What clinical activities do advanced-practice registered dietitian nutritionists perform? Results of a delphi study

Activities performed by advanced-practice registered dietitian nutritionists (RDNs) have yet to be clearly elucidated. The study aimed to gain consensus on the practice activities of advanced-practice RDNs who provide direct clinical nutrition care. A three-round Delphi study was conducted. Purposive sampling identified 117 RDN experts working as clinicians and/or managers in direct care settings that met inclusion criteria for advanced-level practice. In Round 1, 85 experts provided open-ended advanced-level practice activities linked to the Nutrition Care Process sections. Using content analysis, the responses were coded into activity statements. In Round 2, experts rated the essentiality of these activities. In Round 3, experts re-rated statements not reaching consensus while viewing their previous rating, the group median, and comments. Median ratings of 1.0 to 3.0 were defined as essential, 4.0 were neither essential nor nonessential, and 5.0 to 7.0 were nonessential. Consensus was reached when the interquartile range of responses to each question was <2.0. Seventy-six (89.4%) experts completed all rounds. From 770 comments, 129 activity statements were generated. All statements reached consensus: 97.7% as essential; 0.8% as nonessential; and 1.5% as neither. Of essential activities, 67.5% were highly essential with limited variability (median=1.0; interquartile range≤2.0). Advanced-practice RDNs' tasks are patient-centered and reflect complex care; involve a comprehensive and discriminating approach; are grounded in advanced knowledge and expertise in clinical nutrition; include use of advanced interviewing, education, and counseling strategies; and require communication with patient, families, and the health care team. The high-level of consensus from experts suggest advanced-level clinical nutrition practice exists and can be defined.