Do health causal attributions and coping strategies act as moderators of quality of life in peritoneal dialysis patients?

Abstract

Objective

The present study aimed at testing the relationships between health causal attribution and coping mechanisms with quality of life (QOL) in patients who have end-stage renal disease (ESRD) undergoing a peritoneal dialysis (PD) treatment. It was hypothesized that QOL should be negatively associated with the severity of the disease. Problem-focused coping, internal health-related locus of control (HRLOC) and medical power HRLOC were hypothesized as positive moderators preserving a better QOL, after controlling for the severity of the disease.

Methods

A total of 47 PD patients completed the Kidney Disease Quality of Life (KD-QOL) scale encompassing the Medical Outcomes Study Short-Form (MOS SF-36) self-administered questionnaire, the Multidimensional Health Locus of Control scale and the Ways of Coping Check-List (WCCL) scale.

Results

Low scores for all QOL scores were found except for pain dimension, as compared with scores available from a general French population. Globally, QOL was not related to the severity of the disease. Univariate analysis showed that the physical component score (PCS) of QOL was positively associated with internal HRLOC (r=.35; P<.05), and negatively with medical power HRLOC (r=−.36; P<.05). Multivariate analysis adjusting for age confirmed these results. Mental component score (MCS) was negatively associated with the use of emotion-focused coping and seeking social support (r=−.45; P=.001 and r=−.30; P<.05, respectively), the first association persisting in multivariate analysis. Neither PCS nor MCS was linked to the use of problem-focused coping.

Conclusion

These results suggest that physical QOL is all the more preserved when patients are more convinced that their behaviour can influence their health condition and that psychological QOL is all the more impaired when health condition is perceived as less controllable, requiring emotion-focused coping (avoidance strategies). Health causal attributions and coping act respectively as moderators of physical and psychological components of QOL.

Introduction

Besides hemodialysis (HD), chronic peritoneal dialysis (PD) begins to grow in popularity as a treatment modality for patients who have end-stage renal disease (ESRD). This more recent technique has certain medical advantages, but, overall, for a number of patients, its ambulatory form presents several social advantages including an increased chance of employment, more flexible holidays and the home-based nature of the treatment avoids the necessity of attending a dialysis centre three times a week. The percentage of ESRD patients using chronic PD varies widely in different parts of the world (from more than 95% of patients in Mexico to less than 5% in Japan in 1993) [1]. Other nonmedical factors that may influence the modality of treatment selection in countries such as Mexico include: availability of economical resources, social support, cultural habits and the most important factor for selection in nearly every country or region, the cost benefit of this treatment modality [2].

Several studies were carried out to compare the impact on quality of life (QOL) of different modalities of treatment: HD, PD and, in some cases, renal transplantation (RT). Generally, PD patients are better off than those on centre HD and worse off than those on home HD and RT patients with regard to their functional behaviour and QOL [2], [3], [4], [5], but the most critical issue of these studies is the fact that patients are not randomly assigned to a given modality [2], [4]. Furthermore, some studies using generic QOL instruments showed that QOL was not different in these clinical populations from general population, which can be rather surprising [6]. This result could be explained by the fact that without treatment, all ESRD patients would be dead, so as their perception of their QOL takes into account the obvious benefit to be alive. An overestimation of QOL could also result from the effect of coping mechanisms, such as denial [7].

Other studies found an impaired QOL in ESRD patients. Many factors can contribute to such an impact of the disease: uncertainty about the future, lack of energy, functional impairment, inability to work, biochemical status and physical symptoms [8], [9]. The choice of the instrument to assess QOL proved important. Health profiles (usual HRQOL scales) and health preferences (single indicator to express QOL, generally a number) showed poor correlations within a group of HD and PD patients. For the authors, coping strategies and other attitudes towards health may affect the preference scores more than they influence health profile outcomes [10].

Finally, health-related QOL seems influenced by dialysis adequacy, that is to say compliance with the treatment and regimen. Poor compliance inevitably leads to short-term health consequences on physical well-being and long-term consequences as cardiovascular complications.

An important goal of research on coping in clinical populations is to identify which coping mechanisms are better suited to a particular clinical problem. There is little consensus to define what really constitutes an “adaptative” coping strategy for a medically ill individual. When considering dialysis treatment, HD was mainly studied, particularly because patients undergoing HD have to face strict guidelines regarding their diet and the amount of fluid intake. The association of a particular type of coping to patient adherence was predicted to depend on the specific type of stressful condition being considered [11]. A Scandinavian study found that an optimistic coping style was both the most widely adopted by men and women on dialysis and the most effective in terms of dealing with stressful aspects of treatment [12]. Although patients perceive high levels of stress, they use rather problem-focused oriented coping when they have to face HD [13]. Overall, internal, unstable and controllable attributions were indirectly associated with positive psychological adjustment through the use of emotion-focused coping [14]. Problem-focused coping is associated with more favourable outcomes in illnesses that offer the most opportunities for control, whereas emotional-focused coping is adopted in less controllable illnesses [15]. The importance of the conceptual framework has been underlined. Thus, adherence (and consequently QOL) is more favourable when the patient's preferred style of coping with illness and treatment is congruent with the specific type of medical intervention. A more vigilant and active style of coping is associated with more favourable adherence for patients undergoing home-based dialysis treatment modalities that are highly patient directed. Among patients receiving hospital-based treatment, a less vigilant or more passive coping style is more appropriate for adherence [16]. Recently, religious and spiritual aspects of QOL have been assessed with ESRD patients treated by HD. Religious beliefs may act as coping mechanisms for these patients [17]. HD and PD patients who use emotive, evasive and palliative coping strategies extensively (according to the Jalowiec coping scale) seem to be less effective at handling their illnesses. The optimistic style was the most widely adopted and the most effective in terms of dealing with stressful treatment aspects [18].

According to Roesch and Weiner [19], the effectiveness of a coping strategy should be evaluated in relation to its impact on the outcome: health-related QOL appears as a good indicator of physical and psychological well-being and can be used as a measure of the effectiveness of coping strategies.

Health-related locus of control (HRLOC) is a way of describing how an individual considers his/her participation in maintaining or not his/her health and refers to the type of attributions, internal or external (chance or medical power), of each individual. Its links with QOL were insufficiently explored. When patients have the right health beliefs, this predict a better long-term adherence [20]. Moreover, patients with internal HRLOC adjust better to their illness than those with external HRLOC [21], [22], [23], and this does not depend on the duration of the illness.

To our knowledge, the relationship between coping, HRLOC and QOL has yet to be studied. One could think that the way that an individual copes with a stressful event like ESRD and dialysis, as well as his/her expectations from his/her own participation in treatment (internal LOC), and his/her trust in medical power (external LOC) might influence well-being and QOL in a chronic disease that offers opportunities for control.

This cross-sectional study had two purposes: to describe the QOL of ESRD patients treated by PD, and to search for predictors of QOL in this population. We hypothesized that:

• QOL should be negatively associated with the severity of the disease.

• Problem-focused coping as well as internal HRLOC and medical power HRLOC should be positively associated with QOL in univariate analyses and after controlling for the severity of the disease.