End-stage renal disease (ESRD) is a complex chronic disease that will cause drastic changes, which inevitably reduce a patient’s quality of life (Finkelstein, Wuerth & Finkelstein, 2009). Haemodialysis, a renal replacement therapy (RRT) used to manage ESRD, depends upon two core processes: the removal of waste in the blood through dialysis and the restriction of nutrients and fluid (Denhaerynck et al, 2007). Patient adherence to the regimen is thus vital to treatment success. (Kutner, 2001; Leggat et al, 1998; Newmann & Litchfield, 2005).
However, the complexity of the regimen makes adherence difficult for patients to achieve (Macdonald, Garg & Haynes, 2002). As such, non-adherence rates worldwide have been found to range between 8. 5% and 22. 1% and have even been reported to be as high as 86% (Matteson & Russel, 2010). These numbers are worrying indeed, especially when one considers the myriad of medical complications that can arise from non-adherence to dialysis regimen such as cardiovascular disease and hyperphosphatemia (Stamatakis, Pecora and Gunel, 2007).
Mortality rates for RRT patients are similarly disappointing, particularly for new or incident patients. In Singapore, the survival rate of patients after the first year is 89. 3%, while in the United Kingdom, 8% of dialysis patients die within the first year of treatment (MCYS Singapore, 2010; UK Renal Registry, 2010). Elsewhere, it has been found that mortality rates are highest during the first year of RRT (Wingard, Chan, Lazarus & Hakim, 2009; Bradbury et al, 2007).
Considering the importance of adherence in successful haemodialysis treatment, along with the increased mortality rates for new haemodialysis patients, it is puzzling why little research has been conducted on adherence in new patients. As treatment period lengthens and patients become more accustomed with the regimen, adherence to professionally prescribed regimens may decrease. This pattern has been found in other patient populations such as diabetics and COPD patients.
Therefore, we expect this to be replicated in the current study’s sample (Donnelly, Donney, Morrist, Palmer & Donnan, 2008; Vinker et al, 2008; Turner, Wright, Mendella & Anthonisen, 1996). Self-efficacy theory purports that behavioural change and maintenance are the products of both efficacy expectations and outcome expectations of the patient (Brady, Tucker, Alfino, Tarrant & Finlayson, 1997). Thus, self-efficacy is considered to be a factor that plays a heavy hand in determining the level of adherence in haemodialysis patients (Lindberg, Wikstrom & Lindberg, 2007; Tsay, 2003).
However, because incident patients are relatively inexperienced in the management of their chronic illness, I expect them to have lower self-efficacy than established or prevalent patients. If adherence in incident patients is indeed higher than prevalent patients and self-efficacy is conversely found to be lower in incident patients, then this could show preliminary evidence that self-efficacy is less of a predictor of adherence in incident patients than in prevalent patients. It is thus important to uncover the other factors that may play a larger role in determining adherence in new patients.
Relationships between demographics and adherence have been found to be inconsistent and hence, they will not be studied in the current research (Ghaddar, Shamseddeen & Elzein, 2009). What will be of interest are the factors of depression and anxiety and how they can have a negative effect on adherence. Living on dialysis can be a wearisome experience as one faces threats to autonomy and functional status (Cukor, Peterson, Cohen & Kimmel, 2006). As such, depression has been regarded as the most common psychiatric disorder in ESRD patients (Kimmel, 2002).
The stressors that haemodialysis patients face as a result of their condition can also lead to increases in anxiety. In fact, the prevalence of severe anxiety in haemodialysis patients has been found to be as high as 51. 6% (Alavi, Aliakbarzadeh & Sharifi, 2009). Incident haemodialysis patients are unaccustomed to their treatment regimen, ergo we should find that levels of anxiety are higher in incident patients than in prevalent patients. The elevated levels of depression and anxiety in incident haemodialysis would thus warrant the need to explore the relationships between depression and anxiety, and adherence.
The current study aims to show that adherence is higher in incident haemodialysis patients than in prevalent patients. A second aim is to show that self-efficacy is lower in incident patients than prevalent patients. Thirdly, we hope to reveal that self-efficacy has a weaker relationship with adherence in incident patients than in prevalent patients. A fourth aim is to show that both depression and anxiety are elevated more in incident patients than in prevalent patients. Lastly, we hope to uncover the relationships between depression and anxiety, and adherence in both incident and prevalent haemodialysis patients.
In this final stage of our study, we hope to show that depression and anxiety have stronger relationships with adherence in incident patients than in prevalent patients. Methods Participants The participants for this study were all randomly selected ESRD patients who receive weekly haemodialysis treatment from National Kidney Foundation (NKF) dialysis centres in Singapore. All participants are aged 21 and over. All participants did not have any functional psychosis, organic brain disorder or impaired cognition.
Patients who had started haemodialysis less than 6 months before the questionnaires were administered were considered to be incident patients. Patients who had been on haemodialysis for more than 6 months prior to the administration of the questionnaires were considered to be prevalent patients. There were 70 incident patients and 166 prevalent patients (Total = 236) in our sample. Procedure Patients were randomly selected from various NKF dialysis centres in Singapore. After their haemodialysis sessions, patients were asked whether they were willing to take part in the study.
Upon agreement, patients were then led to a quiet room away from the treatment area. Research assistants then briefed the patients about the study and attained informed consent from them, upon which participants would complete the questionnaires. Participants were allowed to leave as soon as they had completed the questionnaires. Measures 1. Adherence was measured using the Renal Adherence Behaviour Questionnaire (RABQ) (Rushe & McGee, 1998). The RABQ consists of 25 items measuring self-reported adherence.
The items measure 5 different aspect of adherence in renal patients: adherence to fluid restrictions (factor 1), adherence to potassium and phosphate restrictions (factor 2), adherence regarding self-care (factor 3), adherence during times of difficulty (factor 4), and adherence to sodium restrictions (factor 5). 2. Self-efficacy was measured using the self-efficacy for managing chronic disease scale (Lorig et al, 2001). The product of this scale is the sum of self-efficacy for managing the general demands of chronic disease. Patients rated their confidence in performing tasks pertaining to chronic disease self-management.
These tasks included seeking information about their condition, obtaining help from others and communicating with physicians, maintaining role function, and managing symptoms. 3. The Hospital Anxiety and Depression Scale (HADS) was used to measure levels of anxiety and depression in patients (Zigmond & Snath, 1983). This scale has been used extensively to measure anxiety and depression in medical patient populations with satisfactory reliability and validity (Bjellang, Dahl, Haug & Neckelmann, 2002). This scale has two 7-item components, which measure anxiety and depression respectively.