preserving good health?” The attribution questions were: “What percentage of the time do you feel that you successfully adhere to your fluid restrictions?,” “What percentage of the time do you feel that your adherence is due to your own efforts?,” and “In general, how difficult is it for you to resist fluid intake?” Patients self-completed all secondary measures within the dialysis unit.

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Sample Size Cohen17 recommends a 0.80 level of power. However, the current study represents a pilot investigation of a newly developed treatment. To establish the feasibility of the intervention, the current study was more tolerant of making a potential type II error. Based on 0.70 power to detect a significant difference (P ⫽ 0.05, 1 sided), 19 participants were required for a control group and 22 participants were needed for an intervention group. This calculation was based on SDs from baseline data extracted from Christensen et al.11 Within-group variance may have changed posttreatment. To compensate for any discrepancy, 5 additional participants were added to each group. Furthermore, some level of attrition was anticipated during the study. Therefore, the study sought to recruit approximately 30 participants for each group (60 in total).

Randomization To compensate for any effects of treatment diffusion, it was decided to randomize shifts, rather than individuals. Shifts, or clusters, were allocated on an individual basis to either the ITG or DTG according to an automated computergenerated randomization procedure. All clusters had an equal probability of assignment to each group. No restriction in randomization was used. Allocation concealment was ensured because recruitment of participants was performed in ignorance of the group to which the cluster would be assigned.

Blinding The present study is an open nonblind trial. As active recipients of the intervention, participants could not be ignorant of treatment administration. The evaluator was not blinded to treatment allocation. The primary outcome measure, IWG, was a routine objective measure calculated by renal nursing staff independent of the trial. Secondary outcome measures were self-rated assessments and questionnaires. Therefore, selection of outcome measures enabled the minimization of observer bias.

Data Analysis Independent t-tests and Pearson chi-square analysis were used to determine whether any significant differences existed between the 2 groups for continuous and categorical variables, respectively. All analyses were conducted according to the intention-to-treat principle. Independent t-tests found no systematic differences between participants with complete data and participants with missing data on all primary and secondary outcome measures at prerandomization assessment. Missing data were estimated through inputation of randomized group median for the appropriate assessment stage. Descriptive statistics were generated related to sample characteristics and variables of interest. Acute-phase analysis consisted of conducting 1-way analysis of variance for primary and secondary outcome measures, with and without adjustment for corresponding baseline covariates. Longitudinal analysis of treatment effect combined data obtained at baseline, posttreatment,


Fig 1. trial.

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Flow diagram of

and follow-up from the ITG and DTG. Repeatedmeasures analyses of variance were used to analyze longitudinal effects of treatment for each dependent variable. When a main effect was identified, differences between assessment periods were investigated by using paired-samples t-tests. The use of multiple tests increased the probability of a type I error. There was no adjustment to compensate for this increased error rate. For purposes of the current pilot investigation, an inflated type II error

rate was deemed acceptable to identify important primary and secondary outcomes for additional research.

RESULTS

Participant Flow and Baseline Data Participant flow and retention are shown in Fig 1. From November 2003 through March

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2004, a total of 10 clusters (n ⫽ 56) were randomly assigned to the ITG (5 clusters, n ⫽ 29) or DTG (5 clusters, n ⫽ 27). Characteristics of randomized participants at baseline are listed in Table 1. Baseline analysis showed no significant differences between the ITG and DTG for sex, age, marital status, occupational status, education, time on dialysis therapy, baseline IWG, and all HADS subscales. From the SF-36, no significant differences were shown, with the exception of Role–Emotional (t54 ⫽ 2.52; P ⬍ 0.05). No significant differences were shown in Health Beliefs A and B. A significant difference was shown in Health Belief C (t54 ⫽ 2.18; P ⬍ 0.05). No significant differences were shown in Attributions A and C. A significant difference was shown in Attribution B (t54 ⫽ 2.15; P ⬍ 0.05). Baseline differences between groups were taken into account in the repeated-measures analysis by using baseline values as covariates when appropriate. Outcomes and Estimation Dependent variables were participant’s weekly mean IWGs, HADS scores, SF-36 scores, and self-ratings of Attributions and Health Beliefs. For ease of comparison, outcome data relating to the primary outcome measure IWG are shown in Fig 2. Acute-Phase Analysis The acute-phase analysis investigated data from week 0 to week 4. This period related to the treatment phase for the ITG, whereas the DTG served as a between-group no-treatment control. Results are reported as a summary of the change from week 0 to week 4 and mean difference (with 95% confidence interval) in this change between the 2 groups in Table 2. Week 4, there was no significant difference in IWGs between the ITG and DTG (F1,54 ⫽ 0.03; P ⬎ 0.05). Comparison of adjusted means continued to be nonsignificant (F1,53 ⫽ 0.87; P ⬎ 0.05). For secondary outcomes, 1-way analyses of variance found no significant differences between treatment groups at week 4, with the exception of the SF-36 subscale Mental Health (F1,54 ⫽ 6.51; P ⬍ 0.05). After adjustment for appropriate baseline covariates, analysis of covariance found significant differences on the SF-36 subscales Mental Health (F1,53 ⫽ 12.93; P ⬍ 0.01), Role–

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Emotional (F1,53 ⫽ 18.78; P ⬍ 0.01), and Attribution C (F1,53 ⫽ 8.01; P ⬍ 0.01). Longitudinal Analysis of Treatment Effect Data combined from both groups produced a significant main effect for mean IWG (F1.76,96.80 ⫽ 9.10; P ⬍ 0.001). Within-group IWG means were compared. Differences between baseline and posttreatment IWG values were nonsignificant (t55 ⫽ 1.12; P ⬎ 0.05). Differences between baseline and follow-up IWG values were significant (t55 ⫽ 3.85; P ⬍ 0.001), reflecting improved adherence over time. There were no main effects for any of the HADS subscales or those from the SF-36. There was a main effect for Health Belief A (F1.36,74.71 ⫽ 13.61; P ⬍ 0.001). Differences between baseline and posttreatment ratings (t55 ⫽ 3.77; P ⬍ 0.001) and baseline and follow-up ratings (t55 ⫽ 3.97; P ⬍ 0.001) were significant. There was a main effect for Health Belief B (F1.46,80.24 ⫽ 12.41; P ⬍ 0.001). Differences between baseline and posttreatment ratings (t55 ⫽ 4.69; P ⬍ 0.001) and baseline and follow-up ratings (t55 ⫽ 3.39; P ⬍ 0.01) were both significant. Again, a main effect for Health Belief C was shown (F1.24,68.18 ⫽ 8.68; P ⬍ 0.01), with differences between baseline and posttreatment ratings (t55 ⫽ 2.80; P ⬍ 0.01) and baseline and follow-up ratings (t55 ⫽ 3.18; P ⬍ 0.01; significant). No significant main effects for Attributions were observed, with the exception of Attribution B (F1.75,96.37 ⫽ 3.41; P ⬍ 0.05). Differences between baseline and posttreatment ratings (t55 ⫽ 2.42; P ⬍ 0.05) were significant; however, differences between baseline and follow-up ratings (t55 ⫽ 0.17; P ⬎ 0.05) were nonsignificant. The study considered gains of 2.5 kg or greater to indicate problematic fluid-intake adherence. At baseline assessment, 100% of patients were classified as nonadherent with fluidintake restrictions. At posttreatment assessment, 11 participants (19.6%) were classified as adherent. At follow-up assessment, 21 participants (37.5%) had achieved an IWG less than 2.5 kg. Means ⫾ SDs of all dependent variables across 3 assessment periods (baseline, posttreatment, and follow-up) are listed in Table 3. Levels of


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Table 1. Baseline Characteristics by Randomized Treatment Group Characteristic

Sex Male Female Mean age (y) Marital status Married Single Cohabiting Divorced Separated Widowed Occupational status Full-time employment Part-time employment Retired In further education Unemployed Education Standard/O grades Higher levels Certificate of sixth year studies/A levels Scottish vocational qualification Further education diploma University degree None Other Time on dialysis (mo) IWG (kg) HADS Anxiety Depression Total SF-36 Physical function Role–physical Bodily pain General health Mental health Role–emotional Social function Vitality Health beliefs* (%) Question A Question B Question C Attributions† (%) Question A Question B Question C

ITG (n ⫽ 29)

DTG (n ⫽ 27)

18 (62.1) 11 (37.9) 56.05 ⫾ 12.73

20 (74.1) 7 (25.9) 52.52 ⫾ 12.70

17 (58.6) 5 (17.2) 2 (6.9) 0 (0) 1 (3.4) 4 (13.8)

11 (40.7) 7 (25.9) 1 (3.7) 4 (14.8) 1 (3.7) 3 (11.1)

4 (13.8) 1 (3.4) 16 (55.2) 0 (0) 8 (27.6)

8 (29.6) 2 (7.4) 7 (25.9) 1 (3.7) 9 (33.3)

2 (6.9) 3 (10.3) 1 (3.4) 2 (6.9) 2 (6.9) 1 (3.4) 17 (58.6) 1 (3.4) 42.52 ⫾ 31.24 3.42 ⫾ 0.88

3 (11.1) 1 (3.7) 0 (0) 1 (3.7) 1 (3.7) 5 (18.5) 15 (55.6) 1 (3.7) 66.22 ⫾ 59.60 3.72 ⫾ 0.93

7.41 ⫾ 3.28 6.66 ⫾ 3.06 14.00 ⫾ 5.71

7.44 ⫾ 4.49 7.07 ⫾ 4.67 14.52 ⫾ 8.58

53.79 ⫾ 35.75 48.28 ⫾ 33.10 54.02 ⫾ 27.49 37.41 ⫾ 21.00 65.52 ⫾ 18.58 66.09 ⫾ 29.31 60.34 ⫾ 26.31 36.85 ⫾ 21.67

41.67 ⫾ 33.11 37.27 ⫾ 29.59 50.21 ⫾ 32.96 34.30 ⫾ 17.06 60.56 ⫾ 21.63 46.30 ⫾ 29.44 52.31 ⫾ 28.17 41.44 ⫾ 23.52

77.62 ⫾ 21.92 76.69 ⫾ 23.49 84.48 ⫾ 20.50

85.93 ⫾ 17.20 83.33 ⫾ 21.40 68.74 ⫾ 32.61

53.83 ⫾ 30.30 74.31 ⫾ 25.27 66.03 ⫾ 26.40

54.63 ⫾ 22.62 59.78 ⫾ 25.29 67.59 ⫾ 24.42

NOTE. Data expressed as number of participants (percent) for categorical data and mean ⫾ SD for continuous data. *Health beliefs: question A, “To what extent do you believe that excessive fluid consumption is hazardous to your health?”; question B, “To what extent is it important for you to avoid excessive drinking?”; and question C, “To what extent do you believe that restricting fluid intake will help you in preserving good health?” †Attributions: question A, “What percentage of the time do you feel that you successfully adhere to your fluid restrictions?”; question B, “What percentage of the time do you feel that your adherence is due to your own efforts?”; and question C, “In general, how difficult is it for you to resist fluid intake?”

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SHARP ET AL

Fig 2. Line graph showing effects on IWG of immediate treatment and deferred treatment across the experimental period.

probability are offered when significant differences were found. Ancillary Analyses Information elicited from patient evaluation forms showed the feasibility of the approach. No significant logistical problems were encountered during the trial. Overall, GULP was well appreciated by participants, with a mean rating of 65.36 ⫾ 22.80 on a scale of 0 to 100. With regard to the program length, 15 participants (26.8%) thought the intervention was “too short,” 27 participants (48.2%) believed it was “just right,” and 4 participants (7.1%) considered the group “too long.” No participant believed the group speed of progression was “too slow,” 32 participants (57.1%) believed the speed of progression was “just right,” and 14 participants (25%) believed it was “too fast.” Most patients (n ⫽ 27; 48%) reported spending less than 30 minutes per week on homework assignments. DISCUSSION

Participation in GULP resulted in no significant improvement in adherence, measured by means of IWG, during the 4-week treatment phase. The ITG and DTG showed minimal mean changes between baseline and posttreatment. Al-

though no significant improvements were made during the treatment phase, there was a significant reduction in IWG from baseline to 10-week follow-up. GULP purposefully was designed to be a short intervention, comprising only 4 treatment sessions. It is reasonable to speculate this did not permit a protracted period for patients to establish significant treatment gains. For example, the program may not have been of sufficient duration for participants to apply the knowledge and consolidate the skills acquired through treatment within 4 weeks. It is reasonable to conclude that the ongoing decreases in IWG after treatment cessation were attributable to the development and refinement of effective cognitive and behavioral management strategies. A similar effect was shown by Christensen et al.11 This cohort study compared a group receiving a self-regulation intervention with a no-treatment control. Although no significant group differences were found after treatment, IWGs between the treatment and control groups were significantly different at an 8-week follow-up assessment. As in the current study, decreased IWG levels were not only maintained after treatment, but continued to improve. However, the significant finding evidenced at follow-up in the study of Christensen et al11 was, in part, a function of

Week 0

Week 4

Change 4 Weeks – Baseline

Outcome Measure*

ITG

DTG

ITG

DTG

ITG

DTG

ITG-DTG Unadjusted

P

ITG-DTG Adjusted

IWG (kg) HADS Anxiety Depression Total SF-36 Physical function Role–physical Bodily pain General health Mental health Role–emotional Social function Vitality Health beliefs† (%) Question A Question B Question C Attributions‡ (%) Question A Question B Question C

3.42 ⫾ 0.88

3.72 ⫾ 0.93

3.46 ⫾ 0.76

3.80 ⫾ 0.83

0.03 ⫾ 1.17

0.08 ⫾ 0.70

⫺0.05 (⫺0.57-0.47)

NS

⫺0.25 (⫺0.66-0.16)

NS

7.41 ⫾ 3.28 6.66 ⫾ 3.06 14.00 ⫾ 5.71

7.44 ⫾ 4.49 7.07 ⫾ 4.67 14.52 ⫾ 8.58

6.66 ⫾ 2.87 6.27 ⫾ 3.00 12.66 ⫾ 5.51

7.29 ⫾ 3.60 6.91 ⫾ 3.83 14.02 ⫾ 6.94

⫺0.75 ⫾ 3.14 ⫺0.39 ⫾ 2.94 ⫺1.34 ⫾ 5.29

⫺0.15 ⫾ 2.18 ⫺0.16 ⫾ 2.16 ⫺0.50 ⫾ 4.00

⫺0.60 (⫺2.06-0.86) ⫺0.23 (⫺1.62-1.16) ⫺0.85 (⫺3.37-1.68)

NS NS NS

⫺0.61 (⫺1.82-0.60) ⫺0.37 (⫺1.58-0.84) ⫺1.02 (⫺3.20-1.16)

NS NS NS

53.79 ⫾ 35.75 48.28 ⫾ 33.11 54.02 ⫾ 27.49 37.41 ⫾ 21.00 65.52 ⫾ 18.58 66.09 ⫾ 29.37 60.34 ⫾ 26.32 36.85 ⫾ 21.67

41.67 ⫾ 33.11 37.27 ⫾ 29.59 50.21 ⫾ 32.96 34.30 ⫾ 17.06 60.56 ⫾ 21.63 46.30 ⫾ 29.45 52.31 ⫾ 28.17 41.43 ⫾ 23.52

57.07 ⫾ 33.02 48.71 ⫾ 30.50 54.02 ⫾ 26.18 40.55 ⫾ 18.28 70.69 ⫾ 14.92 72.70 ⫾ 22.48 59.48 ⫾ 23.06 39.66 ⫾ 15.69

42.41 ⫾ 28.47 32.41 ⫾ 23.96 48.15 ⫾ 29.72 34.56 ⫾ 19.69 55.19 ⫾ 19.68 42.28 ⫾ 27.05 55.09 ⫾ 27.13 39.12 ⫾ 19.66

3.28 ⫾ 27.03 0.43 ⫾ 23.50 0.00 ⫾ 12.60 3.14 ⫾ 22.78 5.17 ⫾ 13.33 6.61 ⫾ 23.08 -0.86 ⫾ 20.03 2.80 ⫾ 17.00

0.74 ⫾ 25.71 ⫺4.86 ⫾ 27.37 ⫺2.06 ⫾ 13.09 0.26 ⫾ 25.72 ⫺5.37 ⫾ 17.45 ⫺4.01 ⫾ 19.66 2.78 ⫾ 16.75 -2.31 ⫾ 16.55

2.54 (⫺11.62-16.69) 5.29 (⫺8.35-18.93) 2.06 (⫺4.82-8.94) 2.88 (⫺10.12-15.88) 10.54 (2.26-18.83) 10.62 (⫺0.91-22.15) ⫺3.64 (⫺13.57-6.29) 5.12 (⫺3.88-14.12)

77.62 ⫾ 21.92 76.69 ⫾ 23.50 84.48 ⫾ 20.50

85.93 ⫾ 19.20 83.33 ⫾ 21.40 68.74 ⫾ 32.61

89.45 ⫾ 12.12 88.59 ⫾ 13.08 89.34 ⫾ 12.59

91.22 ⫾ 12.79 91.89 ⫾ 13.52 83.61 ⫾ 16.31

11.83 ⫾ 21.29 11.90 ⫾ 19.58 4.86 ⫾ 22.08

5.30 ⫾ 10.75 6.53 (⫺2.61-15.67) 8.56 ⫾ 12.24 3.34 (⫺5.49-12.17) 14.87 ⫾ 28.91 ⫺10.01 (⫺23.73-3.72)

NS NS NS

1.06 (⫺4.61-6.73) ⫺0.60 (⫺5.87-4.67) 2.66 (⫺4.97-10.29)

NS NS NS

53.83 ⫾ 30.30 74.31 ⫾ 25.27 66.03 ⫾ 26.40

54.63 ⫾ 22.62 59.78 ⫾ 25.29 67.59 ⫾ 24.42

62.48 ⫾ 21.61 78.14 ⫾ 18.98 56.21 ⫾ 19.90

57.29 ⫾ 18.71 68.33 ⫾ 19.27 69.15 ⫾ 17.91

8.66 ⫾ 24.90 3.83 ⫾ 22.66 -9.83 ⫾ 22.51

2.67 ⫾ 19.98 5.99 (⫺6.16-18.14) 8.56 ⫾ 13.88 ⫺4.73 (⫺14.89-5.43) 1.56 ⫾ 22.22 ⫺11.38 (⫺23.38-0.61)

NS NS NS

5.53 (⫺3.50-14.56) 2.46 (⫺5.56-10.49) ⫺12.33 (⫺21.07-⫺3.59)

NS NS ⬍0.01

NS 7.28 (⫺5.20-19.76) NS 10.18 (⫺1.52-21.87) NS 2.68 (⫺3.74-9.11) NS 5.40 (⫺4.71-15.51) ⬍0.05 12.64 (5.59-19.69) NS 18.78 (8.62-28.95) NS ⫺1.18 (⫺10.24-7.87) NS 2.97 (⫺4.12-10.06)

P

NS NS NS NS ⬍0.01 ⬍0.01 NS NS


Table 2. Acute-Phase Analysis: Comparison Between the ITG and DTG of Primary and Secondary Outcome Measures at Week 0 and Week 4

NOTE. Data expressed as mean ⫾ SD and mean change (95% confidence interval). Abbreviation: NS, not significant. *Improvement indicated by negative change score on IWG and HADS subscales and positive change score on SF-36 subscales. †Health beliefs: question A, “To what extent do you believe that excessive fluid consumption is hazardous to your health?”; question B, “To what extent is it important for you to avoid excessive drinking?”; and question C, “To what extent do you believe that restricting fluid intake will help you in preserving good health?” ‡Attributions: question A, “What percentage of the time do you feel that you successfully adhere to your fluid restrictions?”; question B, “What percentage of the time do you feel that your adherence is due to your own efforts?”; and question C, “In general, how difficult is it for you to resist fluid intake?”

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SHARP ET AL Table 3. Longitudinal Comparison of Primary and Secondary Outcome Measures Between Baseline, Posttreatment, and Follow-Up Assessment Periods Assessment Period

Level of Significance (P)

Outcome Measure

Baseline

Posttreatment

Follow-Up

Baseline to Posttreatment

Baseline to Follow-Up

IWG (kg) HADS Anxiety Depression Total SF-36 Physical function Role–physical Bodily pain General health Mental health Role–emotional Social function Vitality Health beliefs* (%) Question A Question B Question C Attributions† (%) Question A Question B Question C

3.56 ⫾ 0.91

3.38 ⫾ 0.95

2.96 ⫾ 1.09

NS

⬍0.001

7.43 ⫾ 3.87 6.86 ⫾ 3.89 14.25 ⫾ 7.17

6.97 ⫾ 3.23 6.58 ⫾ 3.41 13.31 ⫾ 6.22

6.87 ⫾ 3.38 6.85 ⫾ 3.65 13.72 ⫾ 6.49

NS NS NS

NS NS NS

47.95 ⫾ 34.73 42.97 ⫾ 31.67 52.18 ⫾ 30.03 35.91 ⫾ 19.09 63.13 ⫾ 20.08 56.55 ⫾ 30.80 56.47 ⫾ 27.28 39.06 ⫾ 22.50

50.00 ⫾ 31.51 40.85 ⫾ 28.50 51.19 ⫾ 27.84 37.66 ⫾ 19.04 63.21 ⫾ 18.91 58.04 ⫾ 28.95 57.37 ⫾ 24.97 39.40 ⫾ 17.55

48.83 ⫾ 31.25 43.92 ⫾ 27.41 55.37 ⫾ 27.63 38.58 ⫾ 18.43 62.56 ⫾ 19.51 60.28 ⫾ 25.71 58.32 ⫾ 24.82 39.99 ⫾ 18.23

NS NS NS NS NS NS NS NS

NS NS NS NS NS NS NS NS

81.63 ⫾ 20.89 79.89 ⫾ 22.56 76.89 ⫾ 27.92

90.30 ⫾ 12.37 90.18 ⫾ 13.27 86.58 ⫾ 14.66

92.46 ⫾ 10.36 89.91 ⫾ 12.99 89.63 ⫾ 11.46

⬍0.001 ⬍0.001 ⬍0.01

⬍0.001 ⬍0.01 ⬍0.01

54.21 ⫾ 26.63 67.30 ⫾ 26.10 66.79 ⫾ 25.25

59.98 ⫾ 20.25 73.41 ⫾ 19.58 62.45 ⫾ 19.89

55.36 ⫾ 25.35 67.82 ⫾ 24.52 61.36 ⫾ 22.03

NS ⬍0.05 NS

NS NS NS

NOTE. Data expressed as mean ⫾ SD. Abbreviation: NS, not significant. *Health beliefs: question A, “To what extent do you believe that excessive fluid consumption is hazardous to your health?”; question B, “To what extent is it important for you to avoid excessive drinking?”; and question C, “To what extent do you believe that restricting fluid intake will help you in preserving good health?” †Attributions: question A, “What percentage of the time do you feel that you successfully adhere to your fluid restrictions?”; question B, “What percentage of the time do you feel that your adherence is due to your own efforts?”; and question C, “In general, how difficult is it for you to resist fluid intake?”

increasing IWG levels within the control group and not solely attributable to gains established through treatment. The hemodialysis treatment regimen has been shown to affect social and psychological functioning.18 It is possible that more intensive management could lead to increased feelings of burden and subsequent negative effects on psychological well-being and quality of life. Thus, benefits of improved adherence would have to be weighed against their negative impact on psychological well-being and quality of life. Conversely, no change in psychosocial measures could be viewed as a positive outcome. There were no significant within-group differences between any of the HADS subscales or any of the 8 SF-36 subscales. The findings suggest that participation in GULP

and improvement in self-management do not impact negatively on psychosocial functioning. The current trial gave limited attention to mechanisms underlying the evidenced adherence enhancement. It could be speculated that the improvement in fluid-restriction adherence likely was a result of a change in attitudes and beliefs regarding hemodialysis treatment. Significant differences from baseline to posttreatment and from baseline to follow-up were evidenced in all 3 measures of health beliefs. Changes were all in the desired direction, with participants generally showing a tendency to hold more functional and accurate beliefs regarding fluid restrictions in hemodialysis. No measures of attributions significantly changed from baseline to follow-up. Friend et al16 suggested that different factors may be


involved when predicting stability and changes in fluid-restriction adherence. Although attributions may be important in maintaining adherence, a patient’s beliefs are likely to motivate change. By extension, the initial focus of adherence-enhancement interventions should seek to modify patients’ health beliefs, which may be constraining their commitment to change. Early sessions of GULP placed a significant emphasis on education of the importance of fluid restriction. Although modification of beliefs may have been responsible for some behavioral change, it is unlikely that all improvement can be attributed to this. There are a number of rewards inherent in effective self-management. For example, hemodialysis patients typically enjoy close relationships with nursing staff, with whom they have regular contact. Improvement in adherence is likely to receive social rewards, the most basic level representing verbal praise. In addition, there are a number of tangible health benefits from improved adherence. These may have included decreased cramps, a reduction in symptomatic hypotensive episodes, increased activity levels, and a shorter time on dialysis. Previous intervention studies based on behavioral paradigms have relied on using both social and tangible rewards to foster behavior change. However, it frequently was logistically difficult to maintain these contingencies over time. Consequently, IWG often returned to pretreatment levels. The current study did not rely exclusively on external schedules of reinforcement to promote change. Instead, change was propagated by the acquisition of knowledge, modification of dysfunctional cognitions, and development of self-management skills. To date, few research studies have evaluated the effects of CBT with regard to improving adherence to fluid restrictions. Therefore, integrating the current findings into the existing literature was somewhat constrained. However, results and findings of the current trial can be related to the wider psychological literature on adherence to treatment. For example, a metaanalysis investigating the effectiveness of interventions to improve patient adherence to medical regimens concluded that multicomponent interventions were more effective than single-component interventions.5 To date, the majority of studies of fluid-restriction adherence have used

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single-focused strategies, typically behavioral. GULP represents a multicomponent treatment package and, consistent with the literature, an approach that is more likely to successfully enhance adherence. The majority of previous studies in this field were characterized by their use of behavioral interventions that often failed to show long-term maintenance of gains.5 Nevertheless, many of these studies showed considerable promise. Results from the current study lend support to previous research showing the effectiveness of psychological treatments for improving adherence. As part of their systematic review, Sharp et al5 noted the absence of studies investigating the effectiveness of interventions using an RCT design. The current study’s use of an RCT design permits more confidence in the findings of this study and confirms previous findings relating to the effectiveness of psychological intervention, in which external validity was limited.19 However, although the observed improvement in adherence is encouraging, findings should be interpreted with caution. A statistically significant reduction in IWG during the trial was clearly shown. However, it is questionable whether this reduction was clinically significant. The baseline measure of mean IWG was 3.56 ⫾ 0.91 kg. At follow-up assessment, this mean value had decreased to 2.96 ⫾ 1.09 kg. Although this represents a statistically significant change, this value is still clearly in excess of the predefined criteria of 2.5 kg thought to be indicative of problematic adherence. Within the literature, what represents clinically significant weight gain remains unclear. Previous studies have varied considerably in their estimations. Identified definitions of desired weight gain vary between 1,20 2,21,22 and 3 kg.16 Most commonly, average IWGs greater than 2.5 kg are considered to reliably indicate problematic adherence.23,24 Despite mean IWG continuing to exceed the defined criteria, any reduction in IWG can be considered beneficial because it represents a decrease in cardiovascular stress.25 Furthermore, at follow-up assessment, IWG was continuing to decrease. It is uncertain whether continued long-term monitoring of IWG would have shown a pattern of decline at less than the 2.5-kg level. The nature of the current study, with a strict time frame imposed on trial completion, did not permit a

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follow-up assessment exceeding 10 weeks. A follow-up of at least 6 months would be more informative with regard to long-term effects of GULP. However, it should be noted that although mean IWG continued to exceed 2.5 kg, clinically significant improvements in IWG were made in 37.5% of participants. One of the principal reasons for fluid consumption is to quench thirst. Thirst is controlled by plasma osmolality, which, in turn, is determined largely by serum sodium concentration. Thirst and therefore fluid consumption hence are affected by excessive dietary salt intake. During the program, patients were advised to limit salt intake. However, dietary sodium intake was not formally assessed. Measurement of this variable potentially could have shown objective information relating to patients’ efforts to manage dietary aspects of their treatment. An additional limitation relates to the failure to assess treatment fidelity. Measuring fidelity to psychological intervention would require attention to the therapist’s behaviors and multiple structural and administrative characteristics of the program. The current study did not have adequate resources available to formally measure fidelity. Because of such limited resources, the individual responsible for data collection also administered the intervention. This represented a potential source of bias. However, primary and secondary measures used in the current study arguably were resistant to such bias. IWG is an objective measure with little potential for reporting error. Similarly, the SF-36 and HADS assessments are objective, standardized, self-report instruments. Such measures would be unlikely to foster observer bias. A methodological limitation regarding sample size calculation has been identified. Sample size calculation was based on a study that computed IWG during a 2-week period. The current study used 1-week mean IWG. Throughout the course of the trial, patients frequently commented on the lack of information they received before starting hemodialysis therapy. No formal assessment of patient knowledge was conducted. However, it was clear that there were significant discrepancies between patient’s knowledge of hemodialysis treatment. Nearly all patients were aware of the recommen-

SHARP ET AL

dation to reduce fluid consumption. However, few patients were able to expound a satisfactory explanation of why these restrictions were advised. An interesting extension of the current study could involve an investigation of patient knowledge relating to fluid restriction at the onset of hemodialysis therapy. Entering into a life-changing treatment of a chronic illness in ignorance of the major adaptations required does not offer a good prognosis for effective management. Without sound understanding of the rationale of treatment, effective self-care and maintenance of motivation would be unlikely. Administration of an informative program, discussing reasons for fluid restrictions and effective means of management, before patients started hemodialysis therapy could prove beneficial for long-term self-regulation of behavior. To summarize, GULP is a promising CBT intervention designed to assist hemodialysis patients to manage their fluid restriction more effectively. GULP had a beneficial effect on adherence to fluid restrictions during the trial period. Treatment seemed acceptable, with a low rate of participant attrition. However, long-term follow-up to evaluate whether any treatment gains achieved are sustained over time would be preferable. Results from this pilot investigation warrant further implementation and evaluation. Future development of GULP would allow access to psychological treatment for dialysis populations that struggle with adherence to fluid restrictions. REFERENCES 1. Bame SI, Petersen N, Wray NP: Variation in hemodialysis patient compliance according to demographic characteristics. Soc Sci Med 37:1035-1043, 1993 2. Lin CC, Liang CCA: The relationship between health locus of control and compliance of hemodialysis patients. Kao Hsiung I Hsueh Tsa Chih 13:243-254, 1997 3. Leggat JE Jr, Orzol SM, Hulbert-Shearon TE, et al: Noncompliance in hemodialysis: Predictors and survival analysis. Am J Kidney Dis 32:139-145, 1998 4. Summerton H: End-stage renal failure: The challenge to the nurse. Nurs Times 91:27-29, 1995 5. Sharp J, Wild MR, Gumley AI: A systematic review of psychological interventions for the treatment of nonadherence to fluid-intake restrictions in people receiving hemodialysis. Am J Kidney Dis 45:15-27, 2005 6. Roter DL, Hall JA, Merisca R, Nordstorm B, Cretin D, Svarstad B: Effectiveness of interventions to improve patient compliance: A meta-analysis. Med Care 36:1138-1161, 1998


7. McDonald HP, Garg AX, Haynes RB: Interventions to enhance patient adherence to medication prescriptions. JAMA 288:2868-2879, 2002 8. Beck AT: Cognitive Therapy and the Emotional Disorders. New York, NY, Int Universities Press, 1976 9. Ellis A: Reason and Emotion in Psychotherapy: A Comprehensive Method of Human Disturbances. New York, NY, Carol, 1994 10. Christensen AJ, Moran PJ, Wiebe JS: Assessment of irrational health beliefs: Relation to health practices and medical regimen adherence. Health Psychol 18:169-176, 1999 11. Christensen AJ, Moran PJ, Wiebe JS, Ehlers SL, Lawton WJ: Effect of behavioural self-regulation intervention on patient adherence in hemodialysis. Health Psychol 21:393-397, 2002 12. Hener T, Weisenberg M, Har-Even D: Supportive versus cognitive-behavioural intervention programs in achieving adjustment to home peritoneal dialysis. J Consult Clin Psychol 64:731-741, 1996 13. Altman DG, Schulz KF, Moher D, et al: The revised CONSORT statement for reporting randomised trials: Explanation and elaboration. Ann Intern Med 134:663-694, 2001 14. Zigmond AS, Snaith RP: The Hospital Anxiety and Depression Scale. Acta Psychiatr Scand 67:361-370, 1983 15. Ware JE, Sherbourne CD: The MOS 36-Item ShortForm Health Survey (SF-36). I. Conceptual framework and item selection. Med Care 30:473-483, 1992 16. Friend R, Hatchett L, Schneider MS, Wadhwa NK: A comparison of attributions, health beliefs, and negative emo-

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tions as predictors of fluid adherence in renal dialysis patient: A prospective analysis. Ann Behav Med 19:344-347, 1997 17. Cohen J: Quantitative methods in psychology: A power primer. Psychol Bull 112:155-159, 1992 18. Tsay S-L, Healstead M: Self-efficacy, depression, and quality of life among patients receiving hemodialysis in Taiwan. Int J Nurs Stud 39:245-251, 2002 19. Molzahn AE: Primary nursing and patient compliance in a haemodialysis unit. ANNA J 16:267-272, 1989 20. Christensen AJ, Smith TW, Turner CW, et al: Family support, physical impairment, and adherence in hemodialysis: An investigation of main and buffering effects. J Behav Med 15:313-325, 1992 21. Wolcott DL, Maida CA, Diamond R, Nissenson AR: Treatment compliance in end-stage renal disease patient dialysis. Am J Nephrol 6:329-338, 1986 22. Kimmel PL: Psychosocial factors in adult end-stage renal disease patients treated with hemodialysis: Correlates and outcomes. Am J Kidney Dis 35:132-140, 2000 23. Feinstein EI: Nutritional therapy in maintenance haemodialysis patients, in Dialysis Therapy. Philadelphia, PA, Hanley & Belfus, 1986 24. Christensen AJ, Benotsch E, Smith TW: Determinants of regimen adherence in renal dialysis, in Gochman DS (ed): Handbook of Health Behaviour Research, vol 2. New York, NY, Plenum, 1997, pp 231-244 25. DiClemente CC, Prochaska JO: Self-change and therapy change of smoking behavior: A comparison of processes of change in cessation and maintenance. Addict Behav 7:133-142, 1982