Intelligence and adjustment to chronic hemodialysis

Two OF the most important aspects of adjustment to chronic hemodialysis are (1) adherence to the diet regimen, and (2) continued vocational functioning. Compliance with medical recommendations, especially with the dietary requirements of dialysis, is often the deciding factor between relatively good health and death. The patients’ potential for continued vocational functioning (rehabilitation) is important, and not only for their own welfare while on dialysis. In many places there are insufficient facilities for chronic dialysis so that the potential for rehabilitation is often the official or unofficial criteria for patient selection. Unselected patients die, while patients selected for dialysis can live for years. Factors that influence or predict adjustment are therefore of great importance. Intelligence is one of the factors thought to influence patients’ adjustment. The precise relation between intelligence and various aspects of adjustment is, however, as yet unclear. Different studies have used different and sometimes unsatisfactory methodology and have produced contradictory findings: Sand [l] reported “a small but consistent tendency for the more intelligent patients to be seen as showing better cooperational and emotional adjustment” in a group of patients with an IQ range of 94 to 143 (x = 115). Similarly, Gombos [2] is of the opinion that average and above average intelligence is required in order to meet the demands of self care. Sheldon [3] on the other hand prefers patients with average intelligence to patients with higher than average intelligence. Davis [4] in a recent summary of the literature reported the impression that patients of lower socio-economic class and patients with little education comply less well with medical recommendations and are therefore less adjusted. His further studies, however, do not support this impression since no demographic factors were found to influence compliance. Borkman [5] in a recent study based on questionnaires from many dialysis units, found that estimated intelligence level is moderately but significantly associated with rehabilitation but not associated with most aspects of dietary adherence. Education was found to influence rehabilitation and diet adherence in a similar way; i.e. moderately associated with rehabilitation but not associated with diet adherence. The situation as regards the relation between intelligence and adjustment is neatly summarized by Husek [6] in her (unpublished) review of the psychological aspects of chronic dialysis: “Evidence regarding any possibility of a relationship between intelligence and probability of successful adaptation to dialysis is meager. Perhaps some minimal amount of intelligence is all that is required; perhaps there is a strong linear correlation between intelligence and rehabilitation or adaptation. At this time there is no evidence to choose between these two very different hypotheses.”