Healthcare professionals (eg, physicians, dietitians, and nurses) should undergo a brief training period before using SGA. This training is recommended to increase precision and skill in using SGA. The four items currently used to assess nutritional status are weight change over the past 6 months, dietary intake and gastrointestinal symptoms, visual assessment of subcutaneous tissue, and muscle mass.
Weight change is assessed by evaluating the patient's weight during the past 6 months. A loss of 10% of body weight over the past 6 months is severe, 5% to 10% is moderate, and less than 5% is mild. This is a subjective rating on a scale from 1 to 7, where 1 or 2 is severe malnutrition, 3 to 5 is moderate to mild malnutrition, and 6 or 7 is mild malnutrition to normal nutritional status. If the weight change was intentional, the weight loss would be given less subjective weight. Edema might obscure greater weight loss. Dietary intake is evaluated and includes a comparison of the patient's usual and recommended intake to current intake. Duration and frequency of gastrointestinal symptoms (eg, nausea, vomiting, and diarrhea) are also assessed. The interviewer rates this component of SGA on the 7-point scale with higher scores indicative of better dietary intake, better appetite, and the absence of gastrointestinal symptoms.
The physical examination includes an evaluation of the patient's subcutaneous tissue (for fat and muscle wasting) and muscle mass. Subcutaneous fat can be assessed by examining the fat pads directly below the eyes and by gently pinching the skin above the triceps and biceps. The fat pads should appear as a slight bulge in a normally nourished person but are "hollow" in a malnourished person. When the skin above the triceps and biceps is gently pinched, the thickness of the fold between the examiner's fingers is indicative of the nutritional status. The examiner then scores the observations on a 7-point scale. Muscle mass and wasting can be assessed by examining the temporalis muscle, the prominence of the clavicles, the contour of the shoulders (rounded indicates well-nourished; squared indicates malnutrition), visibility of the scapula, the visibility of the ribs, and interosseous muscle mass between the thumb and forefinger, and the quadriceps muscle mass. These are also scored on a 7-point scale, with higher scores indicating better nutritional status. The scores from each of these items are summated to give the SGA rating. It is recommended that SGA be used to measure and monitor nutritional status periodically in both MHD and peritoneal dialysis patients.