Assessing adherence to dietary recommendations for hemodialysis patients: the Renal Adherence Attitudes Questionnaire (RAAQ) and the Renal Adherence Behaviour Questionnaire (RABQ).

This article describes preliminary investigations into the psychometric properties of two scales for hemodialysis patients (N=35): the Renal Adherence Attitudes Questionnaire (RAAQ), a 26-item scale measuring attitudes toward adherence: and the Renal Adherence Behaviour Questionnaire (RABQ), a 25-item scale measuring self-reported dietary (diet and fluid) adherence. Factor analysis of the RAAQ yielded a four-factor structure. These factors were attitudes to social restrictions, well-being, self-care/support, and acceptance. The scale demonstrated high internal and test-retest reliability. Factor analysis of the RABQ gave a five-factor structure: adherence to fluid restrictions; adherence regarding potassium and phosphate restrictions, adherence regarding self-care; adherence regarding sodium intake; and adherence in times of particular difficulty. This scale had moderately high internal reliability and high test-retest reliability. Validity for the RABQ was tested with independent measures of adherence; biochemical (serum potassium, serum phosphate, and interdialytic weight gain) and dietician-rated (potassium and fluid). There was little association among the differing measures of adherence. These scales facilitate empirical evaluation of dietary adherence for hemodialysis patients.