[Adherence to therapy in patients on hemodialysis]

The percentage of patients on dialysis who do not adhere to their dietary and therapeutic regimens ranges from 25% to 86%. These data are relevant because nonadherence to the prescribed diet affects the mortality and morbidity of these patients. The aim of this study was to evaluate some indicators of nonadherence to drug therapy and diet. Patients showing serum potassium levels >6 mEq/L, serum phosphate levels >5.5 mg/dL, or interdialysis weight gain >5.7% of their body weight were considered as nonadherent. Behaviors, habits and adherence to prescribed therapies were investigated by administering a drug and diet questionnaire to the patients. The percentages of values exceeding the nonadherence threshold were 16.4% for potassium, 30.2% for phosphate, and 7.5% for weight gain. The weight gain index was significantly related to both potassium (p<0.01) and phosphate (p<0.05) indexes. Age was inversely correlated with non -adherence indexes of both phosphate (p<0.05) and weight gain (p<0.05). Residual diuresis was associated with better adherence to potassium (p<0.01). Factor analysis of the questionnaire suggested a 4-factor solution. None of these subscales were correlated with nonadherence indexes. ''Continuity in the intake of drugs'' showed a correlation with the ''trust in the drugs'' factor (p<0.01). Measurements of nonadherence remain a crucial step for understanding the impact on patients' quality of life.